Presenting authors are first mentioned; exceptions are underlined.

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Factors influencing survival in transarterial chemoembolization (TACE) of hepatocellular carcinomas Helmberger T., Holzknecht N., Ertl-Wagner B., Auer C., Reiser M. University of Munich, Institute of Clinical Radiology, Germany

Role of selective hepatic arterial Lipiodol chemoinfusion as pretreatment for liver transplantation (OLT) in hepatocellular carcinoma (HCC) Lubienski A., Bitsch R.G., Kimpel M., Duex M., Grenacher L., Aretz K., Kauffmann G.W. Ruprecht Karls University Heidelberg, Diagnostic Radiology, Heidelberg, Germany

Purpose: Evaluation of the factors determining the survival of patients with hepatocellular carcinoma (HCC) undergoing TACE. Materials and Methods : One hundred and twenty patients (59% Child’s A cirrhosis, 11% Child’s B, 5.5% Child’s C, 24.5% no cirrhosis) with proven HCC underwent superselective TACE (Epirubicin, Lipiodol). Kaplan-Meier survival analysis was performed in all the patients and for subpopulations with regard to tumor size, grading, number of tumor nodules, Child’s class and AFP levels. Results : The mean survival time was 15.7 months, with 34.1% of the patients living at 12 months. The tumors size, the number of tumor nodules, or the grading did not affect the survival. However, the survival of 50% of the patients with a Child’s C cirrhosis or with AFP levels >1000 ng was less than 6 months, with none of them living longer than 36 months. In patients with Child’s A cirrhosis and/or normal AFP levels the mean survival was 14 and 17 months respectively, while about 10% of these patients lived more than 60 months. Conclusion : In patients with non-resectable HCC, TACE is an effective therapy that may prolong patients’ survival. However, Child’s class in cirrhotic patients and elevation of AFP levels have to be considered as prognostic factors for a life-extending TACE therapy.

Purpose : Whether Lipiodol chemoinfusion or chemoembolization may serve as a bridge to transplantation and prevent malignant recurrence is still under debate. Materials and Methods : In 9/42 HCC patients selective hepatic arterial chemoinfusion served as bridge to transplantation. Underlying liver cirrhosis was present in eight patients due to excessive alcohol abuse (n=4) and hepatitis B and/or C (n=4). In one patient no cirrhosis or underlying disease was observed. Liver function was found to be Child A in seven and Child B in two patients. Results : Five of the nine patients were removed from the waiting list because of tumor progression (n=4) or death due to liver disease (n=1). The remaining four patients underwent OLT after a mean of 1.2 Lipiodol chemoinfusion sessions. The median interval between chemo-infusion and OLT was six months. One patient died of severe retroperitoneal bleeding related to OLT, another patient showed a mechanical obstruction of the main bile duct. Mean follow-up was 10.3±1.2 months. During follow-up, one patient died after GI-bleeding without recurrence, another due to multiple tumor recurrence. Conclusion : More than half of the patients either died or developed tumor progression which rendered them ineligible for OLT. Malignant recurrence after OLT could not be prevented in all cases.

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Factors affecting the therapeutic results of segmental chemoembolization for hepatocellular carcinomas Sakaguchi H., Anai H., Tanaka T., Nagasawa M., Yamamoto K., Sueyoshi S., Nakagomi M., Nishimura Y., Hirohashi S., Kichikawa K., *Ohishi H., Uchida H. Nara Medical University, Radiology, *Oncoradiology, Nara, Japan

Use of CT scanning following hepatic embolization Whigham C.J., Ketcham W.D., Trinh C.C., Fisher R.G. Baylor College of Medicine, Radiology, Houston, TX, USA Purpose : Hepatic embolization is an accepted technique to control bleeding following traumas. Some authors have supported the idea that a follow-up CT-scan is not necessary on a routine basis post-operatively. Our purpose in this study was to evaluate the need for CT imaging following embolization. Materials and Methods : From 1995 to 2000, a chart review at a Level 1 trauma center was performed. A total of 73 patients was reviewed (52 men and 21 women). Forty-five patients had blunt and 28 had penetrating trauma. Of those patients with injury, ten underwent embolization with either gelfoam or coils. Nine patients underwent surgical repair. Six of the ten patients who received embolization underwent a post-procedure CT. The nine surgical patients had a follow-up CT. Results : None of the patients who received a post-procedure CTscan showed an enlarging hematoma or an active bleeding by CT. One patient underwent re-embolization for hypotension. The remaining patients did well and did not have routine follow-up CT-scan. Conclusion : Based on this study, we feel that routine CT-scans following embolization do not need to be performed, unless in case of an appropriate clinical indication. This is a small series and ongoing review must be performed.

Purpose :To evaluate the therapeutic results of hepatic segmental chemoembolization (Seg) for hepato-cellular carcinoma (HCC) in relation to the tumor diameter, the degree of intrahepatic metastases (IM), UICC stages and Child’s classification. Materials and Methods : Two hundred and thirty one patients underwent Seg. Cumulative survival rates after Seg were assessed in relation to the main tumor diameter, IM, the UICC stage and Child’s classification. Results : The survival rates at one, three and five years were as follows. In tumors <2cm, survival rates were 91, 68, and 51%, respectively. Those patients with tumors ranging from 2.1 to 3 cm, had survival rates of 91, 67, and 31%, respectively. In patients with tumors ranging from 3.1 to 5 cm, they were 87, 60, and 36%, respectively. In those patients with IM0, survival rates were 92, 68, and 42% at one, three and five years. In those with IM1, rates were 85, 59, and 28%. In those with IM2, they were 87, 60, and 23%, respectively. In those with IM3, survival rates were 60, 0%, and 0%. Patients at stage I of UICC had survival rates of 97, 76, and 56%. In those at stage II, they were 90, 65, and 37%, respectively. In those at stage III, they were 90, 62, and 24%. In those at stage IV, they were 82, 45, and 18%. Survival rates of those patients in Child’s A classification were 96, 70, and 45%, respectively. In those in Child’s B were 89, 62, and 30%. In those in Child’s C, they were 74, 51, and 23%. Conclusion : Seg offers satisfactory results when HCC is small, solitary, at low-stage and when the patient has a good liver function. Although the results are less favorable in more advanced stages, the technique is feasible and may offer a positive outcome even in HCCs at advanced stages or in patients with poor liver function. S123

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Enhanced gray-scale ultrasonography by C-cube-mode in the assessment of interstitial laser photocoagulation of hepatocellular carcinomas Tarantino L., Giorgio A. D. Cotugno Hospital, Interventional Ultrasound, Naples, Italy

MRI-guided percutaneous radiofrequency ablation of neoplasms: first technical and clinical experiences Kettenbach J., Berger J., *Peer K., Bach K., **Gustorff B., Grgurin M., Dirisamer A., Lammer J. University Hospital of Vienna,Dept. of Radiology, *Dept. of Radiotherapy and Radiobiology, **Dept. of Anaesthesia and Intensive Care (B), Vienna, Austria

Purpose : Assessment of the efficacy of interstitial laser photocoagulation (ILP) of hepatocarcinoma (HCC) by a new enhanced ultrasonographic technique. Materials and Methods : Eight patients with a single HCC (2.05.5 cm) treated with ILP underwent three-phase helical computed-tomography (CT). All the patients underwent enhanced gray-scale ultrasonography (C3-ModeTM, Esaotebiomedica, Genoa, Italy) after i.v. injection of a micro-bubble contrast agent (Levovist, Schering, Berlin, Germany). Four grams of Levovist (300 mg/ml) were injected and C3-ModeTM scans were recorded at the times of 20”, 40”, 60”, 2’, and 3’. Results of C3-ModeTM were compared with those of CT. Results : In six patients with a complete necrosis of HCC at CT, C3-ModeTM did not show any intra-lesional enhancement. In one HCC, CT and C3-ModeTM showed an intratumoral enhancement at the same corresponding areas. In the remaining patient, CT showed a complete necrosis of the nodule. Howewer, enhanced spots along the inferomedial margin of the lesion suggested a parenchymal infiltration, untreated by ILP. C3ModeTM did not show any enhancement and a cutting needle biopsy did not show any malignancy at the corresponding area. Follow-up of the patient is in progress. Conclusion : C3-ModeTM seems to well reproduce the results of three-phase helical CT in the evaluation of the efficacy of HCC ablation by ILP.

Purpose : To evaluate the safety and feasibility of interactive MRguided radiofrequency ablation (RFA) of tumor tissue performed entirely within a C-arm MR scanner (Magnetom Open, Siemens, Erlangen). Materials and Methods : In nine patients, one liver cell carcinoma, ten liver and three pelvic metastases (diameter 1.5-8 cm) were percutaneously treated using a commercially available MR-compatible RFA system (Elektrotom, Berchtold, Tuttlingen, Germany). Using fast T1-weighted sequences, 16-G, MRcompatible, perfused electrodes with active lengths of 1.5 cm were placed within the tumor. Results : No significant morbidity was noted. The mean energy dose applied was 26.207 J (8.829-68.500 J), whereas the mean RF-ablation time was 18.8 minutes. The mean procedure time (including MR imaging) was 138 minutes. In all neoplasms, the region of tissue destruction was visible, as confirmed on subsequent contrast-enhanced MR or CT images. Conclusion : MR-guided RFA of tumor tissue using the MRcompatible RF system and perfused electrodes is feasible and safe on a clinical 0.2-T C-arm system with only a minor patient morbidity. Technical effectiveness depends on tumor size, vascularity and the energy dose applied.

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Interstitial laser photocoagulation under ultrasound guidance of liver tumors: results in 128 treated patients Giorgio A., Tarantino L., de Stefano G., Farella N., Mariniello N., Liorre G., Esposito F. D. Cotugno Hospital, Interventional US, Naples, Italy

Correlation of the ablation size as depicted on contrastenhanced CT and on low-field, non-enhanced open MR Gillams A., Lees W.R., Sellars P. Middlesex Hospital, Medical Imaging, London, United Kingdom Purpose : An accurate assessment of treatment efficacy is critical to evaluate effective thermal ablation. Contrast-enhanced CT was compared with resected specimens and resulated accurate to within 1-2 mm. Interventional MR, however, is probably a better technique for monitoring thermal ablation of larger lesions. We compared contrast-enhanced CT and open MR. Materials and Methods : Fourteen tumours in 11 patients were studied. MR imaging was performed on an open 0.2T Viva system. An inversion recovery and a breathhold T1W 2-D sequence were performed. Spiral-CT was performed with 5-mm collimation, 50s after pump injection of 100-150 ml of contrast material. Maximal cross-sectional diameters of thermal-induced lesions were measured. Results : On both STIR and T1, two distinct areas of the lesions could be identified, a large central area of low or high signal intensity, respectively and a thin penumbra of high or low signal respectively. Mean thermal ablation lesion diameter on CT was 5.9 cm. The central low signal intensity area on STIR consistently underestimated the lesion size but inclusion of the peripheral high signal intensity resulted in overestimation of the final lesion size. On paired data analysis, measurement of central and peripheral zones on T1 best correlated with CT. Conclusion : T1 imaging best reflected the final lesion size on CT.

Purpose : Evaluation of interstitial laser photocoagulation (ILP) efficacy for focal ablation of liver tumors. Materials and Methods : One hundred and twenty eight patients, 95 with 103 nodules of hepatocellular carcinoma (HCC) on cirrhosis and 33 patients with hepatic metastases (MTX)(30 colon carcinomas, two lung carcinomas, one breast carcinoma) underwent ILP under US guidance with Nd: YAG laser under general anesthesia . HCC diameters ranged from 10 to 66 mm (mean 32), while MTX ranged from 30 to 90 mm (mean 42). Necrosis of the nodules was evaluated with a triphasic contrastenhanced CT. Results : CT showed a complete necrosis in 79/99 (80%) HCC nodules in 76 patients and in 25/33 (77%) MTXs. Twenty HCC nodules in 16 patients and six MTXs showed an incomplete necrosis (more than 50% of nodules volume in all cases). Three patients with four HCC nodules dropped out the CT control because of severe liver failure associated in one case with a paralytic ileum. One of these patients died two months after treatment. Two patients with MTX dropped the completion of the treatment because of one paralytic ileum and one gastric haemorrhage. Conclusion : ILP seems to be an effective tool for the complete ablation of liver tumors, although severe complications, including death, may occur.

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Radiofrequency thermal ablation of liver tumors: spiral-CT findings in a 24-month follow up Fiore F., *Izzo I., **Pignata S., **Daniele B., D'Angelo R., **Ottaiano A., **De Maio E. Cancer Institute, Radiology,*Surgical Oncology, **Medical Oncology, Naples, Italy

Clinical and morphological results of long-term follow-ups for deep vein thrombosis treated by fibrinolysis Hennigs S., *Martin M. Evangelisches und Johanniterklinikum, Radiology, *Städtische Kliniken Duisburg, Geriatrie, Duisburg, Germany Purpose : The extent of post-thrombotic syndrome (PTS) was clinically and morphologically defined in long-term follow-ups after fibrinolysis. Materials and Methods : The clinical evaluation was performed in 102 patients who received ultra-high streptokinase (UHSK) systemically. Follow-up was 8.02 +/- 3.44 years. Definiton of the extent of PTS was assessed by quality of life questionnaire and PTS score by Widmer and Retz. Sixty-six patients who had received locoregional UHSK had a follow-up phlebography 3-33 months after fibrinolysis. Results : The patients' quality of life was 3.28 (0-10, 10=worst). Major complaints rate (swelling pain, ulcer, total 65.7%) was 7.8%. Depending on the direct outcome, the average PTS score was 6.04 +/- 4.08 (maximum 22). Phlebographically, the group with a partial recanalization as a direct outcome showed in some cases an improvement and in some deterioration, while the groups with full and no recanalization remained phebographically unchanged. Conclusion : The clinical and morphological long-term result after fibrinolysis is strongly dependant on the previous recanalization rate. In those cases where a full recanalization seems possible, fibrinolysis is indicated.

Purpose : To examine spiral-CT findings in the evaluation of the response and the follow up after RFA (Radiofrequency Ablation) of liver tumors. Materials and Methods : Since December 2000, 304 patients treated with RFA were evaluated by spiral-CT: 121 (40%) had HCC, 141 (46%) had colorectal metastases, and 42 (14%) had metastases from other primary sites. In 11 patients with HCC, RFA was preceded by chemoembolization (lesions diameter: >cm 5). Spiral-CT was performed one month after RFA and every six months, with a biphasic technique. The first phase: 20-45 seconds after i.v. contrast injection, the second phase: 45-90 seconds after i.v. contrast injection. Results : One month post-treatment, a residual tumor was observed in 56 patients and a local recurrence at the RFA site in 27 patients (9%). New liver or extrahepatic metastases developed in 142 patients (47%). The following minor adverse events were noted: pleural and peritoneal effusion, biliary duct dilatation, thermal injury of the adjacent structures and one case of local haemorrhage. Conclusion : Spiral-CT is a non-expensive, rapid, non-invasive, and dynamic technique. For these reasons, it is considered the standard technique in the evaluation of residual tumors and recurrences after RFA of liver tumors. It can provide further information on metastases occurance in other sites and on other minor adverse events after RFA.

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Hepatic vein hemodynamic assessment predicts pathologic findings from transjugular liver core biopsy Murthy R., Hastings G.S., Richard H.M., Lund G., Boyd-Kranis R.B., Radack D.M., Stainken B.F. University of Maryland Medical System, Radiology, Baltimore, MD, USA

Long-term results after stent recanalization of chronic iliocaval occlusions Ivancev K., Lindh M., Uher P., *Malina M., *Sonesson B., *Lindblad B., *Akesson H. Malmö University Hospital, Radiology, *Vascular Diseases, Malmö, Sweden

Purpose : To determine the safety and efficacy of transjugular liver core biopsy (TJLCB) and to determine if hemodynamic and venographic findings are predictive of biopsy results. Materials and Methods : All TJLCBs performed between 1/1/1998 and 3/31/2000 were retrospectively reviewed. Indications, hepatic venographic findings, and hemodynamic assessment were tabulated. Technical success and complications were recorded. The relationship of wedged venographic findings and pressure measurements to biopsy results was examined. Results : One hundred patients (68 men, 32 women). Ninety eight of 100 (98%) TJLCBs were successful. All specimens were found to be adequate for histologic diagnosis. Hemodynamic assessment in 76 patients yielded pressures in mm/Hg: hepatic vein wedge pressure (HVWP)=17.1±9.8; free hepatic vein pressure (FHVP)=10.3±8.5; corrected sinusoidal pressure (CSP)= 6.8±5.8. Wedged hepatic venograms (WHV) were filmed on 40 patients. Portal vein branches were seen on 23. In 49 patients (47 of whom were biopsied for pre-transplant evaluation), the pathologist assigned a grade, 0 through 4, for the degree of inflammation and fibrosis. HVWP and CSP were found to correlate with the degree of fibrosis (p=015 and p=.013, respectively). CSP<6 mm/Hg had 85% positive and 57% negative predictive value. Conclusion : TJLCB is a safe procedure. HVWP and CSP correlate with the degree of fibrosis, but portal vein visualization on WHV does not.

Purpose : To evaluate the long-term outcome of stent recanalization of chronic ilio-caval occlusion. Materials and Methods : Two groups were formed. The first consisted of 23 patients with chronic ilio-caval occlusions presenting with oedema, pain, claudication, and ulcers with a median duration of 102 months (10 months-57 years). The second group consisted of 13 patients with acute upon chronic ilio-caval occlusions. Severe oedema and pain were the most prominent symptoms. Thrombolysis was performed in all 13 patients. Duplex, phlebography, and CT were used for diagnosis and follow-up in both groups. Results : Median follow-up in the first group was 798 days (1531785). The symptoms remained unchanged in three patients only, whereas an improvement occurred in the remaining 20 patients. Primary stent patency was 74%, secondary 96%. Median followup in the second group was 756 days (192-1685). Two patients had unchanged symptoms, whereas the remaining 11 improved. Primary stent patency was 46%, secondary 62%. Complications occurred in two patients (haemorrhage due to thrombolysis, requiring blood transfusion). Conclusion : Chronic ilio-caval venous occlusions can be safely and successfully recanalized. Long-term patency is good in chronic occlusions, but less encouraging in acute upon chronic occlusions. Symptom relief is substantial in both groups.

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Interventional treatment of venous anastomotic stenoses after liver transplantation Ko G.Y., Sung K.B., Song H.Y., Seo T.S., Yoon H.K. Asan Medical Center, Radiology, Seoul, Korea

Direct ultrasonography-guided puncture of innominate veins for hemodialysis access in patients with limited access sites Kinney T.B., *Lau T.N. University of California Medical Center, San Diego, CA, USA; Singapore General Hospital, Diagnostic Radiology, Singapore

Purpose : To evaluate the efficacy and safety of interventional management for the treatment of venous anastomotic stenoses after liver transplantation. Materials and Methods : From March 1997 to January 2001, 34 of 281 patients who had undergone liver transplantation were treated by means of interventional management. The stenotic sites were the hepatic vein (n=16), the portal vein (n=16), and the inferior vena cava (n=2). Five patients with hepatic venous stenoses and three patients with portal venous stenoses underwent balloon angioplasty; the remaining patients underwent stent placement. Follow-up included duplex-ultrasound, CT and clinical evaluations. Results : A technical success was achieved in all patients and a rapid, dramatic resolution of symptoms was achieved in 28 (82%) patients after the procedure. Five patients died of unrelated hepatic failure. During the mean follow-up period of 42 (range, 1-200) weeks, primary and secondary patency rates on duplexultrasound or CT were 88 and 97%, respectively. Delayed complications occurred in two patients: each case had main portal venous thrombosis and hepatic artery pseudoaneurysm. The pseudoaneurysm was treated successfully by means of transcatheter embolization. Conclusion : The interventional treatment is a safe and useful adjunct in the treatment of venous anastomotic stenoses in patients who have undergone liver transplantation.

Purpose : To describe ultrasonography-guided direct puncture of innominate veins for central hemodialysis access in patients with limited access sites. Materials and Methods : Three chronic hemodialysis patients (two women, one man, with ages ranging from 24 to 60 years) were studied and found to have occluded or thrombosed jugular and/or subclavian veins. One patient had prune belly syndrome, the second patient had hypertensive renal failure, and the last patient had diabetes as the cause for renal insufficiency. Using a suprasternal window, a 7.5-MHz probe was used to direct a micro-access needle into the innominate vein. A hemodialysis catheter was then placed in the standard fashion. Results : Direct puncture of the innominate vein with US-guidance was successful in all the three cases. Pre-procedure imaging including venograms, US, CT, and MRV helped in planning the access route. The catheters were used successfully from 18 days to three months. Two of the three catheters were successfully removed without complications. One patient died of sepsis with the catheter in place (endocarditis). Conclusion : Direct ultrasonography-guided puncture of innominate veins offers a safe alternative in patients with limited access sites. Pre-procedure planning is critical in the performance of these procedures.

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Safety and feasability of Trapease inferior venacava filter (TIVCF) insertion using a single venipuncture and intravascular ultrasound guidance Murthy R., Richard H.M., Lund G., Hastings G.S., Boyd-Kranis R.L., Radack D.M., Stainken B.F. University of Maryland Medical System, Radiology, Baltimore, MD, USA

Totally implantable venous access port systems for patients undergoing chemotherapy for haematological malignancies: a prospective study Noeldge G., Hansmann J., *Egerer G., Libicher M., Richter G. M., Kauffmann G.W. University Hospital of Heidelberg, Radiology, *Internal Medicine V, Heidelberg, Germany

Purpose : To assess the safety and feasibility of TIVCF with a single venipuncture and intravascular ultrasound (IVUS) guidance. Materials and Methods : Eight patients (four men) underwent IVUS-guided infrarenal TIVCF insertion through a Brite tip sheath (BTS) (Cordis Endovascular, Warren, NJ). Indications were prophylactic in six and contraindication to anticoagulation in two patients. The common femoral vein was accessed. IVUS probes (IVUSP) (Boston Scientific, Natwick, MA) were utilized to evaluate the IVC from the right atrium to the common iliac vein. The IVUSP was positioned at the inferior margin of the lowest renal vein (LRV). The BTS was advanced over the IVUSP until the characteristic artifact of the echogenic radioopaque marker tip distorted the image. Fluoroscopy was then utilized to confirm appropriate sheath positioning. The IVUSP was removed and the filter deployed with the standard technique. A spot film was obtained. Results : No IVC thrombus or anomaly was present. The LRV was identified. The mean infrarenal IVC diameter was 21.8 mm (18-26.7 mm). Superimposition of the BTS and the IVUSP without need for repositioning was confirmed with fluoroscopy prior to deployment in all patients. Conclusion : Single venipuncture TIVCF insertion is safe and feasible with IVUS-guidance through a BTS. This may provide a reasonable alternative to fluoroscopic-guided insertion.

Purpose : To determine the outcome of radiological placement of central venous access devices in patients with haematological malignancies, we prospectively evaluated the rate of short- and long-term complications of the Z-Port-F-8 system (Zambon Biomedica, France). Materials and Methods : In 122 patients with haematological malignancies, port systems were placed radiologically. Median follow-up was 9.5 months (range 6-15 months). Success and complication rates (immediate and long-term) were recorded. Results : Medium age of the patients was 53 years (range, 16-78). No extravasation, skin necrosis or leakage occurred during 16.536 days. Perioperative complications were recorded in six patients (4.9%): pneumothorax in two (1.6%), bleeding in two (1.6%), and hematoma in other two patients (1.6%). In seven cases (5.7%) late complications occurred: catheter disconnection in one (0.8%), thrombosis in three (2.5%) and subcutaneous portal infections in three patients (2.5%). Late complications were higher in those patients receiving chemotherapy prior to 24 hours following implantation. Patency of the PAC-system was maintained using a flushing schedule every 28 days. Conclusion : The Z-Port-F-8 system provides a safe and reliable method for venous access in patients requiring intermittent or prolonged intravenous chemotherapy. To reduce the rate of late complications, a 24-hour interval after implantation should be awaited.

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Venous port salvage utilizing low-dose tPA Whigham C.J., Lindsey J.L., Goodman C.J., Fisher R.G. Baylor College of Medicine, Radiology, Houston, TX, USA

Comparison of two suture-mediated percutaneous arteriotomy closure devices in a pig model Hofmann L.V., Arepally A., Geschwind J.F., Magee C.M. Johns Hopkins Hospital, Cardiovascular and Interventional Radiology, Baltimore, MD, USA

Purpose : To evaluate the efficacy of low-dose tPA for catheter salvage in cases of fibrin sheath formation in patients with venous access ports. Materials and Methods : A prospective evaluation was accomplished in those patients with venous ports and catheter malfunction. There was a total of 50 patients and 55 occlusive events. Each patient had a catheter injection documenting the fibrin sheath. The patient population included 45 cases for chemotherapy and five for antibiotics. A low-dose tPA regimen was instilled into the port and, upon successful return of the function, a completion venogram was accomplished. Results : Fifty patients were enrolled into the study with an average time between placement and dysfunction of 99 days. Four patients had a second occlusive event (38.5 days) and one had a third event (27 days). All patients had a venogram confirming a fibrin sheath as the cause of catheter malfunction. The average dose of tPA was 2.16 mg (range 1-4 mg). Success was achieved in 51 out of the 55 occlusive events (92.7%). There were no bleeding complications. Conclusion : Catheter occlusion is a common complication of venous access ports. An aggressive therapy with low-dose tPA can salvage the function. It provides a safe and effective therapy for venous port malfunction secondary to fibrin sheath.

Purpose : To compare the efficacy, as well as short- and long-term effects of two suture-mediated arteriotomy closure devices. Materials and Methods : Sixteen vessels from eight pigs were studied. Six-French sheaths (n=8) and 8-F sheaths (n=8) were used to create arteriotomies in the external iliac arteries for the Closer (Perclose, Redwood City, CA) and the 8-F SuperStitch (Sutura, Fountain Valley, CA), respectively. Pre- and postdeployment angiograms were obtained. Two pigs were sacrificed immediately and six pigs were sacrificed at four weeks. Results : Perclose did not have any failures. Sutura had one device-related failure and one operator- related failure on the same vessel. Following deployment, mean reductions in the lumen diameter–primarily due to spasm–were 47.0% and 59.3% for the Sutura and the Perclose devices, respectively. At four weeks, angiograms (n=12) were normal. All knots were on the vessel wall, except one Perclose explant’s knot which was 5 mm above the vessel wall. At four weeks, all the vessels had a «fibrous hood» around the suture and the vessel. Conclusion : Both devices seem similarly efficacious. At four weeks, a fibrous reaction around the sutures is seen. No adverse effects from these devices were seen at four weeks.

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Clinical and morphological follow-up of radiologically implanted forearm ports Hennigs S., *Illmer I., Neuerburg J. Evangelisches und Johanniterklinikum, Radiology, *Medicine, Duisburg, Germany

New potential indications for a vascular closure device after endovascular procedures requiring large introducer sheath Willoteaux S., Lions C., Cocheteux B., *Haulon S., Beregi J.-P. Hopital Cardiologique, Radiology, *Vascular Surgery, Lille, France Purpose : To assess the interest and potential indications of a vascular closure device (Perclose device, Prostar XL) to close access sites after endovascular procedures from 10 to 22 French. Materials and Methods : The device permitted to close, percutaneously, the femoral access site by means of two or four needles and stitches. One or two devices were used, depending on the size of the sheath. If two devices were used (>12-F introducer sheath), they were put in the form of a cross on the femoral artery. Results : The device was used in 18 patients, essentially for the prevention of high risk of hemorrhage, in procedures using highdiameter sheaths (10 to 22 F) and in patients who cannot lie down. The technical success rate and the primary success rate were 15/18 and 13/18, respectively. It provided an improvement to the patients as well as more comfort to the para-medical staff. Moreover, new indications emerged: the possibility of performing a fibrinolysis 24 hours after a procedure with a 12-F sheath or a routine percutaneous endovascular procedure with a 16-F sheath (extension of a stent-graft). Conclusion : The use of this vascular closure device brings new perspectives in endovascular treatments. A training curve is however necessary to its safe use.

Purpose : Superficial and deep vein changes, as well as complications and subjective patients’ complaints after interventional insertion of forearm ports were investigated. Materials and Methods : In 50 patients, silicon portcatheters were interventionally implanted either in the basilic, cephalic, or brachial vein for chemotherapy. The titanium port chamber was fixed in the subcutaneous fat of the volar forearm. Duplexsonography and phlebography were performed before implantation. Thirty-five days post-implantation, after the first course of chemotherapy, a clinical follow-up and duplexsonography of superficial and deep arm veins were performed, along with the distribution of a patients' and nurses' questionnaire. Results : Data, which are still in progress of being statistically evaluated, will be presented. The tendency is that implantation of forearm ports has a low complicaton rate, is well tolerated by the patients and is user-friendly. Morphological changes of the superficial veins, such as occlusion, partial thrombosis, or thrombophlebitis may occur, but they remain clinically undetected in most of the cases. No subclavian vein thombosis has occurred as yet. Conclusion : We recommend the implantation of forearm ports. It is a small intervention with a very low risk of complications, well accepted by both the patients.

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Day-case vascular intervention: two-year outcomes in a single center Cleveland T.J., Gaines P.A. Sheffield Vascular Institute, Vascular Radiology, Sheffield, United Kingdom

Balloon-expandable stent-grafts in emergency and in elective vascular procedures Fanelli F., Salvatori F.M., Rossi M., Venditti F., *Pierleoni M., Rossi P. University of Rome «La Sapienza», Interventional Radiology, *Diagnostic and Interventional Radiology, Rome, Italy

Purpose : To review outcomes for a dedicated day-case vascular unit. Materials and Methods : Suitability for day-case procedures was assessed according to agreed protocols. An episode was defined as any procedure/s through a single access site at one attendance. Retrospective case-note review was performed. Results : There were 697 day-case episodes between April 1998 and May 2000, (294 interventional, and 403 diagnostic procedures), comprising 25% (697/2769) of the total workload. Follow-up is available in 218; 38 of these were transfers from outlying hospitals and were excluded from analysis. One hundred and eighty were true outpatients. There were 98 iliac and 46 femoropopliteal interventions, two aortic stents, one renal and five upper-limb angioplasties (PTAs), five embolisations, eight Hickman lines, one line stripping, three atherectomies, four chemical sympathectomies, one dialysis-graft PTA and six bypassgraft PTAs. Sixty-eight closure devices were used. Twelve patients were converted to inpatients (6.6%, 12/180). The readmission rate was 3.3% (6/180). The reattendance rate was 1.1% (2/180), both subsequently attending for day-case duplex to exclude pseudoaneurysm. The major complication rate was 2.2% and the delayed major complication rate was 1.6%. Conclusion : Outpatient vascular intervention is safe with appropriate protocols and with careful patient selection. Local vascular services benefit from the release of inpatient beds.

Purpose: To report our experience using covered stent-grafts in emergency and in elective vascular cases. Materials and Methods : Twenty-eight patients were treated using 36 balloon-expandable e-PTFE covered Jostents (Jomed). Five patients were treated in emergency: two for an iliac artery rupture during angioplasty; one for a common femoral artery leakage following coronary catheterization; one for an iliac dissection; and in the last patient to exclude an hepatic pseudoaneurysms thus avoiding bleeding. Twenty three patients were treated in election: 11 for iliac and femoral arteries recanalization; three for a superior vena cava syndrome (one of whom also presented a pulmonary artery stenosis); one for renal artery stenosis; eight for TIPS revision. Results : All the emergency procedures were successfully managed. The Jostent was also risolutive in the three patients with the vena cava syndrome, by preventing thrombus displacement and tumor ingrowth. After six months, 6/7 iliac arteries, 3/4 femoral arteries, 1/1 renal artery are patent. One iliac and one femoral artery required a revision. Patients with TIPS revisions present a patent shunt after eight months, with no sign of restenosis. Conclusion : PTFE covered stent-grafts seem to be helpful in both emergency and elective vascular procedures.

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Embolism protection in peripheral angioplasty: value of the Angioguard system Koenig C.W., Pusich B., Hahn U., *Wendel H.-P., Tepe G., *Schneider W., Duda S.H. University of Tübingen, Diagnostic Radiology, *Thoracic and Cardiovascular Surgery, Tübingen, Germany

Stentgraft in the treatment of arterial aneurysms, pseudoaneurysms and traumatic iatrogenic arterial injuries Kuhelj D., Surlan M., Kljucevsek T., Berden P., Klancar J., Kunst T., Salapura V. Clinical Center, Clinical Institute of Radiology, Ljubljana, Slovenia Purpose : To present our experience with stentgraft implantation. Materials and Methods : In the last three years, 22 patients were treated with stentgraft implantation. Twelve patients had aneurysms: seven of the IA, three of the femoropopliteal artery, one of the brachial artery and one of the renal artery. Four patients had pseudoaneurysms, two of the IA and two of the FA. Four patients had rupture of the EIA after PTA. Two patients had serious bleeding: the first one, with coagulopathy, after mispuncture of the subclavian artery (during TIPS) and the other (chronic dialysis) after transaxillary PTA. Three aneurysms and three ruptures were treated with Passager stentgraft. Two large aneurysms of the CIA were treated by specially made dacron stentgraft (Ella). Other cases were treated by Jostent peripheral stentgraft. Follow-up was clinical and by Doppler. Results : Stentgraft treatment was successful in all cases. In one case additional stentgraft was needed due to too short Jostent stentgraft. The patient with TIPS died because of posthaemorrhagic shock. Conclusion : Intraarterial stenting is an effective treatment for aneurysms, iatrogenic arterial wall traumas, and haemorrhages.

Purpose : To evaluate the deliverability and embolism protection capabilities of the Angioguard device during angioplasty of peripheral arteries. Materials and Methods : The Angioguard™ emboli capture guidewire system (Cordis Europe, filter size 5 to 6 mm) was applied during angioplasty of renal (n=3) and femoral (n=7) lesions. Data on ease of delivery, lesion crossing and detectable filter embolisation were recorded. Filter membranes were harvested for electron-microscopic evaluation for possible microembolisation. Results : System delivery was successful in all but one patient. The filter was placed after 3-4 mm predilation in the renal cases. In the femoral artery, lesion crossing with Angioguard was feasible in three patients with the device having been reinforced with a 5F braided catheter. Four lesions were primarily crossed with a 6-F CSI and the Angioguard device deployed before balloon angioplasty. Substantial embolisation was observed in three femoral cases. In one patient embolic material could be trapped but not completely removed, necessitating subsequent aspiration embolectomy. Conclusion : In complex lesions, embolisation during angioplasty seems to occur more frequently than previously reported. The use of the Angioguard embolisation protection device in peripheral arteries is feasible and could be of value for high risk stenoses with a limited out-flow.

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Endovascular stent-graft placement for the management of post-traumatic arterial lesions Goffette P., *Laterre P.F., **Gigot J.F., *Reynaert M.S. Saint-Luc University Hospital – UCL, Interventional Radiology, *Intensive Care, **Surgery, Brussels, Belgium

Angioplasty of the internal iliac artery for intractable buttock claudication Misra S., *Doherty M.G., Stanson A.W., Breen J.F., Andrews J.C. Mayo Clinic, Vascular and Interventional Radiology, *Radiology, Rochester, MN, USA

Purpose : To evaluate the immediate efficacy and medium-term patency of covered stents for the treatment of traumatic arterial injuries. Materials and Methods : Over two years, eleven patients (median age 43) with post-traumatic (six) or iatrogenic (five) arterial injuries underwent percutaneous stent-graft implantation. Twelve covered-stents (nine Jostent, two Passager, one Corvita) allowed to treat four ruptures (renal, iliac and two axillary), two dissections (subclavian and popliteal) and five pseudoaneurysms (two carotid, one subclavian, one brachiocephalic and one hepatic). In five patients, stent-graft implantation was a rescue modality either to stop active bleeding (n=3) or to manage injuryinduced acute limb ischemia (n=2). Stent-grafting was performed as a primary treatment in nine patients, after failure of balloon tamponade or conventional stenting in two cases. Results : All but one procedures were completely successful (91%); one endoleak was excluded by coils packing in the residual sac. Emergent stent-graftings were effective to control bleeding or restore the distal flow in ischemic territories. Two procedural complications (18%), one embolus and one puncture-site pseudoaneurysm were successfully managed by thromboaspiraton and thrombin injection, respectively. During the followup (median eight months, 0.5-24), a persistent exclusion of all pseudoaneurysms was observed; one carotid and one popliteal stent occlusions were respectively left untreated and surgically managed. Conclusion : Covered-stent implantation is an effective and minimally invasive method to deal with post-traumatic arterial injuries, especially for emergent control of bleeding .

Purpose : A retrospective study was conducted to evaluate the outcome of percutaneous revascularization of the internal iliac artery for the treatment of buttock claudication. Materials and Methods : From January 1990 to September 2000, seven patients (four men and three women, with an age range from 50 to 83 years, mean = 69) underwent percutaneous revascularization of the internal iliac artery for buttock claudication at the Mayo Clinic Rochester. All available patient charts and angiograms were reviewed. Follow-up ranged from five days to 57 months (mean = 18.8 months). Results : All the seven patients underwent percutaneous transluminal angioplasty and none had an endovascular stent placed. Four patients had right internal iliac artery stenoses, two had left internal iliac artery stenoses, and one had bilateral internal iliac artery stenoses. Three patients had internal iliac intervention alone, while four patients had other vessels dilated: common iliac arteries in three, and external iliac arteries in one. There were no complications. Five patients reported a symptomatic improvement, and two were lost to follow-up. Conclusion : Angioplasty of the internal iliac artery is a safe, viable option for the treatment of intractable buttock claudication.

