Urologic Radiology

Urol. Radiol. 2, 95-98 (1980)

Obstructive Hydronephrosis: Long-Term Follow-Up H o w a r d J. Mindell Department of Radiology, Medical Center Hospital of Vermont, and the University of Vermont College of Medicine, Burlington, Vermont, USA

Abstract. Two cases o f complete distal ureteral obstruction were studied radiologically 20 and 30 years after inadvertent ureteral ligation. These cases are presented as unique illustrations of expected radiologic/ultrasonic findings after this duration of obstruction.

Key words: H y d r o n e p h r o s i s - Ureteral ligation.

Placement of a surgical ligature around the distal ureter has been described as the " m o s t c o m m o n ureteral injury" [1], with such injuries estimated to occur in 1% of all m a j o r gynecologic operations [2], 10% of radical pelvic exenterations [2], and just under 1% of rectal operations [4]. A l m o s t invariably, such leH.J. Mindell, M.D., Department of Radiology, University of Vermont College of Medicine, Burlington, VT 05401, USA

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sions are detected, if not at the time of surgery, then in the first few weeks afterward, when s y m p t o m s o f flank pain and fever b e c o m e manifest [2]. Occasionally, however, such patients m a y show no signs or s y m p t o m s [5], and an u n k n o w n n u m b e r of silent ureteral injuries are thought to occur, " w h e r e the patient suffers hydronephrotic a t r o p h y o f the kidney without knowing i t " [6]. In a 9-year span at the Medical Center Hospital of V e r m o n t ( M C H V ) , 2 such cases of hydronephrosis, presenting respectively 30 and 20 years after unrecognized surgical ureteral ligation, have been encountered. A comprehensive literature review failed to reveal such similar long-term followup with r a d i o g r a p h i c / s o n o g r a p h i c evaluation, albeit that Newell [7] reported 6 such cases found at autopsy. These 2 M C H V cases are herein briefly reported as unique illustrations of radiographic/sonographic alterations that might occur after long-term complete ureteral obstruction.

Fig. 1. Case 1. KUB for outside urogram demonstrating a left upper quadrant calcific rim (arrows) that proved to lie in the renal wall

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H.J. Mindell: Obstructive Hydronephrosis Fig. 2. (left) Case 1. Selective left renal angiogram showing 1-2 mm renal parenchymal rim (open arrows), calcific rim (black arrow), and loss of arcuate arteries (interlobar vessels)

Fig. 3. (below, left) Case l. High-power photomicrograph. Compressed renal parenchyma with no visible glomeruli, much collagen tissue (top), large " t h y r o i d i z e d " dilated tubules (center), and peripelvic fat (bottom)

Case Reports Case 1. F.B., a 74-year-old female with a pertinent prior history of ovarian cyst removal 30 years previously, had an IVU at an outside hospital because of left flank mass which showed (Fig. 1) left renal calcification and a nonfunctioning kidney. With presumption of h y p e r n e p h r o m a at the M C H V , a selective left renal angiogram (Fig. 2) showed renal parenchyma of 1 ~ m m thickness. Predating ultrasound availability, exploratory surgery was performed. At operation, a ligature was found around the distal ureter which was dilated proximally to 3 cm with ureteral wall thickening to

0.1 cm. Pathologic examination revealed the left kidney consisting primarily of dilated pelvis with marked attenuation of parenchyma which focally contained calcifications. Microscopic examination (Fig. 3, high power) confirmed extreme cortical thinning wit'h dilated " t h y r o i d i z e d " tubules, chronic pyelonephritic atrophy, and excessive peripelvic fat.

Case 2. E.B., a 74-year-old female who had undergone abdominal perineal resection for colon carcinoma 20 years previously, had an outside IVU done during evaluation o f a cystocele which showed (Fig. 4) curvilinear left renal calcifications and a faint, rim-like

H.J. Mindell: Obstructive Hydronephrosis

Fig. 4. Case 2. Urogram with faint, rim-like nephrogram, left kidney (open arrows), and calcification (black arrow)

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Fig. 5. Case 2. Sagittal prone sonogram showing portion of dilated left renal pelvic (black arrow) to left, and to the right, distal ureter dilated to at least 5 cm (open arrows)

Fig. 6. (left) Case 2. Left antegrade pyelogram (black arrow to medial wall of hydronephrotic sac). Dilated ureter to 5 cm (larger open arrows). Site of ureteral ligature (smaller arrows)

nephrogram. An outside left retrograde urogram showed an obstruction just below the brim of the bony pelvis. At MCHV, grayscale sonography revealed hydronephrosis and a dilated ureter (Fig. 5) to a point corresponding to the obstruction on the retrograde study. Fine-needle antegrade pyelography illustrated a sharply defined convex distal obstruction in keeping with ligature obstruction (Fig. 6). Because of the patient's age, no further studies were felt necessary.

