J Hepatobiliary Pancreat Surg (2001) 8:221–223

Laparoscopic necrosectomy for acute necrotizing pancreatitis Vicken N. Pamoukian and Michel Gagner Department of Minimally Invasive Surgery, Mount Sinai Medical Center, 19 East 98th Street, Suite 5A, New York, NY 10029, United States

Abstract Severe acute pancreatitis (SAP), a disease state that is often complicated by an intricate pathologic process, has remained difficult to manage and is associated with high morbidity and mortality rates. Approximately 80% of patients have a mild form of the disease, while the other 20% develop a severe life-threatening form of the disease. These patients are at great risk for infection, multisystem organ failure, and, possibly, death. Necrotizing or infected pancreatitis requires a multimodal approach and often offers an indication for surgical intervention. The retroperitoneum of the patient with necrotizing pancreatitis should be treated as an abscess cavity, and drainage and debridement of all necrotic tissue should be performed. Over the past several decades, great achievements have been made in the treatment of the patient that presents with acute pancreatitis. However, the morbidity and mortality have remained high, according to recent literature. The laparoscopic era brings new alternatives in the surgical management of pancreatic diseases. Advances in laparoscopic technology and instrumentation allow the utilization of minimally invasive techniques, and lessen the stress of surgery in the already compromised pancreatitic patient. Key words Laparoscopic · necrosectomy · pancreatitis

Introduction Advances in laparoscopic pancreatic surgery have stemmed from the increasing use of laparoscopy in staging pancreatic malignancies. Surgeons recognized that a thorough staging of pancreatic disease could be achieved laparoscopically with results similar to those achieved with an open technique. This entailed being able to perform a laparoscopic Kocher maneuver, exploration of the lesser sac, and biopsy of pancreatic tissue and lymph nodes. Learning these maneuvers en-

Offprint requests to: M. Gagner Received: July 4, 2000 / Accepted: December 28, 2000

abled the surgeon to perform more advanced and complex minimally invasive procedures on the pancreas. Laparoscopic surgery can be used in several pancreatic pathologies, ranging from benign processes, such as cysts, pancreatitis, pseudocysts, and abscesses, to the neoplastic pathologies. Over the past several years, we have performed laparoscopic pancreaticoduodenectomy for malignant pancreatic disease, as well as chronic pancreatitis. In addition, distal pancreatectomy and enucleation of tumors have also been performed by our team of surgeons. A side-to-side pancreaticojejunostomy procedure has also been performed by our surgical team.

Anatomy and exposure The pancreas is a soft pink gland that lies in the retroperitoneum. It measures 15 cm in length and extends from the duodenum to the splenic hilum. The uncinate process, which lies in front of the aorta, surrounds the mesenteric vessels. The upper border of the head of the pancreas is delineated by the first portion of the duodenum, and the third and fourth portions of the duodenum are located inferiorly and to the right of the mesenteric vessels. The portal vein, common bile duct (CBD), and the vena cava are all located posterior to the pancreas. A groove between the neck and the body of the pancreas cradles the gastroduodenal artery. The splenic vessels are found posterior to the pancreas and course all along its body to enter the hilum of the spleen. Laparoscopic approaches to the pancreas parallel the open techniques. The pancreas may be approached via the gastrocolic ligament or via the hepatogastric ligament. Another approach to the pancreas is through the transverse mesocolon. Care must be taken to avoid injury to the middle colic vessels and their tributaries when this route is taken.

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V.N. Pamoukian and M. Gagner: Laparoscopic necrosectomy for ANP

The retroperitoneal approach to the pancreas is almost solely used for maturing peripancreatic necrosis or infection. This approach allows for examination of the posterior pancreas and allows for drains to be left in place postoperatively.

Intraoperative evaluation of the pancreas Tactile evaluation of the pancreas during laparoscopic procedures is limited, although it has been shown that the differentiation of structures and morphology of tissues is still maintained through the instruments used during laparoscopy. However, adjunctive measures are necessary. We use intraoperative ultrasound routinely in all our patients. A transducer type 8555 (B and K Medical Systems, Marlborough, MA, USA) is commonly used. The transducer has an outside diameter of 9.8 mm and readily fits into a 10-mm trocar. The tip can be angulated for maximal surface contact. The transducer is capable of B-mode, M-mode, spectral Doppler, and color-flow monitoring. It has a frequency range of 5 to 7.5 MHz. Using the B-mode with a frequency of 7.5 MHz, masses may be delineated within the gland. The pancreatic duct is also well visualized using this frequency. We also use Doppler and color-flow monitoring to locate the splenic vessels, superior mesenteric vessels, and the portal vein. Pancreatic ductograms may also be performed laparoscopically, using a small gauge needle (22-gauge is commonly used). After identification of the duct, using the laparoscope, the needle is inserted into the duct through the anterior body of the pancreas, and dye is injected under fluoroscopy.