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MR imaging using an intraluminal receiver coil to delineate gastric wall layers: an animal study Düx M., Kuntz C., Grenacher L. University of Heidelberg, Diagnostic Radiology, Heidelberg, Germany

Percutaneous treatment of iliac occlusive disease with stent placement. Long-term results Brountzos E., Papaioannou G., Alexopoulou E., Koutrouveli E., Papathanasiou M., Kelekis D.A. University of Athens, 2nd Department of Radiology, Athens, Greece

Purpose : The aim of this study was to evaluate intraluminal MR imaging using a newly developed MR-coil concept to delineate gastric wall layers in pigs. Materials and Methods : Five stomachs of five pigs were examined post mortem in a 1.5 T MR unit (Siemens Symphony, Erlangen, Germany) using a newly developed gastric coil concept for endo-luminal imaging. Standard MR sequences (T1-weighted Flash, T2-weighted TSE, opposed phase) in three planes were obtained. The number, visibility, and signal intensities of gastric wall layers were analysed. MR findings were correlated with histological cuts to anatomically name the layers visible at MRI. Results : In all the cases, up to five layers of the gastric wall were visible on MRI. T2-weighted images were best suited for the identification of different gastric wall layers. The mucosa, the muscularis mucosae, the submucosa, the proper muscle layer and the subserosa/serosa may be distinguished on MR scans. Conclusion : Intraluminal MR imaging is a valuable technique for the visualization of different gastric wall layers, a conditio sine qua non to perform local staging of gastric tumors. If the technique can be used in humans (endoscopic MR imaging) it may have the potential to improve the staging accuracy of gastric cancer.

Purpose : To evaluate the long-term results of stent placement in iliac arteries. Materials and Methods : Between 1995 and 1999, 131 patients (165 limbs) with stenosis (n=145) and occlusions (n=20) in the aortoiliac segment were treated with stents; 69.7% of the lesions involved the common iliac arteries, 19.2% the external iliac arteries, while 12.8% both common and external iliac arteries. In 13 patients (10%) the lesions involved the aortic bifurcation; 13.7% of the lesions were category 1 (Rutherford classification), 53.6% were category 2, 18.3% were category 3, and 14.4% were category 4. Primary stenting was performed in all lesions with the Palmaz stent (n=148) and the Wallstent (n=66). Follow-up included physical examination, with ABI index measurement, color-Doppler ultrasonography, and DSA. Median follow-up was 14.2 months (1-60 months). Results : Technical success was 97.7% and clinical success was 89%. Complication rate was 6.7%. Primary patency was 86.7%. Secondary patency was 96.8%. Restenosis rate was 13%. At the time of the last follow-up, 81.2% of our patients had clinically improved, 16.7% were stable, while 2.1% had worsened. Conclusion : Stenting of complex iliac lesions is a safe and effective treatment modality. Long-term clinical benefit is influenced by the presence of diffuse multilevel vascular disease.

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Influence of acute hemobilia on vital signs Maynar M., Pineda L.F., Crisostomo V., Sun F., de Miguel C., *Lima J.R., ****Qian Z., **Hernández F.J., ***Usón J., *****Lunderquist A. CCMI, Universidad de Las Palmas de Gran Canaria, Endoluminal Therapy and Diagnosis, *Anaesthesiology, **General Surgery, *** Scientific Direction, Cáceres, Spain; ****Louisiana State University Medical Center, Radiology, Louisiana, USA; University of Lund, Diagnostic Radioloy, Lund, Sweden

Percutaneous bioprosthetic venous valve: an experimental long-term study in sheep Pavcnik D., Uchida B.T.U., Timmermans H.A.T., *Corless C.L.C., Rosch J.R, Keller F.S.K, Oregon Health Sciences University, Dotter Interventional Institute, *Veterans Hospital, Pathology, Portland, OR, USA Purpose : To evaluate a new, percutaneous, bio-prosthetic, bicuspid, venous valve in a long-term study. Materials and Methods : Valves were constructed from squarestents covered by porcine small intestinal submucosa (SIS). Valves sizes ranged from 10 to 16 mm and were placed through 9-F sheaths. Twelve sheep received 26 valves in the external jugular vein bilaterally. The valves were studied by immediate venograms in supine position. Animals had follow-up venograms at four weeks (n=2), three months (n=5), and six months (n=5) and were then sacrificed for gross and histologic evaluation. Results : A good valve function on immediate venograms was observed in 25 valves (96%). Twenty-three valves (88%) remained patent with no leak on follow-up venograms prior to sacrifice. Two valves (8%) were patent but exhibited leaks due to a slight misalignment in curved veins. At autopsy, a smooth incorporation of the SIS valves into the vein wall was observed in 25 valves (96%). Histologic evaluation of the SIS valves demonstrated SIS remodeling with endothelial cells, variable fibrocytes, capillaries and some inflammatory cells. Conclusion : SIS valve is a promising, one-way competent valve. Valve remodels as ingrowths of host cells transforms its SIS cover into the body’s own structures.

Purpose : To investigate the causes leading to potentially fatal complications after percutaneous therapy or liver trauma in patients suffering obstructive jaundice. Materials and Methods : Ten pigs were used for this study. Under general anaesthesia, the common bile duct was ligated. Forty milliliters of bile were obtained from direct gallbladder puncture six days later. Bile was injected in the inferior vena cava at 4 ml/sec (n=4), 2 ml/sec (n=2), 1 ml/sec (n=2) and 0’5 ml/sec (n=2). EKG, mean arterial blood pressure (MABP) (pulmonary and systemic) and arterial blood gas (PO2) were continuously monitored. An additional injection was performed in the left ventricle after retrograde catheterization in one animal (4 ml/ sec, total 40 ml). Blood was sampled before, during, and after this injection for electrolyte assay. Results : All animals showed arrhythmias, peripheral MABP decrease (>50%), central MABP decrease (>65%) and PO2 decrease (>80%). Death occurred four to 16 minutes postinjection (n=9). One animal was euthanized 63 minutes postinjection. In this animal, bile injected into the right atrium caused a temporary increase in pulmonary MABP. K+ increased and Ca++ decreased during injection. Pathology showed microthrombus in heart and lung. Conclusion : Bile passes from pulmonary to systemic circulation. Bile may cause death from a combination of pulmonary reaction and cardiac toxicity.

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Percutaneous isolated hepatic perfusion for the treatment of liver metastases Schultze Kool L.J., **Rothbarth J., ***Ivancev K., ****Jeppson B., **van Dierendonck J.H., *Pijl M., **van de Velde C. The Netherlands Cancer Institute, Radiology, Amsterdam, Leiden University Medical Center, *Radiology, **Surgery, Leiden, The Netherlands; Malmö Medical Center, ***Radiology, ****Surgery, Malmö, Sweden

Development of a new percutaneously implantable staple device for the treatment of the vessel wall. A work-inprogress Polak J.F. Brigham and Women’s Hospital, Radiology, Boston, MA, USA Purpose : To introduce a new device for the treatment of postPTA arterial dissection and for fixation of vascular implants to the vessel wall which is possibly less traumatic than stents. Materials and Methods : A prototype of an intravascular staple device was developed for percutaneous implantation through an angiographic catheter. The stainless steel staple has a helical shape, a length of approximately 1.5 mm and a diameter of 1 mm, mounted onto a special flexible driver. After insertion through a flexible, preshaped catheter with a lumen of 5 F, the staple is released into the arterial wall by rotation. The new device was tested in vitro and in human cadaver arteries. Results : With the new prototype, the staple can be placed at the desired vessel site. Experimentally created vessel wall dissections and intimal flaps could be attached firmly as well as implant materials such as grafts or venous valves. Conclusion : First experimental in vitro results are promising. With this device, refixation of post-PTA dissections or intimal flaps and attachments of implants to the vessel wall is feasible.

Purpose : To develop a minimally invasive percutaneous technique for isolated hepatic perfusion. Surgical isolated hepatic perfusion (IHP) was developed as a treatment for non-resectable metastases confined to the liver. In data obtained from phase I/II studies (n=105) we have shown that this procedure can lead to a significant response resulting in a median life expectancy of 28 months, with even 5-year survivors with a good quality of life. IHP however, is an invasive, technically difficult, non-repeatable demanding operation. A minimally invasive percutaneous method for isolated hepatic perfusion (PIHP) is under development to enable widespread use of this treatment. Materials and Methods : Yorkshire pigs (n=20) weighting approximately 60 kg were used. Leakage was quantified by adding Technetium to the isolated circuit. Different perfusion techniques were tested (antegrade, retrograde, with or without occlusion outflow) and flow characteristics and leak rates were evaluated. Results : The most promising technique is retrograde perfusion with inflow from the hepatic veins/artery and outflow through the portal vein. Flow rates exceeding 300 cc per minute could be achieved. By adjusting portal pressures during perfusion, leakage could be controlled. An update of recent experiments will be presented. Conclusion : Percutaneous isolated hepatic perfusion technique is feasible. S130

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An experimental model of abdominal aortic aneurysm in pigs Maynar M., *Hernández FJ, Crisóstomo V., de Miguel C., Sun F., Pineda LF., **Martin MF., ****Qian Z., ***Usón J. CCMI, Universidad de Las Palmas de Gran Canaria, Endoluminal Therapy and Diagnosis, *General Surgery, **Anaesthesiology, ***Minimaly Invasive Surgery Centre, Scientific Direction, Cáceres, Spain; ****Louisiana State University Medical Center, Radiology, Louisiana, USA

Evaluation of endoleak management techniques in an experimental abdominal aortic aneurysm model Redd D. Emory University Hospital, Radiology, Atlanta, GA, USA Purpose : The aim of this study was to evaluate the effects of endoleak management in an infrarenal abdominal aortic aneurysm (AAA) flow model under physiological conditions. Materials and Methods : An AAA flow model was created using a 25-mm diameter latex tubing flow circuit with pulsatile flow (60 bpm) varied between 4-8 L/minute at 125-200 mmHg. Pressures within the aorta and the aneurysm sac were monitored following a variety of endovascular interventions. Results : Deployment of a stentgraft divided the AAA into an aortic flow lumen and an aneurysm sac. With a PTFE tubular stentgraft and no endoleak, the aortic sac pressure was reduced to 66% peak systolic pressure (PSP). After creation of a Type-I proximal endoleak, pressure within the aneurysm sac was increased to 80% PSP. After creation of a Type-II endoleak (IMA inflow and lumbar artery outflow), pressure was reduced to 50% PSP. Following IMA embolization, sac pressure was reduced to 2% PSP. Conclusion : These results suggest that in the absence of an endoleak, significant pressurization of the aneurysm sac may occur due to transmitted pressurization or endotension. Ongoing assessment of stentgraft materials and embolic agents is proceeding in an effort to more fully characterize the problems related to endovascular aneurysm repair.

Purpose : To develop an abdominal aortic aneurysm (AAA) model that resembles human aneurysms with potential for further growth. Materials and Methods : An infrarenal AAA model was created with a peritoneal patch in 27 domestic swine. Pre- and postsurgical digital subtraction aortograms (DSA) were obtained to document the appearance and dimensions of the aneurysm. Animals were followed with DSA up to five months. Laparoscopic examinations and ultrasounds were carried out in two animals at 30 and 60 days following surgery. Histological examination was performed in four animals. Results : All the animals survived the surgical procedure. The aneurysmal mean diameter increased from 10.27+-1.24 to 16.69+-2.29 mm immediately after surgery, to 27.6+-6.59 mm at 14 days and to 32.45+-8.76 mm at 30 days (P<0.01). Rupture occurred more frequently in aneurysms over 6 cm in length than in shorter aneurysms (p<0.05). Laparoscopy showed strong pulses and undetectable suture lines on the aneurysmal wall. On pathology, the patches were well incorporated into the aortic wall. Conclusion : This model proved to have potential for further aneurysmal growth and a tendency to rupture, so this might be a better model than those with a non-compliant wall for the preclinical evaluation of stent-grafts.

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High-resolution 3T MR microscopy imaging of arterial walls Sailer J., *Berg A., **Sulzbacher I., ***Hölzenbein T., Lammer J., Rand T. University Clinic of Radiodiagnostics, Angiography and Interventional Radiology,, University of Vienna, *Institute of Medical Physics, **University Clinic of Pathology, ***University Clinic of Surgery, Vienna, Austria

Development of a new design for aorto-iliac stentgrafts Polak J.F. Brigham and Women’s Hospital, Radiology, Boston, MA, USA Purpose : To introduce a new prototype for the treatment of aorto-iliac aneurysms. Materials and Methods : This new design is based on a selfexpanding aortic stent consisting of two nitinol wire filaments with a preshaped double helical structure. It is introduced longitudinally through a catheter in a parallel fashion thus forming a stent-like device at the vessel site to be treated. In its lower part there is a stretchable membrane oriented horizontally, which blocks the blood flow proximal to the aneurysm. Two iliac stentgrafts are introduced through the membrane sealing the connection and holding the stentgrafts in place. This new device was tested in vitro and experimentally in five dogs with experimentally created AAAs, with clinical and angiographic follow-up. Results : The stent with the membrane can be introduced through a 9-F vascular sheath. Bilateral stentgrafts can be fixed within the membrane, thus preventing dislocation. The new device could be successfully implanted in all dogs. Aneurysms were excluded immediately and blood flow to the external iliac arteries was restored by the stentgrafts. A peri-interventional thrombotic occlusion of one iliac stent-graft (1/10) occurred. Conclusion : This new device was able to exclude AAAs in an experimental setting.

Purpose : To achieve high-resolution MR microscopic images of the inner structure of arteriosclerotic arteries using a dedicated microscopic coil device and to compare the findings with those of histological images. Materials and Methods : T2-weighted images (TR/TE:3470 ms/30 ms) of arteries were obtained in six specimens using a 3T MR unit (Medspec 30/80 Avance) in combination with a dedicated MR-micro-scopy system. Field of view (FOV) was 1.2 cm, slice thickness 600 mm. Volume measurement and classification of intimal proliferations, thickness and morphology of the arterial walls were evaluated and compared with histological results. MRmeasurement of the arterial tissue was undertaken directly after surgical sampling, followed by histological examination. Results : We found a correlation between MR images and histology for the morphology and extension of intimal proliferations and arterial wall components. We were able to differentiate fibrous and calcificated from lipid plaque components with different signal intensity. Furthermore, we achieved a high resolution in the imaging of arterial wall layers. Conclusion : High-resolution high-field MR imaging of arterial walls may demonstrate morphological features of atheromatous intimal proliferations. MR-microscopy allows visualization of arterial structure in vitro. Perspectives for in vivo application include differentiation of hard and soft plaques, decisive for further interventional or surgical strategy. S131

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Gastro-oesophogeal stent placement for palliation Uberoi R. Queen Elizabeth Hospital, Gateshead, XRay, Newcastle-upon-Tyne, United Kingdom

Corrosive esophageal strictures: safety and long-term effectiveness of balloon dilation Seo T.-S., Ko G.-Y., Lee K.-H., Sung K.-B., Song H.-Y. AMC, University of Ulsan College of Medicine, Radiology, Seoul, Korea

Purpose : To review gastric and oesophogeal stenting in a DGH. Materials and Methods : There were 28 men and 12 women, mean age 68 (39-91). Pre-stent, nine patients had dysphagia for solids only, three for semi-solid food, seven for fluids, 17 had total dysphagia and no severity was recorded in four. Thirty-six patients had primary oesphogeal/gastric tumours and four had extrinsic compression (lung cancer, including two fistulae). Tumours were at the distal third in 17 cases, at the gastro-oesophogeal junction (GOJ) in eight, at the mid third in seven, at the proximal third in one, in five the whole stomach was involved, and in two they were recurrences. Results : All the patients had a successful stent placement. In five, the stents migrated (three GOJ, one lower third and one stomach body) and in one, it perforated. Post-stent implantation, 17 had no dysphagia, 13 had some dysphagia for solids, one for fluids (one vocal cord palsy), and no data were recorded in eight. Four required further stenting for tumor overgrowth. Six had poststent dilatation. Initial stay was 11 days (0-36). Seventeen had no further admissions, 14 were re-admitted once and nine on three occasions. Total stay was 19 days (0-98). Sixty six percent survived >one month (two to >300 day). Conclusion : Gastro-oesophogeal stenting is safe, effective and worthwhile. Uncovered stents should be avoided. Covered stents should be avoided at the GOJ/proximal stomach.

Purpose : To evaluate the safety and long-term efficacy of balloon dilation in corrosive esophageal strictures. Materials and Methods : We performed fluoroscopically-guided balloon dilations in 72 consecutive patients with corrosive esophageal strictures. A 5–8 mm diameter balloon was used in the initial attempt and gradual dilations up to 15–20 mm in adults and up to 12 mm in children were subsequently performed. To assess the clinical improvement, the swallowing capacity was classified into 6 grades. Initial success was defined as an increase in the stricture diameter and as an improved swallowing capacity. Follow-up period ranged from 12 to 149 months (mean, 35 months). Results : A total of 240 sessions of balloon dilation in 72 patients and 1-16 sessions per each patient (mean, 3.1 sessions) were performed. Initial success was achieved in 64 (89%) patients. Strictures recurred in 27 (42%) patients and were treated by repeated balloon dilations in 13, temporary stenting in 13, and surgery in one. Procedure-related complications were severe pain in 36 (47%) and esophageal rupture in 28 (39%). Conclusion : Fluoroscopically-guided balloon dilation is an effective initial treatment modality in corrosive esophageal strictures, but frequent repeated balloon dilations are needed because of the high recurrence rate. The high rupture rate indicates need for cautiousness.

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Balloon dilation followed by chemotherapy or radiotherapy for palliation of dysphagia due to malignant esophagogastric junction obstruction Ko G.Y., Song H.Y., Hong H.J., Sung K.B., Seo T.S., Yoon H.K. Asan Medical Center, Radiology, Seoul, Korea

Development of a multi-functional gastroduodenal coil catheter Lee J.-H., *Seo T.S., *Lim J.O., *Ko G.-Y., Kim T.-H., Huh S.J., Song H.-Y. Asan Medical Center, Biomedical Engineering, *Radiology, Seoul, Korea

Purpose : To evaluate the efficacy and safety of balloon dilation followed by chemotherapy or radiation therapy for the treatment of dysphagia due to malignant strictures involving the esophagogastric junction. Materials and Methods : From May 1995 to August 2000, 18 consecutive patients with dysphagia due to obstruction of the esophagogastric junction were treated by means of balloon dilations followed by chemotherapy or radiation therapy. The causes of the strictures were squamous cell carcinoma (n=6) and adenocarcinoma (n=10). To assess the clinical improvement, dysphagia was classified into six scores (0 = aphagia; 5 = all foods). Results : There were no technical failures or major complications. After balloon dilation, 17 (94%) patients showed an improvement of dysphagia. Dysphagia score was 2.1 before balloon dilation and 3.7 after balloon dilation. All the patients died 3–64 (mean, 24) weeks after balloon dilation because of diffuse metastases. Nine (50%) of them did not need further balloon dilation because of an improved swallowing capacity until death. The remaining patients underwent repeated balloon dilations (n=7) or placement of expandable metallic stents (n=2). Conclusion : Balloon dilation followed by chemotherapy or radiation therapy seems to be a safe and effective initial therapy for patients with dysphagia due to malignant strictures involving the esophagogastric junction.

Purpose : To evaluate the effectiveness of a multi-functional coil catheter developed for gastro-duodenal interventions. Materials and Methods : Two models of catheters were developed and each one of them was classified into three types. The catheter was made of a stainless steel coil with radiopaque markers. Models A and B have unelongated and elongated distal parts, respectively. No wires were attached on Type 1, whereas Types 2 and 3 have 65- and 240-cm nitinol wires for force transmission, respectively. Twelve experiments were performed in three mongrel dogs to evaluate the functions and effectiveness of the catheters. Results : The catheters were useful for measuring the length of the small bowel and for injecting the contrast medium. They successfully passed the 30-cm tract from the pylorus on the first attempt. Approaching to 120 cm, the success rates of Models A and B were 100% with a number of attempts <5 and 70% with 10 attempts, respectively. The catheter tip successfully passed the folded segment of the small bowel after an average number of attempts of 3, 2, and 3 for Types 1, 2, and 3, respectively. Conclusion : Multi-functional coil catheters are effective for the injection of contrast media and for length measurement, and Model A-Type 2 seems to be the most valuable.

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Percutaneous evacuation (PEVAC) of complicated echinoccal cysts: first results of a modified PAIR method Laméris J.S., *Schipper H.G., van Delden O.M. Academic Medical Center, Radiology, *Tropical Medicine and AIDS, Amsterdam, The Netherlands

Endovascular management of visceral artery bleeding Mansueto G.C., D'Onofrio M., Ferrara R.M., *Salvia R., Procacci C. University of Verona, Radiology, *Surgery, Verona, Italy Purpose : To evaluate the efficacy of the endovascular treatment of visceral artery bleeding. Materials and Methods : From October 1992 to December 2000, 35 patients with visceral artery bleeding were treated with endovascular techniques. The arterial lesion was due to severe pancreatitis in nine patients and to chronic pancreatitis in five cases. In 18 patients the lesion was iatrogenic (12 after surgery and six after percutaneous procedure). In three patients the cause was a ruptured splanchnic aneurysm. In 32 patients, embolization of the bleeding artery (coils in 16 cases, coils with acrylic-glue in seven and acrylic-glue in nine cases) was performed. In the remaining three cases, a covered-stent was placed for bleeding artery repair. All the patients were followed-up at three months with CT. Results : In 29/35 patients the bleeding was definitively stopped, but two patients died due to hepatic failure (procedure-related complication). Other six patients died although a final angiographic control had shown the cessation of bleeding and despite the surgical revision. After 2 months another patient died of pancreatitis complications. At three-month follow-up 26/35 patients were still alive. Conclusion : Visceral artery bleeding is a life-threatening condition. In our experience, the endovascular treatment can reach a clinical success rate of 70%.

Purpose : Surgery is the treatment of choice in echinoccocal cysts with cystobiliary (CB) fistulas. PAIR (puncture, injection and reaspiration of scolecidals) is contraindicated in these cases. This study evaluates a modified PAIR method for the treatment of such complications. Materials and Methods : Eight patients with Gharby type III cysts with intrabiliary rupture, cyst infection, obstructed portal or hepatic vein were included. The treatment was the following: USguided cyst puncture, insertion of a 12-F catheter, aspiration and evacuation of the liquid part. In a second session, we inserted a large-bore, rigid, polyethylene sheath (14-18F), then percutaneous aspiration and evacuation (PEVAC) of solid debris was carried out. Injection of scolecidals was done only if there were no CB fistulas. The external drainage of CB fistulas was combined with endoprosthesis or sfincterotomy. After closure of the fistula, the catheter was removed. Results : In six patients with CB fistulas and infection, the cyst mean size was 10.1 (6-20) cm, the catheter time 62.8 (32-126) days, the hospital-stay 39 (29-55) days. At 11.3-month (3-24) follow-up, all cysts had disappeared competely). In two patients with CB fistulas, the cyst size was 14.4 (12.7-16), the cathetertime 8.8 (3-13) days, the hospital-stay 11.5 (8-14) days. At ninemonth follow-up, the cyst size was reduced of 57% (54-62) . Conclusion : PEVAC has results comparable with those of surgery for Type-III echinoccal cysts with or without CB fistulas which contain solid, degenerated material.

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Hydatid liver cysts: 11 years of experience with the treatment by percutaneous aspiration and ethanol injection Giorgio A., Tarantino L., de Stefano G., Mariniello N., Farella N., Liorre G., Esposito F. D. Cotugno Hospital, Interventional US, Naples, Italy

Superselective embolization in acute gastrointestinal hemorrhage Cancellieri R., Fabiano S., Gandini R., Lupatelli T., Pocek M., Simonetti G. Tor Vergata University, Radiology, Rome, Italy

Purpose : To present our 11-year experience with double percutaneous aspiration/injection of ethanol (D-PAI) of hydatid liver cysts (HLCs). Materials and Methods : Between January 1988 and January 1999, we studied 129 patients with 174 HLCs (diameter range: 2-20 cm; mean: 6.4 cm). Fifty five non-vital, solid or calcified cysts were not treated; 76 unilocular (type 1-2), 26 septated or multivesciculated (type 3) and 17 cysts with an inner membrane detachement (type 4) underwent D-PAI. Follow-up was performed by US every month for the first three months and every six months thereafter; a chest X-ray and an abdominal CT were performed every six months and every two years, respectively. Results : One patient died for anaphylactic shock during the procedure. Four patients were re-treated due to a relapse six, 12, 15 and 24 months after the first D-PAI. At last US examination during follow-up, 56 cysts (47%) were no more detectable, 55 (46.3%) showed a solid pattern and eight cysts (6.7%) showed a liquid pattern with detached membranes floating in a hydatid fluid. In none of the patients, lung recurrences at chest X-ray or abdominal spreading of the disease at CT have been observed. Conclusion : Our experience shows a high long-term efficacy of D-PAI treatment for HLCs.

Purpose : To evaluate the efficacy and complication rate of embolization in upper and lower gastro-intestinal hemorrhages. Materials and Methods : From May 1997 to January 2001, 21 patients (age range 19-77 years; mean 69.6 years) with acute gastrointestinal hemorrhage (seven upper tract, 14 lower tract) and an unsuccessful endoscopic evaluation were treated with superselective embolization. This was performed as much peripherally as possible with the use of coaxial catheter systems. Embolizations were perfomed by straight (four patients), microcoils and polyvinyl alcohol particles (four patients), microcoils and gelatin sponge particles (four patients) and gelatin sponge particles (nine patients). Results : In all the patients hemostasis was achieved. In 18 patients the bleeding could be successfully stopped with the first intervention. In three patients, two interventions were needed to completely stop the hemorrhage. After superselective embolization, there were no complications and no evidence of intestinal ischaemia. Conclusion : Superselective embolization is an efficient and safe method in the treatment of gastro-intestinal bleedings. This technique can reduce the ischaemic area and can provide the direct control of hemostasis.

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Long-term results after embolization therapy of gastrointestinal bleedings Kröger J.C., Jagow A., Bartolomaeus A., Schulze C.G., Heller T., *Plath F., **Adam U., **Schareck W., **Pfeiffenberger J., Hauenstein K. University of Rostock, Institute of Diagnostic and Interventional Radiology, *Dept. of Gastroenterology, **Dept. of Surgery, Rostock, Germany

One-step biliary stenting: results after a five-year experience Cancellieri R., Pampana E., Gandini R., Spinelli A., Guazzaroni M., Simonetti G. Tor Vergata Rome University, Radiology, Rome, Italy Purpose : To evaluate the efficacy and feasibility of one-step biliary stenting by assessing post-procedural and long-term follow-up. Materials and Methods : From March 1994 to December 2000, 87 patients with biliary tract neoplastic obstruction were treated by one-step stent implantation: 23 Ultraflex stents (group A) and 64 Wallstents (group B). In four patients, a second stent was necessary because of malposition during deployment (one patient) and bilateral drainage (three patients). In all the patients an external drainage catheter was left at the confluence of the biliary tree for 48 hours after stent placement. Results : A successful stricture stenting was achieved in all patients. Mean hospital stay after the procedure was 6.4 days (group A) and 5.4 days (group B). No major complications were observed. All the patients had reduction of the mean bilirubin values: from 14.5 to 4.3 mg/dl in group A and from 12.3 to 3.9 mg/dl in group B. The patients were followed up at one-month intervals for a period of 20 days-14 months. All the patients died (20 days-14 months) with a mean survival rate of 7.1 months (group A) and 7.8 months (group B). Average stent patency was 6.4 months and 7.3 months, respectively. Conclusion : Self-expandable stents implanted in one session is technically easy and clinically effective. Hospitalization costs can be reduced.

Purpose : To demonstrate long-term results after embolization of gastrointestinal hemorrhages. Materials and Methods : From 1992 to 1999, 68 patients (39 women, 29 men, 32-88 years) with acute gastro-intestinal hemorrhage were treated by embolization therapy. Bleeding was a complication of pancreatitis (28), intestinal angiodysplasia (23), colonic diverticulitis (7), Crohn’s disease (1), neoplasia (3), after therapeutic procedures (5) and trauma (1). We analysed primary technical success and long-term follow-up ( 20-96 months, mean 38.4 months). Results : Complications of pancreatitis should be divided into two groups; completely embolized pseudo-aneurysms have an excellent prognosis. Embolization of bleeding pseudocysts is temporary successful. In two patients, repeated embolizations were necessary. Embolization of angiodysplasia was successful in 18 patients. Recurrent bleeding (7) was caused by multi-locular angiodysplasia. Embolization of iatrogenic lesions and bleeding diverticulitis was sufficient in all cases. Embolization of bleeding tumors and Crohn’s disease has a short time effect, and recurrent hemorrhages were recorded 6-22 days after intervention. Conclusion : Embolization of acute gastrointestinal hemorrhages is primary successful in most of the indications. A definitive embolization effect is expected in those patients with postpancreatitic pseudoaneurysms, diverticulitis and iatrogenic lesions. Embolisation of pseudocysts and malignant tumors shows a temporary effect. In patients with angiodysplasias, a long-term success can be proven; recurrent bleeding depends on the occurrence of further angiodysplasias.

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Rotational digital cholangiography (RDC) and 3Dcholangiography: A new imaging technique for the guidance of percutaneous biliary drainage procedures Alfke H., Kalinowski M., El Sheik M., Klose K.J., Wagner H.J. Philipps University of Marburg, Marburg, Germany

A single-step procedure in biliary stent placement: usefulness of hepatic tract plugging Gil S., de Espana F., de la Iglesia P., Irurzun J., Verdu J. Hospital General Universitario de Alicante, Radiology, Alicante, Spain

Purpose : To evaluate if RDC helps to clarify anatomic details in biliary duct disease and whether this is useful in the guidance of drainage procedures. Materials and Methods : RDC was done in ten consecutive patients who had undergone PTCD for biliary duct stenosis (eight men, two women, mean age 68.7 years). Images were obtained after initial bile duct puncture during a single breathhold from 120 projection angles using a rotating C-arm. These images were immediately available and evaluated for facilitating the definite drainage procedure. For additional 3-D reconstruction, data were sent to a dedicated workstation. Results :The availability of a rotating data set of images was judged to be helpful in two patients with complex anatomical situations. In all the other patients, there was no diagnostic benefit in comparison with conventional C-arm fluoroscopy. However, RDC holds the potential to reduce fluoroscopy time. Threedimensional reconstructions allowed analysis of the hepatic bifurcation from different viewing angles in all cases with a high spatial resolution (mean Voxel size 480 µmE3). This may lead to a better classification of hilar obstructions. Conclusion : Images from RDC and 3-D reconstruction are helpful in guiding PTCD procedures and for diagnosis in selected patients with hilar biliary duct stenoses.

Purpose : To present our experience with a one-step procedure in biliary stent placement by using hepatic tract embolization. Materials and Methods : In a 9-year period (1992-2000), 366 bilary stents (11Strecker, 13 Sinus, 16 Wallstent and 326 Memotherm) were placed in 334 patients. In the last six years, stent deployment was made in a single-step procedure in 264 patients: CTPH, stent placement and hepatic tract plugging in the same session. The hepatic tract was plugged by introducing hand-made cylinders of gel-foam (Spongostan) in the hepatic tract with a 7-F peel-away introducer, also used to deploy the stent. Results : This one-step procedure was not performed in those cases where the stent worked properly, in case of haemobilia and cholangitis and when it was impossible to pass the stricture on the first attempt. In the remaining cases, the hepatic tract was embolized without complications. We have also observed a reduced post-procedural abdominal pain due to the decrease of bile and blood leakage. Conclusion : The one-step procedure allows to reduce the time of hospitalization and the number of transfers. We believe that this procedure is especially useful in those Interventional Units with a large amount of patients coming from other hospitals.

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Innovative access for the biliary Wallstent in malignant biliary obstructions Ho C.S., Voss M.D. University of Toronto, Dept. of Medical Imaging, Toronto, Canada

Cost-effectiveness analysis of percutaneous transhepatic metal versus plastic biliary stent implantation for the treatment of malignant biliary obstruction Guo Y., Yong C., *Pengfei L., **Hong S., Yanhao L. NanFang Hospital, Radiology, *People Hospital of Guangdong Province, Radiology, **3rd affiliated Hospital, Sun Yat-Sen University, Radiology, Guangzhou, China

Purpose : Insertion of self-expandable metallic stents is a widely accepted palliative treatment for inoperable malignant biliary obstructions. Stent occlusion often requires a new percutaneous biliary drainage (PBD). This can be both risky and technically difficult. We describe an innovative approach that eliminates the need for a new PBD. Materials and Methods : Sixteen patients (mean age 72.8 years) with malignant extrahepatic biliary obstruction had insertion of a Wallstent after failure of internal/external drainage. A 4-F percutaneous access catheter was left across the stent in the duodenum and fixed flush with the skin with a low-profile catheter fixation device. In stent occlusions this provided a convenient access for cholangiography or re-intervention. Results : The mean stent patency duration was 5.1 months (range 1-12 months). Eleven patients (68%) required 35 biliary reinterventions for stent occlusion. The access catheter facilitated all re-interventions, none of them requiring a new puncture. Average monthly re-interven-tions before and after stent insertion were 1.5 and 0.4, respectively, with no significant difference in the frequency of cholangitis (0.09 vs 0.07/month). Conclusion : Inserting a small catheter at the stent placement site provides a safe access for re-intervention.

Purpose : To compare metal versus plastic stent implantation for the treatment of malignant biliary obstruction in clinical efficacy and cost-effectiveness ratio (CER). Materials and Methods : Percutaneous transhepatic self-expandable metal stent (n=61,group A) or 10-F plastic stent (n=34,group B) implantation were performed in 95 patients with malignant biliary obstruction. All the patients were followed up until death. Kaplan-Meier analysis was used to compare patients survival and stent patency rates. CERs of two groups were calculated. The main indexes were CER survival period (total cost/median survival period) and CER patency period (total cost/median patency period). Results : The 30-day mortality rate was lower in group A (6/61; 9.8%) than in group B (9/34; 26.5%; p<0.05). The median stent patency rates and the median patients survival rates were 230d224d in group A and 90d-94d in group B, respectively (P<0.01). The total costs of treatment were 53177±3139 yuan (RMB) in group A and 42564±4950 yuan (RMB) in group B(p>0.05). The CER was superior in group A (CER survival period was 237.4 yuan /d vs 452.6 yuan/d; the CER patency period was 231.2 yuan/d versus 472.9 yuan/d, respectively). Conclusion : Metal stent implantation is superior to plastic stenting in both clinical efficacy and CER for the treatment of malignant biliary obstruction.

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First clinical experiences with the Gore biliary endoprosthesis Schoder M., *Rossi P., **Uflacker R., Schöfl R., Cunningham J., Cejna M., Lammer J. University of Vienna, Angiography and Interventional Radiology, Vienna, Austria, *Rome, Italy, **Charleston, SC, USA

Management of isolated right segmental hepatic duct injury following laparoscopic cholecystectomy (IRSHDI) Uflacker R., Selby J.B., *Perini R., *Cunningham J.T. Medical University of South Carolina, Interventional Radiology, *Digestive Disease Center, Charleston, SC, USA Purpose : To present our experience in the management of IRSHDI after laparoscopic cholecystectomy and long-term follow-up after treatment with combined endoscopic, surgical and percutaneous interventions. Materials and Methods : Ten patients (seven women) with IRSHDI (mean age 44.5 yrs) were reviewed. Charts and images were recorded. Patients’ demographics, presentation, management and outcomes were analyzed. Results : The symptoms included pain, sepsis and jaundice. Previous treatments included ERCP, percutaneous drainage and surgery, isolated or in combination. Median referral time was 42 days. Biliary leak, biloma (n=9) and obstruction of the right hepatic duct (n=1) were diagnosed. We used a combination of ERCP w/stent (n=9), percutaneous drainage/stent (n=9) and surgery (n=6). The final treatment modality was ERCP/stenting (=2), PTC/stenting (n=3) (2 metallic) and surgery (n=5). Followup ranged from two to 80 months. Recurrences of stenosis (n=2) were treated by PTC/stenting (at 72 months), and surgery (at 24 months). No mortality or morbidity was observed. Conclusion : IRSHDI following laparoscopic cholecystectomy is a serious complication and its diagnosis by ERCP is hard due to a difficult opacification of the involved ducts. The treatment requires a multidisciplinary approach. Percutaneous and endoscopic procedures were required in all cases, even when surgery became necessary as the definitive treatment (50% of cases). The combination of PTC and ERCP proved successful in treating patients.

Purpose : To characterize the safety and performance of the Gore biliary endoprosthesis in patients with strictures caused by unresectable malignancies. Materials and Methods : During the last 12 months, a total number of 51 biliary endoprosthesis was implanted transhepatically in 38 patients. Obstructive jaundice was due to carcinoma of the pancreas in 27 cases, carcinoma of the bile duct in two patients, metastatic disease in eight patients, and lymphoma in one patient. The Gore biliary endoprosthesis consists of a nitinol stent with anchoring fins. The inner tubular lining is constructed from ultrathin non-porous ePTFE-TEP (fluorinated ethylene propylene). Stents are either fully covered or designed with transmural drainage holes for 1.5 cm along the proximal end. Results : Stent implantation was technical successful in all the patients. None of the stents migrated or were inadequately expanded. Complications in four patients included cholecystitis in three and perihepatic fluid in one. Twenty five patients were available at the one-month follow-up; 23/25 patients (92%) had a normal or a slightly increased serum bilirubin level. A threemonth follow-up was done in 11 patient and none of them had jaundice. Conclusion : Our initial results show that the Gore biliary endoprosthesis can be accurately deployed transhepatically, and short-term patency appears promising.

