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Endoscopic retrograde cholangiopancreatography in the management of pancreatic pseudocysts
Endoscopic Retrograde Cholangiopancreatography in the Management of Pancreatic Pseudocysts
L. Card Laxson, PhD, Columbus, Ohio John J. Fromkes, MD, Columbus, Ohio Marc Cooperman, MD, Columbus, Ohio
Pancreatic pseudocysts are a serious and relatively common complication of pancreatitis. The incidence of pseudocyst formation varies from 2 to 60 percent depending on the patient population studied and the diagnostic tests utilized [I]. The development of abdominal ultrasonography and, more recently, computerized axial tomography has greatly facilitated the diagnosis of these lesions. With the use of these techniques, it is relatively uncommon to fail to detect a clinically significant pseudocyst. Furthermore, these imaging methods are sufficiently sensitive that serial examinations can be used to follow these lesions and, in some cases, document spontaneous resolution. Endoscopic retrograde cholangiopancreatography (ERCP) has achieved widespread use in the diagnosis and management of disease of the pancreas and biliary system; however, its use in patients with pancreatic pseudocysts is controversial. Despite the fact that pseudocysts may compress the bile duct, thus producing jaundice, and associated chronic pancreatitis can result in clinically significant stricture of the common bile duct, ERCP has not been routinely employed preoperatively in patients with pseudocysts. The reluctance stems in large part from early anecdotal reports of sepsis complicating ERCP [2]. The purpose of the present study was to assess both the efficacy and safety of ERCP in the management of pancreatic pseudocysts. Patients and Methods
Between 1979 and 1984, ERCP was performed in 25 patients with pancreatic pseudocysts. There were 17 men From the Departments of Medicine and Surgery, The Ohio State University Colleoe of Medicine. Columbus. Ohio. Requests for rep;ints should be addressed to Marc Cooperman. MD. Ohio State University College of Medicine, 410 West Tenth Avenue, Columbus, Ohio 43210. Presented at the 37th Annual Meeting of the Southwestern Surgical Congress, Las Vegas, Nevada, April 28-May 2, 1985.
Volume 150, December 1965
and 8 women who ranged in age from 11 to 74 years (mean 43.7 years). The cause of the pseudocyst was alcoholism in 14 patients (56 percent), hiliary disease in 9 patients (36 percent), and trauma in 2 patients (8 percent). The most common symptom was pain (19 patients, 86 percent) followed by anorexia (11 patients, 44 percent), emesis (9 patients, 36 percent), abdominal mass (3 patients, 12 percent), and fever (3 patients, 12 percent). Hyperamylasemia was present in 13 patients (52 percent). Other laboratory abnormalities included elevated alkaline phosphatase levels (12 patients, 48 percent), serum glutamic pyruvic transaminase levels (9 patients, 36 percent), serum glutamic oxalacetic transaminase levels (13 patients, 52 percent), and bilirubin levels (1 patient, 4 percent). As well as undergoing ERCP, all patients underwent either abdominal ultrasonography or abdominal computerized axial tomography, or both. A total of 19 patients had ultrasonography and 10 had computerized axial tomography. Of the 25 patients, 17 received antibiotics before ERCP was performed. Results
ERCP was successful in all patients with cannulation of both the pancreatic and biliary ductal systems. There were no septic complications, but one patient experienced exacerbation of his pancreatitis. ERCP demonstrated filling of the pseudocyst with contrast material in 17 patients (68 percent). In seven patients, there was either complete obstruction or severe distortion of the pancreatic duct. The pancreatic duct was found to be normal in one patient (4 percent) with a small 2 cm pseudocyst diagnosed by ultrasonography. Abnormalities of the biliary tract were demonstrated by ERCP in seven patients (28 percent). These included stricture of the common bile duct in four patients (16 percent), common bile duct dilatation in two patients (8 percent), and cystic duct obstruction in one patient (4 percent). Of the 19 patients who had abdominal ultrasonography, pseudocysts were demonstrated in 11, for an overall accuracy of 57 percent. Abdominal com-
683
Laxson et al
puterized axial tomography successfully diagnosed a pancreatic pseudocyst in all 10 patients in whom it was employed. The results of ERCP differed from the other two imaging methods in 10 patients. ERCP detected pseudocysts in six patients in whom ultrasonography failed to diagnose a pseudocyst and in whom an abdominal tomographic scan had not been obtained. In three patients the size of the pseudocyst was underestimated by either computerized axial tomography or ultrasonography. ERCP failed to detect a small pseudocyst in one patient. ERCP changed the surgical management of eight patients (32 percent). In four patients who were suspected of having biliary tract disease preoperatively, the need for an operative cholangiogram was eliminated. Of the four patients found to have a biliary stricture, in three it was clinically significant and required surgical treatment. Of these three patients, a biliary bypass procedure was performed in two and an operative cholangiogram documenting resolution