Diagnosis and treatment of pancreaticobiliary maljunction in children.

Pancreaticobiliary maljunction (PBM), which may be called by synonymous terms such as "anomalous arrangement of the pancreaticobiliary duct" or "anomalous union of biliopancreatic ducts," is defined as an anatomical maljunction of the pancreatic duct and the biliary duct outside of the duodenal wall beyond the influence of the sphincter of Oddi. Pancreaticobiliary maljunction is classified into three groups according to the type of the pancreaticobiliary junction. Pancreaticobiliary maljunction is diagnosed mainly by endoscopic retrograde cholangiopancreatography; however, in pediatric patients, it may be diagnosed by intraoperative cholangiography, and more recently has been diagnosed by computed tomographic cholangiography or contrast-enhanced helical computed tomography. Children with PBM without choledochal cysts usually do not show any symptoms except for abdominal pain and hyperamylasemia. Pancreaticobiliary maljunction is considered to be a major risk factor for biliary tract malignancy. In patients with PBM, free reflux of pancreatic juice into the biliary tract might induce biliary tract damage and biliary carcinogenesis. Thus, total resection of the extrahepatic bile duct and hepaticojejunostomy are recommended in children diagnosed with PBM with choledochal cyst. Early diagnosis and early surgical treatment provide a good prognosis with few complications. In addition, successive follow-up is necessary for early detection of biliary tract malignancy, especially in patients demonstrating postoperative complications.