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Biliary tract isolation: implications in biliary drainage Brody L.A., Brown K.T., Getrajdman G.I., Covey A.M., *Robson P.C. Memorial Sloan Kettering Cancer Center, Radiology, *Nursing, New York, N.Y., USA

Percutaneous interventions for the treatment of venous complications after orthotopic liver transplantation (OLT) Goffette P., *Cicarelli O., **Laterre P.F., *Lerut J.P. Saint-Luc University Hospital – UCL, Interventional Radiology, *Digestive Surgery, **Intensive Care, Brussels, Belgium

Purpose : The purpose of the study was to determine the impact of hilar obstruction with isolation of a part, or parts, of the biliary tree in the management of those patients requiring percutaneous biliary drainage. Materials and Methods : A retrospective study of all the patients undergoing primary percutaneous biliary drainage from October 13, 1998 through Febriuary 28, 2000 was performed. Each case was evaluated for the presence and extent of isolation, which was then classified as complete, effective or impending. Laboratory, radiographic and chart data were reviewed to determine the efficacy of each procedure. Timing of conversion to internal stent(s), if performed, as well as the need for drainage of other segments, was also noted. Results : One hundred and twenty patients underwent 150 primary percutaneous drainage procedures during the study period. Isolation was present in over half of the cases. We will present data to help to determine the need for and timing of additional drainage procedures as well as internal stent placement. We will also examine the effect of isolation on drainage efficacy. Conclusion : Management of patients with biliary tract isolation is challenging. Care must be individualized in these often complicated cases. Our data may help to guide treatments based on clinical and/or radiographic findings.

Purpose : Venous problems after liver transplantation are rare (1-3%) and surgically very demanding. The purpose of this study was to determine the value of percutaneous interventions to treat these complications. Materials and Methods : Following classical (n=7), split (n=1) or portocaval hemitransposition (n=1) OLT, nine patients (median age: 56) had portal vein stenosis (n=6), occlusion (n=1), torsioninduced hepatic vein stenosis (n=1) and piggy-back IVC compression (n=1) (median delay: four months). Main clinical symptoms were ascitis (6), variceal bleeding (3) and elevation of liver enzymes (4). Classic anastomotic portal stenoses (n=5) were immediately treated by primary stenting and portocaval anastomotic strictures (n=1) by PTA alone. The extended portal thrombosis was treated by lysis (rTPA) via a TIPS approach. The IVC compression and the hepatic vein stricture were respectively managed by Gianturco stent implantation and PTA. Results : All percutaneous interventions were successful. Stents were primarily placed in six patients to overcome immediate elastic recoil after PTA (5 PV; 1 IVC). In other two cases, symptomatic portal or hepatic vein restenosis occurred later (delay: 1-3 months) after PTA, necessitating a secondary stenting. A complete declotting of the portal system allows to disclose an anastomotic stenosis requiring PTA only. During follow-up (2-22 months, median eight months), portal and hepatico-caval outflows were maintained in all the eight patients alive with a full clinical restoration. Conclusion : Primary percutaneous stenting, in some cases combined with lysis, seems to be the first choice treatment modality for venous complications after OLT.

54 Advantages of transhepatic balloon dilatations in post splitliver transplant benign biliary duct stenoses in young children *Bartal G., Belenky A., Bachar G., **Mor E., **Bar-Nathan N., Newman-Lewin M. *Hillel Yaffe Medical Center, Diagnostic Imaging and Interventional Radiology, Hardera, Rabin Medical Center, Radiology, **Organ Transplantation Dept., Petach Tikva, Israel

56 Main portal vein access for TIPS procedures: threedimensional ultrasound (3-D US) to ensure safety Rose S.C., Roberts A.C., Pretorius D.H., Nelson T.R., *Hassanein T.I. University of California Medical Center, Radiology, *Medicine, San Diego, CA, USA

Purpose : Transhepatic balloon dilatations of benign biliary strictures in adults have unfavorable long-term follow-up. We evaluated the outcome of repeated balloon dilatations of benign biliary duct stenoses in young children post split-liver transplant. Materials and Methods : Between 1997 and 2000, we treated four children (aged one to four years) with post-left lateral liver segment transplant benign biliary stenosis. We completed 3/4 sessions of repeated transhepatic balloon dilatations (10 minutes each) with an average of ten-day interval between sessions. We gradually increased the caliber of the angioplasty balloon from 3 to 4 and 5 mm in each session, consecutively. We placed 6-F external-internal biliary drainages between sessions. Criteria for completion were: normal liver tests and a patent common bile duct. Results : All the patients showed a full clinical recovery and cholangiography revealed patent bile ducts upon treatment completion. Five-month/four-year clinical and radiological follow-ups showed normal liver tests, normal ultrasonography and normal nuclear medicine scans. Conclusion : Repeated transhepatic balloon dilatation of benign biliary stenoses in children with split-liver transplant has a favorable outcome. We recommend this approach as an initial treat-ment for these patients.

Purpose : To document the safety of main portal vein (PV) access to create TIPS shunts, provided that 3-D US can document that the puncture entered an intrahepatic surface of the PV. Materials and Methods : In ten patients who underwent conventional TIPS (9) or transjugular portocaval shunt (1) procedure, the puncture was found angiographically to enter the main PV. Five were at the PV bifurcation and five were located caudally. 3-D US was used to determine whether the point of the portal vein entry was intra- or extra-hepatic. The puncture site was considered to be intra-hepatic if the liver covered the puncture site on all three orthogonal imaging planes (sagittal, coronal, and transverse). If the puncture site was determined to be intrahepatic, the access was used to deploy a noncovered Wallstent. Medical records were reviewed for evidence of hemorrhagic complications. Results : In all the ten patients, 3-D US was diagnostic and established that the liver completely covered the portal vein access site. All TIPS and direct portacaval shunt procedures were technically successful. No hemorrhagic complications occurred. Conclusion : The main PV can be safely used for TIPS procedures, provided that the access is proven to be intra-hepatic. 3-D US can confidently determine if PV entry site is intra-hepatic.

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Transjugular portosystemic shunt placement under general anesthesia VanHa T.G., Kim R., *Hofer M., Funaki B., Lorenz J., Rosenblum J., Leef J. University of Chicago Hospitals, Radiology, *School of Medicine, Chicago, IL, USA

Potential factors influencing TIPS patency Chovanec V., Krajina A., *Skrabkova Z., **Fejfar T. Charles University Hospital, Radiology, *Statistics, **Medicine, Hradec Kralove, Czech Republic Purpose : To reveal factors which may influence TIPS patency, two groups of selected patients were statistically analysed. The group A included patients with TIPS with no need for reintervention, the group B included patients with repeated shunt failure during at least a two-year follow-up. Materials and Methods : The group A included 32 patients: 17 men, 15 women: mean age 57.9 years (range from 28 to 80), Child Pugh mean score 8. The group B included 18 patients, 11 men, seven women, mean age 41.7 years (range from 10 to 66), Child Pugh mean score 7.9. The following parameters were analysed: age, portal vein diameter, the angle between the spine and the main portal vein, the angle between the shunt and the branch of the portal vein in AP view, central or peripheral shunt location type of implanted stent, blood count, total albumine, serum creatinine and bilirubine levels. Results : Only the age did reach statistically significant differences. The patients with a poor shunt patency were younger than those with a good patency (p=0.00004). Other evaluated parameters were not significantly different. Conclusion : The age was statistically lower in the group of selected patients with a poor two year-TIPS patency.

Purpose : To evaluate the safety and efficacy of transjugular portosystemic shunt (TIPS) placement performed under general anesthesia. Materials and Methods : Between January 1991 and December 1998, a total of 213 TIPS procedures was performed at our institution in 212 patients (ages 2-80 years; mean 51 years) under general anesthesia. Indications for shunt placement were gastroesophageal variceal hemorrhage not responding to the endoscopic therapy (164/213), intractable ascites (41/213), rectal varices (4/213), small bowel varix (1/213), and three unspecified indications. The most common underlying liver diseases were alcoholic cirrhosis, hepatitis B or C, and cryptogenic cirrhosis. Results : Technical success was 98% (208/213). There were 11 procedural complications (5%): carotid puncture (n=1); liver laceration (n=1); entry site hematoma (n=1); pneumothorax (n=1), portal vein tear (n=1), stent migration (n=1); portal vein pseudoaneurysm (n=1); portal venous thrombus (n=1), bile duct laceration (n=1), hepatic infarct (n=1), and bacteremia (n=1). None of the complications was related to the general anesthesia. The 30-day mortality rate was 9%. There were seven TIPS revisions with angioplasty within 30 days. Ten patients underwent liver transplantation within 30 days. Conclusion : TIPS placement under general anesthesia is safe and effective. Our results were comparable with other reported series performed using conscious sedation.

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TIPS: five-year follow-up Popovic P., Kljucevsek T., Klancar J., Berden P.,Surlan M. Clinical Centre, Clinical Institute of Radiology, Ljubljana, Slovenia

Changes in the liver circulation following TIPS with uncovered stent and stent-graft. An experimental study Keussen I., Bajc M., *Song H.Y., Cwikiel W.B. University Hospital, Diagnostic Radiology, Center for Medical Imaging and Physiology, Lund, Sweden; *Assan Medical Center, Diagnostic Radiology, Seoul, Korea

Purpose : To evaluate the five-year results of control and treatment complications of portal hypertension. Materials and Methods : From April 1994 to September 2000, 61 patients underwent TIPS. In 47 patients, TIPS was carried out to prevent recurrent varicose bleeding, in 13 for refractary ascites, and in one for acute Budd-Chiari. The cirrhosis was alcohol-induced in 33 patients, inflammatory in 27. The Child’s grade was A in six, B in 30, and C in 25 cases. Wallstent diameter was 12 mm. Follow-up was clinical and by Doppler. Results : TIPS was successfully performed in 60 patients (98.4%). Shunt stenoses/occlusions were detected in 14 patients, five with rebleeding and six with recurrent ascites. Shunt revision was successful in 13 cases, two with stentgraft (bile-fistulas) and one with creation of a new shunt. Forty two patients are still alive, seven underwent liver transplantation. Eighteen patients died, 11 because of liver failure, one of varicose bleeding and six for other causes. The cumulative survival was 57% after five years. There was no greater difference between the degree of encephalopathy before and after TIPS. Conclusion : TIPS is successful in the prevention of recurrent varicose bleeding and in the treatment of refractory ascites.

Purpose : To evaluate changes in the liver blood flow following stent insertion and subsequent stent-graft in the TIPS channel. Materials and Methods : All experiments were performed in eight healthy pigs under general anesthesia. In other pigs outflow from the liver veins was checked repeatedly by contrast injection through a percutaneously inserted catheter. The distribution of blood flow through the liver was examined by scintigraphy, following selective injection of macro-aggregate of 99Tcm-labelled human serum albumin (99Tcm HSA) in the hepatic artery. This examination was done before and after creation of the TIPS with a stent-graft and, subsequently, after insertion of a stent-graft in the cranial portion of the shunt channel. Results : One pig died during the procedure and another pig was excluded due to dislodgement of the hepatic artery catheter. The inserted stent-graft obstructed the venous outflow from the right liver lobe. A non-significant increase of the 99Tcm HSA activity in the liver was observed after TIPS with the stent-graft, but was significantly increased (p<0.005) after insertion of the stent-graft. Conclusion : In experimental pig models, distribution of the arterial blood flow in the liver is significantly affected by the creation of TIPS with a stent-graft.

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Transjugular intrahepatic portosystemic shunt: early clinical experience using a PTFE- covered stent-graft. Work-inprogress Deutschmann H.A., Portugaller H., Hausegger K.A. University Hospital Graz, Radiology, Graz, Austria

PTFE-covered TIPS endoprostheses: effects of intraluminal radiation in an animal model Portugaller H.R., Hausegger K.A., *Stranzl H., *Mayer R., Tauss J., Schedlbauer P., Deutschmann H., *Stuecklschweiger G. Univ. Clinic of Radiology, LKH Graz, Angiography and Interventional Radiology, *Univ. Clinic of Radiotherapy, Graz, Austria

Purpose : To evaluate early results of a PTFE-covered stent-graft (Viatorr) in transjugular intrahepatic portosystemic shunt (TIPS). Materials and Methods : Fourteen patients (12 men; mean age 58 years; age range 40.6 to 70.4) were included in this study. Indications were refractory ascites in 12 and recurrent esophageal bleeding in two patients. Nine patients had a Child class B and five a Child C cirrhosis. A Viatorr stent-graft (max. diameter 10 mm) was used in all patients; the length of the covered portion was 6/8 cm. Follow-up was performed by ultrasound after five days and after one, three and six months; venography was carried out after six months. The primary endpoint for the analysis was an angiographic patency after six months. Observation time ranged from one to nine months (mean 5.5). Results : TIPS placement was successful in all patients. No complications were observed. Mean portosystemic gradient decreased from 19.7 to 13.1 mmHg. Three patients died from liver failure. The 30-day mortality rate for Child’s B patients was 0% and 14.2% for Child’s C patients. All sonographic and angiographic studies showed widely patent shunts. No recurrent bleedings were observed. Two Child’s C patients developed a severe encephalopathy. Conclusion : Early results suggest an improved patency for TIPS using Viatorr stent-grafts. There seems to be a higher tendency to hepatic encephalopathy due to an increased shunt patency.

Purpose : To evaluate the performance of endoluminal irradiated PTFE–covered TIPS endoprostheses in a pig model. Materials and Methods : For TIPS creation, PTFE-covered endoprostheses were implanted in ten pigs. Animals were divided into two groups. Group 2 received intraluminal irradiation of 18 Gy with Irridium-192. Group 1 served as control group without radiation. Angiographic TIPS evaluation was performed every two weeks. During an observation period of eight weeks, the animals of both groups were gradually sacrificed every two weeks and histological and electron-microscopical work-up was performed. Results : TIPS insertion was successful in all animals. Two pigs died early due to procedural complications. Of the remaining eight pigs (four of each group), one (group 1) developed encephalopathy and died seven weeks after implantation. Another pig (group 2) scheduled for a six-week survival, showed shunt occlusion after two weeks and was sacrificed thereafter. TIPS in group 1 were patent at all angiographic controls. In group 2, one shunt occluded after two weeks, another shunt showed 60% stenosis after two weeks. In group 1, all the endoprostheses were firmly adhering to the surrounding liver tissue. Intraluminal surface gradually became covered by endothelium-covered fibrous connective tissue. In group 2, implants were partially or completely nonadhering to the liver and thrombi were seen in two implants. Conclusion : The endoprostheses used in this animal study, without radiation, revealed a good TIPS patency. Intraluminal radiation with Irridium-192 seems to impair natural healing processes.

62 Stent-graft in TIPS: our experience Rossi P., Salvatori F.M., Bezzi M., Fanelli F., Pepino D., Venditti F University of Rome «La Sapienza», Interventional Radiology, Rome, Italy

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Purpose : To report our three-year experience using commercially available stent-grafts (W.L. Gore & Associates) in TIPS to prevent shunt stenosis. Materials and Methods : Our experience can be divided into two groups; the first group was studied from 1998 to 2000 and includes seven patients treated with a commercially available vascular nitinol stent-graft covered with PTFE (Hemobahn; W.L. Gore & Associates). The second group was studied from January 2000 and includes 20 patients treated with the Viatorr stent (W.L. Gore & Associates), a self-expanding e-PTFE covered nitinol stent with a 2-cm uncovered portion for the portal region. Results : The technical success was 100% with a reduction of the PSG gradient in all cases. In the first group (mean follow-up:17.7 months) five patients are in good health with a patent shunt and a primary patency of 84%. One patient (8%) died three days after the procedure for a multiorgan failure. In one case (8%) a minor revision was necessary. In the second group (mean follow-up: 5.8 months) 17 patients are in good health with a patent shunt (primary patency 85%). In the remaining three cases (15%), a revision was necessary, using a new stent in two cases and balloon dilatation in the other case. Conclusion : These good results suggest that PTFE stentgrafts can probably reduce the number of revisions.

Purpose : To determine the efficacy of cerebral protection systems for the prevention of particle embolization in an in vitro flow model. Materials and Methods : A simulation of embolization from supposed carotid angioplasty (n=150) was performed with Contur™ particles (150-1000µm) in a closed flow model (pulsatile, dicrote flow 700ml/min, pressure 91/58 mmHg) simulating the carotid bifurcation made from elastic sili-cone tubes. Particles (150-250µm, 250-355µm, 710-1000µm; 5 mg each) were inserted into the internal carotid artery (ICA) proximally to the placed protection device Angio-guard™ (AG alone) or PercuSurge™ (PS alone). Additionally, AngioJet™ (Angio-Jet) and aspiration catheter (Aspiration) were used for removing emboli. The weight of embolic particles behind the ICA and the external carotid artery (ECA) was determined in the filter system. Results : All used protection devices, even with used modifications showed high risk and potential for embolization into ICA and ECA. Overall emboli measured as follows: AG alone (3%/ 5%), PS alone (7%/7.6%), AG AngioJet (5.8%/4.7%), PS AngioJet (5.1%/5.6%) and AG Aspiration (3.2% p<0.005/3.1% p<0.05). Conclusion : In vitro, none of the tested devices or the modifications of application had the ability of completely preventing emboli. An occlusion balloon might lead to a «dangerous» embolization into the ECA. A filter basket (AG) alone or in combination with a final aspiration prior to the removal of the collapsible basket seems superior.

In vitro effectiveness of cerebral protection devices for carotid angioplasty Müller-Hülsbeck S., Grimm J., Bergmeyer M., Heller M. University Hospital, Radiology, Kiel, Germany

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Clinical results on the use of different filter devices for cerebral protection during stent implantation in the carotid artery Jaeger H., Drescher R., Hauth E., Demirel E., Gissler H.M., Mathias K.D. Staedtische Kliniken Dortmund, Radiologische Klinik, Dortmund, Germany

Technical success and complication rate of stent implantation of the carotid artery under cerebral protection Jaeger H., Drescher R., Hauth E., Gissler H.M., Mathias K.D. Staedtische Kliniken Dortmund, Radiologische Klinik, Dortmund, Germany Purpose : The purpose of this study was to determine the technical success and complication rate of stent implantation of the carotid artery under cerebral protection. Materials and Methods : In 108 patients 108 high-grade stenoses of the carotid artery were treated with stent implantation under cerebral protection. In 76 procedures (70%) protection was performed with an occlusion balloon (Percusurge, Medtronic AVE) and in 32 procedures (30%) this was carried out with a filter device (Angioguard, Cordis / Johnson & Johnson). Results : Stent implantation was successfully performed in all 108 stenoses. In 94 (87%) interventions, the whole procedure could be protected, in six (6%) only the post-dilation of the stent and in eight (7%) procedures the protection could not be performed. In 13 of 108 (12%) patients temporary neurological signs and symptoms occurred during the procedure. Two patients (2%) had a minor stroke and other two patients (2%) a major stroke. No mortality occurred. Conclusion : In the majority of the procedures, cerebral protection with an occlusion balloon or filter device is technically feasible. The complication rate of stent implantation in the carotid artery is acceptable. The use of a cerebral protection during stent implantation of the carotid artery should be considered.

Purpose: The purpose of this study was to determine the technical success and complication rate of different filter devices for cerebral protection during stent implantation in the carotid artery. Materials and Methods : In 45 patients 45 high-grade stenoses of the carotid artery were treated with stent implantation under cerebral protection with a filter device. In 33 procedures the Angioguard filter (Cordis/Johnson&Johnson) was used, in four cases the Neuroshield (Mednova) and in the remaining eight procedures the EPI filter (Embolic protection). Results : The stent implantation could be successfully performed in all the 45 stenoses. In 34 (76%) interventions the whole procedure could be protected, in five procedures (11%) the protection could be carried out during the stent post-dilation only, and in six cases (13%) no protection could be performed. Cause of failure was the inability to pass the stenosis and/or elongation and kinking of the carotid artery due to the rigidity and the large profile of the filter devices. Conclusion : In the majority of procedures, cerebral protection with filter devices was technical feasible. Further developments of these devices are necessary to improve the technical success rate. Their use during stent implantation in the carotid artery should be considered.

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Protected carotid stenting: safety and efficacy of the Mednova NeuroShield filter. The UK experience Gaines P.A., Macdonald S., Cleveland T.J. Sheffield Vascular Institute, Vascular Radiology, Sheffield, United Kingdom

Diffusion-weighted MR imaging following angioplasty and/or stent implantation of brain-supplying arteries Jaeger H., Drescher R., Hauth E., Gissler H.M., Mathias K.D., Bockisch G., Demirel E., Staedtische Kliniken Dortmund, Radiologische Klinik, Dortmund, Germany

Purpose : Neuroprotection devices have the potential to reduce neuroembolic sequelae. We report the UK experience of Neuro Shield. Materials and Methods : Prospective review of 35 patients. Thirty-two had atherosclerotic stenosis of the carotid bifurcation between 70-95% (NASCET). Three had re-stenosis post endarterectomy. Twenty-nine were symptomatic (amaurosis fugax nine, hemispheric TIA/CVA in 20). Six were asymptomatic: four pre-CABG, two for global hypoperfusion. Primary stenting was performed. Debris from the filter was analysed in 11. Results : Technical success was 34/35 (97%); tortuosity precluded one filter placement. Spasm occurred in five: one flow limiting and four minor. All remained asymptomatic. There were no procedural and no 24-hour neurological events. One conservatively managed femoral pseudoaneurysm occurred despite the use of a closure device. A 30-day follow-up was available in 25 cases: no strokes or deaths occurred. Mean particle number per patient was 12 (range 0-41). Mean particle diameter 284.9 microns (range 31-1430). Mean retrieved ellipsoid volume load 0.1602 mm3 (range 0.0005-0.1968 mm3). Debris included fibrin, cholesterol clefts, organised thrombi and red and white cell aggregates. Conclusion : NeuroShield is safe and effective at trapping embolic debris generated by carotid stenting.

Purpose : The purpose of this study was to determine the incidence and type of new areas of cerebral ischemia detected by diffusion-weighted (DW)-MR imaging after revascularization procedures of brain supplying arteries. Materials and Methods : In 32 patients, 37 revascularization procedures were performed. Eleven interventions were done at the distal internal carotid artery, two at the external carotid artery, two at the common carotid artery, five at the innominate artery, five at the vertebral artery and 12 at the proximal subclavian artery. DW-MR imaging of the brain was performed before and 24 hours after the procedure. Results : In eight of the 37 procedures (22%) new hyperintensities were visible in the DW-MR images. A total of 35 new cerebral lesions could be seen, 33 (94%) of them were in the vascular territory supplied by the treated vessel. None of the patients in whom new diffusion abnormalities were found had new neurological symptoms or deficits. No new lesions could be demonstrated after the procedure in the two subclavian arteries. Conclusion : Revascularization procedures of brain supplying arteries are associated with a substantial number of areas of cerebral ischemia detected by DW-MR imaging. DW-MR imaging can be used to assess the impact of modifications of the procedural technique on the occurrence of such lesions.

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Mid-term patency after percutaneous transluminal angioplasty (PTA) and stent placement of supraaortic arteries Winkler C.E., Müller-Hülsbeck S., Brossmann J., Grimm J., Jahnke T., Heller M. CAU Kiel University, Diagnostic Radiology, Kiel, Germany

Internal carotid artery ruptures: treatment with the Wallgraft endoprosthesis Greenberg R., Clair D., Srivastava S., Green R.M., Waldmann D., Ouriel K. Cleveland Clinic Foundation, Vascular Surgery/Biomedical Engineering, Cleveland, OH, USA

Purpose : Assessment of the technical success and mid-term patency after PTA and/or stent implantation in stenoses or obliterations of brachiocephalic arteries. Materials and Methods : Between January 1994 and December 2000, 48 patient were enrolled into a prospective study for the treatment of stenoses and obliterations of brachiocephalic arteries. There were 54 lesions in total (atherosclerotic n= 52, dissection with pseudoaneurysms n=2), located in the subclavian artery (n=35), the brachiocephalic trunk (n=7), the axillar artery (n=6), the common carotid artery (n=4) and the vertebral artery (n=2). In addition to an insufficient PTA, 19 stents were implanted (Wallstent n=10; Palmaz n=4; Bridge n=3; Corinthian n=2). Results : A primary technical success was achieved in 43/54 lesions with a remaining stenosis of <26%, in 9/54 lesions there was a reduction of the stenosis, in 2/54 lesions recanalization failed. There were no complications. Twenty nine of the 48 patients (lesions n=34) underwent angiographic, colour-duplex or clinical control; primary patency rate was 89% after an average of 32 months. Fifteen patients (lesions n=15) refused the follow-up, while four patients died or were cases for nursing (independent of the interventional treatment). Conclusion : PTA and stent implatation of brachiocephalic arteries are interventional-radiologic standard procedures with a high technical rate of success. Mid-term results are promising.

Purpose : To assess the utility of Wallgraft in the treatment of internal carotid artery pseudoaneurysms. Materials and Methods : Three patients presenting with rupture of the internal carotid artery were treated with a Wallgraft endoprosthesis using a combined interventional and surgical approach. One patient presented with a stab wound, one had had a gunshot wound to the neck years before, and the third patient had a spontaneous rupture following fibromuscular dysplasia. The charts, radiographs, and follow-up studies were reviewed. Results : All the three patients were successfully treated using a technique which included a proximal carotid artery cutdown, a retrograde perfusion of the internal carotid and placement of a Wallgraft into the internal carotid artery. The mean follow-up is 11 months (1-24 months). No adverse events were encountered. Conclusion : The Wallgraft in the treatment of internal carotid arterial rupture has acceptable short- to mid-term results. The insertion technique may be different in other locations in an attempt to accommodate its short working length and reduce the risk of stroke.

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Bilateral arterial embolization of the sheep uterus: hormonal changes Pelage J.P., *Martal J., *Huynh L., **Bonneau M., ***Merland J.J., Rymer R., ***Laurent A. Hôpital Lariboisière, Body and Vascular Imaging,***Neuroradiology, *INRA, Physiology Unit, **Research Laboratory of Interventional Radiology, Paris, France

Initial results of a pilot study: carotid stenting versus endarteriectomy Link J., Manke C., *Kasprzak P., **Horn M., Borisch I.,**Draganski B. Universitätsklinikum Regensburg, Institut für Röntgendiagnostik, *Klinik für Chirurgie, **Klinik für Neurologie, Regensburg, Germany

Purpose : To study the effects of uterine artery embolization on clinical oestrus and progesterone levels in the adult non-pregnant pre-Alpes sheep. Materials and Methods : Non-pregnant adult sheep were treated by bilateral embolization of the uterine arteries. Three groups of six animals each were studied: the PVA group (600-1000 µm PVA particles, Ultra-Ivalon), the MS group (700-900 µm calibrated microspheres, Embosphere, Biosphere Medical) and the control group without embolization. Clinical oestrus and progesterone levels were evaluated daily during two cycles. Results : The total number of clinical oestrus was 8/12, 10/12 and 4/12 in control, MS and PVA groups (p=0379, chi-2), respectively. The «biological oestrus» (progesterone level below 1 ng/mL) was 10/12, 10/12, and 9/12 in control, MS, and PVA groups, respectively (ns, chi-2). The maximum levels of progesterone were different in the control group compared with the embolized group (p=0136, Mann-Whitney). The minimum level of progesterone was observed four and three days later in the embolized groups compared with the control group after the first and second cycles, respectively. Conclusion : Embolization is associated with: a decrease in progesterone levels and a delayed ovulation. No major difference was found between the two embolized groups. It might be hypothesized that embolization with large particles can cause reversible damage to normal myometrium.

Purpose : The purpose of this ongoing study is to evaluate the efficacy of carotid stenting as compared with carotid endarteriectomy in a prospective, randomized, and controlled study. Materials and Methods : Up to now, 44 patients were included in the study (nine women and 35 men; mean age: 68 years). Twenty two patients were assigned for carotid stenting and 22 for surgery. Carotid stenting was performed without predilatation and without a protection device. Inclusion criteria were symptomatic patients based on a clinically neurologic examination and an angiographically proven stenosis >70% according to the NASCET criteria. Results : There was a good primary success in all the cases but one surgically treated patient who had a dissection after surgery and underwent additional stent placement. In another surgical patient there was a severe wound infection followed by multiple surgical revisions. In the stenting group, one reperfusion syndrome occurred; the patient presented with hemiparesis which resolved after four days. Another patient of the stenting group had a TIA. Conclusion : Up to now there were no deaths or major strokes in none of both groups. Results in a greater number of patients have to be awaited to draw further conclusions.

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Sexual functioning after uterine artery embolization Gomez-Jorge J., *Amman A., *Spies J. University of Miami / Jackson Memorial Medical Center, Radiology / Vascular and Interventional Radiology, Miami, FL, *Georgetown University Hospital, Radiology, USA

Anatomic abnormalities at the origin of the uterine artery. A cause of UAE failure and how to overcome it Nicholson A.A., Ettles D.F. Hull and East Yorkshire Hospitals Trust, Radiology, Hull, United Kingdom

Purpose : To evaluate the impact of uterine artery embolization on sexual functioning. Materials and Methods : Two hundred and thirty patients underwent uterine artery embolization (UAE) with six-month follow-up. A questionnaire was sent to all patients, addressing their sexual interest, the frequency of sexual intercourses, and orgasms. Summary statistics were used to analyze data. Results : One hundred and fifteen patients returned the questionnaires (50%). Frequency of sexual encounters was more than five times in the last month (34% of patients), while 28% were not sexually active. Thirty-nine percent of patients described their orgasms as strong, 6% reported no orgasms. The majority of patients (80%) reported frequency of sexual desire of more than once a week; 8% were not interested in sex. Internal orgasms (uterine contractions) were reported in 56%, while 19% did not experience it. After UAE, the majority of patients had no change or increase in the strength of orgasms (70%). The majority of patients had no change or increase in the frequency of sexual desire (61%). Conclusion : Our preliminary experience suggests that, for the majority of patients, sexual functions remain intact and may be improved after UAE. A prospective evaluation with a validated questionnaire is needed prior to concluding that UAE does not adversely affect patients’ sexual lives.

Purpose : To describe the incidence of abnormal uterine artery origin anatomy, the incidence of UAE technical failure due to this and methods for overcoming the anatomy and completing UAE. Materials and Methods : During UAE in 87 patients, an abnormal right uterine artery origin was encounterd in eight patients (9%) and an abnormal left origin in one (1.15%). A survey of British and American radiologists suggested that this was one of the commonest causes of UAE technical failure. It can also lead to an excessive irradiation of the pelvis. The following methods have been used including coaxial catheters, balloon inflation in the anterior division to deflect a wire, catheter tip modification and unilateral UAE with interval repeat procedure. Results : Eventually all but one uterine artery was successfully embolized. In the nine patients with abnormal anatomy there was an average increase in the radiation dose of 20%. Coaxial catheters were the quickest and most effective way of overcoming the anatomical difficulty. Conclusion : Corkscrew uterine artery occurs most commonly on the right side. Once recognized, a strategy to cannulate the artery should be used. Coaxial catheters are the method of choice.

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Uterine leiomyomata embolization: relevant anatomy Gomez-Jorge J., *Keyoung A., *Levy E., *Spies J. University of Miami / Jackson Memorial Medical Center, Radiology / Vascular and Interventional Radiology, Miami, FL, *Georgetown University Hospital, Radiology, USA

Uterine artery embolisation in the treatment of fibroids: complications requiring re-hospitalization Belli A.M., Mehta H., Matson M. St. George’s Hospital & Medical School, Radiology, London, United Kingdom

Purpose : To categorize the anatomy of uterine arteries and to determine the incidence of menopausal symptoms if tubo-ovarian branches were seen prior to embolization. Materials and Methods : From July 1997 to June 2000, 256 leiomyomata embolizations were performed at our institution. Uterine arteries (n=514) were classified as: Type I (uterine artery as first branch off the inferior gluteal artery), Type II (2nd or 3rd branch off the inferior gluteal artery), Type III (uterine artery, inferior, superior gluteal arteries as a trifurcation), Type IIIA (inferior gluteal artery off the superior gluteal artery), and Type IV (uterine artery as 1st branch off the hypogastric artery ). Tuboovarian branches were recorded if visualized prior and/or post embolization. Menopausal symptoms were recorded using questionnaires. Results : Of 516 uterine arteries evaluated, 38% were of classifiable type, 23% were inconclusive, and 39% were not studied. Classification was as follows: 45% Type I, 6% Type II, 43% Type III, 1% Type IIIA, and 5% Type IV. Tubo-ovarian arteries were seen in 36/256 patients prior to embolization. In this group, 25 patients reported transient menopausal symptoms. Six patients did not answer the questionnaires. Conclusion : Type I is most commonly encountered. Tuboovarian branches may be visualized prior and/or after embolization. Menopausal symptoms were transient in those patients where tubo-ovarian arteries were seen prior to embolization.

Purpose : A retrospective review of complications of uterine artery embolisation requiring re-hospitalization is presented here. Materials and Methods : Between June 1998 and April 2000, 42 patients (31-54 years, mean 42) were treated for fibroids by bilateral uterine embolisation (UAE) using PVA. Peri-procedural antibiotic prophylaxis was administered. Eighty six percent of women were Afro-Caribbean, 9% were Caucasian and 5% were Asian. Results : Fibroids measured 5-22 cm. Thirty-seven patients (88%) showed a reduction of fibroid size and a decreased symptomatology. Seven patients (17%) had to be readmitted one to 29 weeks post-embolization for symptoms and signs of infection which required intravenous antibiotics. Half of them were related to fibroid protrusions and resolved post-evacuation of the fibroid. An organism was isolated in four patients. Four of these seven patients were Afro-Caribbean, two were Asian and one (2%)–who required an hysterectomy–was Caucasian. Fibroid size in this group ranged from 7 to 16 cm. Conclusion : Re-hospitalization rate post-UAE was 17%. All the patients had large fibroids and presented with signs and symptoms of infection, associated with fibroid impaction in half of them. Re-hospitalization was necessary up to 29 weeks postembolization but was not always related to an adverse final outcome.

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Combined embolization and myomectomy for symptomatic uterine fibroids Pelage J.P., *Ferrand J., *Wassef M., Le Dref O., **Jacob D., ***Laurent A., Rymer R. Hôpital Lariboisière, Body and Vascular Imaging, *Pathology, **Obstetrics and Gynecology, ***Neuroradiology, Paris, France

Cytokine response after uterine artery embolization. Its role in post-embolization syndrome Engelke C., Matson M., Patel U., Perry M., Marriot B., Morgan R., Belli A.-M. St. George’s Hospital, Radiology, London, United Kingdom Purpose : To evaluate the acute phase inflammatory marker response in patients undergoing uterine artery embolization (UAE) for the management of fibroids aimed at improving postembolization morbidity. Materials and Methods : Thirteen patients (38-51 years, mean 44 years) undergoing bilateral UAE for the treatment of fibroids had measurements of serum interleukin-1b (IL-1b), interleukin-6 (IL-6) and TNF-a levels before and 2-72h after the procedure. The samples were analysed to assess a marker protein elevation and its correlation with pyrexia and pain. Results : There was no IL-1b activity in any patient before and after UAE. TNF-a activity was within normal limits in all patients. IL-6 showed a significant elevation after UAE (mean IL-6 pre UAE 2.02 pg/ml; mean IL-6 post UAE 44.9 pg/ml, range 0168 pg/ml). However, the level of response did not correlate well with the amount of pain killer required or with the body temperature. At the administered doses none of the analgesics interfered with the serum levels of circulating cytokines. Conclusion : The observed IL-6 response was high and in a similar range recorded post-hepatic chemo-embolization or major surgery such as hysterectomy. Further work is required to determine whether suppression of the IL-6 response will decrease t h e amount of pain and post- embolization fever.

Purpose : To evaluate the interest of pre-operative embolization of uterine fibroids. To describe pathological features. Materials and Methods : Ten women with symptomatic uterine fibroids were treated with embolization of the uterine arteries followed by myomectomy. Embolization alone was considered too risky because of the size and/or location of the fibroids. Embolization was performed using calibrated microspheres (Embosphere). Surgery consisted in the resection of dominant fibroids. The efficacy of the procedure was based on the blood loss amount and ease of surgery. The pathologic aspects of the uterus and the location of the microspheres inside the arterial net-work were evaluated. Results : A successful embolization was obtained in all women. In eight women multiple myo-mectomies were performed the same day without blood transfusion. Delayed surgery was performed in two women. One hysterectomy was performed instead of the planned myomectomy because of adenomyosis. Pathogic specimens exhibited an excellent correlation between the diameter of the microspheres used and the level of arterial occlusion. Conclusion : Pre-operative embolization allows easy surgical resection without blood loss. Microspheres are associated with targeted devascularization. Combined embolization and surgery with resection of the dominant fibroids may become a first line treatment in case of contra-indication to embolization alone. Longer follow-up should be performed to verify the absence of growth of small fibroids.