after pseudocyst drainage was performed in the other. In one patient, a distal pancreatectomy rather than internal drainage was performed based on preoperative ERCP. In an additional six patients (24 percent), ERCP detected small pseudocysts that had been missed on ultrasonography. Although five of these six patients were successfully managed nonoperatively, ERCP was the only method that established the diagnosis. In another patient, ERCP demonstrated resolution of a small pseudocyst. ERCP was particularly useful in the 12 patients clinically suspected of having biliary tract disease. These patients either had no history of alcoholism or had serum alkaline phosphatase levels greater than twice the upper limit of normal. Biliary tract disease was demonstrated by ERCP in 6 of these 12 patients (50 percent). In contrast, of the 13 patients in whom the clinical suspicion of biliary tract disease was low, a biliary abnormality (common duct dilatation that did not require operative treatment) was only found in one (8 percent). Comments The use of ERCP in the diagnosis and management of pancreatic pseudocysts has been controversial in regard to associated complications and its value in surgical planning. The most serious complication that has arisen from ERCP is sepsis, which has been reported in about 1 percent of all patients [2]; however, the occurrence of septic complications may be as high as 15 percent in patients with pancreatic pseudocyst [3]. Sepsis did not develop in any of our 25 patients after ERCP. Performing ERCP 24 to 48 hours before surgery and prophylactic antibiotic coverage may reduce the risk of sepsis. A more common complication of ERCP is acute pancreatitis, which has a reported incidence of 0.7 to 7.4
684
percent [2]. The clinical picture of pancreatitis after ERCP developed in only one patient (4 percent) in our series. Our experience demonstrates that ERCP can safely be performed in patients with pancreatic pseudocysts. The use of ultrasonography and computerized axial tomography have greatly facilitated the diagnosis of pancreatic pseudocyst. In several series the sensitivity of ultrasonography has been 88 to 100 percent with a specificity of 92 percent [4]. The sensitivity of ultrasonography in our study was only 57 percent. More recent experience with ultrasonography in our institution has shown an improved accuracy in the diagnosis of a pseudocyst. For diagnosing a pancreatic pseudocyst, ultrasonography should usually be the first method utilized because of its accuracy, cost, and noninvasive nature [5]. If the results are not diagnostic, then computerized axial tomography or ERCP should be performed depending on the clinical course of the patient. Computerized axial tomography has been shown to be at least as sensitive and accurate as ultrasonography [4], and in our experience, its sensitivity was 100 percent. The use of ultrasonography and computerized axial tomography allows the diagnosis of a pancreatic pseudocyst to be made in most cases without the need for ERCP. In our series, six pseudocysts were detected which had been missed on ultrasonography. However, of these, five were less than 3 cm in diameter and did not require surgical drainage. Although ERCP did not alter the planned nonoperative management of these patients, it did establish the diagnosis of a pseudocyst. The most common finding by ERCP in the patient with a pancreatic pseudocyst is filling of the cyst cavity with contrast material. This is reported in 62 to 80 percent of patients [6,7]. In those patients in whom the pseudocyst is not filled, obstruction of the pancreatic duct is usually seen. Our findings are consistent with those reported in the literature; the pseudocyst was filled in 68 percent of the cases and ductal obstruction was observed in 28 percent. Despite the fact that the diagnosis can usually be established without it, ERCP provides additional information about the pancreatic and biliary ductal systems that cannot be obtained by computerized axial tomography or ultrasonography. The importance of recognizing biliary tract disease occurring in association with pancreatic pseudocysts that have formed as a complication of chronic pancreatitis should be emphasized. Common bile duct stricture occurs frequently in chronic pancreatitis and requires surgical decompression if the degree of obstruction is significant [8]. The earliest laboratory finding in patients with significant biliary tract obstruction is an elevation of the serum alkaline phosphatase level [9]. Compression of the common bile duct by the pseudocyst can also result in functional obstruction [&IO]. If this is the case, it is necessary
The American Journal of Surgery
Endoscopic Retrograde Cholangiopancreatography
