Hepatobiliary and pancreatic: Anomalous pancreatobiliary ductal junction

Abstract

A young man, aged 16 years, was referred for evaluation because of recurrent episodes of pancreatitis. At the age of 14 months, his liver function tests were found to be abnormal and he was treated by operative sphincteroplasty for stenosis of the lower bile duct. Since that time, he has had approximately two episodes of mild pancreatitis each year. Over the past 2 years, however, episodes of pancreatitis have increased in frequency and severity, and have often been accompanied by changes in liver function tests. At duodenal endoscopy, he had a satisfactory bile duct orifice and cholangiography revealed a bile duct at the upper limit of normal, air in the biliary system and an anomalous pancreatobiliary junction (Fig. 1). The main pancreatic duct and side-branches were near-normal. There was minor thickening of the gallbladder wall (3.8 mm) on an ultrasound study and exaggerated enhancement and thickening of the gallbladder wall on a computed tomography scan (Fig. 2). No gallbladder stones were seen. Because of relapsing pancreatitis, laparoscopic cholecystectomy was performed. Histological evaluation of the gallbladder revealed mild chronic cholecystitis and cholesterolosis. Anomalous pancreatobiliary ductal junction has been defined as a common channel of at least 15 mm. The disorder is associated with congenital anomalies of the biliary system (usually choledochal cysts) and with disorders such as relapsing pancreatitis, chronic pancreatitis, biliary strictures and gallbladder cancer. At least some patients with relapsing pancreatitis can be improved by endoscopic biliary sphincterotomy. However, in the patient described above, episodes of pancreatitis continued despite an adequate operative sphincteroplasty. As this patient had evidence of cholecystitis, a possible explanation for pancreatitis was biliary inflammation, perhaps accompanied by biliary debris. This appears to be caused by the excessive reflux of pancreatic juice into the biliary system. At least some of these patients are improved by cholecystectomy and, in addition, are protected from the longer-term risk of gallbladder cancer.