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Uterine embolization in the management of post-partum hemorrhage related to placenta accreta Le Dref O., Pelage J.P., *Jacob D., **Rossignol M., Boudiaf M., Rymer R. Hôpital Lariboisière, Body and Vascular Imaging, *Obstetrics and Gynecology, **Anesthesiology and Critical Care, Paris, France

Clinical outcome of bilateral internal iliac artery embolization. Simultaneous versus sequential intervention Engelke C., Elford J., Morgan R.A., Belli A.-M., St. George’s Hospital, Radiology, London, United Kingdom Purpose : To evaluate the outcome of bilateral internal iliac artery (IIA) embolization. Materials and Methods : Thirteen patients (63-84 years, mean 74 years, two women), eight with AAA, four with bilateral CIA and one with unilateral IIA aneurysms underwent IIA embolization. Five patients underwent bilateral simultaneous IIA embolization prior to endovascular aortic repair (EVAR), (group A). Five patients had sequential IIA embolization (mean interval: 9 weeks), (group B). Three patients had only one IIA patent prior to the procedure, the other being chronically occluded (group C). The outcome was assessed by clinical follow-up. Results : In group A, one patient died of MI on day two post EVAR, one patient developed bilateral thigh claudication which resolved at 6 months and three patients had no symptoms. In group B, one patient developed bilateral buttock and thigh claudication which resolved after one year. One developed impotence. Three patients had no symptoms. In group C, no patients had any complications or symptoms. Conclusion : Although this is a small patient group, our results of sequential and simultaneous bilateral IIA embolization are similar. There was only one serious permanent complication of impotence and two cases of buttock and thigh claudication, which resolved after 6-12 months.

Purpose : To evaluate the efficacy and safety of selective arterial embolization in the management of intractable post-partum hemorrhage caused by placenta accreta. Materials and Methods : Eight consecutive women with postpartum hemorrhage caused by placenta accreta were treated by embolization of the uterine arteries. Six women presented a placenta accreta and two women a placenta percreta with bladder invasion. In all the patients, hemostatic embolization was performed because of intractable hemorrhage that could not be controlled by the medical treatment. One woman with placenta percreta was embolized after failed hysterectomy and cystectomy. Results : Angiography revealed pathological uterine hypervascularization in six women. Embolization of the uterine arteries was performed using Gelfoam in all cases. Disappearance of external bleeding was observed in all cases. One woman required another embolization six hours after the first session for recurrence of bleeding. One woman required delayed hysterectomy for recurrence of bleeding. The woman with placenta percreta treated conservatively had normal uterus and bladder on MRI 24 months after embolization. Conclusion : Placenta accreta is associated with a high risk of maternal mortality. Hysterectomy is often required in cases of intractable bleeding. Arterial embolization is an effective procedure to correct DIC and control hemorrhage and should be the first line treatment.

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Endovascular embolization in complex treatments of AVMs of the head and neck Sitnikov A.V., Kokov L.S., Dan V.N. A.V. Vishnevsky Institute of Surgery, Interventional Radiology, Moscow, Russian Federation

Embolization of head and neck tumors and AVMs with superabsorbent polymer microspheres (SAP-MS); clinical results and histopathological studies Osuga K., Okada A., Sugiura T., Maeda M., Murakami T., Nakamura H., *Hori S. Osaka University Graduate Medical School, Radiology, *Rinku General Medical Center, Radiology, Osaka, Japan

Purpose : To evalute the possibilities of angiography and endovascular occlusion of the afferent vessels both as a palliative method and as a stage in the combined surgical treatment for arteriovenous malformations (AVM). Materials and Methods : Since 1979 to 1999, 54 patients with head and neck AVM were treated at our Department. Their age range was 7-69 years. All the patients underwent carotid angiography which showed the formation and spreading of a pathological process. Twenty five patients (46.3%) underwent endovascular occlusion of the afferent vessels with polyhydroxyethylmethacrilat. Four patients (7.41%) underwent a palliative embolization. Twenty one patients (38.88%) had a combined treatment with embolization at the first stage. Twenty nine patients underwent surgical correction. Results : A surgical radical removal of the angioma was carried out in 32 (59.29%) cases of limited defects with good cosmetic result; during a two-year follow-up, no relapse was observed. A combined treatment was performed in 20 patients with diffuse defects (37.03%) with no relapse within the same period of time, but without removing the cosmetic defect. A palliative embolization was used in two cases of unresectable AVM, with two relapses observed within the same period of time. No complications during embolization occurred. Conclusion : The use of selective carotid angiography allows to choose a rational method of surgical treatment. Endovascular occlusion of afferent vessels makes radical operations available for those patients with diffuse AVM and diminishes the risk of intraoperative hemorrhage.

Purpose : To evaluate the safety and efficacy of embolization of head and neck tumors and AVMs with superabsorbent polymer microspheres (SAP-MS), a new embolic material. Materials and Methods : SAP-MS are uniformly spherical, nonresorbable, and precisely calibrated microspheres with no toxicity. Pre-operative embolizations with SAP-MS were performed in eight hypervascular head and neck lesions (two angiofibromas, one neurofibroma, two hemangiomas, one hemangiopericytoma, two AVMs). All the lesions were supplied by branches of the ECA and the lidocaine test was done before embolization. Surgery was performed within a week and the histopathologic property of SAP-MS was evaluated. Results : All embolizations were successful. Six lesions were totally and two partially resected without recurrences during the follow-up terms (mean 26.7 months). The blood loss volume was minimized (mean 348 ml). No ischemic damage was observed adjacent to the lesions. No neurological complication was seen. Microscopically, SAP-MS expanded by absorbing the serum and tightly occluded the vessel lumen. Intimal or perivascular reaction was mild around the particles. The surrounding soft tissues did not show any inflammation or necrosis, probably because the normal capillary circulation was preserved. Conclusion : SAP-MS is a safe and effective embolic material for the devascularization of head and neck lesions, when the prevention of ischemic injuries to the soft tissues and the nervous systems is essential.

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Endovascular therapy in patients with a combination of various intracranial vasculopathies Kröger J.C., Grau G., Grossmann A., Bartolomaeus A., *Knoop M., *Ascher P.W., **Rolfs A., *Sola S., *Barner T., Hauenstein K. University of Rostock, Institute of Diagnostic and Interventional Radiology, *Dept.of Neurosurgery, **Dept. of Neurology, Rostock, Germany

A new horizon in the endovascular treatment of intracranial aneurysms: the liquid embolic agent Onyx with or without stent Cekirge H.S., Saatci I., Mawad M., Balkanci F., Besim A. Hacettepe University Hospitals, Radiology, Ankara, Turkey Purpose : To present our experience in the endovascular treatment of intracranial aneurysms with the liquid embolic agent Onyx. Materials and Methods : Onyx is a liquid polymer of ethylene vinyl alcohol and dimethylsulphoxide mixed with tantalum powder. Twenty three intracranial aneurysms in 22 patients were treated using Onyx. Twelve aneurysms were giant. All but two of the aneurysms originated from the internal carotid arteries; one was located at the basilar tip and another one at the origin of the superior cerebellar artery. In 13 patients, a stent was first placed crossing the aneurysm neck and then the aneurysm sac was filled with Onyx. In the remaining patients, no prior stent placement was performed. Onyx was injected with balloon protection. Results : In one patient, vision loss occurred after the treatment due to occlusion of the ophthalmic artery at its origin. There was one procedure-related mortality. No complications occurred in the remaining patients. Conclusion : Liquid polymer Onyx is an effective material in the endovascular treatment of intracranial aneurysms, particularly in giant ICA aneurysms.

Purpose : To demonstrate therapeutic strategies and results of endovascular and surgical treatments in patients with a combination of several vasculopathies. Materials and Methods : From 1995 to 2000, in a group of 688 patients who had undergone cerebral angiography, occurrence of multiple aneurysms was detected in 18 and a combination of several vasculopathies in 12 patients: intracranial aneurysm combined with AVM (5), with dural fistulas (3), with carotid cavernosus fistula (1), with ICA stenosis (1), AVM and ICA stenosis (2). Four patients had intracerebral or subarachnoidal hemorrhage. In case of combination with an AVM, the aneurysm was treated first. MCA aneurysms were treated surgically. Aneurysms in other localizations were embolized with GDC. Embolization of vascular malformations was performed with Histoacryl. ICA stenoses were treated first because of transient ischemic symptoms. Results : Interventions were technically successful and well tolerated by all the patients. In all of them, aneurysms were completely packed by GDC. A small posterior infarction after emboliza-tion of a wide neck aneurysm was recorded. Vascular malformations were embolized completely in nine of 11 patients, the residual feeder parts in two patients were treated by gamma knife therapy. Conclusion : Therapy of various combined intra- and extracranial vasculopathies should be defined by the interventional radiologist, the vascular or the neurosurgeon, and the neurologist. The treatment is determined by clinical symptoms. Complication S143

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Initial experience with Trispan in the endovascular treatment of intracranial aneurysms Cekirge H.S., Saatci I., Balkanci F., Besim A. Hacettepe University Hospitals, Radiology, Ankara, Turkey

Neck swelling from cold thyroid nodules: treatment by USguided percutaneous ethanol injection Tarantino L., Giorgio A. D. Cotugno Hospital, Interventional US, Naples, Italy

Purpose : To present our initial experience with Trispan in the endovascular treatment of intracranial aneurysms. Materials and Methods : Three patients, two with basilar tip and one with carotid bifurcation aneurysms, were treated with Trispan and coil occlusion. All three aneurysms were wide-necked and previous treatment attempts had failed. Trispan is an electrically detachable device which prevents the coils to fall into the parent artery (that is what occurred during previous coiling attempts) and holds the coils in place. Trispan is detached after the complete occlusion of the sac by coils. Results : In all the three patients, Trispan successfully held the coils in place and we were therefore able to pack the aneurysms. No difficulty was encountered during the procedures and no complication occurred. Conclusion : Trispan is a good alternative as a neck protector in the treatment of wide-necked aneurysms.

Purpose : To evaluate percutaneous ethanol injection (PEI) in the treatment of neck swelling due to cold thyroid nodules. Materials and Methods : Forty two patients (36 women; age range 16-66 years) with 1-3 thyroid cold nodules (volume range 13-90 ml; mean: 23 ml) underwent 2-11PEI sessions per patient with injec-tion of 3-14 ml of ethanol per session (total amount per patient: 17-120 ml). Before the treatment, US-guided fine needle biopsy (FNB) was performed in all nodules to rule out malignancy. Efficacy of PEI was assessed by physical examination and measurement of the nodule size every two months for six months and every six months afterwards. Results: FNB excluded malignancy in all cases. At follow-up (range: 12-54 months; mean: 30 months) all nodules showed a decrease of 50-90% than the pre-treatment volume. Six months after treatment, 29 patients showed a normal neck shape and 13 patients referred the aesthetical results as very good. Conclusion : PEI is an effective therapy for the aesthetical treatment of neck swellings due to thyroid cold nodules. Larger experiences are needed to assess the risks and the future indications of this technique.

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Accurate frameless stereotaxy using a non-invasive vacuumaffixed dental cast that acts as a reference base: A phantom study and initial applications Bale R.J., Martin A., Rieger M., Giacomuzzi S.M, Vogele M., Burtscher J., Kofler A., Jaschke W., University Clinic Innsbruck, Radiology I, *Neurosurgery, Innsbruck, Austria

Nasolacrimal stent obstruction and its management Lanciego C., *De Miguel S., **Padilla M., ***Rodriguez Merlo R., *Perea, M., Garcia Garcia L. Hospital Virgen de la Salud, Radiologia Vascular Interventionista, *Servicio de Oftalmologia, **Servicio de ORL, ***Servicio de Anatomia Patológica, Toledo, Spain Purpose : To assess the clinical efficacy of polyurethane stents in the percutaneous management of epiphora. Materials and Methods : Between February 1997 and February 2001, 224 patients (mean age = 54; range 22-85; 184 women) with a severe epiphora were referred to us by the ophthalmologist. Under fluoroscopic guidance, 260 stents were implanted in 252 systems to treat complete (n=245) or partial (n=7) obstruction of the nasolacrimal duct or sac. Many aspects of the original technique both in the placement and in the retrieval of the stents were modified. Results : Initial success rate was 93.8%. To-date, with a mean follow-up of 18.5 months (range one week - 46 months), 197 stents remain patent; primary patency is 76%. The main problem was stent obstruction. In follow-up we had 62 obstructions (24%); in 51 cases the stent had to be withdrawn and, of these, seven had a successful second stenting. Of those with a mean follow-up of 20 months (range one week - 33 months), 37% remain asymptomatic. Conclusion : Our results with polyurethane nasolacrimal stents are encouraging, especially for primary patency. Success mostly depends on technique improvements and appropriate patient selection. However, the persisting problem of obstruction requires further studies and longer follow-ups, especially with respect to secondary patency.

Purpose : The authors present the results of a phantom study, a cadaver study and initial clinical experiences with frameless stereotactic localization of cranial targets using the VBH head holder. Materials and Methods : A prosthesis of the upper dentition was glued to the underside of a test phantom and a VBH vacuummouthpiece was created. CT scans with three different slice thicknesses were obtained. After mouthpiece-based registration the targeting device was adjusted with 3D-guidance. The phantom was repositioned and the needle was inserted producing impressions on an aluminium foil. Each of the 12 fiducials was targeted 30 times, 4 steps per scan totalling 270 punctures. In addition, the trigeminal ganglion was targeted through the foramen ovale in 3 cadavers (6 times) and in 7 patients with drug resistant trigeminal neuralgia. Results : The mean localization error (MLE) was: 5mm axial: MLE 1,84 mm, SD 0,96 mm, 3mm axial: MLE 1,38 mm, SD 0,65 mm, 1mm axial: MLE 1,31 mm, SD 0,67 mm. In addition, in all cadavers and in all patients the foramen ovale (5 to 3 mm in diameter) could be reached at the first attempt. Conclusion : Our experiences indicate that frameless stereotaxy allows for accurate targeting of cranial structures, comparable to the accuracy achieved with stereotactic frames.

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Interventional sialography in salivary duct diseases Salerno S., Lo Casto A., Cannizzaro F., *Barresi B., *Speciale R. Policlinico Universitario, Istituto di Radiologia «P. Cignolini» *Clinica Otorinolaringoiatrica B, Palermo, Italy

Evaluation of peripheral bypass grafts with moving-bed MR-angiography on a 1.0T system Loewe C., Cejna M., Grgurin M., Sailer J., Schoder M., Lammer J., Thurnher S.A. University of Vienna, Angiography and Interventional Radiology, Vienna, Austria

Purpose : To evaluate the efficacy of interventional sialography in the treatment of chronic recurrent sialoadenitis due to salivary sialoliths or to duct’s strictures. Materials and Methods : Fifteen patients (11 men, five women; mean age: 42 years), underwent interventional sialography, ten because of salivary stones and five for strictures of the main duct. Eight stones were in the Wharton’s duct, two in the Stensen’s duct; four strictures were in the Stensen’s duct while one was in the Wharton’s duct. A three-wire basket was used for stone extraction and a 3-mm, 2 cm long, balloon was used to dilate the stricture. All the patients were followed up for 6-12 months. Results : In eight of the ten patients with stones, these were successfully removed; in the remaining two, the procedure failed: in one because sialoliths were adhering to the duct wall and in the other because of the large size of the sialolith. A dilatation of the main salivary duct stricture was obtained in all the five patients with strictures. A rapid resolution of symptoms was achieved in 12/15 patients. In one patient, an acute sialoadenitis resolved after an antibiotic therapy. Conclusion : Interventional sialography is a safe and acceptable alternative procedure to surgery and can be considered the first line in the treatment of symptomatic sialoadenitis due to a salivary stone or to main duct strictures.

Purpose : To assess the potential of moving-bed magnetic resonance angiography (MRA) in the evaluation of peripheral bypass grafts. Digital subtraction angiography (DSA) served as a standard of reference. Materials and Methods : Thirty two patients underwent DSA and contrast-enhanced MRA after peripheral bypass graft surgery. MRA was performed using a moving-bed software on a 1.0 T system before and during administration of 40 ml of gadolinium. For the evaluation, every bypass graft was divided into three parts and every leg in fourteen segments. Disease severity was scored in four categories. Results were compared with those of DSA. A total of 37 bypass grafts and 821 vessel segments were classified. Results : In 101 out of 108 assessable bypass segments, the stenosis grading with both methods was corresponding, but seven stenoses were overestimated by MRA of one class. Only four bypass segments could not be classified due to clip artifacts after bypass graft surgery. In 757 vessel segments there was a full grading conformity, but in 54 there was a difference of 1 grade and in ten of 2 grades. Conclusion : Moving-bed MRA on a 1.0T system is a feasible and useful non-invasive tool for the detection of failing peripheral bypass grafts.

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Whole body 3-D MRA in 72 seconds: five steps and a single injection Ruehm S.G. , Goyen M., Barkhausen J., Bosk S., Truemmler K.H., Debatin J.F. University Hospital, Dept. of Diagn. Radiology, Essen, Germany

High-resolution renal MRA detection of renal artery stenoses Loehr S.P., Regan J.D., D'Souza V.J. Wake Forest University School of Medicine, Radiology, WinstonSalem, NC, USA

Purpose : To assess the performance of a 3-D MRA strategy to display the vasculature from supraaortic arteries to distal run-off vessels. Materials and Methods : Twenty patients referred for DSA were examined. MRA was based on the acquisition of 5 3-D data sets during a single bolus administration of Gadobenate dimeglumine (Multihance, Bracco). Acquisition time for each 3-D data set was 10-12 sec. During a 3-second acquisition break the table was manually repositioned to the center of the following image volume. The total scan time was 72 sec. Evaluation was based on 270 vascular segments in which DSA was available for comparison. Results : With DSA as the gold standard, overall sensitivity and specificity of MRA for the detection of hemodynamically significant diseases were 87.6% / 91.3%, and 94.8% / 97.4% for the detection of occlusions. Additional unsuspected findings were found in six patients. Conclusion : Whole-Body MRA strategy allowed an accurate display of the arterial vasculature from supraaortic arteries to the lower extremity vessels.

Purpose : To evaluate the accuracy of high-resolution renal MRA in detecting renal artery stenoses (RAS) Materials and Methods : Twenty-two patients with suspected renal artery stenosis underwent breath-held MR-angiography and digital subtraction angiography. Three-dimension GRE MRA (TE/TR) was performed at 1.5 T using a phased-array body coil. High-resolution MRA (24 cm FOV, 512 x 256 matrix) and a standard dose (0.1 mmol/Kg) of gadolinium was administered via a power injector. Three observers assessed MR-angiography using the computer-assisted reformation, and three observers assessed digital subtraction angiography. Results : Digital angiography identified 39 main renal arteries and seven accessory renal arteries (n=46). MR-angiography depicted all the main renal arteries and five of seven accessory renal arteries. MRA correctly diagnosed 25 of 25 arteries as significantly stenosed (50-99%), 18 of 21 arteries without a significant stenosis (<50%), and three of four occluded arteries; three arterial lesions were overestimated. There were no false positive accessory renal artery lesions identified by MRA. Interobserver agreement was high. Sensitivity and specificity of renal MRA for detecting RAS were 100% and 88%, respectively. Conclusion : High-resolution renal MRA using a bolus timed acquisition and a standard dose of gadolinium is a precise method for detecting and grading the severity of renal artery stenosis.

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Advantages of renal MRA in planning percutaneous renal interventions Loehr S.P., Regan J.D., D'Souza V.J. Wake Forest University School of Medicine, Radiology, WinstonSalem, NC, USA

Comprehensive pre-harvest MR-based imaging in living donor-related liver transplants (LDLT) Ruehm S.G., Goyen M., Barkhausen J., Bosk S., Malago M., Debatin J.F. University Hospital Essen, Diagnostic Radiology OZII, Essen, Germany

Purpose : To assess the efficacy of diagnostic renal MRA in planning percutaneous renal artery revascularization. Materials and Methods : Twenty-six patients with suspected renal artery stenosis (RAS) underwent diagnostic MRA to determine the need for revascularization. All the patients had renal insufficiency (mean creatinine: 3.5) and ten patients had suboptimal renal duplex sonograms. Three independent observers assessed the following: 1) degree of stenosis; 2) size of renal arteries 3) accessory renal arteries; 4) orientation of renal arteries; 5) kidney size; 6) degree of atherosclerotic disease in the aorta. Findings were compared with subsequent procedural angiograms in 17 patients. Results : Renal MRA correctly identified main renal artery stenosis in 16/17 (94%) patients who underwent intervention. Stenoses of two accessory renal arteries were however missed by MRA. Renal artery size was determined with an accuracy of 67% only. The degree of the aortoiliac plaque, orientation of the renal arteries and kidney size were accurately assessed in 17/17 patients. Two accessory renal arteries were not seen on MRA but were identified on procedural angiography. One occlusion with distal reconstitution was mischaracterized as critical stenosis by MRA. This however did not affect the management. Conclusion : Renal MRA is an accurate method for facilitating percutaneous renal revascularization.

Purpose : To determine the diagnostic accuracy of a MR-based «all-in-one approach» replacing the currently used protocol including CT, DSA, as well as ERCP in selected cases. Materials and Methods : Imaging was performed on a 1.5-T scanner (Sonata®, Siemens). The following image sets were collected: T1 FLASH 2D, T2 HASTE, MRCP, FLASH 3D Angio, ce-T1 FLASH. Three-dimension MRA data were collected following administration of MultiHance® (Bracco, Milan). A second data set in the portal venous phase was acquired. Thirty six potential liver donors were assessed. Sixteen subjects were eliminated. The remaining 20 subjects underwent DSA also, and 14 subjects actually underwent liver harvesting. MRA data sets were correlated with DSA. Results : Patients were excluded as potential donors based on the detection of hepatic hemangiomas (n=5), as well as unfavorable hepatic morphology (n=10). MRA depiction of the hepatic arterial morphology correlated with catheter angiography in all the 20 patients. Conclusion : MRI-based «all-in-one approach» for the preoperative assessment of LDLT is adequate.

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Three-dimensional MR-angiography of the renal arteries: comparison of volume rendering versus maximum intensity projection algorithms Mallouhi A., Schocke M., Wolf C., Dessl A., Judmaier W., Czermak B., Waldenberger P., Jaschke W.R. Leopold-Franzens University, Radiology, Innsbruck, Austria

Portal venous flow: evaluation with a single breathhold ECG-triggered 3-D half-Fourier FSE MR imaging with a selective inversion recovery (IR) tagging pulse Ito K., Koike S., Okada M., Kishimoto K., *Miyazaki M., *Kanazawa H., *Jo C., Matsunaga N. Yamaguchi University School of Medicine, Radiology, *Toshiba Medical, Radiology, Yamaguchi, Japan

Purpose : The aim of this study was to evaluate the efficacy of volume rendering (VR) as a post- processing technique of MRangiography for the detection of renal artery stenoses. Materials and Methods : Twenty-five patients underwent renal 3D-gadolinium-enhanced MR-angiography. The arterial phase was transferred to a workstation (Sun Ultra 60 UPA/PCI, GE Medical systems). Targeted MIP and VR images were then reconstructed for each renal artery in a paracoronal and paraaxial orientation. MIP and VR images were blindly reconstructed and reviewed by two radiologists for each modality. The findings on MIP and VR images were quantitatively compared to those depicted on conventional angiography. Results : The image quality obtained by VR (mean 1.17±0.4) was significantly better than that obtained by MIP (1.2±0.55), p=0.04. VR (1.11±0.31) also showed a greater ability to delineate the lumen of the renal artery than MIP (1.53±0.72) p=0.03. Twenty-eight renal artery stenoses were detected and categorized as 1-49% stenoses (n=10), 50-69% stenoses (n=8), 70-99% stenoses (n=10). In the quantitative analysis of the patency of renal arteries, VR correlated with DSA better than MIP (r=0.97 and r=0.90, respectively). Conclusion : Renal MR-angiography with VR allowed a more accurate and a more comprehensive evaluation of the renal arteries.

Purpose : To evaluate intraportal blood flow distribution from the splenic vein (SV) and/or the superior mesenteric vein (SMV) by noncontrast enhanced MR-angiography (MRA) technique using single breathhold ECG-triggered 3-D half-Fourier FSE with a selective IR tagging pulse. Materials and Methods : Fifteen volunteers were evaluated. After obtaining regular single breathhold ECG-triggered 3-D halfFourier FSE images without a tagging pulse to depict the portal vein (PV), the SMV and the SV, the selective IR tagging pulse was placed on SMV (TAG-A) or on SV (TAG-B) in order to study inflow correlation of tagged blood into the PV. Results : On TAG-A study to suppress signal flow from the SMV into the PV, the most common pattern of the signal loss was observed on right half of the main PV (8/17 subjects). Conversely, on TAG-B study to suppress signal flow from the SV into the PV, signal loss of left half of the main PV was the most common pattern (11/17 subjects). Signal reduction from the splenic venous flow in the left PV was significantly greater than that from the superior mesenteric venous flow (p< .05). Conclusion : Noncontrast enhanced MRA technique with a selective IR tagging pulse has a potential to assess the portal blood flow distribution from the SV and the SMV.

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MR-morphology of the aorta: ex vivo experiments with a prototype of an intravascular receiver coil Aretz K., Grenacher L., Lubienski A., Kimpel M., Kauffmann G.W., Düx M. University of Heidelberg, Radiology, Heidelberg, Germany

Glycolytic rate and expression of hexokinase in an animal model of hepatocellular carcinoma Geschwind J.F., *Ko Y.H., Arepally A., Hoffmann L., *Pederson P. The Johns Hopkins Hospital, Radiology, *Biochemistry, Baltimore, MD, USA

Purpose : To evaluate the morphology of the aortic wall using intravascular MR imaging compared with histopathology. Materials and Methods : Four infrarenal aortic specimens with an unknown degree of arteriosclerosis were examined within 24 hours post-mortem with a small endoluminal MR-receiver coil. Axial and coronal MR imaging was performed in a 1.5-T system (Symphony, Siemens, Erlangen) with standardized sequences (T-w SE and T1-w Flash, T2-w TSE). After fixation, three slices of each specimen underwent histopathological evaluation. Final findings of endoluminal MR imaging concerning the morphology of the aortic wall and the plaques were compared with histology. Results : In all four cases, the three wall layers were differentiated, corresponding to the intima, the media and the adventitia. Highresolution imaging, furthermore, allowed to identify wall thickening and to describe arteriosclerotic lesions corresponding to the histological results. Conclusion : High-resolution endovascular MR imaging allows a reliable differentiation of the three anatomic layers of the aortic wall. Intimal lesions and arteriosclerotic plaques are visible and their morphology can be described. In the future, intravascular MR imaging can become a tool able to classify arteriosclerotic lesions and to optimize interventional treatments.

Purpose : The prognosis of patients with hepatocellular carcinoma remains dismal, with a median survival approaching to six months. The VX2 animal model has proven convenient for the study of this fatal disease since it can be readily implanted into a rabbit liver and grown to an optimal size for study within 2 to 3 weeks. Purpose of this work is to determine whether the VX2 tumor exhibits a high glycolytic phenotype characteristic of a number of well-studied experimental hepatomas. Materials and Methods : The VX2 tumor was implanted into the liver of 18 healthy New Zealand white rabbits and grown for 1 to 5 weeks. Animals were sacrificed and tumors analysed. Several enzymatic assays were performed to measure the rate of glucose metabolism and the expression of hexokinase. Results : As compared with normal liver tissue, the rate of glucose metabolism was markedly elevated within the tumor. Hexokinase activity was also markedly elevated, it displayed a high affinity for glucose and was intimately associated with the mitochondria. The enzymes normally found in non-tumorous livers were not detected in VX2 cancer cells. Conclusion : The VX2 tumor model displays the classic high glycolytic phenotype encountered in most other animal models of hepatomas and can therefore be useful in the study of hepatocellular carcinoma.

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Myocardial MRI to assess iron content: a qualitative and quantitative multi-observer analysis in patients with ßthalassemia major Sias A., Alvino V., Lecca F., Politi C., Mallarini G. University of Cagliari, Institute of Radiology, Cagliari, Italy

Thermal ablation of malignant hepatic lesions with assistance of a computerized CT-guiding system Helmberger T., Holzknecht N., Schöpf U., Ertl-Wagner B., Reiser M University of Munich, Institute of Clinical Radiology, Munich, Germany

Purpose : The purpose of this work is to determine whether MR of the myocardium can provide an accurate diagnostic tool in evaluating myocardial iron level, thus predicting the outcome of patients with ß-thalassemia major. Materials and Methods : We performed MR examination with T1, T2, and GE-EPI T1 axial sequences through the heart in 60 patients with ß-thalassemia major undergoing blood transfusion and in 30 healthy volunteers. Three observers assessed the images independently and graded them accordingly; they also traced ROIs in the myocardium and measured the signal intensity in these areas. A complete set of clinical data was then compared with the myocardial iron content. Results : The inter-observers agreement for the signal intensity averages was very high. The myocardial iron content did not necessarily correlate with the severity of heart disease in the patients group. Conclusion : The inter-observers agreement for the signal intensity averages was very high. The myocardial iron content did not necessarily correlate with the severity of heart disease in the patients group.

Purpose : To evaluate the feasibility of a virtual guiding system (CT-Guide; UltraGuide, Israel) for needle placement in the radiofrequency therapy of malignant liver lesions. Materials and Methods : Forty eight patients (105 lesions) underwent percutaneous radiofrequency or laser ablation therapy. CT was used for imaging when a lesion was depicted during at least one imaging phase. CT images were transferred to the CTGuide and were «3D correlated» with electromagnetic markers fixed to the patient and the probe. The probe's movement was displayed as a trajectory together with the position of the needle tip virtually on CT images. The procedures could be entirely performed outside the gantry. Results : With the virtual guidance, all needle placements were successful. In 62% of the lesions, a double oblique approach was necessary. Even with a «skin-to-lesion» distance of up to 20 cm, in some cases the average needle deviation was 0.7 cm only from the target. Reasons for deviation were: insufficient patient compliance, displacement of the left liver lobe by the RF probe, needle bending, and interference of the scanner couch. Mean procedure time was 18.3 minutes. Conclusion : CT-Guide proved to be a very helpful tool for accessing those lesions at unfavorable locations. CT-Guide also preserves the patients and the interventionalists from radiation exposure during the procedure.

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Evaluation of the efficacy of radiofrequency thermal ablation in the treatment of liver tumors Manzi M, Marangon A., Torsello G. S. Bortolo Hospital, Institute of Radiology, Vicenza, Italy

Results following radiofrequency ablation of solitary colorectal liver metastases Gillams A., Lees W.R. Middlesex Hospital, Medical Imaging, London, United Kingdom

Purpose : To test the efficacy of percutaneous radiofrequency (RF) thermal ablation in the treatment of primary and secondary liver tumors. Materials and Methods : Thirty six nodular liver lesions in 28 patients, 24 with HCC and four with metastatic lesions, underwent RF ablation from January 1999 to December 2000. Twenty eight treatments were performed with the RITA system, while eight procedures were carried out with the Radiotherapeutics system. Some procedures required an anesthesiological assistance for the association with other treatments (TACE, stop flow). Follow-up was performed with TC scan (at one, six and 12 months) and US at three and six months. Every 3/6 months, an alfa-feto protein dosage was performed. Results : The technical success was 99%. In one patient, US could not visualize the lesion because of macronodular cirrhosis. A complete necrosis of the lesion occurred in 33% of nodular tumors, a partial necrosis (>75%) in 20% of cases. None of the patients showed a necrosis <50%. One complication was observed, a hemoperitoneous. The survival rate at 2 years was comparable to that of other treatments (TACE, PEI). Conclusion : RF thermal ablation offers a valid, effective and practical method of treatment for liver tumors, with an the efficacy comparable to TACE and PEI.

Purpose : Very few of the currently available treatment options for neuroendocrine liver metastases result in a reduction in tumour volume. We report our experience in 19 patients treated with thermal ablation. Materials and Methods : 37 treatments were performed, 17 with intersitial laser therapy and more recently 20 with radiofrequency, 10 with a triple cluster electrode and 10 with single electrodes.The primary lesions were carcinoid in 10, gastrinoma in 4, insulinoma 1, adrenal 2 somatostatinoma 1 and vipoma 1. 11 patients had one thermal ablation treatment only, 2 had 2, 4 had 3, 1had 4 and 1 had 6. Seven patients had one lesion, 3 had 2, 2 had 3 and 7 had multiple lesions >6. Lesion size varied from 1.5 – 8cm. Results : Improved symptoms were seen in 5/7 treated specifically to reduce circulating hormone levels. Local control of disease extent was seen in 8. Three patients developed >20 metastases on follow-up. There were two complications a carcinoid crisis in one patient with advanced cardiac disease and a liver abscess in a patient with a bilienteric anastomosis. Conclusion : Radiofrequency can be effective in patients with neuroendocrine liver metastases both to reduce levels of hormone secretion and in controlling the extent of liver disease.

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Latest survival figures from thermal ablation to colorectal liver metastases Gillams A., Lees W.R. Middlesex Hospital, Medical Imaging, London, United Kingdom

Complications after interventional ultrasound of focal liver lesions: a 20-year single center experience Giorgio A., Tarantino L., de Stefano G., Mariniello N., Farella N., Liorre G., Esposito F. D. Cotugno Hospital, Interventional US, Naples, Italy

Purpose : To report changes in survival with evolving thermal ablation technology in 116 patients with inoperable colorectal liver metastases treated since 1995. Materials and Methods : Historically, interstitial laser therapy was the preferred thermal ablation method but improvements in radiofrequency (RF) technology has resulted in RF becoming the preferred technique at our institution since 1998. Seventy-five of 116 (65%) patients were treated with RF and 41/116 (35%) with laser. The mean number of metastases was 2.9 (1-20) and the mean maximum diameter was 3.9 cm (1-12). Date of death was obtained from primary care physicians. Survival figures were stratified for disease extent and treatment method. Results : Historically, the optimal criteria for thermal ablation were <6 tumours, <5 cm in diameter with no extra-hepatic disease. Current optimal criteria for treatment are <10 metastases, <4.5 cm with disease limited to the liver. Median survival from first thermal ablation for this subgoup treated with radiofrequency was 34 months and 23 months for laser, threeyear survival was 34% with RF, 10% with laser. Five-year survival from the diagnosis of liver metastases was 47% for RF. Conclusion : Advances in technology have widened the therapeutic window allowing thermal ablation to be offered to patients with a more extensive disease. Improved technology has impacted survival.

Purpose : To analyze the complications of both diagnostic and therapeutic US-guided interventional procedures observed in a single center during a 20-year period. Materials and Methods : From April 1979 to December 1999, 14,170 patients (age range 7-89 y, mean 59 y; 9,232 men) with 15,198 focal liver lesions underwent diagnostic and therapeutic ultrasound-guided percutaneous procedures. There were 16,648 diagnostic (percutaneous biopsies) and 2,936 therapeutic procedures [abscesses aspiration, hydatid liver cysts aspiration; percu-taneous ethanol injection in multiple (conventional PEI) or single sessions under general anaesthesia (one-shot PEI) mainly of hepatocellular carcinomas on cirrhosis, radiofrequency and interstitial laser photocoagulation, mainly of hepatocellular carcinomas on cirrhosis]. Results : Overall mortality rate was 0.056%. No death was observed in the diagnostic group. In the therapeutic group, mortality rate was 0.66%. One patient died for anaphylactic shock during hydatid liver cysts aspiration; another patient died five weeks after traditional PEI; five patients died after one-shot PEI for large and/or multiple hepatocellular carcinoma on cirrhosis; one patient died after one-shot PEI of a large hepatocellular carcinoma. Conclusion : Our experience confirms that US-guided percutaneous diagnostic biopsy of focal liver lesions can be considered a safe procedure. Nevertheless, mortality can affect therapeutic percutaneous procedures, mainly due to the ablation of malignant primary tumors on cirrhosis.

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Percutaneous transhepatic embolization of the right portal vein prior to partial liver resection Riedl-Huter C.M., *Ladurner R., Waldenberger P., Freund M.C., Dessl A., Jaschke W. University Hospital, Radiology, *Surgery, Innsbruck, Austria

Portal vein occlusion as a method of prophylaxis of hepatectomy complications Kokov L.S., *Vishnevsky V.A., *Nazarenko N.A., **Gavrilin A.V., ***Viliavin M.Y. A.V. Vishnevsky Institute of Surgery, Interventional Radiology, *Abdominal Surgery, **Ultrasound imaging, *** X-Ray, Moscow, Russian Federation

Purpose : To evaluate the efficacy of percutaneous transhepatic embolization of the right portal vein prior to extended right-sided liver resection in malignancies. Materials and Methods : Between April 1997 and December 2000, 16 patients (seven women, nine men; mean age 61.5 years) with primary and secondary liver tumors of the right lobe were treated with percutaneous transhepatic embolization of the right portal vein. In all the patients helical CT scans were performed prior to and five weeks after embolization. The volume of the right and left liver segments were calculated by measuring the corresponding area in each scan. Results : The mean volume of the left liver segments increased from 237 to 467 cm3 in five weeks. The volume of the right segments did not change significantly. Fifteen patients were finally treated by extended right-sided liver resection. One patient was excluded from surgery because of initially unknown lymph node metastases. Postoperative CT follow-up displayed tumor recurrences in two patients after six and 27 months. Conclusion : Selective percutaneous transhepatic embolization of the right portal vein increases the volume of left liver segments significantly. After five weeks, by reaching an optimal liver volume of residual left liver segments, an elective extended rightsided liver resection is possible.