relief of the obstruction with an operative cholangiogram after drainage of the pseudocyst [8]. In this study, common bile duct stricture was demonstrated by ERCP in four patients. In one patient (4 percent), internal drainage of a pseudocyst resulted in decompression of the common bile duct. In two patients, significant biliary strictures were identified that required surgical decompression. Both of these patients also had elevated serum alkaline phosphatase levels. In one patient, the stricture was not of clinical significance. In our experience, ERCP was most valuable in evaluating biliary tract disease in patients with a suggestive clinical history. Seven patients had biliary ductal system abnormalities demonstrated by ERCP. Five of these patients had no history of alcoholism and one patient had an elevation of serum alkaline phosphatase above twice the normal level. Only one patient with common bile duct dilatation who did not require operative treatment had a history of alcoholism and an alkaline phosphatase level within normal limits. Therefore, the patient population most likely to benefit from ERCP includes patients whose pancreatitis is not secondary to alcoholism and patients with elevated alkaline phosphatase levels which indicate possible biliary obstruction. ERCP is also a highly sensitive and specific test for diagnosing choledocholithiasis and cholelithiasis which may occur in conjunction with pancreatic pseudocyst. If preoperative ERCP does not indicate the presence of gallstones in patients suspected of biliary disease on clinical grounds, it is not necessary to perform an operative cholangiogram. Operative cholangiography in the presence of the inflammatory reaction in the hepatoduodenal ligament often found with pseudocysts can be technically difficult, time-consuming, and followed by complications. In four patients in this series, ERCP eliminated the need for an operative cholangiogram. ERCP demonstrates the exact relationship of a pancreatic pseudocyst to the pancreatic ductal system and to the adjoining viscera, thus allowing more exact operative planning. Knowledge of the location of the pseudocyst helps the surgeon to select the most appropriate form of internal drainage. Pseudocysts located in the head of the gland may be best treated by cystoduodenostomy, and those in the body are usually amenable to cystogastrostomy, the most widely used form of drainage. If the cyst is not adherent to the stomach or duodenum, Roux-Y cystojejunostomy will be necessary. If ERCP reveals that the pseudocyst is arising from the tail of the pancreas, as was the case in one patient in our series, then a distal pancreatectomy, a procedure associated with a very low recurrence rate, may be performed. Although there were no patients in this study with pancreatic ascites, the presence of pancreatic asci-
to demonstrate
Volume 150, December 1995
and Pancreatic Pseudocysts
tes is an absolute indication for ERCP in patients with pseudocysts. The exact site of damage to the pancreatic duct can be demonstrated in 50 to 80 percent of these patients, thus surgery can be tailored to the ductal abnormality [4]. This study demonstrates that ERCP is a safe and efficacious procedure that provides useful information for the medical and surgical management of pancreatic pseudocysts. It is most helpful in identifying underlying or coexistent biliary tract disease in those patients with a compatible clinical history or laboratory findings, and it is also useful in diagnosing small pseudocysts that have been missed by ultrasonography or computerized axial tomography. Although ultrasonography and computerized axial tomography remain the initial procedures for the diagnosis of suspected pseudocysts, ERCP can provide essential and otherwise unavailable information in selected patients. Summary The value of ERCP was studied in 25 patients with pancreatic pseudocysts. There were no episodes of sepsis; however, acute pancreatitis developed in one patient for an overall complication rate of 4 percent. Results of ERCP were positive in 24 of the 25 patients (96 percent), with filling of the pseudocyst in 17 and pancreatic ductal obstruction in 7. Biliary tract abnormalities were found in seven patients and included common bile duct strictures in four, bile duct dilatation in two, and cystic duct obstruction in one. ERCP also detected six pseudocysts not diagnosed by ultrasonography, five of which were small and resolved with nonoperative therapy. ERCP is a safe diagnostic procedure for patients with pancreatic pseudocysts and may provide important information about coexistent biliary tract disease not otherwise available. It is also sufficiently sensitive to detect small pseudocysts that otherwise would be missed. References 1. Lawson TL. Acute pancreatitis and its complications. Radio1 Clin North Am 1983;21:495-513. 2. Greenen JE. ERCP and the problem of sepsis. Gastrointest Endosc 1982;28:197-9. 3. Koch H, Classen M, Demling L. Endosteopische retrograde pancreatographie. Dtsch Med Wochenschr 1974;99: 700-10. 4. Kane MG, Krejs &I. Pancreatic pseudocyst. Adv Intern Med 1984;29:271-300. 5. Anderson BN, Hancke S, Damgaard SA, Schmidt A. The diagnosis of pancreatic cyst by endoscopic retrograde pancreatography and ultrasonic scanning. Ann Surg 1977; 185:286-g. 6. Rohrmann CA, Silvis SE, Vennes JA. Evaluation of the endoscopic pancreatogram. Radiology 1974;113:297-304. 7. Sugawa C, Walt AJ. Endoscopic retrograde pancreatography in the surgery of pancreatic pseudocysts. Surgery 1979; 86:639-47. 8. Warshaw AL, Rattner DW. Facts and fallacies of common bile duct obstruction by pancreatic pseudocysts. Ann Surg
665
Laxson et al
1981;192:33-7. 9. Schulte WG, LaPorta AJ, Condon RF, et al. Chronic pancreatitis: a cause of biliary stricture. Surgery 1977;82:303-9. 10. Gonzalez LL, Jaffe MS, Wiot JF, Altemeier WA. Pancreatic pseudocyst: a cause of obstructive jaundice. Am Surg 1985;181:582-7.