Discussion H o d s o n ' s [3] c l a s s i c p a p e r d e s c r i b e d t h e s e q u e n t i a l e v e n t s in h y d r o n e p h r o t i c a t r o p h y f r o m e a r l y c a l y c e a l enlargement through multilocular sac formation to eventual coalescence into a single sac surrounded by a uniform thin layer of parenchyma. The exact role o f " b a c k p r e s s u r e a t r o p h y " in g e n e r a t i n g s u c h h y d r o n e p h r o s i s , h o w e v e r , is o p e n to q u e s t i o n . G i l l e n w a t e r et al. [8] a n d Z i m s k i n d et al. [9], f o r e x a m p l e , h a v e s h o w n t h a t in c h r o n i c a l l y l i g a t e d d o g u r e t e r s u r e t e r a l p r e s s u r e s fall to n o r m a l o r n e a r n o r m a l as s o o n as 4 w e e k s a f t e r l i g a t i o n . T h e f o r m e r d e m o n strated that an elevated renal vascular resistance (post u l a t e d d u e t o a l t e r a t i o n s in r e n a l c a t e c h o l a m i n e m e t a b o l i s m ) c a u s e s r e n a l b l o o d f l o w t o fall t o 20 3 0 %

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o f normal. Witten et al. [10] feel that such obstructive parenchymal atrophy is due to ischemia from compression of interlobar and arcuate arteries as well as direct parenchymal pressure. The cases reported herein provide an in vivo illustration of end-stage hydronephrotic atrophy as predicted by H o d s o n [3], showing that at 20-30 years of total ureteral obstruction the ureter dilates to 35 cm while the kidney is replaced by a sac-like structure (case 1 - essentially all pelvis) with marked attenuation of renal parenchyma. Severe loss of arcuate and interlobar vessels, as described by Gerber [12], is seen in case 1 whereas case 2 shows sonographic and antegrade pyelographic features of endstage obstruction with an ultrasonically visible ureter per descriptions of Moscatello et al. [13]. Sherwood et al. [14] have described the safety and utility of antegrade pyelography in the obstructed kidney, noting that obstruction in a nonexcreting kidney is the "principal indication for this p r o c e d u r e . " It may be of interest to contrast the radiologic features presented here with a few of the other causes for hydroureterectasis. " G i a n t " hydronephrosis, as described by Tripathi et al. [15] and Oschsner et al. [16], is more often associated with proximal and congenital ureteral obstruction as in ureteropelvic junction stenosis. The grossly dilated "refluxing megaure t e r " [17], on the other hand, and primary obstructed megaureter as described by Pagano et al. [18], may well show ureterectasis more p r o n o u n c e d than in the cases reported herein. Both M C H V cases show parenchymal calcification visible radiographically, and hydronephrosis as well as neoplasm may present as a calcified renal mass. Witten et al. [10] have noted that "occasionall y " the obstructed hydronephrotic sac may calcify. Reeder and Felson [19] show hydronephrosis under the u n c o m m o n section of focal or annular renal calcification. Acknowledgments. E.A. Kupic, M.D., performed angiography in case 1. T. Leavitt, R.T., did ultrasound in case 2, and W. Shuman, M.D., did the percutaneous pyelogram in case 2.

References 1. Kochler FP, Uhle CA: Urinary tract injuries incidental to gynecological procedures. Obstet Gynecol 28- 867, 1966 2. Bright TC III, Peters, PC: Ureteral injuries secondary to operative procedures. Report of 24 cases. Urology 22-26, 1977 3. Hodson C J, Craven JO: The radiology of obstructive atrophy of the kidney. Clin Radiol •7:305 320, 1966 4. Graham JW, Goligher JC : The management of accidental injuries and deliberate resection of the ureter during excision of the rectum. Br J Surg 42:151, 1954 5. Herman G, Guerrier K, Persky L: Delayed ureteral deligation. J Urol 107:723, 1972 6. Conger K, Beecham CT, Horrax TM: Ureteral injury in pelvic surgery: current thought on incidence, pathogenesis, prophylaxis, and treatment. Obstet Gynecol 3: 343, 1954 7. Newell QU: Injuries to ureters during pelvic surgery. Ann Surg 109:981, 1939 8. Gillenwater JY, Vaughn D Jr, Shenosky SH II, Agusta VW, Middleton G, Panko WB: Experimental hydronephrosis: a summary of research in progress. Trans Am Assoc Genitourin Surg 64: 128, 1972 9. Zimskind PD, Davis DMD, Lewis PL, Decarstecker J, Berwind RT: Complete obstruction of the ureter; immediate and longterm effects of the renal pelvic pressure in dogs. Surg Forum •9:538, 1968 10. Witten DM, Myers AH, Utz DC: Emmett's Clinical Urography. Vol. 2. Philadelphia: W.B. Saunders, pp 957-967 11. Older RA, Libshitz HI, Kelvin FM: Postobstructive atrophy: often overlooked cause of unilateral small kidney. Urology 8:517-519, 1976 12. Gerber MD : Angiography in hydronephrosis. Urology 2:231 236, 1973 13. Moscatello VJ et al: Ultrasonic evaluation of the obstructed duplex kidney. A JR 129:113-120, 1977 14. Sherwood T, Doyle PT, Williams DI: Antegrade pyelography in adults and children. Proc R Soc Med 67:1210 1215, 1974 15. Tripathi VN, Flint LD: Silent giant hydronephrosis in adults. Lahey Clin Found Bull 18: 17-22, 1969 16. Oschsner MG, Fuselier HA, Brannan W, Simo JB: Congenital giant hydronephrosis in adults. Urology •0:422 425, 1977 17. Witten DM, Myers AH, Utz DC: Emmett's Clinical Urography. Philadelphia: W.B. Saunders, 1977, 1038 18. Pagano P, Passerini G: Primary obstructed megaureter. Br J Urol 49:469 475, 1977 19. Reeder MM, Felson BJ: Gamuts in Radiology, Audiovisual Radiology of Cincinnati, P.O. Box 8942, Cincinnati, Ohio, 1975, Gamut H-5