Purpose : Improvement of hepatectomy results by application of preoperative portal vein occlusion (PVO) in malignant hepatic tumors. Materials and Methods : Since 1996, ten patients (seven men and three women, aged 37-71 years) underwent PVO for hepatocellular cancer: three had gallbladder cancer, one had metastatic cancer, five had malignant carcinoid of the right hepatic lobe, and the last one had RABROM. In nine cases, access was through the right hepatic lobe, in one case, through the left one. In all cases, PVO was indicated for insufficient parenchymatous volume of the left hepatic lobe and low indices of functional reserve. Results : In nine cases, the post-occlusive period was without complications, while in one patient, internal abdominal bleeding occurred, requiring urgent surgery. According to CT scans, the volume of the left hepatic lobe increased in 2-4 weeks after PVO of an average ranging from 254±34.6 to 450.2±100.1 cm3 (p=0.052). Eight patients underwent surgery 2-6 weeks after PVO: there were seven right hemihepatectomy and one atypical resection of 5-6 hepatic segments. In all the cases, intra-operative bleeding did not exceed 1000 ml. Conclusion : Results of PVO in patients with insufficient volume of the left hepatic lobe parenchyma and low functional reserve for prevention of massive intraoperative bleedings and development of postoperative hepatic insufficiency are favourable.

107 Preoperative portal vein embolization in patients with advanced hepatobiliary malignancy: clinical and volumetric assessment Madoff D.C., *Vauthey J.N., Charnsangavej C., *Abdalla E., Herron D., *Encarnacion A.G., Hicks M.E. University of Texas, M.D. Anderson Cancer Center, Diagnostic Imaging, *Surgical Oncology, Houston, TX, USA

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Purpose : To evaluate the safety and utility of preoperative portal vein embolization (PVE) in patients with advanced hepatobiliary malignancy before major hepatic resection. Materials and Methods : From October 1998 to January 2001, 22 patients with hepatobiliary malignancy (17 men, five women; mean age 59 years) underwent PVE. One patient had HCV. PVE was per-formed if the future liver remnant (FLR) was <25%. Twenty-one PVE were performed via a right percutaneous transhepatic approach. Coils and polyvinyl alcohol particles occluded the right portal (n=22) and segmented four veins (n=17) to promote hypertrophy of the FLR (segments 1, 2, 3, ±4). Pre- and post-PVE CT-scans were used to determine FLR hypertrophy. Results : Twelve patients had a successful extensive hepatic resection. Nine patients were not resected [potential cure after the medical therapy (n=1); poor regeneration (n=2); extrahepatic disease undetected before PVE (n=6)]. One patient is awaiting for resection. Five of six patients with biliary obstruction were treated pre-PVE. No patient developed post-embolization syndrome or liver insufficiency (post-PVE/post-resection). Two complications post-PVE did not preclude a successful resection. Median hospital stays were: one day (range 0-7 days) for PVE; seven days (range 6-16 days) for liver resection. Mean absolute FLR increased from 298 to 446 cm3 (49.7%). Conclusion : Preoperative PVE is a safe and effective method for inducing lobar hypertrophy in patients with advanced hepatobiliary malignancy.

Purpose : To study how stent-graft (SG) evolution has influenced the mid-term outcome of AAA repair. Materials and Methods : One hundred and fifty one patients underwent successful endovascular AAA repair. Follow-up consisted of a spiral-CT. Initially, non-supported SG, placed infrarenally, were used (Ivancev-Malmo I monoiliac n=54 patients; median follow-up 906 days, Chuter bifurcated n=14; 1460 days). Vanguard SG were then placed infrarenally in n=15 patients (734 days). Subsequently, fully supported SG, placed transrenally, were utilized (Ivancev-Malmo II mono-iliac n=18; 573 days) and Zenith bifurcated SG n=50; 190 days). Thirty-day mortality, number of late conversions and all reinterventions were recorded prospectively. Results : Total 30-day mortality was 4.6%. Deaths occurred in the early phase and were reduced to 0% when using IvancevMalmo II and Zenith SG. Fourteen late conversions occurred in the initial 68 patients, mostly due to SG migrations. In the last 87 patients, no late conversions occurred. Distal SG migration occurred in 50% of patients treated with Ivancev-Malmo I and Chuter SG, but no migrations were observed in the IvancevMalmo II and Zenith SG. Reinterventions were distributed as follows: Ivancev-Malmo I: n=50, Chuter: n=12, Vanguard: n=7, Ivancev-Malmo II: n=9, Zenith: n=6. Conclusion : Improved columnar support and transrenal fixation seem to result in fewer secondary interventions and late conversions.

The impact of stent-graft evolution on the outcome of AAA repair. A single-center experience Ivancev K., *Resch T., **Malina M., **Sonesson B., Uher P., Lindh M., **Lindblad B. Malmö University Hospital, Dept. of Radiology, *Dept. of Surgery, **Dept. of Vascular Diseases, Malmö, Sweden

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Single centre experience with the Zenith aortic endograft Rose J.D.G., Jackson R.W., Chaudhry S., *Holtham S., *Lees T.A., *Wyatt M.G. Freeman Hospital, Radiology, *Vascular Surgery, Newcastle-uponTyne, United Kingdom

Treatment of abdominal aortic aneurysms with the EVTAncure endograft: mid-term results *Gomes A.S., **Moore W.S., **Quinones-Baldrich W.J., **Baldrich C.L., **Vescera C.L., *Monteleone P.A. UCLA Medical Center, *Cardiovascular and Interventional Radiology, **Surgery, Los Angeles, CA, USA

Purpose : To assess the immediate outcome and medium term results of the Zenith stent-graft for endoluminal repair of abdominal aortic aneurysms (AAA). Materials and Methods : The Zenith endograft (W. Cook) is composed of steel «Z stents» covered with polyester. A proximal uncovered stent provides suprarenal fixation. Between September 1998 and December 2000, 56 patients with a median age of 75 years (56-88) and an AAA diameter of 63 mm (45 - 145) were treated. Results : Forty six bifurcated and ten aortomonoiliac devices were successfully deployed. Median operating time was 120 minutes (70-330), blood loss was 200 ml (50-800), and post-operative stay was five days (2-27). There were three perioperative cardiac deaths (5.4%). One early proximal endoleak required external aortic banding. Despite the use of adjunctive metal stents in two cases of early graft limb kinking, one limb occluded at two weeks. Another occlusion of an aortomonoiliac device was related to an inadequate distal surgical anastomosis. Median follow-up was 16 months (1-28) and there have been six late deaths (unrelated to the aneurysm) and one (Type II) endoleak at three months. There were no graft migrations or open conversions. Conclusion : The Zenith stent graft is a reliable and robust device in the short to medium term.

Purpose : To describe the results of abdominal aortic aneurysm repair with the EVT-Ancure endograft in 102 patients with a minimum of 18-month follow-up. Materials and Methods : Thirty nine patients received a tubegraft; 47 a bifurcated graft, and 16 an aortoiliac graft. Results : Endografts were successfully placed in 92/102 patients. Follow-ups ranged from 18 months to seven years. Ninety two percent of tube grafts, 87% of bifurcated grafts, and 94% of aortoiliac grafts were placed, with a total success rate of 90%. Early endoleaks occurred in 26 (28%) patients. After six months, 14/26 (54%) leaks had resolved spontaneously and after 18 months, 65% of them had sealed. Of the remaining seven chronic leaks, six were treated percutaneously and one with operation. Three patients with bifurcated grafts required angioplasty and four with an aortoiliac graft had stent placement for limb obstruction. Five patients had an attachment device hook fracture, and two a frame break. Graft slippage requiring explantation occurred in one. Paraplegia occurred in one. Thirtyday mortality was 2%. Four patients developed a new late endograft leak. Aneurysm size decreased >5mm in 53 (58%) patients, remained the same in 32 (35%) and increased in seven (8%). Conclusion : Abdominal aortic aneurysms can be treated with the EVT-Ancure endograft.

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Vanguard III endovascular aortic stent-graft for the treatment of AAA: preliminary results of a clinical multicenter study Lammer J., 1)Horsch S., 2)Dueber C., 3)Vasseur M., Schoder M., 4)Kretschmer G., 5)Myhre H. AKH University Clinics, Angiography and Interventional Radiology, 4)Vascular Surgery, Vienna, Austria; 1)Vascular Surgery, Cologne, 2)Radiology, Mainz, Germany, 3)Vascular Surgery, Lille, France, 5)Vascular Surgery, Trondheim, Norway

Clinical results of the Talent stent-graft for abdominal aortic aneurysm (AAA). USA low-risk trial: one-year follow-up Uflacker R., *Robinson J., Selby J.B. Medical University of South Carolina, Interventional Radiology, *Vascular Surgery, Charleston, SC, USA Purpose : To present the results of endovascular repair of AAA with the Talent stent-graft device as compared with open surgery. Materials and Methods : The clinical trial was a multi-center (17 centers), non-randomized, prospective, controlled study. Two hundred and forty six patients were enrolled in the Talent study group (TSG) (90% men, 75.3 yrs) and 123 patients in the surgical control group (SCG) (80% men, 69.8yrs). Results : Initial technical success in the TSG was 77%. Endoleaks were initially present in 22% of cases. Types were: type I (5%), II (18%), III (3%) and IV (59%). Pre-discharge AAA exclusion was 81%, at one month 87%, at six months 88%, and at 12 months 88%. Migration occurred in 4.4%, occlusion in 0.91%. Transfusion was required in 13% of the TSG, and 67% of the SCG. Mean ICU stay was 11 and 56 hours, mean hospital stay was four and nine days for the TSG and the SCG, respectively. Perioperative mortality was 0.8% for the TSG and 0% for the SCG. Mortality at >30 days was 5.3 for the TSG and 4.1% for the SCG. Conclusion : There were statistically significant differences between the two groups in the reduction of blood loss, blood transfusion, procedure time, ICU and hospital stay. There were no significant differences in mortality, but a significant decrease in morbidity. Balance is therefore presently positive for the TSG.

Purpose : To evaluate the safety and mid-term efficacy of the Vanguard III stent-graft for the treatment of AAA, a prospective, multicenter one-year follow-up study was initiated. Materials and Methods : The primary safety endpoints were inability to introduce, deploy and accurately place the device, kinking with limb thrombosis, type III endoleak, and surgical conversion within 30 days. Secondary endpoints were incidence of adverse events (i.e. thrombotic occlusion, endoleak, migration, death) within one year. Follow-up is performed at 1, 3, 6 and 12 months. AAA were >5 cm in diameter, 4-5 cm if rapidly growing or symptomatic. Results : Forty two patients (mean age 69.6y, range 52-84y; 36 men, six women) with AAA 40-78 mm (mean 54.9 mm) in diameter were included. The primary endpoint was reached in 0/42 patients. An adverse event occurred in 14/42 (33.3%) patients including three type II endoleaks (7.2%). In 8/42 patients (19%) the adverse event was severe causing prolonged hospital stay or death (n=1; 2.4%, after subsequent cancer surgery). At one month the AAA diameter was 54.0 mm (37-70 mm). Conclusion : The preliminary data suggest that the Vanguard III aortic stent-graft can be placed safely and accurately. Effective exclusion of AAA can be achieved.

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Radiological appearances of sac pressurization without endoleak following abdominal aortic aneurysm endovascular repair (EVR) Badran M.F., Gould D.A., Sampson C., Meakin S. Royal Liverpool Universtiy Hospital, Radiology, Liverpool, United Kingdom

Secondary endoleaks after endovascular treatment of abdominal aortic aneurysms: diagnosis, treatment and follow-up Maleux G., *Lacroix H., *Nevelsteen A. University Hospitals, Radiology, *Vascular Surgery, Leuven, Belgium Purpose : To describe incidence, CT diagnosis, treatment, and follow-up of secondary endoleaks after endovascular repair of abdominal aortic aneurysms (AAA). Materials and Methods : Between 1995 and 2000, 160 patients underwent endovascular repair of AAA. In 23 patients (15%) a late (persistent primary or secondary) endoleak was diagnosed by CT scan. In ten cases, a secondary endoleak was detected during follow-up: proximal perigraft endoleak (n=5), distal perigraft endoleak (n=4), fabric tear (n=2), gap between two extensions (n=1). In one patient, a proximal and distal perigraft endoleak as well as a fabric tear were found. Secondary endoleaks were treated by open surgical repair in four patients and by endovascular repair in five. Results : Endovascular repair of secondary endoleaks consisted of placement of an additional proximal cuff (n=2), a distal extension stent-graft (n=2) and an additional stent-graft placed in the gap between two previously placed limb-extensions (n=1). All endovascularly treated patients are free from endoleaks (follow-up 1-24 months, mean 12.2 months). Conclusion : Endovascular repair of secondary endoleaks after endovascular repair of AAA is technically feasible in selected cases. Short- and mid-term follow-ups of the treated cases show a consistent technical and clinical success, but long-term follow-up is strictly necessary to evaluate the durability of this treatment.

Purpose : To review the imaging of sac diameter stasis or enlargement in the absence of demonstrable endoleak in order to determine those features which could be associated with sac pressurization. Materials and Methods : Pre- and post-procedure CT scans of 99 patients who underwent EVR were assessed for aneurysm diameter stasis or enlargement. A group with aneurysms of 6 cm or more, without endoleak, were identified. Imaging features were reviewed for evidence of sac pressurization. Results : Eight patients were identified. One, with a spontaneously sealed primary proximal endoleak, had evidence of pressure communication via the aneurysm neck at surgical conversion. Five had a minimal common iliac limb coverage, three received limb extensions, and one–with disruption of a contralateral thrombosed limb–was managed by aortouniiliac stentgrafting. Two patients did not have any relevant, adverse feature on imaging. Conclusion : Some cases with sac diameter stasis or enlargement, without evidence of endoleak, appear to be associated with pathways for potential pressure transmission into the sac. Stentgraft limbs should be extended as close as possible to the internal iliac artery origin.

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Endoleaks post-aortic stentgrafting: a preventable complication? Robertson I., Kessel D.O., Peters K., Patel J. Leeds Teaching Hospitals NHS Trust, Radiology, Leeds, United Kingdom

Internal iliac artery coil embolization prior to endovascular repair of abdominal aortic and solitary iliac artery aneurysms Maleux G., *Lacroix H., *Nevelsteen A. University Hospitals, Radiology, *Vascular Surgery, Leuven, Belgium

Purpose : To highlight the prevalence of endoleaks following endovascular repair of abdominal aortic aneurysm (EVAR) and the importance of preoperative imaging in their prevention. Materials and Methods : EVAR was performed in 40 patients. Pre-operative imaging included spiral-CT and calibrated angiography. Follow-up was with dual-phase CT and colour Doppler ultrasound. Endoleaks were treated by embolization or further stentgrafting, when possible. Results : Aneurysm exclusion was achieved in 38 (95%) with one (2.5%) type-III and one type-II endoleak. All the grafts remain patent at a median follow-up of 18 months. There have been no type-I leaks but six (14%) type-II endoleaks and one (2.5%) typeIII leak. Sixteen patients had a patent inferior mesenteric artery (IMA) and 21 had patent lumbar arteries. Pre-operative embolization of the IMA (n=13) and lumbar arteries (n=9) was performed and no type-II leaks developed in these patients. Six of 12 (50%) patients with patent lumbar arteries developed type-II endoleaks. Embolization eliminated the leak in four patients but did not succeed in two. Conclusion : Patent collateral vessels predispose to type-II endoleaks. Pre-operative embolization protects against subsequent leak developing. Subsequent embolotherapy is time-consuming, expensive, and it does not always succeed.

Purpose : To evaluate the effectiveness and safety of internal iliac artery coil embolization before endovascular repair of aortic abdominal and iliac artery aneurysms. The incidence of buttock claudication after internal iliac artery coil occlusion is also evaluated. Materials and Methods : Between 1996 and 2000, 21 patients underwent coil embolization (MReye coils, Cook Europe, Bjaeverskov, Denmark) of the internal iliac artery prior to endovascular repair of aortoiliac (n=12), solitary iliac aneurysms (n=6) and prior to treat a distal perigraft endoleak (n=3). Two patients underwent bilateral coil embolization. In three patients embolization was performed in the same session as stent-graft placement. Results : Embolization was technically successful in all patients; in 11 cases an immediate and complete occlusion of the internal iliac artery was achieved, in the remaining ten patients perfusion through the coils was still present at the end of the procedure. In one patient a coil migrated in the deep femoral artery and was retrieved percutaneously. In all patients CT-scans after stent-graft placement did not reveal any distal endoleak. Ten patients presented with significant buttock claudication on clinical followup. Conclusion : Coil embolization of the internal iliac artery is safe and effective to prevent endoleak after aortoiliac stent-grafting, but buttock claudication occurs in about half of the cases.

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Retrograde versus antegrade puncture for infrainguinal angioplasty Uberoi R. Queen Elizabeth Hospital, Gateshead, X-Ray, Newcastle-upon-Tyne, United Kingdom

A prospective multi-centre randomised trial comparing balloon angioplasty with primary stenting using the intracoil for complex SFA diseases Cleveland T.J., Gaines P.A., Thomas S.M., Ireland M., *Belli A.M., *Buckenham T., **Nicholson A.A., **Ettles D., ***Ashleigh R. Sheffield Vascular Institute, Radiology, Sheffield, *St. George’s Hospital, Radiology, London, **Hull Royal Infirmary, Radiology, Hull, ***Withington Hospital, Radiology, Withington, United Kingdom

Purpose : To compare traditional antegrade puncture with retrograde puncture technique for infrainguinal angioplasty. Materials and Methods : Patients were randomized to either antegrade or retrograde puncture of the femoral artery. Following retrograde puncture, the guidewire was ‘turned’ and placed into the superficial femoral artery using a curved catheter (Simmonds 1 or SoS Omni). A sheath was placed and angioplasty carried out as standard. The time for gaining access, screening time, radiation dose and height and weight were recorded. Results : Fifty nine patients were randomized, 36 for retrograde and 23 for antegrade puncture. There were 27 men and nine women in the retrograde group and 14 men and nine women in the antegrade group. Mean procedure time, screening time, radiation dose, height and weight were 8.36 minutes (5-18), 2.18 minutes (0.8-6.1), 8373 mG, 173 cm(149-204) and 78 kg (55100) for retrograde punctures and 8.14 minutes (3-27), 0.89 minutes (0,1-2.9),1057 mG, 172 cm and 67.8 kg for antegrade punctures, respectively. An average of 1.1 punctures was required to gain access (1-2) in the retrograde group and 1.8 (1-5) for the antegrade group, with one complete failure. Three small haematomas and a venous puncture occurred post-antegrade puncture and a solitary small haematoma in the retrograde puncture group. Conclusion : Retrograde puncture is technically easier with fewer complications but it results in a higher radiation dose.

Purpose : To compare primary placement of IntraCoil stents with balloon angioplasty (PTA) in complex superficial femoral artery (SFA) diseases. Materials and Methods : Eighty three patients with symptomatic complex SFA lesions (stenotic segment between 10 and 15 cm in length or an occlusion up to 15 cm) were randomised to PTA or stenting in four centres. Patients were followed up clinically and with duplex at 1 day, 6 months and 12 months. Results : Forty five patients were randomised to PTA, and 38 to stenting. Mean ABPIs improved significantly in both groups after one day: from 0.62 to 0.9 for the stented group and from 0.6 to 0.89 for the PTA group; this was maintained for one year. Primary patencies at 1 day, 6 months and 12 months were: 97, 78, and 76% for the stented group and 98, 74, and 71% for the PTA group, respectively. Secondary patencies were: 97, 86, and 84% for the stented group and 98, 83, and 80% for the PTA group, respectively. There were no statistically significant differences between the two treatments. Conclusion : PTA and stenting of the SFA provide a significant improvement in symptoms and pressure indices, which are durable to one year. There was no additional benefit from primary placement of IntraCoils as compared with balloon angioplasty. Primary and secondary patencies compared favourably with the literature.

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Infra-inguinal subintimal angioplasty. Early report of a prospective study McWilliams R.G., 1)Martin J., 2)Vallabhaneni S.R., 2)Brennan J., 2)Gilling-Smith G.L., 2)Harris P.L., 2)Fisher R. Royal Liverpool University Hospital, Interventional Radiology, 1)Vascular Laboratory, 2) Regional Vascular Unit, Liverpool, United Kingdom

Mid-term follow-up after placement of self-expanding nitinol coil-stents for the treatment of femoro-popliteal occlusive disease Jahnke T., Brossmann J., Voshage G., Grimm J., Müller Hülsbeck S., Priebe M., Heller M. University Hospital, Dept. of Radiology, Kiel, Germany Purpose : Evaluation of initial and mid-term patency of Intracoil™ self-expanding nitinol coil stents used in patients with femoro-popliteal occlusive disease. Materials and Methods : Thirty patients presenting with femoro-popliteal occlusive disease were treated using the new Intracoil™ nitinol-stent (IntraTherapeutics, St. Paul, USA). Indication for stent placement was a significant residual stenosis of >50% of the luminal diameter or a hemo-dynamically relevant dissection following angioplasty. Follow-up evaluations with documentation of clinical category and color-duplex sonography were performed before treatment, at discharge, and at one, three, six, 12, and 18 months thereafter. Life-time application of aspirin and a six-week course of clopidogrel were initiated directly following the procedure. Results : An initial technical success was achieved in all patients. In one case, a stent dislocation from the superficial into the deep femoral artery was detected at one month, but percutaneous removal of the prosthesis was successful. So far, 20 patients have been followed-up for at least 12 months, mean follow-up was 13.1±6.1 months (range 1-24 months). Primary and secondary patency rates at 12 months are 90% and 100% respectively. Conclusion : Implantation of the Intracoil™ self-expanding nitinol coil stent for the treatment of femoro-popliteal occlusive disease shows promising mid-term results. In case of stent dislocation, percutaneous removal can be performed easily.

Purpose : This is an early report of an ongoing study to establish the long-term results of infra-inguinal subintimal angioplasty (SPTA) in our practice. Materials and Methods : All the patients undergoing infrainguinal SPTA for critical ischaemia or disabling claudication were prospectively studied. Ankle-brachial pressure index (ABPI) measure-ment and duplex sonography were conducted before angioplasty and at one day, three, six and 12 months after angioplasty. Length of the occlusion and clinical progress were noted. Results : Nineteen patients had attempted SPTA; one of them was unsuccessful due to the inability of reentering the posterior tibial artery lumen. The remaining 18 had a successful recanalization of the occlusions, ranging from 3 cm to total SFA. All these segments were patent on the first post-angioplasty day based on duplex sonography, with an improvement of the ABPI in 14 patients. Thirteen of them were followed for at least six months. Sixmonth patency was 30% (4/13). In eight out of the nine patients who had developed re-occlusion in six months, the three-month duplex scan had already shown a haemodynamically significant stenosis. Conclusion : Patency at six months following SPTA appears to be poor in the absence of re-intervention upon detection of stenosis at the site of original intervention.

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Ten-year survival of claudicant patients after femoropopliteal PTA Jämsén T.S., Manninen H.I., Matsi P.J. Kuopio University Hospital, Clinical Radiology, Kuopio, Finland

Endovascular brachytherapy for the prophylaxis of restenosis after long-segment femoropopliteal stenting: midterm results of a pilot study Wolfram R., *Pokrajac B., Ahmadi R., Maca T., *Pötter R., Minar E. General Hospital, Dept. Of Medical Angiology, *Dept. of Radiotherapy, Vienna, Austria

Purpose : To determine cumulative survival and its predictors, and the causes of deaths in claudicant patients treated with femoropopliteal PTA compared with control population. Materials and Methods : One hundred seventy three claudicant patients (mean age 65 years, range 41-90 years) underwent femoropopliteal angioplasty during the period 1989-1992. Patients were followed-up until 1999. The times and causes of deaths were derived from the records of the «Statistics Finland». Cumulative survival curves were created and compared with those of age- and sex-matched control populations living in the same area. The determinants predicting increased mortality were analysed. Results : Sixty-three patients (36%) died during the follow-up. The most common causes of deaths were cardiovascular diseases, causing 54% (n=34) of deaths. Ten percent (n=6) were caused by cerebrovascular diseases, and 17% of patients (n=11) died of cancer. Cumulative survival rates (+/-SEE) of the patient population at five and ten years were 83±3% and 60±4%. Mortality at ten years was 4% higher compared with the control population. Independent predictors of poorer survival in multivariate analysis were diabetes and more severe claudication, even after stratification by age. Conclusion : Survival among claudicants is only slightly lower than among control population. Diabetes and severe claudication increase mortality.

Purpose : To present mid-term results (mean observation period: 21 months) of a pilot study evaluating the effectiveness of endovascular brachytherapy (BT) in the prevention of restenosis after femoropopliteal PTA and stent implantation. Materials and Methods : Thirty three patients (mean age 66 years) with a mean treated length of 17 cm were included in the present study. After PTA and stent implantation, a 14-Gy dose was applied by Iridium source to the vascular surface. Long-term aspirin (100 mg/day) was combined with clopidogrel (75 mg/day) for one month. Follow up examinations, including Dopplerindex and duplex sonography were performed the day after PTA and after 3, 6, 12, 18, and 24 months. Angiography after six months was performed in 29 patients. Results : Overall recurrence rate was 16/33 (48.5%). Nine patients (27.3%) had a sudden late thrombotic occlusion between months three and 15, and seven patients developed restenosis. In five, restenosis developed within the irradiated segment,while in two restenosis developed in a dilated, but non-irradiated segment. Conclusion : There is a rather high incidence of late thrombotic occlusions in patients treated by femoropopliteal stenting and BT. We therefore changed our therapeutic strategies by prolonging the treatment with clopidogrel to 12 months, and by avoiding femoropopliteal stenting plus BT in those patients with a poor run-off.

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Endovascular treatement of ilio-femoral diseases with ePTFE-covered nitinol stents. Early results from a prospective controlled study Beregi J.P., Lions C., *Duda S.H., **Bosier M., ***Hak J.B., Willoteaux S. Hôpital Cardiologique, Radiology, Lille, France, *University of Tübingen, Radiology, Tübingen, Germany, **Dendermonde Hospital, Vaatchirurgie, ***Cordis Endovascular, Clinical Research

Fourteen years of experience with iliac and femoral stent implantation with regard to post-procedural medication Strecker E.-P., Boos I., Goettmann D., Vetter S. Diakonissenkrankenhaus, Diagnostic Imaging, Interventional Radiology, Karlsruhe, Germany Purpose : To report our long-term results of iliac and femoropopliteal implantation of Tantalum stents (Strecker stents). Materials and Methods : Since 1987, 643 patients with iliac (N=421, 316 stenoses, 105 occlusions) or femoro-popliteal (N=222, 106 stenoses, 116 occlusions) artery lesions entered this single-center prospective clinical study. Post-procedural medication included short-time i.v. unfractionated heparin (UFH) and oral ASS for the long-term. Seventy five patients with femoropopliteal stents received high-dose s.c. reviparin (LMWH) for 3 weeks + ASS instead of UFH+ASS, and 40 patients received clopidogrel + ASS. For determination of acute and late complications and patency rates patients were followed (range 1 to 158 months) by clinical examination, color duplex sonography, and angiography if necessary. Results : Early stent thrombosis: femoro-popliteal 5%, the incidence being lower in the high-dose reviparin group (1/75, p<0.05) as compared with UFH; clopidogrel: 1/32. Consequently, long-term patency also was better with reviparin. Overall primary cumulative patency rates: iliac: 3 years 85%, 5 years 79%, 8 years 71%; femoral: 3 years 55% (reviparin 72%). Lesion type (occlusion) and lesion length (>4 cm) are special risk factors. Conclusion : This stent design provides excellent long-term safety. Thoroughly performed post-procedural medication can improve long-term patency even in femoro-popliteal arteries.

Purpose : To investigate technical performance, safety and initial clinical efficacy of ePTFE-covered nitinol stents for arteriosclerotic iliac and femoral diseases. Materials and Methods : Forty six lesions in 38 patients were treated with ePTFE-covered nitinol stents for iliac and/or femoral obstructions, in a prospective multicentric study (eight centers). The follow-up was made clinically and by Duplex ultrasound (at one, six and 12 months). Data up to discharge were collected in all patients; one-month follow-up data are available for 20 patients. Results : The average lesion length was 47 mm for common and external iliac arteries and 49 mm for femoral arteries. The mean severity of stenoses was reduced from 94 to 5% in iliac arteries and from 98 to 5% in femoral arteries after stent placement and dilatation. The deployement of the stent was easy in all cases but one (initial misplacement treated by surgical intervention). Another adverse event was the formation of a pseudoaneurysm at the puncture point. No stent occlusions or infections occurred. Conclusion : The analysis of this study using ePTFE-covered nitinol stents indicates that primary implantation of this stent type is technically feasible with an acceptable safety profile and a short-term efficacy and safety.

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Treatment of femoro-popliteal occlusive diseases with a selfexpanding stent-graft: mid-term results Brossmann J., Jahnke T., *Andresen R., **Voshage G., Hilbert C., Müller-Hülsbeck S., Grimm J., Heller M. University Hospital, Radiology, Kiel, * Municipal Hospital Güstrow, Radiology, **Klinik der Heniettenstiftung, Radiology, Hannover, Germany

The influence of arterial resistance on balloon diameter in angioplasty Shehab M.E.N., Rees M.R. University of Bristol, Clinical Radiology, Bristol, United Kingdom Purpose : It is a assumed that balloons in vivo reach the same volumes and diameters stated by the manufacturers which are measured in air. Our experiment was designed to show the reduction in balloon diameter at nominal balloon pressures resulting from arterial resistance. Materials and Methods : One hundred and two pig carotid arteries were harvested immediately after killing the pigs. The inner diameter of each artery was measured at 100 mm/Hg using intravascular ultrasound (Endosonics). The size of the balloon was chosen to overdilate the arterial wall between 1 and 100%. Results were divided into nine groups, with an ascending balloon/ artery ratio. Inflation was carried out using a motor driven syringe which injects a constant volume per second (3.6 ml/20 S). Pressures and volumes were simultaneously recorded on line. All the results were measured at 6 atm. Results : The percent balloon cross sectional area reduction in all the arteries ranged from 0 to 47%. Percentage reduction increased with the increase of the balloon/artery ratio. The results at all balloon/artery ratios were statistically significant (P<0.0001, ANOVA). Conclusion : Pressure measurements alone during angioplasty is misleading. Volume measurement is essential to ensure full balloon inflation. 2. The higher the balloon/artery ratio, the higher the pressure needed to reach the nominal balloon diameter.

Purpose : To evaluate mid-term patency rates of transluminally placed self-expanding stent-grafts for the treatment of femoropopliteal occlusive diseases. Materials and Methods : The Hemobahn stent-graft (W.L. Gore, Flagstaff, USA), a self-expanding endoprosthesis with a PTFE tube inside a nitinol stent, was implanted in 46 patients with femoro-popliteal occlusive disease. Follow-up evaluations with documentation of clinical category, color duplex sonography and MRI were perfomed before treatment, at discharge, and at one, three, six, 12, and 18 months thereafter. Life-time application of aspirin and a 6-week course of clopidogrel were initiated directly following the procedure. Results : Endoprosthesis deployment was technically successful in all patients. No major complications were encountered. MRimaging 24 hours after the procedure depicted severe (n=4), moderate (n=3) or mild (n=26) degrees of contrast medium enhancement and soft-tissue edema surrounding the treated arterial segments suggesting perivascular inflammatory reaction. Primary patency rates at six and 12 months after treatment were 89.1 and 84.6%, respectively. Secondary patency rates were 93.4% at six months and 92.3% at 12 months. Conclusion : The implantation of the Hemobahn self-expanding endoprosthesis can be performed with very good initial technical success. Patency rates up to 12 months are encouraging. Clinical relevance of abnormal MR-signal intensity patterns shown 24 hours after the intervention still needs to be assessed.

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Serum levels of vascular endothelial growth factor (VEGF) before and after interventional angiography Grimm J., Müller-Hülsbeck S., Perkams G., Heller M. Christian Albrechts University Kiel, Diagnostic Radiology, Kiel, Germany

Cavitation effect as a mechanism of thrombus dissolution by transverse application of ultrasonic energy to a wire Polak J.F., *Bloch S., *Rabiner R., *Marciante R., *Hare B. Brigham and Women’s Hospital, Radiology, Boston, MA; *Omnisonics Medical Technologies Inc., USA

Purpose : Angiogenesis is regulated by numerous cytokines and the vascular endothelial growth factor (VEGF) is one of the most important. In animals, an increased collateralization was observed in ischemic regions after VEGF application; increased serum VEGF levels (sVEGF) were evaluated in patients after myocardial infarction. We evaluated sVEGF in those patients undergoing interventional angiography. Materials and Methods : In a group of 50 patients undergoing PTA (n=8), stenting (n=23; six femoral, 11 iliac, five renal, one brachiocephalic) or DSA alone (n=19) sVEGF was evaluated by ELISA prior to the procedure and 24 h after. Results : In all the patients, sVEGF increased significantly from 199±190 to 301±237 pg/ml (p=0.0003), showing a large interindividual variance. A significant increase was found in the DSA (p=0.006; 209 vs. 371 pg/ml) and the stent groups (p=0.003; 162 vs. 256 pg/ml), but not in the PTA group (281 vs. 260 pg/ml). Interventional procedures in the femoral region showed no significant changes but in the iliac the increase of sVEGF was significant (p=0.004). Conclusion : Interventional procedures and angiography have a significant influence on sVEGF, depending on the localization and the type of procedure. It is not clear yet why the PTA group showed no increase, but this might be due to the small group studied (n=8). Currently, follow-up evaluations are being performed.

Purpose : Until today, the delivery of ultrasonic energy to dissolve thrombuses was performed with a catheter design that transmitted energy by a longitudinal motion exclusively at the tip. We present here in vitro results of a new device that delivers ultrasound energy along the length of a wire. Transverse oscillations cause local thrombus disruption along the wire (13 cm long by a diameter 0.5 mm) at an ultrasonic frequency of 20 KHz. Materials and Methods : Specimens of human blood were subjected to sonocation in vitro. Delivered energy varied between 0.2 and 4 Watts, at exposure times of 30 seconds. The threshold for inducing cavitation was determined in water and in EDTAtreated human blood by measurement of acoustic noise levels with a hydrophone. Results : Transition to a state of cavitation took place at a threshold of 1 to 2 Watts. EDTA-treated blood specimens showed evidence of hemolysis once cavitation had occurred at 2.2 Watts (5%) and hemolysis increased with energy deposition. Thrombus dissolution remained constant (42%) once cavitation was achieved, despite increases in delivered energy. Conclusion : At an energy delivery of 2 Watts, this prototype ultrasonic wire can achieve a cavitation effect along an effective length of 13 cm and cause thrombus dissolution.

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Influence of application parameters of a local drug delivery device on the amount of intimal hyperplasia. In vivo results in New Zealand white rabbits Kalinowski M., Alfke H., *Barry J.J., Hamann C., Viehhoefer K., Klose K.J., **Wagner H.J. Philipps-University Hospital, Diagnostic Radiology, Marburg, Germany, *Boston Scientific Corp., Natick, MA, **University of Wisconsin, Diagnostic Radiology, Madison, WI, USA

Smooth muscle cell (SMC) proliferation, migration, and matrix synthesis are inhibited by Rhenium-188 (Re-188) incubation in a dose-dependent manner in vitro Wiskirchen J., *Dittmann H., Tepe G., Schoeber W., Claussen C.D., Duda S.H. University Hospital Tübingen, Diagnostic Radiology, *Nuclear Medicine, Tübingen, Germany Purpose : To evaluate the effects of Rhenium-188 on proliferation, migration, and matrix synthesis, depending on the radiation dose administered. Materials and Methods : Human SMC were incubated for 5 days with the combined ß-y emitter Re-188 (T1/2 17h, ßmax 2.1 MeV, max. tissue range < 10 mm) with cumulative doses from 4 to 32 Gy. The clonogenic activity was assessed with colony formation assays, cell cycle was analyzed by flow cytometry. Additionally, Western blotting of P42/44 (cell cycle regulating MAP kinases) was performed. The migratory ability of PDGFstimulated SMC was assessed in a two-compartment migration model. SMCs’ capability to synthesize extracellular matrix was examined by analyzing the distribution of extracellular tenascin by fluorescence microscopy. Results : SMC presented a dose-dependent decrease in clonogenic activity and an increasing G2/M phase block. P42/44 were altered by Re-188 incubation. Groups treated with 16 and 32 Gy showed no clonogenic activity, the 4 and 8 Gy groups showed a partial recovery. Migratory ability of SMC was significantly decreased for all radiation groups on day 5. Tenascin synthesis decreased dose dependently. Conclusion : Incubation with the radionuclide Re-188 inhibits proliferation, migration, and matrix synthesis of cultured vascular SMCs in a dose dependent manner.

Purpose : To evaluate optimum application modalities for the «channelled balloon catheter» to minimize additional vessel trauma. Materials and Methods : Sixty cholesterol-fed rabbits underwent unilateral common iliac artery local application of saline (n=30) or Ringer’s solution (n=30) according to six different protocols: I = application pressure 2atm/application volume 1ml; II = 2atm/2ml; III = 2atm/5ml; IV = 4atm/1ml; V = 4atm/2ml; VI = 4atm/5ml. Each protocol was carried out in five animals. Application of saline or Ringer’s solution was always done using the channelled balloon. The inner balloon of this device was inflated to a pressure of 8atm. The contralateral iliac artery was used as control. Four weeks later angiography was performed, the animals were sacrificed, vessel segments were excised and morphometric measurements were obtained. Results : Local application was successful in all cases, no complications were noted. All treated vessels were patent at 4 weeks. The mean neointimal area did not differ between local drug application (2.5 mm2) and PTA only sites (2.09 mm2; p>.05). No significant differences regarding intimal hyperplasia were found for the six different application protocols or for treatment with saline or Ringer’s solution. Conclusion : Local application of saline or Ringer’s solution up to a volume of 5 ml and a pressure of 4atm using the channelled balloon catheter does not result in excess neointima.