Discussion Jay P. Cannon (Oklahoma City, OK): This is an important study because a relatively large number of patients (25) with pancreatic pseudocysts were all evaluated preoperatively with ERCP. It is fortuitous that 36 percent of the patients had biliary tract disease as the cause of their pancreatitis and subsequent pseudocyst formation. This is a subset of patients who are at a high risk of anatomic abnormalities in either the biliary tract or the pancreatic ductal system, and this needs to be addressed at the first operation. Dr. Cooperman, you described three such patients who required biliary drainage or diversion. In our experience, reported by Dr. O’Malley [this issue, page 6801, ERCP was attempted in 11 of the 69 patients and was successful in 9. We didn’t find it as useful in planning the operative approach as you have, Dr. Cooperman. You report a success rate of almost 100 percent and a very low complication rate of 4 percent. This is a credit to the aggressive stance of you and your co-workers and proof of your skill with ERCP. Dr. David Duman, a gastroenterologist in the Oklahoma City Clinic, has a large series of patients with pseudocysts who have been studied by ERCP preoperatively with a comparably low complication rate. This study confirms, I think, that carefully performed ERCP is safe and helpful. ERCP should certainly be utilized in those cases in which the information obtained may be important for determining the type of management or altering surgical management. Dr. Cooperman, what do you think about the timing of ERCP in relation to surgery? Exactly how do you determine which patients should have ERCP preoperatively? Do you as the surgeon perform endoscopy and ERCP or does the gastroenterologist in your group? Charles K. Harmon (Tulsa, OK): I am aware of at least some anecdotal experience with endoscopic transgastric drainage of pancreatic pseudocysts using the neodymium YAG laser. Dr. Cooperman, do you have any experience with this method? What is your opinion of this method of management?
666
Jon S. Thompson (Omaha, NE): ERCP should be particularly useful in patients with biliary obstruction associated with pancreatic pseudocysts. One of the difficulties in managing these patients is attempting to determine whether or not decompression of the pseudocyst itself will relieve the biliary obstruction or whether, in fact, bypass is necessary. Does ERCP alone provide enough information to arrive at a decision or are additional maneuvers at the time of operation necessary to make the determination? Nicholas P. Lang (Little Rock, AR): Dr. Cooperman, it is unclear to me from the presentation how you decided which abnormalities were anatomic narrowings and which were functional strictures. Marc Cooperman (closing): First, in response to your questions, Dr. Cannon, I think that the timing of ERCP is critically important to avoid septic complications in these patients, and it should be planned within 24 to 48 hours of surgical drainage. I don’t think that every patient who presents with a pseudocyst needs to undergo ERCP. One of the things that our study has shown is that it is possible to identify the group of patients at highest risk for biliary tract disease. I would perform ERCP in the patient with a pancreatic pseudocyst who is not an alcoholic and has no clear cause of pancreatitis, and in the patient who has either elevated liver function values or a dilated common bile duct on ultrasound examination which is suggestive of biliary tract abnormalities. In our institution, endoscopic retrograde cholangiopancreatography is always performed by the gastroenterology staff. Dr. Harmon, endoscopic drainage has not been employed in our institution. I think that it sounds like a promising technique but one that would be suitable only for those patients with simple pseudocysts with no coexisting biliary tract abnormalities. Drs. Lang and Thompson, it is difficult to know preoperatively whether drainage of the pseudocyst alone is going to be sufficient to relieve a common duct stricture. If ERCP shows other evidence of chronic pancreatitis with dilatation and a chain-of-lakes appearance, one should suspect that simply draining the pseudocyst will not solve the problem of the biliary stricture, and biliary diversion should be planned. If there is any question, an operative cholangiogram should be obtained after drainage of the pseudocyst, and if there is persistent stricture, biliary diversion should be performed.
