Pancreaticobiliary maljunction and congenital biliary dilatation

Abstract

Pancreaticobiliary maljunction is a congenital malformation in which the pancreatic and bile ducts join outside the duodenal wall, usually forming a long common channel. Because the action of the sphincter of Oddi does not regulate the function of the pancreaticobiliary junction in patients with pancreaticobiliary maljunction, two-way regurgitation occurs. Reflux of pancreatic juice into the biliary tract is associated with a high incidence of biliary cancer. Biliary carcinogenesis in patients with pancreaticobiliary maljunction is thought to follow the hyperplasia, dysplasia, then carcinoma sequence due to chronic inflammation caused by pancreatobiliary reflux. Pancreaticobiliary maljunction is diagnosed when an abnormally long common channel is evident on imaging studies. Congenital biliary dilatation involves both local dilatation of the extrahepatic bile duct, including the common bile duct, and pancreaticobiliary maljunction. Extrahepatic bile duct resection is the standard surgery for congenital biliary dilatation. However, complete excision of the intrapancreatic bile duct and removal of stenoses of the hepatic ducts are necessary to prevent serious complications after surgery.

Classification of pancreaticobiliary maljunction and its clinical features in adults

“…In PBM, however, because the common channel is so long that the sphincter cannot directly affect the pancreaticobiliary junction, resulting in reciprocal reflux of pancreatic juice and bile (pancreatobiliary and biliopancreatic reflux), causing a variety of pathological states affecting the pancreas and the biliary tract. There are two types of PBM, with biliary dilatation (congenital biliary dilatation) and without biliary dilatation .…”

Intraductal cholangioscopy for the diagnosis of pancreaticobiliary maljunction

“…4; ▶ Video 1). PBM is a congenital anomaly in which the pancreatic and bile ducts are joined outside the duodenal wall, usually forming a long common channel [1]. There are two modes of junction: type I (pancreaticobiliary type) and type II (biliary-pancreatic type) [2].…”

Pancreaticobiliary Maljunction: Markedly High Risk for Biliary Cancer

“…As a result of these changes in the mucosal epithelia, in association with DNA mutations, cancer development and progression are ultimately promoted. The predominant mechanism responsible for the development of biliary tract cancer in patients with PBM appears to be the hyperplasia-dysplasia-carcinoma sequence, which is thought to differ from the predominant mechanisms seen in patients without PBM, which are the adenoma-carcinoma sequence and the de-novo carcinogenesis [4,[6][7][8].…”

“…Since hepatic duct transection can result in intrahepatic calculus formation, recurrent cholangitis, and cholangiocarcinoma, one must perform extended bile duct resection, including the resection of strictures of the hepatic or intrahepatic bile ducts. Dissection of the pancreatic portion of the common bile duct at the level immediately above the pancreaticobiliary junction is needed because postoperative carcinogenesis, pancreatitis, and pancreatic stones occur with a remnant bile duct [4,7].…”

“…However, some surgeons suggest that the extrahepatic bile duct should be removed together with the gallbladder in PBM patients without biliary dil- atation because such patients have a higher risk of bile duct cancer than the general population, and they also reported to have K-ras and/or p53 gene mutations in the bile duct [9]. This is a particularly important tissue in children with PBM, since pancreatic secretions continue to come into contact with the bile during their long lifespan [4,7].…”