Necrotizing pancreatitis Necrotizing or infected pancreatitis is an indication for surgical intervention. The retroperitoneum of a pancreatitic patient can be a focus of infection. The infection can lead to a deleterious systemic effect on the patient. In some cases, even noninfected acute pancreatitis can still lead to a systemic inflammatory response syndrome (SIRS). Drainage of the retroperitoneum should be considered emergent in a patient who presents with clinical deterioration following acute pancreatitis. The approach we use depends largely on the time frame in which the patient presents. Early in the disease process, there is minimal fibrotic tissue, scarring, or thick inflammatory response, making the retroperitoneum easily accessible. We prefer to approach these patients intraperitoneally via the gastrocolic ligament. A preoperative

computed tomography (CT) scan delineates where the maximum amount of disease is located and dictates whether the retroperitoneum is to be approached via the right or via the left side. In addition, intraoperative ultrasound is very beneficial for evaluating the extent of pancreatic injury, for evaluating biliary, or pancreatic stones, and for verifying whether pseudocysts are present. Usually, retroperitoneal collections are found in the retrogastric, retrocolic, and perinephric areas. Three operative approaches have been used for pancreatic debridement: retrogastric-retrocolic debridement, retroperitoneal debridement, and laparoscopic transgastric pancreatic necrosectomy. Gentle debridement of pancreatic tissue is mandatory, and hydrodissection is very useful in this setting. All patients receive a nasogastric tube for decompression of the stomach and a Foley catheter for decompression of the bladder. The entire abdomen is prepped, from the nipples to mid-thigh. Retrogastric-retrocolic debridement This type of approach may be used in the early infected phase of the acute pancreatitis. The intraperitoneal approach is used, from the left or right side, depending on the site of maximal damage to the pancreas. A veress needle is used for the establishment of pneumoperitoneum, with CO2 gas at 15 mmHg. A 30° angled scope is inserted through the umbilicus and an exploratory laparoscopy is performed. Two paramedian trocars are inserted under direct visualization. The retroperitoneum is entered via the gastrocolic ligament, which allows for careful inspection and debridement of the entire body of the pancreas. Another approach is via mobilization of the right colon by the cutting of its lateral peritoneal attachments. Care is taken at this point not to injure the right ureter. Following mobilization of the right colon, a Kocher maneuver is performed, using a Babcock forceps from the epigastric port. In this manner, the pancreatic head can be assessed. If pus or infected fluid is encountered throughout any of these maneuvers, the suction-irrigation probe is used to aspirate and break the peripancreatic debris. The initial aspirate should be sent for histologic and microbiologic examination to identify any offending organisms present in the pus. Debridement is performed with a spoon forceps and the debris is placed in an endobag for retrieval. At the end of the procedure, large sump drains are left in place through the trocar sites. Two to four sump drains may be left in place for continuous lavage of the retroperitoneum in the postoperative period. The left side of the pancreas may also be drained by mobilization of the splenic flexure, following the same principles as those used on the right side. The lesser sac may also be entered via the gastrohepatic

V.N. Pamoukian and M. Gagner: Laparoscopic necrosectomy for ANP

ligament if necessary, with great care being taken to avoid injury to the left gastric artery. Retroperitoneal debridement Retroperitoneal debridement is also suggested as an approach in early necrotizing pancreatitis. This approach can be used if there is minimal fibrotic tissue or thick inflammatory response, and edema is minimal. The patient is placed in the lateral decubitus position and the retroperitoneum is entered from the right or left side, again, depending on where the maximal damage is. A 0° scope is placed through a trocar in the flank between the iliac crest and the twelfth rib posteriorly. The retroperitoneum is insufflated to 15 mmHg with CO2 gas. The right and left kidneys are used for landmarks to progress toward the head or tail of the pancreas. The procedure used for debridement and drainage is the same as that described previously. Laparoscopic transgastric pancreatic necrosectomy This approach is recommended in a patient who presents with late onset of infected pancreatic necrosis, pancreatic abscess, or infected pseudocysts. The abdomen is entered after the establishment of pneumoperitoneum. Intraoperative gastroscopy is performed to visualize the posterior wall for any bulging and for insufflation of the stomach throughout the procedure. The stomach is punctured with radially expanding trocars (Innerdyne, CA, USA). This type of trocar has a balloon at the tip, which anchors it during the intragastric portion of the procedure. Two to three additional trocars are placed, each of 5- to 7-mm, which can be closed at the end of the procedure with a single 2-0 suture. Debridement can be performed using 5-mm biopsy trocars, and the necrotic tissue can be left in the stomach once adequate tissue is taken for sampling. No drains are left in the gastrostomy after the procedure.

Postoperative considerations In our experience, we encountered necrotizing pancreatitis in the pancreatic head in 29% of patients, in the body and tail in 54%, and extending into the retroperitoneum along the psoas and retrocolic gutters in 27% of patients. The retrogastric and retrocolic approach were used for 50% of the operations, followed

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by the transgastric approach in 37%, and the retroperitoneoscopic approach in 13% of the operations. Our success rate after the first drainage was about 75% in eight patients.

Conclusion The morbidity and mortality rates of patients with acute necrotizing pancreatitis remain high. Those patients who undergo surgical intervention have a morbidity rate, manifested by endocrine and exocrine insufficiency, of 57%,9 and a mortality rate of about 15%.10 Patients with acute necrotizing pancreatitis consume enormous amounts of hospital resources (ten times more than any other intensive care unit admission). Any decrease in their hospital stay has a significant impact on cost. By using the laparoscopic approach in treating the patient with acute pancreatitis, the same goals can be reached as in open surgery, with similar outcome and greater benefit to the already compromised patient.

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