The American Journal of Surgery
L. Card Laxson, PhD, Columbus, Ohio John J. Fromkes, MD, Columbus, Ohio Marc Cooperman, MD, Columbus, Ohio
Pancreatic pseudocysts are a serious and relatively common complication of pancreatitis. The incidence of pseudocyst formation varies from 2 to 60 percent depending on the patient population studied and the diagnostic tests utilized [I]. The development of abdominal ultrasonography and, more recently, computerized axial tomography has greatly facilitated the diagnosis of these lesions. With the use of these techniques, it is relatively uncommon to fail to detect a clinically significant pseudocyst. Furthermore, these imaging methods are sufficiently sensitive that serial examinations can be used to follow these lesions and, in some cases, document spontaneous resolution. Endoscopic retrograde cholangiopancreatography (ERCP) has achieved widespread use in the diagnosis and management of disease of the pancreas and biliary system; however, its use in patients with pancreatic pseudocysts is controversial. Despite the fact that pseudocysts may compress the bile duct, thus producing jaundice, and associated chronic pancreatitis can result in clinically significant stricture of the common bile duct, ERCP has not been routinely employed preoperatively in patients with pseudocysts. The reluctance stems in large part from early anecdotal reports of sepsis complicating ERCP [2]. The purpose of the present study was to assess both the efficacy and safety of ERCP in the management of pancreatic pseudocysts. Patients and Methods
Between 1979 and 1984, ERCP was performed in 25 patients with pancreatic pseudocysts. There were 17 men From the Departments of Medicine and Surgery, The Ohio State University Colleoe of Medicine. Columbus. Ohio. Requests for rep;ints should be addressed to Marc Cooperman. MD. Ohio State University College of Medicine, 410 West Tenth Avenue, Columbus, Ohio 43210. Presented at the 37th Annual Meeting of the Southwestern Surgical Congress, Las Vegas, Nevada, April 28-May 2, 1985.
Volume 150, December 1965
and 8 women who ranged in age from 11 to 74 years (mean 43.7 years). The cause of the pseudocyst was alcoholism in 14 patients (56 percent), hiliary disease in 9 patients (36 percent), and trauma in 2 patients (8 percent). The most common symptom was pain (19 patients, 86 percent) followed by anorexia (11 patients, 44 percent), emesis (9 patients, 36 percent), abdominal mass (3 patients, 12 percent), and fever (3 patients, 12 percent). Hyperamylasemia was present in 13 patients (52 percent). Other laboratory abnormalities included elevated alkaline phosphatase levels (12 patients, 48 percent), serum glutamic pyruvic transaminase levels (9 patients, 36 percent), serum glutamic oxalacetic transaminase levels (13 patients, 52 percent), and bilirubin levels (1 patient, 4 percent). As well as undergoing ERCP, all patients underwent either abdominal ultrasonography or abdominal computerized axial tomography, or both. A total of 19 patients had ultrasonography and 10 had computerized axial tomography. Of the 25 patients, 17 received antibiotics before ERCP was performed. Results
ERCP was successful in all patients with cannulation of both the pancreatic and biliary ductal systems. There were no septic complications, but one patient experienced exacerbation of his pancreatitis. ERCP demonstrated filling of the pseudocyst with contrast material in 17 patients (68 percent). In seven patients, there was either complete obstruction or severe distortion of the pancreatic duct. The pancreatic duct was found to be normal in one patient (4 percent) with a small 2 cm pseudocyst diagnosed by ultrasonography. Abnormalities of the biliary tract were demonstrated by ERCP in seven patients (28 percent). These included stricture of the common bile duct in four patients (16 percent), common bile duct dilatation in two patients (8 percent), and cystic duct obstruction in one patient (4 percent). Of the 19 patients who had abdominal ultrasonography, pseudocysts were demonstrated in 11, for an overall accuracy of 57 percent. Abdominal com-
683
Laxson et al
puterized axial tomography successfully diagnosed a pancreatic pseudocyst in all 10 patients in whom it was employed. The results of ERCP differed from the other two imaging methods in 10 patients. ERCP detected pseudocysts in six patients in whom ultrasonography failed to diagnose a pseudocyst and in whom an abdominal tomographic scan had not been obtained. In three patients the size of the pseudocyst was underestimated by either computerized axial tomography or ultrasonography. ERCP failed to detect a small pseudocyst in one patient. ERCP changed the surgical management of eight patients (32 percent). In four patients who were suspected of having biliary tract disease preoperatively, the need for an operative cholangiogram was eliminated. Of the four patients found to have a biliary stricture, in three it was clinically significant and required surgical treatment. Of these three patients, a biliary bypass procedure was performed in two and an operative cholangiogram documenting resolution after pseudocyst drainage was performed in the other. In one patient, a distal pancreatectomy rather than internal drainage was performed