Recent advances and problems in the management of pancreaticobiliary maljunction: feedback from the guidelines committee.

Clinical practice guidelines on how to deal with pancreaticobiliary maljunction (PBM) were made in Japan in 2012, representing a world first. Using a narrow definition, congenital biliary dilatation involves only Todani type I (except type Ib) and type IV-A, both of which are accompanied by PBM in almost all cases. Prospective ultrasonographic study revealed that the maximum diameter of the common bile duct increased with age. Pathophysiological conditions due to pancreatobiliary reflux occur in patients with high confluence of the pancreaticobiliary ducts, a common channel ≥ 6 mm long and occlusion of communication during contraction of the sphincter of Oddi. Since PBM can be diagnosed by magnetic resonance cholangiopancreatography, multi-planar reconstruction multi-detector row computed tomography and endoscopic ultrasonography, the current diagnostic criteria should be revised to take these diagnostic imaging modalities into consideration. According to a nationwide survey, biliary cancer occurred in 21.6% of adult patients with PBM with biliary dilatation and 42.2% of patients with PBM without biliary dilatation. In biliary cancer associated with PBM without biliary dilatation, 88.1% were gallbladder cancer. Treatment for PBM with biliary dilatation is prophylactic flow-diversion surgery, but further investigations and surveillance studies are needed to clarify the appropriate surgical strategy for PBM without biliary dilatation.