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LU 135252 inhibits atherosclerotic formation induced by hypercholesterolemia in rabbits but not after balloon denudation Tepe G., *Brehme U., Seeger H., **Raschack M., Claussen C.D., Duda S.H. University of Tübingen, Diagnostic Radiology, *Occupational and Social Medicine; **Knoll AG, Endothelin Research, Tübingen, Germany

Inhibition of rabbit vascular smooth muscle cell proliferation with NfkB decoy oligonucleotides Alfke H., Kalinowski M., Kleb B., Klose K.J. Philipps University of Marburg, Radiology, Marburg, Germany Purpose : To evaluate if inhibition of the transcription factor NfkB by means of transfection of decoy oligonucleotides leads to the inhibition of rabbit vascular smooth muscle cell (RBVSMC) proliferation. Materials and Methods : RBVSMC were cultured under standard conditions. Oligonucleotides (ODN) containing the binding site of NfkB and control oligonucleotides (scrambled ODN) were transfected into the cells using a cationic lipid vector (Tfx, Promega). We used 100ng ODN/8000 cells and a ratio of vector: ODN of 4:1. Co-culture was done for 24 and 48 hours respectively. Cells were also incubated with 100ng ODN alone and with Tfx without any ODN or cultured without coincubation. Cell number was measured by an MTT assay. Results : Transfection with NfkB ODN leads to a decrease in the cell number after 24 and 48 hours (20% as comparison with control) indicating an inhibition of cell proliferation. This was not seen with scrambled ODN indicating a specific inhibition sequence of cell proliferation due to NfKb inactivation. Proliferation was not inhibited by ODN co-incubation alone or by the cationic vector Tfx alone. Conclusion : NfkB decoy oligonucleotides inhibit the proliferation of RBVSMC in vitro. This inhibition transcription factor may be applied to inhibit restenosis after percutaneous transluminal angioplasty or stent insertion.

Purpose : The purpose of the study was test the capability of the endothelin A (ETA) receptor antagonist LU 135252 to reduce neointimal formation in rabbits after balloon denudation with and without the presence of hypercholesterolemia. Materials and Methods : Twenty-eight New Zealand White male rabbits underwent balloon denudation of the infrarenal aorta. The animals were divided into four different groups. After balloon denudation, group 1 (n = 6) and 2 (n = 7) received a standard diet, and group 3 (n = 8) and 4 (n = 7) were fed a 0.5% cholesterol diet. One week prior to intervention, a medical treatment with LU 135252 was started in group 2 and 4. After 6 weeks the animals were sacrificed for further morphometric and histological analysis. Results : Rabbits in all treatment groups developed neointimal hyperplasia. By additional systemic treatment with LU 135252, the mean neointima to media ratio was significantly reduced only in the hypercholesterolemic animals of group 4. ET receptor blockade in group 2 and 4 did not have an effect on plasma levels of cholesterol, VLDL-, HDL-, and LDL-cholesterol. Conclusion : In conclusion, LU 135252 was efficacious in the reduction of lipid-induced atherosclerotic changes but was ineffective in inhibiting restenosis induced by balloon denudation.

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Mechanical method of abrasion and isolation of human vascular endothelial cells for a quantitative sufficient culture Priebe M., Grimm J., *Paulsen F., Jahnke T., Heller M., MüllerHülsbeck S. Christian-Albrechts University of Kiel, Diagnostic Radiology, *Anatomic Department, Kiel, Germany

Comparison of plain and hirudin-coated stents and stentgrafts in the iliac arteries: experimental results Schürmann K., *Roos A., Meyer J., Haage P., *Klee D., *Lahann J., **Vorwerk D., Günther R.W. University of Technology, Diagn. Radiology, Institute of Textile and Macromolecular Chemistry, Aachen,**Clinics of Ingolstadt, Diagn. and Interventional Radiology, Ingolstadt, Germany

Purpose : Isolation of human vascular endothelial cells for a quantitative sufficient culture and later coating of stents. Materials and Methods : Newborns umbilical cords were used to isolate vein endothelial cells. The umbilical vein was rinsed clotfree of blood, dilated up to 5 mm in diameter with phosphate buffered saline and divided in segments. A Cragg thrombolytic brush catheter was inserted by a rotating mechanical hand and pushed back. The brush was put in a sterile tube filled with cell medium containing 20% fetal calf serum or albumin containing saline and shaked out about 5 seconds by the highest engine performance of the connected catheter motor drive. This procedure was repeated five times for each segment. The tube was then centrifugated 15 min. by 200 g. The cells were resuspended in RPMI medium in a fibronectin-coated culture flask. Results : The nylon brush catheter is able to abrate viable human umbilical endothelial cells. We successfully tested different saline solutions to isolate these cells from the brush. The cell-viability is time-dependent on the age of the umbilical cord. Conclusion : A new mechanical catheter abrasion is an effective method to isolate viable human umbilical vein endothelial cells and to culture them. Perhaps we can use this method to isolate patients endothelial cells.

Purpose : To evaluate the influence of hirudin coating on the patency of endovascular prostheses in vivo. Materials and Methods : Hirudin was covalently bound to the surface of Memotherm stents and PTFE stentgrafts through a polymer. The polymer coating was achieved by chemical vapour deposition (CVD) technique. In 20 sheep, 80 prostheses, two per artery, were inserted. Arteries were pretreated with a Fogarty maneuver. Five different prostheses were used: plain and hirudincoated stents, plain, CVD-coated, and hirudin-coated stentgrafts. Only one type of prosthesis was placed into the same artery. Animals were followed with intravascular ultrasound (IVUS) and angiography for one or six months. Follow-up examinations were performed immediately after implantation and after one, three, and six months. Results : IVUS showed that the patent lumen of all prostheses increased immediately after implantation. During follow-up the true and relative patent lumen of hirudin-coated stentgrafts was reduced compared with the other prostheses. Reduction was most pronounced after one and three months. Patency of hirudin-coated stents was similar to that of the other prostheses. No relevant difference in patency was observed between hirudin-coated and plain stents and non-hirudin-coated stentgrafts. Conclusion : In an experimental setting, patency rate of hirudincoated prostheses was not improved compared with non-coated prostheses.

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The effect of a platelet glycoprotein 2b/3a receptor inhibitor on thrombus formation with covered stent placement. A feasibility study in canine models Dowling K., Paulis B., Siskin G., Stainken B., Dolen E., Quarfordt S., Mitchell N., Sansivero G. Albany Medical College, Interventional Radiology, Albany, NY, USA

Role of embolotherapy in the management of acute pelvic hemorrhage Tesdal I.K., *Gaa J., *Pöckler C., *Düber C., Friedrichshafen Hospital, Institute for Radiology and Nuclear Medicine, Friedrichshafen, *University Hospital of Mannheim, Institute for Clinical Radiology, Mannheim, Germany

Purpose : Thrombus formation has become problematic with the use of certain coverings on intra-vascular metallic stents. The purpose of this study was to determine the effect of the platelet inhibitor Tirobifan (Merck) on thrombus formation in stents coated with a poly-urethane/silicon mixture. Materials and Methods : Animal care and use committee approval was first obtained. Six animals were divided into three groups to be sacrificed at 2, 4, and 6 weeks. Wallstents (Boston Scientific) were coated with a polyurethane/silicon compound (Cardiothane-51, Arrow). Covered and non-covered Wallstent were placed in each animal via a 6-F sheath. One animal in each group received a loading dose and infusion of Tirobifan. Histopathological analysis was performed. Results : Angiography showed a minimal (<10%) neointimal hyperplasia and no discrete thrombus. Histologically, covered and non-covered stents showed respectively an average stenosis at the mid stent of 7 and 3% in the Tirobifan group, and 8 and 4% in the non-drug group. No thrombus was seen. Neointimal hyperplasia was slighty greater on the ends of the stents but not significantly greater in the drug versus the non-drug group. Conclusion : Tirobifan conferred no advantage in thrombus or neointimal hyperplasia formation as compared with aspirin and heparin alone. Because of its smaller profile, this covered stent may have human application.

Purpose : To assess the role of transcatheter arterial embolization in the management of intractable pelvic hemorrhage. Materials and Methods : Fifty-six consecutive patients (between November 1993 and July 2000) with acute pelvic hemorrhage due to malignant pelvic tumors (n=25) and trauma (n=31) were treated with trans-catheter arterial embolization. Acute bleeding was defined as hemorrhage necessitating specific emergency therapeutic management. Rebleeding was defined as any hemorrhage necessitating a blood transfusion. The vascular pattern of the abdomen and pelvis was studied by digital subtraction angiography. Embolotherapy was performed using polyvinyl alcohol particles (PVA) in combination with coils. Follow-up data after discharge were based on phone interviews with the patients and their primary physicians. Results : After embolotherapy, 86% of patients were free of rebleeding. The risk of recurrent hemorrhage and 30-day mortality (23%) depended on the etiology and severity of blood loss, respectively. Those patients with prostatic carcinoma presented the highest rebleeding rate (43%). Major complications occurred in one patient (acute ischemia of the lower limbs). We did not observe any procedure-related mortality. Conclusion : Embolotherapy using PVA in combination with coils is an effective method for treating intractable pelvic hemorrhage.

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Superselective embolization therapy of bleeding due to cervical carcinoma using the axillary access Jargiello T., Janczarek M., Grzechnik B., Szczerbo-Trojanowska M. University School of Medicine, Interventional Radiology, Lublin, Poland

Percutaneous aortic «stop-flow» perfusion and hemofiltration for the regional cytotoxic therapy of pelvic malignancies Tsetis D.K., *Romanos J., **Metaxari E., Hatzidakis A.A., *Michalakis J., *Tsiftsis D., Gourtsoyiannis N.C. University Hospital of Heraklion, Radiology, *Surgical Oncology, **Anesthesiology, Heraklion, Greece

Purpose : The aim of our study was to assess the utility and complications of internal iliac embolization using the axillary access in those patients with severe bleeding due to advanced cervical carcinoma. Materials and Methods : Eighty four procedures via a left axillary access were performed since 1995. All the patients were suffering from severe bleeding due to advanced cervical carcinoma. Embolization was performed as a palliation treatment or to prepare the patients for further oncologic therapy. Usually, 4- and 5-F Headhunter catheters were used. Superselective embolization of the pathologic vascular bed was done with polivinyl alcohol (various particle sizes) and, in some cases, with coils. Results : The left axillary artery access enabled a successful bleeding control in all the patients. Superselective catheterization was quick and easy in 76 cases. In eight patients, the technical difficulties were due to atherosclerotic and tortuous common and internal iliac arteries. Embolization procedures lasted from 25 to 60 minutes (average 35). There were no brachial plexus injury complications. Four patients had a small puncture site hematoma resolved without treatment. Conclusion : The axillary access allows a simple catheterization of the internal iliac arteries. The use of typical cerebral catheters allows a superselective embolization. Axillary access procedures are shorter than those with a groin access, especially when bilateral. The possibility of walking immediately after procedure is also very important for the patients. The number of complications is minimal.

Purpose : To report our preliminary experience in a modified aortic «stop-flow» technique followed by hemofiltration (ASFPH), using percutaneously inserted balloon occlusion catheters in patients with unresectable pelvic malignancies. Materials and Methods : Five patients (mean age: 72 years) with unresectable carcinomas of the cervix (two patients), the bladder, the vulva and the rectum received seven courses of ASFPH. Under general anesthesia, 8-F aortic and inferior vena cava balloon occlusion catheters were introduced through 11-F percutaneously inserted femoral sheaths over a guidewire and were inflated fluoroscopically above the aortic and vena cava bifurcation. After the establishment of hypoxia, the drugs were infused. Mean time of hypoxia was 20 min. Hemofiltration started 5 min. before the end of the «stop-flow» and continued for a mean time of 25 min. until the removal of 4L of ultrafiltrate. Results : The procedure was well tolerated by all the patients. Complications included balloon rupture (one case) and hemorrhage from the puncture site (one case). No drug toxicity was observed. Four patients reported a decrease of pain. All the patients are still alive and are followed up with CT scans and tumor markers. Conclusion : Percutaneous catheter insertion seems to be an effective modification of the original ASFPH. It facilitates repeat ASFPH sessions by minimizing perivascular scarring.

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Primary postpartum haemorrhage: early selective embolization of uterine arteries Lions C., *Laloux C., *Ducloy-Bouthors A.S., *Provost N., Willoteaux S., Beregi J.P. Hôpital Cardiologique, Radiology, *Hôpital Jeanne de Flandre-Lille, Obstetrics, Lille, France

Early experience with radiofrequency ablation (RFA) of cortical renal tumors Ahrar K., *Pisters L.L., Gupta S., Wallace M.J., Morello F.A. jr., Hicks M.E., *Scott S.M. M.D. Anderson Cancer Center, Vascular and Interventional Radiology, *Urology, Houston, TX, USA

Purpose : To evaluate the safety of early selective arterial embolization in the management of primary postpartum haemorrhages. Materials and Methods : Forty-one women with primary postpartum haemorrhage underwent uterine embolization between 1996 and 2000. A medical treatment with uterotonic drugs (ocytocine, sulprostone) according to a rigorous protocol and evaluation of blood loss was first started (450 patients). This treatment failed to stop haemorrhage in 41 cases. Embolization was decided in case of a persistent haemorrhage after 90’ of medical therapy infusion at a maximal dose. The procedure consisted of selective embolization of uterine artery, or of anterior division of internal iliac arteries; both uterine arteries were embolized using a unilateral femoral approach. Absorbable gelatin sponge was used in all cases but one (micro-particles). Results : Cessation of the external bleeding was observed in all cases. Neither death nor general complications, such as cardiogenic pulmonary edema or disseminated intravascular coagulo-pathy, occurred. Three local complications occurred: one vulvar ischemia (after the use of micro-particles) and two transient foot ischemia. Conclusion : Arterial embolization is a safe and effective way of controlling primary postpartum haemorrhage. An early endovascular approach permits to avoid general complications of blood loss and reanimation as compared with other protocols.

Purpose : To evaluate the safety and feasibility of RFA of cortical renal tumors. Materials and Methods : Seven cortical tumors (0.8 to 2.5 cm in diameter) were treated with RFA in patients who had had a previous nephrectomy for renal cell carcinoma and subsequently developed new tumor(s) in the contralateral kidney. Four lesions were treated percutaneously. Three others were treated intraoperatively with intraoperative ultrasound. Results : All seven tumors were treated successfully. Follow-up ranged from 13 days to 4 months. There were no complications such as hematuria, perinephric hematoma or hemorrhage from the tract. Renal function tests were available for five treated tumors and remained normal. Follow-up MRI was performed at three months for two lesions and demonstrated a decrease in the size of the lesions with no residual enhancement. Conclusion : RFA may be safely used for the treatment of cortical lesions in the kidney. For lesions located along the posterior, lateral or anterolateral aspect of the kidney, ultrasound-guided percutaneous approach is preferred. Intraoperative RFA may be reserved for those lesions that cannot be reached percutaneously. Long-term results need to be evaluated

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Preliminary experience with percutaneous ultrasound-guided injection of alcohol or acetic acid into canine prostate Bagheri M.H., 1)Tanideh N., 2)Tadayon A.R., 3)Kumar V., 4)Heyati M., 4)Heyati K. Shiraz University of Medical Sciences, Radiology, 1)Animal Lab, 2)Urology, 3)Pathology, 4)Medical School, Shiraz, Iran

Treatment of testicular varicocoele in children by embolisation Butt S.H., Sabharwal T., *Clark S., **Agrawal M., Reidy J. Guy’s and St. Thomas Hospital, Radiology, **Paediatric Urology, *University Hospital Lewisham, Surgery, London, United Kingdom

Purpose : To evaluate the effect of percutaneous injection of ethyl alcohol (99%) or acetic acid (15% and 30%) into canine prostate by ulrasound-guidance. Materials and Methods : Twelve dogs were selected and divided into three groups. After sedation, percutaneous ultrasound-guided transperineal injection of about 2 cc of ethyl alcohol 99%, acetic acid 15%, and acetic acid 30% was done in these three groups, respectively. After 3-5 weeks, a follow-up sonography was done, the prostates were removed, and histopathologic changes were recorded. Results : Two dogs died three days after injection of 30% acetic acid due to a lower GI bleeding and the pathology showed bowel perforation and autolysis of the prostate. Generalized or focal decreased echogenecity in six dogs and foci of increased echogenecity in two dogs were found. Microscopically, the main histopathological findings were fibrosis, inflammation and fatty change, more severe in the acetic acid groups. No capsular or urethral invasion was found in ten dogs. Conclusion : Both acetic acid 15% and ethyl alcohol 99% can cause fibrosis and can be used in the treatment of prostatic cancer or benign prostatic hyperplasia. Acetic acid 30% may cause more severe changes with more complications.

Purpose : The aim was to show that radiologically-guided testicular vein embolisation is an effective alternative to the surgical approach. Materials and Methods : Between 1985 and 2000, 60 patients, mean age 13.5 years (range 9-18 years) were referred for varicocoele embolisation. All the patients had been seen by the paediatric urologist and had had ultrasound scans.The majority of the procedures (55) was done under a light sedation and local anaesthesia. Five patients required a general anaesthesia. In all the patients, coil embolisation was performed after obtaining testicular venograms. Patients were followed up on an out-patient basis. Late follow ups were done by telephone interviews or questionnaires by mail. Clinical outcomes were graded as «good», «moderate» and «poor,» according to various criteria. Results : The procedure was successful in 55 patients (60%). Forty six patients (76%) had a «good» clinical outcome. Five patients (8%) reported a recurrence of varicocoele and were operated. Four patients were lost to follow up and were not included in the final result. Conclusion : Because of the advantage of performing the procedure on an out-patient basis, the rapid recovery time and the low complication rate, we believe that testicular vein embolisation is the treatment of choice for varicocoele in children.

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Iatrogenic ureteral injuries: reconstruction with the rendezvous technique Cancellieri R., Gandini R., Pampana E., Reale C., Guazzaroni M., Pocek M., Simonetti G. Tor Vergata Rome University, Radiology, Rome, Italy

Sclerotherapy of epidydimal cysts Pieri S.,Agresti P., Assegnati G., Carnabuci A., de Medici L. Az. Osp. «S. Camillo-Forlanini», Cardioscienze, Rome, Italy Purpose : Epidydimal symptomatic cysts are frequent in male population and they are normally treated with the surgical option. We report here our experience with the percutaneous treatment. Materials and Methods : In the 1999-2000 period, we examined 45 epidydimal cysts. Twenty five of them only had a diameter greater than 5 cm. Under sonographic guidance, we drained the liquid and then we used Atossisclerol 3%. Results : We had a resolution of the epidydimal cyst in 15 patients (cysts' diameters were less than 6 cm). We had a partial resolution in six (all the cysts were 7 cm in diameter) and we treated twice those cysts with a diameter greater than 8 cm. We had not complications. Conclusion : The percutaneous treatment is a safe, effective, and economic option to correct epidydimal cysts without the complications of the surgical option.

Purpose : To evaluate the efficacy of a combined percutaneousendoscopic reconstruction of iatrogenic ureteral lesions by double-J catheter stenting. Materials and Methods : Between February 1996 and December 2000, plastic stents were placed in five patients with a combined technique for post-surgical ureteral lesions. In all the patients, a double approach (percutaneous and endoscopic) was performed as the distal ureter could not be reached through the nephrostomy. Ureteroscopy confirmed the evidence of ureteral transec-tion in four patients and ureteral ligation in one. A guidewire, advanced in the retro-peritoneum under cystoscopic guidance, is then captured with a goose-neck snare (advanced from the nephrostomy) and retracted through the proximal ureteral portion and the kidney. After ureteral continuity was restored with wire, a double-J catheter was placed and a neprostomy was kept for three days. Results : A technical success was achieved in all patients with no contrast media leak evidence. The mean catheter permanence was six months. The double-J catheter was changed in two patients after three, eight and nine months, two other patients died for under-lying neoplastic pathologies before the plastic stent could occlude. One patient is still alive and symptom- free. Conclusion : For its high success rates, this combined technique can be considered as a valid alternative to surgical ureteral repair.

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146 MR-hysterosalpingography as an alternative hysterosalpingography Sias A., Alvino V., Lecca F., Politi C., Mallarini G. Università di Cagliari, Istituto di Radiologia, Cagliari, Italy

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Can interventricular septal deviation on chest CT predict right ventricular dysfunction in patients with pulmonary embolism? Contractor D., Contractor S. New Jersey Medical School UMDNJ-Newark, Radiology, Newark, NJ, USA

Purpose : The purpose was to establish th possible role for MRhysterosalpingography as an alternative to hysterosalpingography (HSG), which represents the «gold standard» in the visualization of fallopian tubes. Materials and Methods : We performed MRhysterosalpingography in 40 women diagnosed with infertility. The examination was performed on a 0.5-T magnet. T1 and T2 imaging was performed before and after administering 20 ml of saline injection through a catheterization tube previously introduced in the uterus. All patients subsequently underwent HSG for results confirmation Results : Ninety eight percent of the patients claimed that MRhysterosalpingography was less traumatic and painful than HSG. The fallopian tubes were visualized in 80% of patients, in the remaining 20% only a fluid in the lower abdomen was noted. HSG confirmed the results of MR-hysterosalpingography in 90% of those patients in whom the fallopian tubes were visualized. Conclusion : The advantages of MR-hysterosalpingography include the lack of ionizing radiations and the clear visualization of the pelvic organs. In addition, the examination seems better tolerated by the patients. Disadvantages include its high cost and the fact that interventional procedures cannot be carried out during the same setting. The role of MR-hystero-salpingography is to visualize patent fallopian tubes in most patients: these patients may avoid an unnecessary HSG and its radiations.

Purpose : Evaluate the role of chest CT in predicting right ventricular (RV) strain in patients with pulmonary embolism (PE). Materials and Methods : A retrospective review of chest CT scans was done from 7/1/1999 to 12/1/2000. Scans were performed using a PE protocol on a GE helical scanner. Scans were reviewed for the presence of PE and RV strain seen as deviation of the interventricular septum to the left or the dilated RV cavity. Patients were classified as with a normal scan (no evidence of PE), as PE without RV strain, and as PE with RV strain. Other studies (ultrasound, pulmonary angiogram) were reviewed to corraborate the presence of RV dysfunction. Results : One hundred and forty eight studies were performed during this period. Results were: normal=107, PE but no RV strain=32, PE with RV strain=9. Of the 107 studies without PE, three patients had evidence of RV strain (two had bullous emphysema and one had bilateral pneumonia). Of the 32 patients with PE without RV strain on CT,18 underwent ultrasound which showed two RV strain. Of the nine patients with RV strain on CT, seven had ultrasound evidence of RV strain. Patients with RV strain were treated with thrombolysis. Conclusion : CT is useful in predicting RV strain in patients with PE. Since thrombolytic therapy is recommended if there is RV strain, identification of this without a second study would be of considerable clinical importance.

147 Imaging in the differential diagnosis of right ventricular hypoplas Hu W.M. General Hospital of PLA, Radiology, Shenyang, China

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Purpose : To evaluate the effectiveness of imaging in the differential diagnosis of right ventricular hypoplasia. Materials and Methods : The study includes nine cases of isolated right ventricular hypoplasia; two cases of atypical Ebstein’s anomaly; two cases of trilogy of Fallot, complicated by the absence of the trabecular portion of the right ventricle; one case of arrhythmogenic right ventricular hypo-plasia. All cases were confirmed by surgery. All the patients underwent pathological, angiocardiographic and echo-cardiographic investigations before surgery; in four cases, MRI was also performed. Results : The nine cases with isolated right ventricular hypoplasia showed absence of the trabecular portion of right ventricle, small right ventricular cavity, short inflow portion of right ventricle and normal pulmonary artery and interatrial communication (secondary atrial septal defect and patent foramen ovale), while three showed a small tricuspid orifice. The two cases of atypical Ebstein’s anomaly showed a slight displacement of the tricuspid valve, with apparent absence of the trabecular portion of the right ventricle. The cases of trilogy of Fallot were complicated by the absence of the trabecular portion of the right ventricle and pulmonary artery stenosis. The case of arrhythmogenic right ventricular hypoplasia showed enlargement of the right ventricle and adipose tissue in the myocardium. Conclusion : Right ventricular angiocardiography and echocardiography are complementary tools in the diagnosis of right ventricular hypoplasia. They permit a correct preoperative diagnosis of the trilogy of Fallot, thus helping in the selection of the surgical approach. MRI is better than right ventricular angiocardiography in the diagnosis of arrhythmogenic right ventricular hypoplasia.

Purpose : Second harmonic imaging (SHI) enhances heart chamber visualization compared with conventional fundamental imaging (FI). Its role during fetal heart imaging is not well established yet. The purpose of this work is to evaluate the increase in heart visualization and chamber depiction during US fetal monitoring in all image planes. Materials and Methods : We performed US imaging in 112 women during pregnancy as part of the standard programmed controls. The examiners acquired the same total number of heart images with both FI and SHI. The investigation time was also recorded, with separate records for SHI or FI. The quality of the images was subsequently graded by an independent examiner. Results : SHI improved overall fetal heart visualization in all patients, resulting in a modified diagnosis in 16% (from a suspected cardiac abnormality to normal findings). Conclusion : SHI allowed the visualization of finer details in fetal heart diagnosis, and easiness of application did not cause an increase in the time of examination, often resulting in a shorter examination time. SHI aided the visualization of fetal heart also in difficult patients (oligoidramnios, obese, etc).

Value of second harmonic imaging (SHI) in fetal cardiac US Sias A., Alvino V., Lecca F., Politi C., Mallarini G. University of Cagliari, Institute of Radiology, Cagliari, Italy

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The use of intravascular ultrasonography (IVUS) to assess the dimensions of patent ductus arteriosus Demin V.V., Zheludkov A.N., Zelenin V.V., Demin A.V., Degtyarev A.G. Orenburg Regional Clinical Hospital, Interventional Cardiology and Radiology, Orenburg, Russian Federation

Renal multi-slice spiral-CT angiography: the role of threedimensional reconstructions in follow-up of renal artery stenting Mallouhi A., Rieger M., Czermak B., Waldenberger P., *Seiler R., Jaschke W.R. Leopold Franzens University, Radiology, *Vascular Surgery, Innsbruck, Austria

Purpose : To study the diagnostic potential of IVUS to determine accurate dimensions of patent ductus arteriosus (PDA). Materials and Methods : IVUS was used simultaneously with angiography to measure the diameter of PDA in 12 patients. The study was carried out on a complex Oracle In-Vision by a diagnostic catheter Visions Five-64 F/x with a frequency of 20 MHz. The patients’ ages ranged from 2.8 to 37.9 years. Results : By comparing IVUS and angiography data, the diameter was less in eight and more in three cases according to the ultrasound research. The length of the duct appeared to be the same with both techniques in six patients; it was shorter by IVUS in five patients; the complete identity of morphometric measurements was found in one patient only. Based on these data, we carried out transcatheter closures in eight patients with a ductus diameter of 2 to 4 mm. For the embolization, we used a Flipper PDA closure access set with detachable Gianturco coils (Cook). All the procedures were done without complications thanks to the exact selection of the coils. Conclusion : The use of IVUS gave us the opportunity to determine more accurately the dimensions of the PDA and to perform safely its transcatheter closure.

Purpose : The aim of this study was to evaluate the role of curved reformats (CR), volume rendering (VR) and virtual endoscopy (VE) utilizing a multi-slice spiral-CT to follow up patients treated with renal artery stents. Materials and Methods : Thirty six patients with 41 renal artery stents underwent contrast-enhanced CT-angiography of the renal arteries. Targeted paraxial and paracoronal CR and VR images as well as VE were performed on a workstation (Sun Ultra 60 UPA/PCI, GE Medical systems). A scoring system (1=very good–4=unsatisfactory) was introduced to express image quality, delineation of the lumen and image artifacts. DSA exams were available in 11 cases. Results : The best image quality was obtained by VE (1.12±0.33), CR (1.17±0.38) and VR (1.26±0.44) in the axial planes (p>0.05). The lumen was most correctly delineated using also VE (1.19±0.45), VR (1.24±0.43) and CR (1.26±0.5) in the axial planes (p>0.05). Curved reformats showed less artifacts (1.43±0.59) than volume rendering (2.04±0.21) p<0.0001. In patients demonstrating restenosis (n=7), CR correlated better than VR with DSA (r=0.95 and r=0.90 respectively). VE tended to underestimate the restenosis (r=0.65). Conclusion : Multi-slice spiral-CTA allows high-quality threedimentional evaluation of the patency of an implanted renal artery stent. CR and VR showed more ability than VE in displaying subvolumes in stent's lumen.

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Grading of carotid artery stenoses with multislice CT-angiography: comparison with DSA Kreuzer S.H., Prokop M., *Ahmadi R., Loewe C., Fleischmann D., Thurnher S., Cejna M. University Hospital Vienna AKH, Radiology, *Angiology, Vienna, Austria

The value of multislice spiral-CT angiography (CTA) in the detection of hemo-dynamically significant lesions in peripheral arterial occlusive disease Portugaller H.R., Hausegger K.A., *Amann W., Tauss J. Univ. Clinic of Radiology, LKH Graz, Angiography and Interventional Radiology, *Vascular Surgery, Graz, Austria

Purpose : To compare multislice CT-angiography (MCTA) and digital substraction angiography (DSA) for grading carotid artery stenoses. Materials and Methods : We studied 42 patients (12 women; 30 men; mean age: 70) using MCTA (Somatom Volume Zoom) and DSA. With MCTA, the volume from the aorta to the sella was covered with 4x1 mm section thickness using a 0.7-mm reconstruction increment. Intravenous contrast medium was tailored individually based on a test bolus injection. We used curved planar reformats through the internal (ICA), external (ECA) and common carotid arteries (CCA) to classify stenoses according to the NASCET criteria.In case of doubt, axial source images were evaluated. Severity of stenoses was graded in 10% steps. Stenoses above 70% were considered significant. DSA was used as the gold standard. Results : A total of 72 carotid arteries was included in our study. With MCTA 37/39 (sensitivity 95%) of the significant ICA stenoses, 8/9 (89%) of the significant ECA stenoses and 2/2 of the CCA stenoses were correctly diagnosed. The specificity was 95, 94, and 99%, respectively. No significant stenosis in DSA was graded less than 60% with MCTA. The biggest difference was noticed in eccentric stenoses. Conclusion : MCTA is similar to DSA in the evaluation of internal carotid artery stenoses.

Purpose : To evaluate the potential of multislice CTA in the detection of hemodynamically significant (≥70%) lesions of aortoiliac, femoropopliteal and infrapopliteal arteries. Materials and Methods : Twenty three patients (20 men, three women; age: 50-86 years) with peripheral arterial occlusive disease (PAOD) underwent multislice spiral-CTA and digital subtraction angio-graphy (DSA) from the infrarenal aorta to the supramalleolar region. CT parameters were: 4x2.5-mm collimation, 1.5-cm table increment (pitch 6, high speed mode) and 1.25-mm reconstruction increment. Axial slices, volume rendering technique (VRT) and maximum intensity projection (MIP) studies were reviewed for ≥70% arterial cross sectional area reductions. DSA was the standard of reference. Results : In 21 patients, 123 lesions were detected (49 stenoses, 74 occlusions). In the detection of all ≥70% lesions, sensitivity/specificity for axial images were: 0.92/0.92 aortoiliac, 0.95/0.76 femoropopliteal and 0.86/0.72 infrapopliteal, for VRT studies: 0.75/0.99 aortoiliac, 0.86/0.91 femoropopliteal and 0.78/0.70 infra-popliteal and for MIP studies: 0.92/0.75 aortoiliac, 0.86/0.83 femoropopliteal and 0.86/0.68 infrapopliteal. Conclusion : In PAOD, multislice CTA yields useful information on hemodynamically significant arterial lesions in aortoiliac and femoropopliteal, but not in infrapopliteal regions.

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Correlation of coronary calcium scores measured by electron-beam computed tomography with the results of coronary angioplasty Belkind M., *Sinitsyn V., Lyakishev A., **Matchin Y., *Gagarina N., Naumov V. Cardiology Research Centre, Atherosclerosis, *Tomography, **Interventional Cardiology, Moscow, Russian Federation

Closure of extra-cardiac fenestration combined with total cavo-pulmonary connection (TCPC) using the Porstmann method Takamiya M., Kimura K., *Yamada S., *Echigo S. National Cardiovascular Center, Radiology, *Pediatrics, Osaka, Japan Purpose : To propose a method for closing an artificial fenestration after surgery. Materials and Methods : A six-year old girl with a postoperative complex cardiac anomaly (DILV, tricuspid stenosis, and DORV), was treated by TCPC when she was three-year old. A recent balloon occlusion test of the fenestration led us to the decision of closing the shunt. The fenestration had been performed using a Goterex graft connecting the cavo-pulmonary graft and the atrial septum; it was angiographycally measured: 7.7 mm in length and 4.1 mm in diameter. We found it difficult to close the fenestration with detachable coils or other commercially available PDA occluders because of the high possibility of dislodgement or residual shunt. A home-made Ivalon plug was tailored in a dumbbell shape (12 mm in length, 7/4/10 mm in diameter). The plug was introduced from the femoral vein to the fenestration and wedged by a modified Porstmann method. Results : The fenestration was completely closed with an Ivalon plug. The patient had a non-bacterial pyrexia a few days after plug closure. At the four-month follow-up, she was in good physical conditions with a normalized arterial oxygen saturation. Conclusion : The Porstmann method is the method of choice to close tubular shape fenestrations combined with TCPC, if coil embolization is difficult or unsuccessful.

Purpose : The purpose of our study was to estimate the correlation between the degree of coronary calcifications measured by electron-beam computed tomography (EBCT) and the outcomes of PTCA. Materials and Methods : Eighty patients with 96 coronary artery stenoses underwent balloon angioplasty. Before the intervention all the patients were examined by EBCT. Complications and restenoses were estimated. Results : Complications during PTCA were registered in 24 cases. Restenosis was detected in 23 dilated segments. Among those patients with restenosis, the average calcium score in the coronary segments submitted to PTCA was 74.5±89.9 as comparing with the score of 22.9±32.8 among those patients without restenosis (p<0.01). By applying the ROC-analysis, we determined the sensitivity and specificity of EBCT in forecasting complications and restenosis. The critical calcium score in the PTCA segment was 27 for restenosis (sensitivity 79%, specificity 62%), and 23 for complications (sensitivity 81%, specificity 70%). The patients were divided into two groups with significant and insignificant segments calcium score. The frequency of complications caused by PTCA and restenosis were notably higher in the group with a significant calcification (p<0.04). Conclusion : The high calcium score in a segment of the coronary arteries submitted to PTCA is associated with an increased risk of complications and restenoses. These observations may be important in selecting the devices for the endovascular therapy.

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Operation planning using spiral CT: 3-D visualization of calcification, stenosis and function in coronary artery bypass grafting (CABG) patients Albers J., *Bahner M.L., *Boese J., Tremper J., Heggemann F., Schroeder A., Vahl C.F., Hagl S. University of Heidelberg, Cardiac Surgery, *Radiology, Heidelberg, Germany

Percutaneous thoracic duct (TD) blockage for treating chylothorax complicating cardiac surgery Cope C. University Hospital Penna, Radiology, Philadelphia, PA, USA Purpose : To demonstrate the technique for transabdominal retroperitoneal lymph duct embolization and needling to treat thoracic duct (TD) leakage. Materials and Methods : Five patients (four men) were treated percutaneously for high output chylothorax following coronary artery bypass (n=3), cardiac transplant (n=1), and atrial tumor excision (n=1). Pedal lymphography was performed to opacify the cisterna chyli (CC) or the proximal TD; CC or TD were accessed by transabdominal puncture with a Chiba needle and a 3-F catheter inserted over a guidewire to embolize the TD with microcoils and particles; when the CC and TD were not opacified, lymph collaterals feeding the TD leak were occluded by needling. Results : A successful TD embolization was performed in two cases and lymphatic needling in three. Chylothorax subsided within five days (n=4) and within three weeks in the remaining patient. Temporary pleural effusion recurred at two months in the cardiac transplanted patient. There was no procedural morbidity or need for surgical TD ligation. Conclusion : Percutaneous transabdominal lymph duct blockade is a safe and effective treatment for chylothorax post-cardiac surgery;it can replace open surgical TD ligation.

Purpose : Cardiac CT is presently restricted to the assessment of coronary calcifications. In patients undergoing CABG, however, additional functional and morphological data are needed for the operation planning. Materials and Methods : We studied 30 patients with severe three-vessel CAD. To improve the temporal resolution of spiralCT (Siemens, Somatom Plus 4 VZ), a retrograde gating was used. Native scanning plus one scan after application of the contrast medium (70 ml) was performed. ECG and X- ray signal were recorded simultaneously. Three-dimension visualization was performed using raytracing. Demonstration of 3-D videos to cardiac surgeons was performed. Results : Reconstruction of retrograde gated image data resulted in improved temporal resolution (up to 70 ms). The entire cardiac cycle could be assessed, determination of endsystolic and enddiastolic frames was possible, ejection fraction correlated with angiography. Three-dimension visualization showed the distribution of coronary calcifications. Moreover, non-calcified lesions were clearly visualized. Conclusion : Morphology of coronary artery stenoses was determined in patients before CABG. Additionally, functional cardiac CT imaging with high temporal resolution and demonstration of 3-D videos enhanced clinical acceptance of the method.