based on preoperative ERCP. In an additional six patients (24 percent), ERCP detected small pseudocysts that had been missed on ultrasonography. Although five of these six patients were successfully managed nonoperatively, ERCP was the only method that established the diagnosis. In another patient, ERCP demonstrated resolution of a small pseudocyst. ERCP was particularly useful in the 12 patients clinically suspected of having biliary tract disease. These patients either had no history of alcoholism or had serum alkaline phosphatase levels greater than twice the upper limit of normal. Biliary tract disease was demonstrated by ERCP in 6 of these 12 patients (50 percent). In contrast, of the 13 patients in whom the clinical suspicion of biliary tract disease was low, a biliary abnormality (common duct dilatation that did not require operative treatment) was only found in one (8 percent). Comments The use of ERCP in the diagnosis and management of pancreatic pseudocysts has been controversial in regard to associated complications and its value in surgical planning. The most serious complication that has arisen from ERCP is sepsis, which has been reported in about 1 percent of all patients [2]; however, the occurrence of septic complications may be as high as 15 percent in patients with pancreatic pseudocyst [3]. Sepsis did not develop in any of our 25 patients after ERCP. Performing ERCP 24 to 48 hours before surgery and prophylactic antibiotic coverage may reduce the risk of sepsis. A more common complication of ERCP is acute pancreatitis, which has a reported incidence of 0.7 to 7.4
684
percent [2]. The clinical picture of pancreatitis after ERCP developed in only one patient (4 percent) in our series. Our experience demonstrates that ERCP can safely be performed in patients with pancreatic pseudocysts. The use of ultrasonography and computerized axial tomography have greatly facilitated the diagnosis of pancreatic pseudocyst. In several series the sensitivity of ultrasonography has been 88 to 100 percent with a specificity of 92 percent [4]. The sensitivity of ultrasonography in our study was only 57 percent. More recent experience with ultrasonography in our institution has shown an improved accuracy in the diagnosis of a pseudocyst. For diagnosing a pancreatic pseudocyst, ultrasonography should usually be the first method utilized because of its accuracy, cost, and noninvasive nature [5]. If the results are not diagnostic, then computerized axial tomography or ERCP should be performed depending on the clinical course of the patient. Computerized axial tomography has been shown to be at least as sensitive and accurate as ultrasonography [4], and in our experience, its sensitivity was 100 percent. The use of ultrasonography and computerized axial tomography allows the diagnosis of a pancreatic pseudocyst to be made in most cases without the need for ERCP. In our series, six pseudocysts were detected which had been missed on ultrasonography. However, of these, five were less than 3 cm in diameter and did not require surgical drainage. Although ERCP did not alter the planned nonoperative management of these patients, it did establish the diagnosis of a pseudocyst. The most common finding by ERCP in the patient with a pancreatic pseudocyst is filling of the cyst cavity with contrast material. This is reported in 62 to 80 percent of patients [6,7]. In those patients in whom the pseudocyst is not filled, obstruction of the pancreatic duct is usually seen. Our findings are consistent with those reported in the literature; the pseudocyst was filled in 68 percent of the cases and ductal obstruction was observed in 28 percent. Despite the fact that the diagnosis can usually be established without it, ERCP provides additional information about the pancreatic and biliary ductal systems that cannot be obtained by computerized axial tomography or ultrasonography. The importance of recognizing biliary tract disease occurring in association with pancreatic pseudocysts that have formed as a complication of chronic pancreatitis should be emphasized. Common bile duct stricture occurs frequently in chronic pancreatitis and requires surgical decompression if the degree of obstruction is significant [8]. The earliest laboratory finding in patients with significant biliary tract obstruction is an elevation of the serum alkaline phosphatase level [9]. Compression of the common bile duct by the pseudocyst can also result in functional obstruction [&IO]. If this is the case, it is necessary
The American Journal of Surgery
Endoscopic Retrograde Cholangiopancreatography
relief of the obstruction with an operative cholangiogram after drainage of the pseudocyst [8]. In this study, common bile duct stricture was demonstrated by ERCP in four patients. In one patient (4 percent), internal drainage of a pseudocyst resulted in decompression of the common bile duct. In two patients, significant biliary strictures were identified that required surgical decompression. Both of these patients also had elevated serum alkaline phosphatase levels. In one patient, the stricture was not of clinical significance. In our experience, ERCP was most valuable in evaluating biliary tract disease in patients with a suggestive clinical history. Seven patients had biliary ductal system abnormalities demonstrated by ERCP. Five of these patients had no history of alcoholism and one patient had an elevation of serum alkaline phosphatase above twice the normal level. Only one patient with common bile duct dilatation who did not require operative treatment had a history of alcoholism and an alkaline phosphatase level within normal limits. Therefore, the patient population most likely to benefit from ERCP includes patients whose pancreatitis is not secondary to alcoholism and patients with elevated alkaline phosphatase levels which indicate possible biliary obstruction. ERCP is also a highly sensitive and specific test for diagnosing choledocholithiasis and cholelithiasis which may occur in conjunction with pancreatic pseudocyst. If preoperative ERCP does not indicate the presence of gallstones in patients suspected of biliary disease on clinical grounds, it is not necessary to perform an operative cholangiogram. Operative cholangiography in the presence of the inflammatory reaction in the hepatoduodenal ligament often found with pseudocysts can be technically difficult, time-consuming, and followed by complications. In four patients in this series, ERCP eliminated the need for an operative cholangiogram. ERCP demonstrates the exact relationship of a pancreatic pseudocyst to the pancreatic ductal system and to the adjoining viscera, thus allowing more exact operative planning. Knowledge of the location of the pseudocyst helps the surgeon to select the most appropriate form of internal drainage. Pseudocysts located in the head of the gland may be best treated by cystoduodenostomy, and those in the body are usually amenable to cystogastrostomy, the most widely used form of drainage. If the cyst is not adherent to the stomach or duodenum, Roux-Y cystojejunostomy will be necessary. If ERCP reveals that the pseudocyst is arising from the tail of the pancreas, as was the case in one patient in our series, then a distal pancreatectomy, a procedure associated with a very low recurrence rate, may be performed. Although there were no patients in this study with pancreatic ascites, the presence of pancreatic asci-
to demonstrate
Volume 150, December 1995
and Pancreatic Pseudocysts
tes is an absolute indication for ERCP in patients with pseudocysts. The exact site of damage to the pancreatic duct can be demonstrated in 50 to 80 percent of these patients, thus surgery can be tailored to the ductal abnormality [4]. This study demonstrates that ERCP is a safe and efficacious procedure that provides useful information for the medical and surgical management of pancreatic pseudocysts. It is most helpful in identifying underlying or coexistent biliary tract disease in those patients with a compatible clinical history or laboratory findings, and it is also useful in diagnosing small pseudocysts that have been missed by ultrasonography or computerized axial tomography. Although ultrasonography and computerized axial tomography remain the initial procedures for the diagnosis of suspected pseudocysts, ERCP can provide essential and otherwise unavailable information in selected patients. Summary The value of ERCP was studied in 25 patients with pancreatic pseudocysts. There were no episodes of sepsis; however, acute pancreatitis developed in one patient for an overall complication rate of 4 percent. Results of ERCP were positive in 24 of the 25 patients (96 percent), with filling of the pseudocyst in 17 and pancreatic ductal obstruction in 7. Biliary tract abnormalities were found in seven patients and included common bile duct strictures in four, bile duct dilatation in two, and cystic duct obstruction in one. ERCP also detected six pseudocysts not diagnosed by ultrasonography, five of which were small and resolved with nonoperative therapy. ERCP is a safe diagnostic procedure for patients with pancreatic pseudocysts and may provide important information about coexistent biliary tract disease not otherwise available. It is also sufficiently sensitive to detect small pseudocysts that otherwise would be missed. References 1. Lawson TL. Acute pancreatitis and its complications. Radio1 Clin North Am 1983;21:495-513. 2. Greenen JE. ERCP and the problem of sepsis. Gastrointest Endosc 1982;28:197-9. 3. Koch H, Classen M, Demling L. Endosteopische retrograde pancreatographie. Dtsch Med Wochenschr 1974;99: 700-10. 4. Kane MG, Krejs &I. Pancreatic pseudocyst. Adv Intern Med 1984;29:271-300. 5. Anderson BN, Hancke S, Damgaard SA, Schmidt A. The diagnosis of pancreatic cyst by endoscopic retrograde pancreatography and ultrasonic scanning. Ann Surg 1977; 185:286-g. 6. Rohrmann CA, Silvis SE, Vennes JA. Evaluation of the endoscopic pancreatogram. Radiology 1974;113:297-304. 7. Sugawa C, Walt AJ. Endoscopic retrograde pancreatography in the surgery of pancreatic pseudocysts. Surgery 1979; 86:639-47. 8. Warshaw AL, Rattner DW. Facts and fallacies of common bile duct obstruction by pancreatic pseudocysts. Ann Surg
665
Laxson et al
1981;192:33-7. 9. Schulte WG, LaPorta AJ, Condon RF, et al. Chronic pancreatitis: a cause of biliary stricture. Surgery 1977;82:303-9. 10. Gonzalez LL, Jaffe MS, Wiot JF, Altemeier WA. Pancreatic pseudocyst: a cause of obstructive jaundice. Am Surg 1985;181:582-7.