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Mammotome biopsy guided by digital mammography or ultrasound in detecting pre-clinical breast pathologies. Our experience Popiela T.J., Podsiadlo-Kleinrok B., *Urbanik A., *Chrzan R. Jagiellonian University, 1st Dept. of General Surgery and Gastrointestinal, *Radiology, Krakow, Poland

Comparison of CT-guided automated needle biopsy with fine needle aspiration in the diagnosis of benign lung lesions Thanos L., Takis F., Mylona S., Karapataki K., Karas P., Batakis N. Korgialeneio-Benakelo Hellenic Red Cross Hospital, Radiology, Athens, Greece

Purpose : The study aims at evaluating the efficiency of mammotome breast biopsy (MBB) in differentiating non palpable lesions, <1cm in size, detected during screening mammography (SM) or ultrasound (US) examination. Materials and Methods : According to the different type of breast tissue and/or the type of pathology, either digital mammography (DM) or US-guided MBB were performed. Results : Group I included 148 women,with an age range of 4872 years who underwent DM-guided biopsy, and group II included 74 patients, with an age range of 39-58 years, who underwent US-guided biopsy. In group I, 18 cases of cancer (four invasive ductal carcinomas, three malignant intraductal papillomas, nine in situ ductal carcinomas, two in situ lobular carcinomas), 33 ductal hyperplasias, and six fibroadenomas were detected. The remaining lesions were benign. In group II, 11 breast cancers (four invasive ductal carcinomas, two medullary carcinomas, one malignant intraductal papilloma; four in situ ductal carcinomas), three lipomas, and ten cysts were detected. The remaining lesions were benign. Conclusion : These results confirm the high efficiency of MBB in assessing asymptomatic, non-palpable lesions detected by either SM or US.

Purpose : To compare the diagnostic yield of percutaneous core needle biopsy (CNB) with fine needle aspiration (FNA) in patiens with benign lung lesions. Materials and Methods : From December 1999 to January 2001, 36 patients who had undergone percutaneous CT-guided biopsy and presented benign lung lesions were retrospectively examined. In all the patients samples were obtained using both CNB, with an automated biopsy gun and an 18-G cutting needle, and FNA with a 20-G syringe. Results : The diagnosis of benignity was reached in four patients only with FNA (11.1%) while in 28 patients the same diagnosis was reached only with CNB (77.8%). In four patients, the diagnosis was reached by either method (11.1%). The main complications encountered were pneumothorax (n=3) and haemoptysis (n=2), yielding a total complication rate of 13.8%. Conclusion : CNB using an automated biopsy gun has a higher diagnostic accuracy in benign lung disease biopsies, as compared with the yield of FNA, although both methods seem to be mutually complementary. Complications should be considered, and proper patient observation should follow the procedure.

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Targeting peripheral pulmonary nodules by CT-guided percutaneous hookwire localization Poretti F., *Brunner E., Rosen T., Vorwerk D. Klinikum Ingolstadt, Diagnostic and Interventional Radiology, *Surgery, Ingolstadt, Germany

Correlation of patient position with complication rate post Fotheringham T., Haslam P.J., Logan P.M., Lee M.J. Beaumont Hospital, Radiology, Dublin, Ireland Purpose : The aim of the study was to determine whether placing the patient with the biopsy side down (i.e. decubitus), or biopsy site down (prone, supine or decubitus) influences the incidence of complications following fine needle lung biopsy. Materials and Methods : A prospective evaluation of all consecutive patients undergoing fine needle aspiration biopsy of a lung mass was performed. Patients were randomised to either decubitus or site down post procedure. The biopsy was carried out under CT guidance in 64 patients, fluoroscopy in 18 and US in 3 patients. Immediately following the biopsy all patients had a PA chest X-Ray, followed by a repeat Chest X-Ray at 4 hours post procedure. Results : There were 54 males, 31 females, with a mean age of 65 years. Randomisation resulted in 42 patients being treated in the decubitus position, 43 with site down. There were 6 and 14 immediate post procedure pneumothoraces respectively, none requiring tube thoracostomy. At 4 hours 1 patient in the site down group had developed a pneumothorax and 2 in the decubitus group. None requiring intervention. Conclusion : The position of the patient, either site down or decubitus post FNAB lung has no influence on complication rates.

Purpose : Video-assisted thoracoscopic surgery (VATS) is an alternative approach to small intra-pulmonary nodules, if transbronchial or percutaneous biopsy have failed. We investigated the feasibility of CT-guided hookwires to localize such nodules. Materials and Methods : Eighteen patients with intrapulmonary nodules underwent CT-guided hookwire localization by application of a X-Reidy -Set (Cook, Inc). The average age of the patients was 60 years (range: 19-75 years), the mean distance between the nodule and the pleura was 7.5 mm (range: 0-2.5 cm) and the mean diameter was 1.4 cm (range: 0.5-2.5 cm). After localization, the patients underwent a VATS resection of the lesion within a mean of 30 min (range 10-48 min). Results : In all cases, resection of the nodules was successful. In four patients, the marking was complicated by poor cooperability. But also in these cases, resection was successfully performed. Five patients developed an asymptomatic pneumothorax: three of them in a minor (rim of max. 2 cm), two of them in a moderate (rim of max. 3 cm) dimension. In three patients, local bleeding was found with hemoptysis in one. In no patient, dislocation of the hookwire system was found. Conclusion : CT-guided placement of a hookwire system is a simple and reasonable procedure which facilitates safe VATS resection of small pulmonary nodules.

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Feasibility of radiofrequency ablation (RFA) for the treatment of small lung carcinomas: description of the technique and the first two patients Rose S.C., *Harrell J.H., Levin D.L., Fotoohi M. University of California Medical Center, Radiology, *Internal Medicine, San Diego, CA, USA

Endovascular treatment of descending thoracic aortic aneurysms and dissections *Lonn L., *Delle M., Lepore V., Bugge M., Jeppsson A., Kjellman U., Radberg G., **Risberg B. Sahlgrenska University Hospital, *Radiology, Cardiothoracic Surgery, **Vascular Surgery, Gothenburg, Sweden

Purpose : Describe the technique used and observations in RFA of small lung carcinomas. Materials and Methods : Two patients with biopsy-proven lung metastases from the colon (3) or the esophagus (1) underwent RFA. Tumor sizes were 2.2 cm, 1.6 cm, 1.0 cm, and 6.6 cm, respectively. Both patients underwent general anesthesia. CTguidance was used to place Leveen RFA probes into the tumors. Intraprocedural duplex US-surveillance of the internal carotid artery was performed on the second patient. Both patients were admitted for observation and support. Chest radiographs were obtained initially, followed by chest CT at one, three, and six months. Follow-up was seven and four months, respectively. Results : Initially, both patients had mild dyspnea, but were discharged on the second post-procedure day. No pneumothoraces occurred. Both developed transient perilesional pulmonary infiltrates and moderate ipsilateral pleural effusions. Intraprocedurally, numerous air bubbles were noted in the carotid artery, but no neurologic sequelae occurred. All the lesions developed cavities. The three smaller lesions decreased in size with no evidence of residual tumor; the largest lesion has evidence of a small peripheral nodule. Conclusion : RFA can be performed for the treatment of small lung carcinomas and appears to be well tolerated by the patients.

Purpose : To evaluate our initial experience of endovascular stent grafting in patients with descending thoracic aortic aneurysms and type-B dissections. Materials and Methods : Over a 14-month period, 15 patients with atherosclerotic aneurysms (n=6), or aortitis (n=2) and aortic dissections (n=7) were treated. Two custom-designed endovascular stent graft systems were used, alone or in combination, based on preoperative CT or MRI. To allow a safe deployment, a preliminary subclavian-carotid artery transposition was performed in two patients. One patient with a 9-cm Lusoria aneurysm was treated by a combined open repair and stent graft placement. Mean follow-up is ten months. Results : Stent graft deployment was successful in all cases. There was no 30-day mortality and no conversions to open repair. Three patients had a perioperative stroke, one with sequelae (hemiplegia). No spinal cord injury was observed. One endoleak required insertion of two more endovascular stent grafts three weeks after the first operation. Two minor endoleaks were treated conservatively and could not be detected at follow-up. No migrations have been noticed. Conclusion : The endovascular approach to descending thoracic aortic pathology is feasible. The data indicate that a combination of different customised graft-systems can give safe and satisfactory initial results. Long-term follow-up is needed to determine the role of this therapeutic modality.

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Mid-term results after endovascular treatment of descending thoracic aortic aneurysms (DTAAs) with the Gore ExcluderTM aortic stentgraft Cartes-Zumelzu F.W., Lammer J., *Grabenweger M., Thurnher S. University Clinic, Dept. of Angiography and Interventional Radiology, *Dept. of Cardiothoracic Surgery, Vienna, Austria

Treatment of thoracic aorta pathologies with the Gore stent graft Bouchard L., Kos X., Chabbert V., Joffre F., Rousseau H. CHU Toulouse Hospital Rangueil, Radiology, for French Tag Trial, Toulouse, France Purpose : Stent grafting is emerging as a new treatment for several pathological conditions involving the thoracic aorta. We studied the feasibility and safety of a particular type (Gore) of thoracic stent-graft. Materials and Methods : Between February 1999 and January 2001, 30 patients (35 to 80 years old; mean 65 years; 28 men) underwent stent-grafting of the aortic isthmus or the descending aorta for the following pathologies: atherosclerotic aneurysms (n=10), traumatic rupture (n=8), dissection (n=6) or penetrating ulcers (n=6). Serial angio-CT were used for the patients followup. Results : Stent-grafting was technically successful (defined as complete exclusion of the pseudo-aneurysmal sac) in 83% of patients. One patient underwent surgical exclusion because of a persistent major endoleak. Minor endoleaks were encountered in eight (27%) patients. Two (7%) are still present at three- and sixmonth follow-up. Major complications occurred: death for an unrelated cause (chronic renal insufficiency) (n=1); death secondary to mediastinitis (n=1); persistent paraparesis (n=1). Conclusion : The Gore thoracic stent graft can be safely used for a variety of thoracic aorta pathologies.

Purpose : To investigate initial and mid-term results of the Gore Excluder self-expandable stentgraft in the endoluminal treatment of DTAAs as an effort to determine the safety and feasibility of this approach. Materials and Methods : Since April 1998 until January 2001, we have treated 34 patients with DTAA [25 men (74%) and nine women (26%)] with the Gore Excluder self-expandable stentgraft system. Patients’ age ranged from 32 to 84 years (median = 69.5). All the patients had one or more comorbidities. Pre-interventional maximum aneurysm diameter ranged from 4.8 to 7.8 cm (median = 6.3 cm). The length of the stentgrafts ranged from 100 to 200 mm and their diameters from 26 to 40 mm. Follow-up time ranged from one to 34 months. Results : A primary success with a proper stentgraft placement and exclusion of the aneurysm from the blood flow was achieved in all patients. No leaks were observed. One patient died; one case of paraplegia occurred. No signs of graft infection were recorded. Conclusion : Our mid-term results indicate that the endoluminal therapy of DTAAs with the Gore Excluder stentgraft is clinically safe being a less invasive procedure with potentially less perioperative morbidity and mortality in high-risk patients.

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Mid-term efficacy of stent-graft treatment of the descending thoracic aorta Pusich B., Duda S.H., *Raygrotzki S., Tepe G., Perreira P., *Aebert H., *Ziemer G., Claussen C.D. Eberhard-Karls-University, Diagnostic Radiology, *Cardiovascular and Thoracic Surgery, Tübingen, Germany

The treatment of thoracic aortic ulcers by stent-grafting Kos X., Bouchard L., Chabbert V., Chemla P., *Conil C., Joffre F., Rousseau H. University Hospital of Rangueil, Central Radiology, *Central Radiology-Anesthesiology, Toulouse, France Purpose : To evaluate retrospectively the efficacy of stent-graft devices placement in patients presenting thoracic aortic ulcers. Materials and Methods : From 1997 to 2000, 10 male patients aged from 62 to 79 (mean 71,5) were treated by stent-grafting for thoracic aortic ulcers. The type of stent was either Talent (N=7) or Gore (N=3) protheses. All lesions involved in the descending aorta. The indications were the potential risk of rupture (N=8), acute hemothorax (N=1) or hemoptysis (N=1). Clinical and radiological (angio-CT) follow-up varied from 4 to 32 months (mean 12,7). Results : The technical success was 100 %. No major complications were observed during the procedure. Complete spontaneous resolution of minor type I endoleaks were observed in 3 patients and 1 patient presented a persistent but progressively regressive type 1 endoleaks. Angio-CT permitted to evaluate the reduction of the ulcer. Conclusion : Thoracic aortic ulcers can be safely treated by endovascular stent-graft placement. However, systematic clinical and radiological follow-up is mandatory.

Purpose : To evaluate the effectiveness and safety of endovascular treatment of various descending thoracic aortic pathologies with covered stent-grafts as an alternative to open surgery. Materials and Methods : Among 16 patients (four type-B dissections, three contained ruptures, two aneurysms, two atherosclerotic blow-outs, one type A-dissection, one thrombosis, one patch-aneurysm, one thoraco-abdominal aneurysm) treated between November 1997 and November 2000, eight patients (six men, two women; mean age 62.5 years, range 38-80 years) received Talent™ stent-grafts and other eight patients (six men, two women; mean age 60.1 years, range 47-76 years) underwent Gore-TAG™ stent-graft implantation. Control CT scans were performed after the procedure and then at six-month intervals. Results : The deployment of the stent-grafts was technically successful in all cases. Sufficient vessel passage reconstruction was achieved in all but one patient who needed surgical treatment. One patient died two days after the procedure for reasons un related to the device. There was no occurrence of distal embolization, paralysis or infection. During follow-up, all patients remained free from recurrences of their disease. Conclusion : Endoluminal treatment of thoracic aortic pathologies with Talent™ and Gore-TAG™ stent-grafts seems to be a safe and feasible method with a long-term efficacy.

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Endovascular treatment of type B dissections and penetrating ulcers with commercially available stent-grafts Sailer J., Peloschek P.L., *Grabenwöger M., **Rand T., Thurnher S., **Lammer J. University Clinic of Radiodiagnostics, Dept. of Angiography and Interventional Radiology, *Dept. of Cardio-Thoracic Surgery, **Dept. of Angiograhpy and Interventional Surgery, Vienna, Austria

Treatment of thoracic Stanford type-B aortic dissections with stent-grafts: mid-term results Czermak B.V., Waldenberger P., Perkmann R., *Fraedrich G., Jaschke W., Mallouhi A. University Hospital of Insbruck, Radiology, *Vascular Surgery, Innsbruck, Austria Purpose : To evaluate the feasibility and safety of endovascular stent-graft placement for the treatment of type-B aortic dissections during mid-term follow-up. Materials and Methods : Since November 1997, ten patients underwent endoluminal repair of thoracic type-B aortic dissection. Efficacy of the procedure was assessed by means of clinical examination and CT at three, six and 12 months and yearly thereafter. Changes of true and false lumen morphology and real-time alterations in shape and structure of the stent-grafts were monitored. Mean follow-up time is 20 months (range three to 40 months). Results : In all but one patient thrombosis of the false lumen and substantial shrinkage of the false lumen along the stent-graft was monitored. Expansion of the true lumen was due to expansion of the stent-graft. In the false lumen distal to the stent-graft, blood flow remained intact. In one patient, persistent blood flow resulted in a subsequent increase of the false lumen. Migration of the stent-graft was observed in two patients. In one patient, endovascular repair was carried out. Conclusion : Mid-term results are encouraging. Long-distance overstenting of the dissected aorta seems to be important to avoid long-term complications. Long-term follow-up is mandatory before recommending this method for a wider use.

Purpose : To report our clinical experience with endovascular repair of type B dissections and penetrating ulcers using stentgrafts. Materials and Methods : We investigated the efficiency of stentgraft insertion (GORE Thoracic-Excluder-Endo-prosthesis) in seven patients with type B dissection and in four patients with penetrating ulcer. We evaluated the extent of dissection, the distance between entry tear and left subclavian artery, and the diameter of the true and false lumen. Results : Stent-graft deployment was successful in all cases. The length of type B dissections (n=7) was 22.31±24.59 cm, and 3.28±1.14 cm for the penetrating ulcers (n=4). The distance between the left subclavian artery and the entry tear was 5.24±3.74 cm (n=11). We observed one major complication, a retroperitoneal haematoma requiring surgical treatment. During follow-up, the diameter of the false lumen in type B dissections decreased from 2.34±0.58 cm to 1.0±0.36 cm (-58%), and the true lumen increased from 1.56±0.5SD cm to 3.5±0.84 cm (+124%). For penetrating ulcers, the false lumen diameter decreased from 1.08±0.67 cm to 0.37±0.32 cm (-65%) and the true lumen increased from 3.88±1.52 cm to 4.53±1.01 cm (+16%). In eight patients (72%), a total thrombosis of the false lumen was achieved. Conclusion : Stent-graft placement is considered a feasible alternative in the treatment of type B dissections or ulcer-like penetrations.

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Mid-term results of a multicenter study on endovascular treatment of aortic dissection Rousseau H.P., Beregi J.P., *Haulon S., Otal P. CHU Rangueil, Radiology *Surgery, for French Multicenter Trial, Toulouse, France

Roles of surgery or endoluminal management prior to stentgraft placement in the treatment of thoracic aortic diseases: expansion of indications Maynar M., Llorens R., Zerolo I., Diaz F., De Blas M., Ysasi A., Kabbani S., *Qian Z. Hospiten Ramala, S.C. Tenerife University, Endoluminal Department, Santa Cruz de Tenerife, Spain, *Louisiana State University Helath Sciences Center, Radiology, New Orleans, LA, USA

Purpose : We conducted a multicenter trial to evaluate endovascular procedures for aortic dissections. Materials and Methods : Data of 66 patients were collected from ten participating institutions. According to the Stanford classification, 34.8% presented a type A dissection, and 65.2% a type B dissection. In 46/66 patients, an endovascular procedure (stent placement, fenestration, or both), concerning the abdominal aorta or a primary aortic branch vessel, was performed for acute complications: bowel pain 41.3%, anuria associated with renal insufficiency 39.1%, lower limb ischemia 32.6%, and uncontrolled hypertension 30.4%. Two or more clinical symptoms were present in 34.8% of cases. In 20/66 patients, stent-graft placement in the descending thoracic aorta was performed for aneurysmal evolution of the false aortic lumen. Results : Medium follow up was 245 days, SD 267 (21-1059). A satisfactory technical result was obtained in 95.7% of patients treated for acute peripheral ischemia, and no clinical symptoms persisted in 63% of cases. Early mortality rate was 17.4%. Technical success was observed in 90% of stent-grafts. One patient presented a transient post-operative paraplegia after complementary surgical procedure. Early mortality rate was 10%. Conclusion : This multicenter study confirms the role of endovascular procedures in the treatment of aortic dissections complications.

Purpose : To determine whether or not pre-stent/grafting surgery or endovascular maneuver could expand the indications for stentgraft (SG) placement in the treatment of thoracic aortic aneurysms (TAA) and type B dissections (TAD-B). Materials and Methods : From August 1999 to January 2001, 13 patients (ages ranging from 22 to 78 years) with TAA (n=9) or TAD-B (n=4) have been treated by endovascular stent-grafting. Pre-grafting surgeries or endovascular procedures were performed in all of these cases because of no adequate proximal necks for SG anchoring, including transposition of the supra-aortic trunk (n=4), subclavian to carotid bypass (n=1), elephant trunk (n=1) and subclavian arterial occlusion (n=7). Endovascular grafting was performed following these procedures. Results : The technical and immediate clinical success rates were 100% with 23% of transient complications, such as declined S-T segment, slight migration, and TIA. Thirty-day mortality was 15%. Up to 29-month (mean: six-month) CT follow-up, all TAAs or TAD-Bs were successfully repaired by SGs, but one which showed a proximal leak. Conclusion : Treatment of thoracic aortic diseases with endoluminal grafting is a new and less invasive technique, but not always suitable to certain thoracic aortic disorders. Prestent/grafting surgery or endovascular maneuver could convert non-candidates to candidates for endoluminal SG placement.

171 Endovascular treatment of complicated aortic dissections involving the thoracic descending and the abdominal aorta: which technique for which lesion Willoteaux S., Lions C., *Haulon S., Gaxotte V., Cocheteux B., Beregi J.P. Hôpital Cardiologique, Dept. of Radiology, *Dept. of Vascular Surgery, Lille, France

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Purpose : To present several techniques of endovascular treatment in the management of complicated aortic dissections. Materials and Methods : Thirty-six patients were treated by endovascular techniques for acute or chronic complications of aortic dissection such as branch vessel malperfusion (renal, digestive or iliac arteries) or dilatation of the false lumen. Results : Eighteen patients were treated by fenestration to reduce the pressure gradient and then treat the dynamic malperfusion of the aortic branch vessels and limit the expansion of the false lumen. In nine cases, the fenestration was associated with an angioplasty with or without stenting of aortic branch vessels or iliac arteries. Seventeen stents in total were placed in the renal arteries of 12 patients; three stents were placed in the superior mesenteric arteries and two in the celiac trunks. Four patients were treated by covered stent implantation to induce thrombosis of the false lumen; in one case, the covered stent was placed for hemothorax due to the rupture of the false lumen. Conclusion : Several endovascular methods are available for the treatment of acute and chronic complications of aortic dissection; these techniques can be associated according to the mechanism of complications. Further studies with long-term follow-up need to be performed to evaluate the benefit of endovascular treatments.

Purpose : The aim of this study was to evaluate the thrombogenicity of different peripheral stent types in a standardized model. Materials and Methods : Different stents (total number: 77; each group with n = 7) were placed in a modified Chandler-Loop. The platelet count, and the TAT (thrombin-antithrombin-III complex) was assessed at 0 and after 2 hours. Results : After two hours, significant differences were seen. TAT (µg/l) ranged between 31±18 (control, no stent), 328±187 (Bard peripheral) and 5897±2203 Jomed SelfX without electropolishing (-ep). The ranking was: Bard peripheral < SMART < Palmaz Corinthian (+ep) < Jomed peripheral (+ep) < Palmaz Schatz < MegaLink < Bridge peripheral< Palmaz Corinthian (-ep) < Jomed periphal (-ep) < Jomed SelfX (+ep) < Jomed SelfX (-ep). Conclusion : This standardized study showed a wide range of platelet activation following stent implantation. Electropolishing (+ep) clearly reduced the thrombogenicity of the stents. Thrombogenicity is an important parameter of an endovascular prosthesis besides physical properties like hoop strength, total mass, and flexibility. This may influence the rate of acute thrombosis and restenosis.

Thrombogenicity of different endovascular stent types. An in vitro evaluation Tepe G., *Wendel H.P., Schmehl J., Wiskirchen J., Claussen C.D., Duda S.H. University of Tübingen, Diagnostic Radiology, *Vascular Surgery, Tübingen, Germany

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Stent placement in monorail-technique for the treatment of renal artery stenosis Müller-Hülsbeck S., Jahnke T., Hilbert C., Brossmann J., Grimm J., Heller M. University Hospital, Radiology, Kiel, Germany

Treatment of ostial renal artery stenosis with stent implantation: mid- and long-term follow-up Mallouhi A., Czermak B., Rieger M., Waldenberger P., Bodner G., *Seiler R., Jaschke W.R. Leopold Franzens University, Radiology, *Vascular Surgery, Innsbruck, Austria

Purpose : To determine the feasibility and safety of a monorailballoon-stent device for the treatment of renal artery stenosis. Materials and Methods : During a period of ten months, 31 patients (severe hypertension n=27, renal insufficiency n=18) with indications for renal artery stenting (calcified ostial lesion n=28, insufficient PTA n=2, dissection n=1) were enrolled into a prospective evaluation. After pre-dilatation, stents (RxHerculink™ 5mm=8, 6mm=22, 7mm=1) were unfolded and manometer-controlled with long-sheath technique (6 French) via femoral (n=26) or brachial approach (n=5). Parameters of hypertension and renal insufficiency were determined before and after the procedure up to 6 months. Restenosis rate was determined with color-duplex ultrasound. Results : Renal artery stent placement (mean diameter 5.8 mm, mean length 16 mm) was technically successful in all cases (100%). Trans-stenotic pressure decreased from 80 mmHg before to 1 mmHg after stent placement. Mean blood pressure (creatine) decreased from 179/95 mmHg to 147/80 mmHg (from 1.9 to 1.7 mg/dl). Two stent occlusions occurred 48 hours after implantation. Conclusion : Renal artery stent placement with the introduced monorail-system is technically superior. In combination with the long-sheath technique (6 French!) an adequate control of the stent deployment is guaranteed during the whole procedure.

Purpose : The purpose of this study was to evaluate the efficacy of renal artery stenting in patients with ostial atherosclerotic stenosis. Materials and Methods : Forty eight patients with 56 ostial renal artery stenoses (50-69% stenoses n=8, 70-99% stenoses n=48) underwent stenting of the renal artery after unsuccessful PTRA between April 1996 and March 2000. Forty patients received unilateral and eight patients bilateral stents. Follow-up (mean 24.5±11.4 months) was performed by means of DSA, duplex sonography or multi-slice CTA with blood pressure and serum creatinine measurements. Results : A primary technical success rate was achieved in all patients. Seven patients developed restenosis (n=8) of more than 50% and one occlusion. Restenosis was managed by re-PTRA (n=8) or aortorenal bypass (n=1). Life-table analysis revealed a cumulative primary patency rate of 65.16% at four years. Mean systolic blood pressure decreased from 181±30 to 152±26 (p<0.001). Mean diastolic blood pressure also improved from 97.6±14 to 85.1±12 (p<0.001). Mean serum creatinine in patients with compromised renal functions (>1.5 mg/dl) before stent placement decreased from 1.97±0.7 to 1.81±0.55 (p=0.364). Conclusion : Renal artery stenting for the treatment of atherosclerotic ostial stenoses showed a high initial technical success rate and a high primary patency rate as well as an improvement of blood pressure and stabilization of the renal function.

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Endovascular therapy of renal artery stenosis: first experience with the Palmaz-Corinthian stent Koenig C.W., Hahn U., Tepe G., 1)Erley C., 2)Schneider W., 3)Ritter W., 4)Beregi J.-P., 5)Goffette P., Pereira P., Duda S.H. University of Tübingen, Diagnostic Radiology, 1)Internal Medicine III, 2)Thoracic and Cardiovascular Surgery; 3)Hospital NurembergSouth, Diagnostic and Interventional Radiology, Nürnberg, Germany; 4)Hôpital Cardiologique, CHRU de Lille, Vascular Radiology, Lille, France; 5)Cliniques Universitaires Saint-Luc, Radiology, Bruxelles, Belgium

Renal stenting via the radial artery: initial experience Robertson I., Kessel D.O., Taylor E., Patel J. Leeds Teaching Hospitals NHS Trust, Radiology, Leeds, United Kingdom Purpose : To describe our initial technical experience of renal arterial intervention from the radial route. Materials and Methods : Twelve patients with hypertension, obesity, dyspnoea, anticoagulation, or a marked caudal angulation of the renal artery had renal intervention attempted from the left radial artery. The Allen’s test was performed: if ulnar and radial arteries were patent, a radial arterial access was obtained. Conventional catheters 100-120 cm in length were used to perform CO2 angiographies and the stenoses transversed with a 260-cm hydrophilic guidewire (Terumo). The wire was exchanged for a 260-cm x 0.018-inch wire and the lesion predilated using a 5/ 6-mm, 4-F balloon catheter. Small Saxx stents (Bard) were crimped onto the balloon and conventionally deployed. Results : In 12 patients the radial route was attempted. An inadequate ulnar artery perfusion precluded the radial puncture in two cases and the radial artery could not be negotiated in one. Stenting was successful in nine patients but complicated by stent migration on the balloon in two occasions; a second stent was required in both instances. There were no haematomas and the radial pulse remained in all but one patient. Conclusion : Transradial renal artery stenting is technically feasible with a low complication rate and may be a useful therapeutic approach in high-risk patients.

Purpose : To evaluate the technical performance of the PalmazCorinthian (PC) stent in the treatment of renal artery stenoses. Materials and Methods : Seventy six Palmaz-Corinthian (50 PC and 26 modified PC-IQ) stents were implanted in 61 patients (72 arteries). Indications were primary stenting of predominantly ostial lesions (n=53), selective stenting following complicated or unsuccessful angioplasty (n=12), recurrent stenosis (n=5) or acute aortic dissection (n=2). Mean severity of stenoses was 81.3%. Data on technical success, complications and delivery characteristics were retrieved from a prospective multicenter registry. Results : Stent delivery was successful in all patients; major complications were not reported. Stent placement was suboptimal in seven of 72 cases: four stents were located too distally in the renal artery, necessitating proximal overstenting in two cases. The distal part of the stenosis was incompletely covered and a segmental branch inappropriately overstented in one case each. One stent was dislodged from the balloon, but subsequently recaptured and replaced. Significant residual stenosis was not observed. Overall stent deliverability and trackability were rated positive, radioopacity was rated fair. Conclusion : The delivery characteristics of the Palmaz-Corinthian stent have significantly improved as compared with the Palmaz design, thus allowing the correct placement in renal artery stenoses with a low complication rate. S166

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Endovascular stent placement in the treatment of ostial atherosclerotic renal artery stenosis (OARAS) Brountzos E., Koutrouvelis H., Papaioannou G., Kelekis A., Stoupis C.S., Kelekis D.A. Eugenidio Hospital, University of Athens, Radiology, Athens, Greece

Endovascular treatment of chronic mesenteric ischemia: 11 patients Garcier J.M., Biard M., De Fraissinette B., Mofid R., Chahid T., Ravel A., Boyer L. CHU Gabriel Montpied, Radiology, Clermont Ferrand, France

Purpose : To evaluate safety, effectiveness, and clinical benefit of endovascular stent placement in patients with OARAS. Materials and Methods : Twenty six patients (35 arteries; mean age: 63.61±8.1years) with OARAS were treated with endovascular stent placement for poorly controlled hypertension and/or for ischemic nephropathy. Seventeen patients had unilateral lesions, while nine patients had bilateral lesions. Stents used included the Palmaz stent, the Wallstent, the Jostent, and the Hercu/link stents. Results : The immediate technical success rate was 100%. Complications occurred in five cases (acute stent thrombosis, early initiation of hemodialysis, extraperitoneal hematoma, acute renal failure and a small hematoma at puncture site). Follow-up, ranging from 0 to 30 months (mean: 9.84±9.08) was performed on 23 patients, and revealed five patients with restenosis (15.6%). A successful revascularization was performed in two of them. Primary and secondary patency rates were 84.3 and 90.6%, respectively. Hypertension was cured in 39.1% of cases, improved in 43.4%, unchanged in 8.6%, and worsened in 8.6%. In those patients with an impaired renal function, serum creatinine levels improved in 55.5%, unchanged in 22.2%, and worsened in 22.2%. Conclusion : Endovascular stent placement is a safe and effective method in the management and treatment of OARAS.

Purpose : To evaluate immediate and mid-term results of percutaneous transluminal angioplasty (PTA) and stent placement in stenotic mesenteric arteries in patients with chronic mesenteric ischemia. Materials and Methods : Eleven patients with chronic mesenteric ischemia were treated: one celiac trunk (CT) stenosis (stented) associated with an occluded superior mesenteric artery (SMA); three double PTA of the SMA and the CT; seven SMA stenoses (three stented). Eight patients had an atheromatous stenosis, two Takayashu’s arteritis with SMA stenoses, one had a post-radio-therapy stenosis of the SMA. Results : A technical success was obtained in all cases. One surgical brachial puncture site hematoma occurred. An immediate clinical success was obtained in all patients. Nine cases were symptom-free at the end of follow-up (1-83, mean: 33 months). In two patients, a recurrent pain was observed: one restenosis was successfully treated with repeated PTA after 36 months; a surgical bypass was performed to treat a severe restenosis six months after stenting of an atheromatous SMA stenosis. Conclusion : Percutaneous endovascular techniques to treat short and proximal SMA and CT occlusive lesions may be attempted prior to surgery in patients with chronic mesenteric ischemia. Stent implantation via brachial access optimizes the anatomic result of PTA.

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A randomized study comparing Jostents with Jografts in the treatment of ostial renal artery stenosis. Preliminary results Ivancev K., Lindh M., Uher P., *Sonesson B., *Malina M., *Lindblad B. Malmö University Hospital, Radiology, *Vascular Diseases, Malmö, Sweden

Chronic mesenteric ischemia: long-term outcome in 16 patients treated by angioplasty Cognet F., Ben Salem D., Dranssart M., Cercueil J.P., Krause D. CHU le Bocage, Radiology and Imaging, Dijon, France Purpose : To evaluate the efficacy, safety, and long-term results of percutaneous transluminal angio-plasty (PTA) of superior mesenteric (SMA) or celiac artery (CA) in case of chronic mesenteric ischemia (CMI). Materials and Methods : Between 1989 and 2000, 16 consecutive patients who presented signs of CMI underwent PTA of visceral arteries. Abdominal angina was present in 13 patients. Ischemic gastropathy was found in two cases and transit trouble was the main sign in one patient. A weight loss was recorded in 11 patients. Involvement of at least two arteries was found in 12 cases (75%). Results : The CA and the SMA were both successfully treated in one case. The SMA alone was revascularized in 11 cases. PTA was successfully performed on the CA alone in four cases. The use of an endoprosthesis proved necessary in six patients. As early outcome, a relief of symptoms was obtained in all patients. During the follow-up (25±10 months), a recurrence of angina due to a restenosis occurred in two cases. PTA could be performed again with a good clinical result. Conclusion : Due to its safety and good long-term results, PTA should be the first logical therapeutic step in case of CMI.

Purpose : To study the effect of stent versus stent-graft (SG) treatment of ostial renal artery stenosis. Materials and Methods : Eleven patients with significant ostial stenosis underwent stent or SG treatment of 13 main renal arteries. The lesions were randomized to stent or to SG following PTA failure. Selective angiography was performed at 6-month intervals for 18 months. Intimal hyper-plasia (IH) thickness was measured with electronic calipers. If the mean pressure gradient exceeded 5 mmHg, repeated PTA or SG placement was performed in the follow-up. Results : Four out of seven stented arteries displayed IH resulting in a significant mean pressure gradient, whereas in six arteries treated with SG only one artery showed a significant pressure gradient. Two of the stented arteries with intra-stent stenosis responded to repeated PTA, whereas the other two required SG placement with successful outcome. The intra-SG stenosis responded well to repeated PTA. No statistical significance was seen between the two groups with regard to IH thickness. However, there was a statistical significance between the IH thickness and recurrent pressure gradient requiring reintervention. Conclusion : Placement of stent-grafts seems to result in a lower frequency of hemodynamically significant IH than uncovered stents.

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US-guided thrombin injection therapy of arterial puncture site complications Tyrväinen E.K., Manninen H.I., Kaukanen E.T., *Räsänen H.T. Kuopio University Hospital, Dept. of Clinical Radiology, *Dept. of Radiology, Kuopio, Finland

Comparison of Embosphere and PVA embolization agents in a porcine renal model Levine A., 1)Worthington-Kirsch R., 2)Kim D., 3)Termin P. Medical Device Development Engineering, Newton; 1)Delaware Valley Imaging, Interventional Radiology, 2)University of Massachusetts – Worcestor, Intervenional Radiology, 3)Lincoln Associate, Pathology, USA

Purpose : To evaluate the utility of US-guided thrombin injection therapy of arterial puncture site complications in a retrospective study with consecutive patients. Materials and Methods : From April 1999 to December 2000, US-guided thrombin injection was used as a primary therapy in 58 femoral and two brachial artery puncture site pseudoaneurysms, and in a case of femoral arteriovenous fistula. The etiology was coronary angiography in 39 cases, PTCA or coronary stenting in 14, peripheral artery angiography or endovascular intervention in eight cases. Results : A mean of 1.3 injections (range 1 - 3) of thrombin with a mean total volume of 1.0 ml (range 0.1 - 5 ml) was used. An immediate complete thrombosis was achieved in 55 cases (90%). A subtotal thrombosis (a small neck remnant) was achieved in six pseudoaneurysms and the therapy was completed either with additional thrombin injection (n= 2) or compression (n= 4). Ongoing anticoagulant or antiplatelet therapy did not affect the primary success. Two femoral artery embolizations were encountered, resulting in a complication rate of 3.3%; both cases were successfully treated by intra-arterial thrombolysis. Conclusion : US-guided thrombin injection is a feasible and highly-effective primary treatment for arterial puncture site pseudoaneurysms associated with an acceptable complication rate.

Purpose : A novel, non-resorbing, hydrogel microsphere of calibrated size and shape has been intro-duced as a new embolic agent. This study compares the vessel size and the radiologic outcome of embolization with Embosphere and PVA in an animal model. Materials and Methods : Access to the renal arteries was obtained using a 5-F catheter through a femoral approach. One physician performed injections while a second physician (blinded to embolization agent) observed an angiographic monitor to determine when a similar flow stasis was achieved. Alternate kidneys were embolized with either PVA particles of 355-500 microns, or Embosphere particles of 500-700, 700-900 or 9001200 micron size ranges. The animals (four) were euthanized and the kidneys examined for the location of the embolizing particles. Results : Angiographically, proximal vessel (renal artery) stasis occurred rapidly during PVA infusion, whereas patchy parenchymal staining developed during Embosphere injection, progressively leading to vessel stasis. Pathologic examination revealed dense agglomerates of PVA and frequent vessel occlusions several times the particle diameter. The Embosphere particles lodged in vessels with a diameter comparable with the particle size. Conclusion : This spherical, embolic particle has shown to cause more distal and predictable embolization when compared with similar injections of PVA.