Discussion Jay P. Cannon (Oklahoma City, OK): This is an important study because a relatively large number of patients (25) with pancreatic pseudocysts were all evaluated preoperatively with ERCP. It is fortuitous that 36 percent of the patients had biliary tract disease as the cause of their pancreatitis and subsequent pseudocyst formation. This is a subset of patients who are at a high risk of anatomic abnormalities in either the biliary tract or the pancreatic ductal system, and this needs to be addressed at the first operation. Dr. Cooperman, you described three such patients who required biliary drainage or diversion. In our experience, reported by Dr. O’Malley [this issue, page 6801, ERCP was attempted in 11 of the 69 patients and was successful in 9. We didn’t find it as useful in planning the operative approach as you have, Dr. Cooperman. You report a success rate of almost 100 percent and a very low complication rate of 4 percent. This is a credit to the aggressive stance of you and your co-workers and proof of your skill with ERCP. Dr. David Duman, a gastroenterologist in the Oklahoma City Clinic, has a large series of patients with pseudocysts who have been studied by ERCP preoperatively with a comparably low complication rate. This study confirms, I think, that carefully performed ERCP is safe and helpful. ERCP should certainly be utilized in those cases in which the information obtained may be important for determining the type of management or altering surgical management. Dr. Cooperman, what do you think about the timing of ERCP in relation to surgery? Exactly how do you determine which patients should have ERCP preoperatively? Do you as the surgeon perform endoscopy and ERCP or does the gastroenterologist in your group? Charles K. Harmon (Tulsa, OK): I am aware of at least some anecdotal experience with endoscopic transgastric drainage of pancreatic pseudocysts using the neodymium YAG laser. Dr. Cooperman, do you have any experience with this method? What is your opinion of this method of management?
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Jon S. Thompson (Omaha, NE): ERCP should be particularly useful in patients with biliary obstruction associated with pancreatic pseudocysts. One of the difficulties in managing these patients is attempting to determine whether or not decompression of the pseudocyst itself will relieve the biliary obstruction or whether, in fact, bypass is necessary. Does ERCP alone provide enough information to arrive at a decision or are additional maneuvers at the time of operation necessary to make the determination? Nicholas P. Lang (Little Rock, AR): Dr. Cooperman, it is unclear to me from the presentation how you decided which abnormalities were anatomic narrowings and which were functional strictures. Marc Cooperman (closing): First, in response to your questions, Dr. Cannon, I think that the timing of ERCP is critically important to avoid septic complications in these patients, and it should be planned within 24 to 48 hours of surgical drainage. I don’t think that every patient who presents with a pseudocyst needs to undergo ERCP. One of the things that our study has shown is that it is possible to identify the group of patients at highest risk for biliary tract disease. I would perform ERCP in the patient with a pancreatic pseudocyst who is not an alcoholic and has no clear cause of pancreatitis, and in the patient who has either elevated liver function values or a dilated common bile duct on ultrasound examination which is suggestive of biliary tract abnormalities. In our institution, endoscopic retrograde cholangiopancreatography is always performed by the gastroenterology staff. Dr. Harmon, endoscopic drainage has not been employed in our institution. I think that it sounds like a promising technique but one that would be suitable only for those patients with simple pseudocysts with no coexisting biliary tract abnormalities. Drs. Lang and Thompson, it is difficult to know preoperatively whether drainage of the pseudocyst alone is going to be sufficient to relieve a common duct stricture. If ERCP shows other evidence of chronic pancreatitis with dilatation and a chain-of-lakes appearance, one should suspect that simply draining the pseudocyst will not solve the problem of the biliary stricture, and biliary diversion should be planned. If there is any question, an operative cholangiogram should be obtained after drainage of the pseudocyst, and if there is persistent stricture, biliary diversion should be performed.
The American Journal of Surgery