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Embolization of arterial pseudoaneurysms using autologous human thrombin Engelke C., *Quarmby J.W., Morgan R.A., Belli A.M. St. George’s Hospital, Radiology, *Vascular Surgery, London, United Kingdom

An in situ curing hydrogel used as a liquid embolic agent for the transcatheter therapy. A preliminary in vitro and in vivo experience Redd D. Emory University Hospital, Radiology, Atlanta, GA, USA

Purpose : To present our experience using autologous thrombin for the interventional therapy of iatrogenic and traumatic peripheral arterial pseudoaneurysms. Materials and Methods : Twelve consecutive patients (1581years, median age 66, five women) with 11 iatrogenic pseudoaneurysms of the common or superficial femoral artery (351 ml, mean 14.4 ml) and one post-traumatic intrasplenic pseudoaneurysm had 16 embolization procedures with injections of autologous thrombin into the aneurysmal sac. The thrombin was previously isolated using 30/50 ml of autologous patient blood under sterile conditions. Results : The handling of autologous thrombin was straightforward in all patients (thrombin activity 75-431 IU, mean 199 IU per injection). No clinical complications occurred. All pseudo-aneurysms were completely thrombosed. Follow-up ultrasound at four months did not reveal any recurrent perfusion of previously thrombosed pseudoaneurysms or an increase of size in any patient. In two patients, no aneurysm could be demonstrated at follow-up. In six patients, the aneurysmal size decreased by at least 50%. The splenic pseudoaneurysm remains thrombosed with decrease in size and the patient is symptom free. Conclusion : Injection of autologous thrombin is a technique that is safe and effective for embolization of procedure-related pseudoaneurysms. Early results suggest that human autologous thrombin can substitute commercial bovine or human thrombin preparations for this therapy.

Purpose : The aim of this study was to evaluate a two-component liquid hydrogel (BioCure, Inc. Atlanta, GA, USA) in a New Zealand white rabbit animal model. Serial angiography and light microscopy assessed the acute and sub-chronic performance of this agent at intervals of up to one month. Materials and Methods : A 3.8-F infusion catheter was introduced into the renal artery and a liquid polyvinyl alcohol hydrogel infused until stasis. Forty-five animals were divided into three groups: acute, 7-day and 30-day survival, with follow-up angiography performed prior to necropsy. Results : Angiographic occlusion of the kidney is durable and occurs within 2/4 seconds. Viscosity of the material was comparable to Omnipaque 350. No catheter occlusion occurred and the catheter tip did not adhere to the vessel. Histological analysis showed that the embolization was complete from the proximal renal artery through the distal arteriolar bed. Polymer was not identifiable at the capillary level. Conclusion : Preliminary animal experiments show that this hydrogel rapidly polymerizes within the flowing blood and it can be reliably delivered via a small-caliber infusion catheter. Renovascular occlusion is identifiable at the arteriolar level. Ongoing experiments are designed to evaluate the duration of the occlusion and to further characterize acute cellular response.

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Angiographic diagnosis and percutaneous management of renal arterial injury Sofocleous C.T., Hinrichs C., Gor D., Contractor D., Barone A., Bahramipour P. New Jersey Medical School UMDNJ-Newark, Radiology, Vascular and Interventional, Newark, NJ, USA

Peripheral vascular malformations: our experience Reyes R., Gorriz E., Pardo M.D., Pulido-Duque J.M, Gallardo L Hospital de Gran Canaria Dr. Negrin, Unidad de Radiologia Vascular Intervencionista, Las Palmas, Gran Canaria, Spain Purpose : To analyze the evolution of a group of patients presenting with vascular malformations (VM), treated with percutaneous embolization (PE) and/or surgical methods. Materials and Methods : From December 1992 to March 2000, 81 patients with VM presented at our deparment. All the patients were treated by PE, surgery or were followed-up clinically. Thirty three patients were men and 48 women, with a mean age of 26 years (1-79). Thirty-six patients were in a quiescent asymptomatic phase and did not require any kind of intervention. Forty-five patients underwent PE and in eight cases the embolization was associated to surgery. Twenty-two out of these 45 patients had hemodinamically active malformations and 23 had hemodinamically inactive malformations. The locations were: upper limb (n=14), lower limb (n=13), face (n=2), pelvis (n=1) and back (n=2). The number of PE sessions was 158 (mean 3.5). The embolic agents were ethanol, zeine or both. Results : All the patients except one presented a clinical improvement at mid-term follow-up. Three patients developed complications. Conclusion : PE is an effective and safe method to manage VMs. The complication rates are low. It is necessary to repeat the embolization until symptoms disappear.

Purpose : Evaluation of angiographic findings and embolotherapy in the management of renal artery trauma. Materials and Methods : We reviewed all cases of renal trauma that underwent arteriography and percutaneous embolization within a 5-year period. Radiologic information, procedural reports and medical records were reviewed to assess clinical presentation, angiographic findings and embolization results. Long-term clinical outcome was obtained by communication with the trauma physicians and chart review. Results : 127 patients were admitted to our trauma center with renal injury resulting from MVA, pedestrian struck, previous biopsy, gunshot and stab wounds as well as falls. In 16/39 patients who underwent angiography findings included extravasation, arteriovenous communication and pseudoaneurysm. All 16 patients (5 women and 11 men) were hemodynamically stable and managed by percutaneous embolotherapy. Selective and superselective embolization of the abnormal vessel was performed. Coils were used in eight, gelfoam in seven and particles in one patient. Combination of embolic materials was utilized in one case. Conclusion : Percutaneous arteriography and embolization is an effective method to diagnose and treat renal vascular injury, eliminating future hemorrhage and decreasing the need for surgery.

189 The usefulness of three-dimensional reconstructed image by rotational DSA for transcatheter arterial embolization Shimizu T., Kodama Y., Endo H., Miyamoto N., Miyasaka K. Hokkaido University School of Medicine, Radiology, Sapporo, Japan

187 Traumatic injury of the internal mammary artery: embolization versus conservative management Whigham C.J., Fisher R.G., Goodman C.J., Trinh C.C. Baylor College of Medicine, Radiology, Houston, TX, USA

Purpose : Three-dimensional reconstructed image by rotational DSA (3D-DSA) is a new modality which provides clear, detailed three-dimensional images of blood vessels in a very short period of time on the image workstation. The purpose of this study was to evaluate the usefulness of 3D-DSA for transcatheter arterial embolization (TAE). Materials and Methods : Data of rotational DSA were sent to an image workstation and then converted to a three-dimensional image (MIP, surface rendering, volume rendering and virtual endoscopy). From July 1999 to January 2001, twenty-eight arteries of 21 cases were examined by 3D-DSA and their diameters measured. The coils diameters were subsequently determined a little larger than the measured arterial diameters and then TAE was performed. Results : 1) 3D-DSA images were provided in 8 minutes in all cases. 2) The image quality was acceptable for the measurement of blood vessels. 3) Common hepatic arteries and its branches, replaced hepatic arteries and splenic arteries were examined and embolized. 4) Accurate and complete embolizations were performed in all cases. In one case, a coil was dislocated but it was removed immediately. 5) There were no complications. Conclusion : 3D-DSA is very useful for an accurate and safe TAE.

Purpose : To compare the outcomes, complications, and effectiveness of embolization versus conservative management in patients with injury to the internal mammary artery. Materials and Methods : Sixteen cases of angiographically proven internal mammary artery injury were identified by a retrospective review. Age range of patients was 17-58 (mean 28). Causes of vascular injury were equally divided (eight each) between penetrating and blunt trauma. Type of trauma, associated injury, plain film findings, treatment complications, and overall out-comes were assessed. Results : Angiographic findings included occlusion, active hemorrhage, or pseudoaneurysm of the internal mammary artery. Of the 16 patients, 11 underwent embolization; the remaining five patients were monitored for surgery. No patients died as a direct result of vascular injury; one patient died of renal failure unrelated to the chest trauma. One patient that was embolized had delayed bleeding and one patient under conservative management developed a delayed hemothorax. Conclusion : This small series demonstrates that embolotherapy offers an effective, efficient, and safe alternative to conservative surgical management of internal mammary artery injuries.

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MR-guided biopsies in the abdomen: initial experience Koenig C.W., Pereira P., Truebenbach J., Mueller-Schimpfle M., Claussen C.D., Duda S.H. University of Tübingen, Diagnostic Radiology, Tübingen, Germany

A new magnetic field navigation system for CT-guided biopsies and interventions. Results of 86 procedures in 70 patients Holzknecht N., Helmberger T., Schoepf U.J., *Ezekiel G., Reiser M. Klinikum Grosshadern LMU Munich, Institute for Clinical Radiology, Munich, Germany; *Ultraguide, Tirat Hacarmel, Israel

Purpose : To evaluate the safety and accuracy of MR-guided abdominal biopsies in an open low-field MR system. Materials and Methods : Twenty six MR-guided diagnostic biopsies in the abdomen, including 22 liver biopsies, were performed in 24 patients (Magnetom OPEN, 0.2 Tesla, Siemens, Germany). Needle guiding was assisted by fluoroscopic imaging in 14 cases. Results : The parenchymal needle path was preferably controlled with non-fluoroscopic T-w sequences. MR-fluoroscopy aided in needle adjustment and avoidance of adjacent organs. MR-guided biopsy provided histological specification of the lesion and was rated clinically effective in 19 cases. Results were clinically ineffective in four patients, requiring additional MR-guided biopsies in two cases. In three patients liver lesions were missed. One liver biopsy resulted in major hemorrhage requiring blood transfusion. Conclusion : MR-guided abdominal biopsies can be performed with acceptable safety and accuracy in an open low-field system.

Purpose : To evaluate the accuracy of a new electromagnetic navigation system for CT-guided interventions. Materials and Methods : CT-Guide 1010 (UltraGuide, Tirat Hacarmel, Israel) is an FDA-approved navigation tool for previously acquired image datasets comprising a transmitter unit and magnetic sensors. In 70 patients, 86 interventions (38 thermoablations and 25 diagnostic liver biopsies, 23 other abdominal biopsies) were performed using Plus4 or VolumeZoom CT (Siemens, Germany). Spiral datasets of the target area were acquired with localizing sensors fixed on the patients skin. Image data were transferred via frame grabbing. Another magnetic sensor was placed at the base of the interventional tool. The system allows for real-time navigation including respiratory gating in the acquired spiral dataset giving the guiding information overlaid in the specified CT-slice. Results : Two subcapsular liver hematomas and one pancreatic fistula occurred not related to use of the navigation system. The deviation between the needle tip specified by the target system and the true position (control scan or CT-fluoroscopy) was 2.0±2.1 mm. The mean procedure time was 14 min. Problems occurred only in less cooperative patients and in needle positions close to the patient table due to electromagnetic interactions. Conclusion : CT-guide is a safe and accurate system for CT-guided interventions.

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Multislice CT versus sequential CT in the guidance of biopsy procedures Kickuth R., Kirchner J., Laufer U., Liermann D. Marienhospital Herne/University of Bochum, Radiology and Nuclear Medicine, Herne, Germany

MR-guided liver biopsy using an open MR-system at 0.2 T Kettenbach J., *Kroencke T.J., **Schamp S., Berger J., Loewe C., Dirisamer A., Thurnher S. University Hospital of Vienna, Dept. of Radiology, **Wilhelminen Krankenhaus, Radiology, Vienna, Austria, *Universitätsklinikum Charité, Berlin, Germany

Purpose : To evaluate the benefit of multislice helical CT(MSCT-) guided biopsies in comparison with the results obtained by sequential CT-guided punctures. Materials and Methods : Sixty patients in total were biopsied because of thoracic and abdominal lesions (group A: 30 patients MSCT-guided puncture; group B: 30 patients - sequential CTguided puncture). Indications were checked by the leading physician of the CT unit, and the interventions were performed by two experienced operators. All the patients gave informed consent. The interventions were performed on the Somatom Plus 4 Volume Zoom and the Somatom Plus 4 Power (Siemens Medical Systems, Forchheim, Germany), respectively. Total procedure times, the applicated irradiation dosage, the number of punctures needed to hit the target and the histopathologic outcomes were compared. Results : There was no significant difference between the two study groups regarding the total procedure time, the applicated irradiation dosage and the needed number of punctures. MSCTguided biopsies showed a sensitivity of 90%, a specifity of 100%, a positive predictive value of 100% and a negative predictive value of 80%. Sequential CT-guided biopsies showed a sensitivity of 71%, a specifity of 100%, a positive predictive value of 100% and a negative predictive value of 60%. Conclusion : MSCT-guided biopsy procedures are superior to sequential CT-guided procedures because of their higher sensitivity.

Purpose : To evaluate the feasibility and efficacy of MR-guided biopsy using an open MR-scanner. Materials and Methods : One hundred and twenty one patients with suspected liver lesions underwent MR-guided biopsy using a 0.2-T MR system (Magnetom Open Viva, Siemens, Erlangen). (Fast) Spin-Echo or STIR sequences were acquired to localize the lesion. Hepatospecific contrast materials (Teslascan 33, Endorem 17, Magnevist 16) were applied in 65 patients. Rapid gradientecho images identified the position and orientation of the biopsy needle based on the associated susceptibility artifacts. Tissue samples were obtained by MR compatible biopsy systems (14/18 G). Results : No major complications were observed. In 65 (54%) patients, 24 primary liver tumors and 41 liver metastases were confirmed, in 14 (12%) patients 14 benign lesions were diagnosed. In 33 (27%) patients the biopsy sample yielded no tumor tissue. In nine patients (7%) the biopsy specimen was not conclusive, either due to an inefficient localization, or to a malfunction of the biopsy system or the MR scanner. Conclusion : MR-guided biopsy of liver lesions is technically feasible and safe. MR-guidance was particularly useful for the needle placement within lesions of the liver dome or to identify lesions not well depicted by other imaging modalities. Administration of hepatospecific contrast materials improved the tumor-to-liver contrast.

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Evaluation of the time and number of passes required for free-hand biopsy performed with a virtual real-time CTguidance system Bartal G., Karpf R., Ertan A., *Brem E., *Ezekiel G., **Gomori J.M. Hillel Yaffe Medical Center, Diagnostic Imaging and Interventional Radiology, Hadera, *Ultraguide Ltd., Tirat Hacarmel, **Hadassah, MRI Unit, Radiology Dept., Jerusalem, Israel

Early experience with «kyphoplasty» in interventional radiology Ahrar K., *Schomer D.F., Wallace M.J. M.D. Anderson Cancer Center, Vascular and Interventional Radiology, *Neuroradiology, Houston, TX, USA Purpose : «Kyphoplasty» refers to balloon-expansion of a compressed vertebral body with subsequent filling of the void with bone void filler. Our goal was to evaluate the safety and feasibility of «kyphoplasty» for the treatment of vertebral compression fractures. Materials and Methods : Over a two-month period, seven vertebral compression fractures (thoracic n=4, lumbar n=3) were treated in five patients. Six fractures were due to osteoporosis, one was due to multiple myeloma. All kyphoplasties were performed in an angiographic suite equipped with a biplane angiography unit. Two introducer cannulas (Kyphon Inc., Santa Clara, CA) were placed in each vertebral body. High-pressure balloons were introduced into the vertebral body. Balloons were inflated to expand the collapsed vertebrae and/or to create an empty space for the controlled injection of bone void filler. Up to 8 milliliters of Simplex P (Howmedica, Rutherford, NJ) were injected into each vertebral body. Results : All nine vertebral bodies were treated successfully with no complications. Immediate pain relief was achieved in all patients. Conclusion : Vertebral compression fractures can be safely treated with «kyphoplasty» in an interventional radiology suite. Biplane fluoroscopy facilitates the procedure. Long-term results and potential advantages over vertebroplasty need to be determined.

Purpose : To measure the time and number of needle passes required for free-hand biopsy performed with a virtual real-time guidance system (CT-Guide, Ultraguide Ltd, Israel). Materials and Methods : Ten radiologists participated to the study (eight completely inexperienced, two experienced). HelicalCT of a turkey phantom with five olive targets was performed. Localizing magnetic sensors were attached to the phantom surface and to the needle. Needle trajectory and targets were displayed in real-time. The number of needle passes and procedure times was evaluated in two sessions two months apart. Results : All the targets were successfully reached (within 2 mm). Experienced radiologists approached the target in the first pass in an average of 60 seconds during both sessions. Trainees approached the target in an average of 3.4 needle passes (total time of 210 seconds) in the first session, and two passes (total time of 130 seconds) in the second session. Conclusion : CT-guide facilitates rapid and accurate biopsy by both experienced and inexperienced interventionists. It is especially helpful for completely inexperienced physicians. It does not expose the interventional radiologist to ionizing radiations.

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Posterior pelvic ring fractures: CT-guided closed reduction and percutaneous screw fixation Staedele H.G., Jacob A.L., *Suhm N., *Regazzoni P., Steinbrich W., *Messmer P. University of Basle, Radiology, *Traumatology, Basle, Switzerland

Fluoroscopically verified real-time guidance of musculoskeletal interventions utilizing prior CT data Bartal G., Karpf R., Ertan A., 2)Gepstein R., 1)Karlin D., 3)Ezekiel G., 4)Gomori J.M. Hillel Yaffe Medical Center, Diagnostic Imaging and Interventional Radiology, 1)Orthopedics, Hadera, 2)Sapir Medical Center, KfarSaba, 3)UltraGuide Ltd., Tirat Hacarmel, 4)Haddasah Medical Center, MRI Unit – Radilogy Dept., Jerusalem, Israel

Purpose : To report clinical and radiological mid-term results of posterior pelvic ring fractures treated by CT-guided or CTnavigated closed reduction and percutaneous fixation (CRPF). Materials and Methods : An interdisciplinary team of radiologists and surgeons treated 99 patients with 116 posterior pelvic ring fractures (AO ASIF type C) with CRPF between October 1993 and December 2000. Sixty five patients with 77 pelvic ring fractures fixed with a total of 157 screws had a mean clinical and radiological follow-up of 27.1 months (5 to 74 months). Results : Thirty three patients out of 65 had no pain even after long mobilization. Twenty eight out of 65 patients had little pain according to a standardized questionnaire. Mean Harris Hip Score was 81.2 (41.7 to 100). Radiological follow-up showed a precise reconstruction of the pelvis in all the three planes in all patients. Mean dislocation was <1.5 mm latero-lateral, <1.3 mm craniocaudal and <1.1 mm dorsoventral. Persistent pain despite anatomical reposition, foraminal callus formation necessitating hemilaminectomy and superficial infection were observed in 1/65 patients, loosening or breakage in 3/157 screws, persistent pain leading to screw removal in 2/157. Conclusion : CT-guided and CT-navigated CRPF of the pelvis are minimally invasive and precise. Because of the low intraoperative trauma the number of early and mid-term complications is low. A high percentage of patients had no or little pain.

Purpose : Evaluation of free-hand CT-based guidance system for musculoskeletal interventions in the interventional radiology (IR) suite. Materials and Methods : CT-Guide (UltraGuide, Israel) utilizes real-time tracking of magnetic sensors. Low-dose helical-CT of the target area (120kV and 50mAs) was acquired with a localizing device attached to the skin. The patient was transferred to the IR suite, where magnetic sensors were connected to the localizing device and the invasive tool. The needle trajectory and its target were displayed in real-time on CT images throughout the interventions. Fluoroscopic spot images verified the needle position. We performed 39 facet blocks and ten discographies. Results : All targets were approached in the first pass. Seven of 50 (14%) deep targets required one or two minor real-time endpath corrections. Fluoroscopic verification averaged 2 seconds per pass. Conclusion : CT-Guide delivers accurate real-time multidirectional guidance for free-hand minimally invasive procedures with any C-arm fluoroscopy system. This tool facilitates rapid single-pass needle placement and significantly reduces intraprocedural physician and patient irradiation.

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MR-guided biopsy of musculoskeletal lesions Koenig C.W., Pereira P., Truebenbach J., Claussen C.D., Duda S.H. University of Tübingen, Diagnostic Radiology, Tübingen, Germany

Carbon dioxide-guided arterial interventions Robertson I., Kessel D.O., Barbour J., Denton L.J., Patel J. Leeds Teaching Hospitals NHS Trust, Radiology, Leeds, United Kingdom

Purpose : To evaluate feasibility and accuracy of MR-guided musculoskeletal biopsies in an open low-field system. Materials and Methods : Thirty MR-guided biopsies were obtained from 20 skeletal and ten soft tissue lesions in 31 patients using an open 0.2-T MR system equipped with interventional accessories. The results from aspiration (n=3), core biopsy (n=15) and transcortical trephine biopsy (n=12) were evaluated for accuracy and clinical efficacy. Results : Specimens were successfully obtained from 29 patients. Results were clinically effective in 23 patients, rated definitive in 16, nonconclusive in nine, and unspecific in two patients. A false diagnosis due to a sampling error occurred in two patients, and biopsy sampling was impossible in one case. The best diagnostic yield was achieved from non-transcortical biopsies of osteolytic or soft tissue masses. Results from transcortical biopsies were less specific due to the predominance of benign lesions. MR-fluoroscopy for needle guidance was applied in 13 patients. Complete needle placement inside the magnet could be performed in 16 patients Conclusion : MR-guided biopsy using an open low-field MR imager is feasible and clinically effective and will become a valuable tool in the management of musculoskeletal lesions.

Purpose : To report the use of carbon dioxide (CO2) angiography to perform arterial interventions. Materials and Methods : Patients with contraindication to conventional iodinated- underwent CO2-angiography. All the procedures were performed on a Siemens Multistar TOP angiography unit with a minimum opacification software. CO2 gas was hand-injected in volumes between 20 and 60 ml. Procedural outcomes, contrast dose and radiation dose were recorded. Results : Seventy two interventions were performed in 66 patients: peripheral angioplasty/stenting (19), renal angioplasty /stenting (17), aortic stent grafts (19), embolization (14) and TIPS (3). Iodinated contrast was used in only seven cases; the mean contrast dose in these cases was 15 mls. CO2 injection caused severe pain in a single patient and necessitated the use of conventional contrast. There were two significant complications due to the use of CO2; in both cases a stentgraft was placed too low due to the failure to correctly identify the renal arteries. Procedural times and x-ray doses were comparable with conventional angiography. Conclusion : CO2 angiography can be safely used to guide the majority of endovascular procedures. Procedure times and radiation doses are not significantly different. The volume of conventional contrast is significantly reduced.

199 The value of CT-guided bone biopsy in the diagnosis of vertebral osteomyelitis Karas P., Thanos L., Nikolaou Ch., Takis F., Batakis N. Korgialeneio-Benakeio Hellenic Red Cross Hospital, Radiology, Athens, Greece

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Purpose : To present our experience in the diagnosis of osteomyelitis of the vertebrae through CT-guided biopsy of the bone lesion. Materials and Methods : Vertebral bone biopsy was performed in 23 patients who had clinical indication and radiological findings of possible osteomyelitis. Eighteen-gauge needle automatic bone biopsy sets were used and specimens for both histologic and microbiologic investigation were obtained. A second biopsy was done in those cases in which an insufficient specimen was obtained. Results : In all the patients, the biopsy was done following the hospital’s protocol, and none of them presented complications during or after the procedure. In 16 patients (69.6%), a positive histological diagnosis was reached. In this group, nine had positive and seven had negative cultures. In the other seven patients (30.4%) both histological and microbiological studies were inconclusive in the first biopsy, while in the second biopsy all of them were histologically proven positive. Conclusion : Percutaneous vertebral biopsy is a safe and highly diagnostic method for the diagnosis of osteomyelitis. It generally provides enough specimen for histological and microbiological studies, and in cases where a diagnosis cannot be reached with a first trial, a second one will yield the diagnosis.

Purpose : To assess CO2-angiography in the investigation of critical limb ischaemia. Materials and Methods : Twenty one patients with contraindications to iodine contrast media and critical limb ischaemia (CLI) (Rutherford grade III/IV) underwent lower limb angiography. All angio-grams were performed on a Siemens Multistar TOP angiography table using hand-injections of CO2. Image post-processing was performed with a propriety minimum opacification software. Images were reviewed by the operator and, in those segments considered non-diagnostic, further runs were performed with iodine contrast. Results : In 20 of the 21 patients, the infrarenal aorta, iliac arteries and femoral vessels were adequately imaged using CO2 alone. The majority of patients (16 /21) required supplemental runs of tibial and pedal vessels. The mean contrast volume of iodinated contrast required for supplemental runs was 45 ml. Three patients experienced a severe discomfort during CO2 injection but in only one subject diagnostic images could not be obtained. Conclusion : In patients with CLI, CO2-angiography provides adequate images at the level of the popliteal artery. The majority of patients required supplemental runs of crural and pedal vessels. In high-risk patients, the volume of iodine contrast is significantly reduced and the risk of subsequent renal impairment minimized.

CO2-angiography for critical limb ischaemia Robertson I., Taylor E., Kessel D.O., Scott D.J.A Leeds Teaching Hospitals NHS Trust, Radiology, Leeds, United Kingdom

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CO2-angiography of pelvic arteries in predialytic patients with end-stage renal disease Drolsum A., Kirk A.H., *Andersson K.S., Kloew N.E. Ulleval Hospital, Cardiovascular Radiology, *Nephrology, Oslo, Norway

Gadobutrol solution (1M) for X-ray digital subtraction angiography. In vivo results in pigs Kalinowski M., Kress O., *Wels T., Alfke H., Klose K.J., **Wagner H.J. Philipps-University Hospital, Diagnostic Radiology, Marburg, Schering AG, Region Europa MBD-Diagnostics, Berlin, Germany,*University of Wisconsin, Diagnostic Radiology, Madison, WI, USA

Purpose : To study effects of CO2 on the renal function in pretransplant and predialytic patients during pelvic angiography. Materials and Methods : Twenty patients were included in the study, ten women and ten men, mean age 58 years (from 40 to 75 years). Creatinine was 488 mmol/l ± 166 (304-974). No side effects were noted during the angiography and after 24 hours. The angiography was performed with abdominal aortic injection of the CO2 in all, selective injection of CO2 and conventional contrast medium injection when it was necessary to obtain good images. Results : Thirteen patients had minor symptoms lasting few seconds during the CO2 injection from the abdomen and the legs. One patient had diarrhea the day after. The mean change in creatinine was +4.4% ± 7.6 (range –7.0, 22). In four patients the angiography was performed with aortic injections only, in 13 cases selective injections were performed, and in one 35 cc of nonionic contrast medium 150 mgI/ml was used. Conclusion : Good images can be obtained from pelvic CO2 angiography and can be performed safely in predialytic patients with minimal effects on the renal function.

Purpose : To evaluate diagnostic accuracy of 1M Gadobutrol as contrast agent for intraarterial digital subtraction angiography in comparison with iodinated contrast media (CM) and 0.5 M Gadolinium-DTPA. Materials and Methods : Bilateral femoral sheaths were placed in ten pigs. Flush aortograms and selective angio-grams were obtained. Digital subtracted angiograms were obtained during injection of non-diluted 1M Gadobutrol, 300 mg/ml iodinated CM or 0.5 M Gadolinium-DTPA. Injection parameters were similar for all three contrast agents. In paired arteries, two different contrast media were used at the same angiographic run. Diagnostic quality and accuracy of the angiograms were evaluated according to a predefined four-stage scale by two independent blinded investigators. Results : Good to excellent diagnostic angiographic images were obtained in all cases using iodinated contrast. Gadobutrol achieved diagnostic non-selective angiograms in 75%, Gd-DTPA only in 25%. Selective angiograms were diagnostic in 92% using Gadobutrol and 69% using GD-DTPA. Adverse reactions to any of the used contrast agents were not noted. Conclusion : Gadobutrol solution (1 M) allows digital subtraction angiography with diagnostic accuracy equivalent to iodinated contrast media if selective injections are performed. Flush aorto-grams are of inferior image quality to iodinated contrast material. Gadobutrol achieves significantly better image quality compared with 0.5 M Gadolinium.

203 Gadolinium-based contrast agents in angiography and interventional procedures Reyes R., Gorriz E., Pardo M.D., Gallardo L., Pulido-Duque J.M, Hospital de Gran Canaria Dr. Negrin, Unidad de Radiologia Vascular Intervencionista, Las Palmas, Gran Canaria, Spain

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Purpose : To evaluate gadolinium in diagnostic and interventional vascular procedures as radiologic contrast in patients with renal insuffiency Materials and Methods : From January through December 2000, 24 patients with serum creatinine levels greater than or equal to 1.5 mg/dL underwent invasive catheter-based procedures performed with gadolinium. The procedures were: renal angiography (n= 5), upper limbs phlebography (n=2), abdominal aortogram (n=3 ), lower extremity angiography (n=3), carotid angio-graphy (n=2), hemodialysis fistula angiogram (n=1), renal PTA (n=4), embolization of arterio-venous fistula in renal trasplant (n=1), and lower limbs percutaneous treatment (n=3). The maximum dose of gadolinium never exceeded 0.4 mmol per kilogram of body weight. In 12 patients, CO2 was also used. The serum creatinine levels were measured before the procedure and 48 and 72 hours after. Results : All gadolinium-enhanced angiographies were considered of satisfactory quality and allowed to perform the interventional procedures; there were no significant changes in serum creatinine levels. The mean serum creatinine level prior to the procedures was 3.24 mg/dL (1.50-7.45), 48 hours after the procedure it was 3.13 mg/dL (1.50-6.48) and at 72 hours it was 2.90 mg/dL (1.096.80). Conclusion : Gadolinium used as the sole contrast or in conjunction with CO2 may provide an alternative to iodinated contrast materials in patients with renal insufficiency.

Gadolinium-based contrast media for DSA in azotemia. The emperor may be undressed! Nyman U.N., *Emlstahl B.A., *Leander P.L. *Nilsson M.N., **Golman K.G., *Almén T.A. Malmö University Hospital, Radiology, Malmö, *University of Lund, Radilogy, Lund, **Nycomed Innovation, Sweden Purpose : To evaluate if gadolinium (Gd) contrast media (CM) really are less nephrotoxic than iodinated (I) agents in azotemia during DSA. Materials and Methods : The literature and our own measurements were analysed regarding equi-attenuating (EA) concentrations of Gd- and I-CM. Animal studies evaluating i.v. LD50 and nephrotoxicity were reviewed. Results : 1) CT: 0.5M Gd-CM were EA with 80-97 mgI/mL at 80 kV; 2) DSA: 0.5M Gd-CM were EA with 63, 73 and 75 mgI/mL at 72, 80, and 90 kV, respectively; 3) At 72 kV, 0.2-0.4 mmol/kg of Gd-CM (80 kg) would result in the same radiopacity as a 2/5-gram iodine dose! 4) At 72 kV, the EA iopromide LD50 dose in mice is 25, 8 and 6 times higher than that of gadopentetate, gadoterate and gadodiamide, respectively; 5) In some animal studies, equi-molar concentration of both diatrizoate and gadopentetate caused more albuminuria than iohexol and gadodiamide, which caused the same increase. All four CM caused a similar degree of increased excretion of renal enzymes; 6) In an ischemic rat model, gadopentetate caused a similar decrease in the renal function as diatrizoate. Conclusion : Isotonic I-CM may be less nephrotoxic than GdCM (all hyperosmolar) when equi-attenuating doses are used, especially during renal interventional procedures.

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Does an ischemic renal porcine model support the thesis that gadolinium contrast medium is less nephrotoxic than iodinated agents for DSA? Nyman U., Elmstahl B., Leander P., Golman K., Almén T. Malmö University Hospital, Radiology, Trelleborg, Malmö, Sweden

Safety and costs considerations for ambulating patients after three hours of bed rest following transfemoral angiography with 4-F catheters or sheaths Dowling K., Todd D., Dolen E., Quarfordt S., Stainken B., Sansivero G.E., Mitchell N., Siskin G. Albany Medical College, Interventional Radiology, Albany, NY, USA

Purpose : To compare the effects on the renal function of gadolinium (Gd) contrast medium (CM) with equimolar and equiattenuating (DSA at about 80 kV) doses of iodinated (I) CM following renal arteriography. Materials and Methods : Forty pigs were randomized to five groups, unilaterally nephrectomized, and 3 mL/kg of 0.5 M gadopentetate, 0.5M gadodiamide, 0.5M iohexol (190 mg I/mL), 70 mg I/mL iohexol (0.18M) and saline were injected (20 mL/min) into the right renal artery during a 10-minute balloon occlusion time. CM plasma concentration was measured repeatedly during 3 hours using X-ray fluorescence technique to calculate the renal clearance. The saline group received 3 mL 300 mg I/mL intravenously. Results : Median (range) renal clearance in the 0.5M gadopentetate, 0.5M gadodiamide, 0.5M iohexol (190 mg I/mL), 70 mg I/mL iohexol (0.18M) and saline group was 0.01 (-1.81.4), 6.3 (4.1-8.0), 12.9 (11.9-14.6), 14.1 (11.9-16.2) and 11.1 (8.6-13.1) ml/min/10 kg, respectively. Renal clearance of 0.5M gadopentetate and 0.5M gadodiamide was significantly less than 0.5M iohexol, 70 mg I/mL iohexol and saline. Conclusion : Based on these results, Gd-CM can not be recommended to replace equiattenuating (70 mg I/mL) doses of I-CM when the renal arteries are directly exposed to the CM.

Purpose : To evaluate our ongoing experience with early ambulation of patients following diagnostic arteriography using 4-F catheters or sheaths via the transfemoral route. Materials and Methods : We have previously randomized 110 patients to 3 or 6 hours ambulation post-diagnostic angiography. No significant groin complications were encountered. We now review our experience since this randomized study. Over the last 12 months, 250 patients were ambulating and then discharged after 3 hours of bed rest. Their records were reviewed for groin complications including pseudoaneurysms, large (>4cm) hematomas, and arterio-venous fistulas. Results : No significant groin complications were encountered. There was a saving of 250 manpower hours (three patients per nurse) by discharging these patients from our recovery room in half of the normal time. In addition, there was 27% of decrease in recovery room charges. Conclusion : Ambulation of patients 3 hours post-diagnostic transfemoral angiography with 4-F catheters or sheaths appears safe. A significant decrease of costs can be realized. In addition, a more efficient utilization of the limited recovery room space is possible.

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Bolus chase versus stepped digital subtraction angiography for lower limb assessment Uberoi R., Timmons G., Shakapur S. Queen Elizabeth Hospital, Gateshead, X-Ray, Newcastle-upon-Tyne, United Kingdom

A newly designed sheath for gastroduodenal interventions: an experimental study in a silicone gastric phantom and in dogs Seo T.-S., *Lee J.-H., Ko G.-Y., Sung K.-B., Lim J.-O., Song H.Y. AMC, University of Ulsan College of Medicine, Radiology, *Asan Medical Center, Biomedical Engineering, Seoul, Korea

Purpose : To compare two different methods of angiographic assessment of lower limb arteries. Materials and Methods : Patients were randomized to either ‘digital subtraction (SDSA)’ or ‘bolus chase’(BC) angiography. Demographic data, examination time, screening time, total radiation dose and contrast volume were recorded. Images were assessed for quality and diagnostic confidence. Results : One hundred and seventy six patients were assessed; 90 had BC and 86 SDSA. Mean age of the patients in the BC group was 67 (41-92) and in the SDSA group 66 (46-91). In the BC group there were 57 men and in the SDSA group 49 men. Average height and weight in the BC group were 167 cm and 71.3 kg and in the SDSA group 166 cm and 71.3 kg. In the BC group mean examination time, screening time, total radiation dose and contrast volume were 4.55 minutes (2-19), 0.36 minutes (0.12.4), 14,418.542 mGy/cm2 (3,620-50,676.6) and 117.2 ml (90200), respectively. For the SDSA group, they were 7.31 minutes (4-12), 0.82 minutes (0.4-2.1), 16,098.23 mGy/cm2 (8,16245,807.5) and 148.7 ml (100-220). Images in the SDSA group scored more in all areas. Conclusion : SDSA took 59% longer to perform, resulted in 11% higher radiation dose and used 26% more contrast. Image quality and diagnostic confidence is improved compared with BC.

Purpose : To evaluate the effectiveness of a newly designed sheath for gastroduodenal interventions. Materials and Methods : We made a regular sheath with a polytetrafluoroethylene tube (4 mm in diameter, 90 cm in length) having a bended tip (4 cm long, 100 degree angle). In a supported sheath, a 5-F catheter was attached to the regular sheath as a side lumen. To evaluate the supportability of sheaths, we measured the moving distance of the sheath’s tip in a silicone gastric phantom while pushing a guidewire or a catheter. In the supported sheath, an additional experiment was performed with a supporting wire in the side lumen. The results were evaluated by t-test. In 12 experiments in six mongrel dogs, we evaluated torques and supportability of the sheath in the stomach while pushing a wire or a catheter under fluoroscopic guidance. Results : The results of the t-test showed that the moving distances of tips for the regular type and the supported type without and with the supporting wire were, respectively, 8.40±0.51cm, 6.23±0.41cm and 4.47±0.32cm during pushing the guidewire (p<0.001), and 7.22±0.70cm, 5.61±0.31cm and 3.91±0.59cm during pushing the catheter (p<0.001). All types were smoothly rotated and were able to guide both the wires and the catheters to the pylorus in all dogs. Conclusion : The newly designed sheath seems to be effective for gastroduodenal intervention.

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