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

Abstract

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.

Pancreaticobiliary maljunction and biliary cancer

“…Since the maximum diameter of the common bile duct correlates positively with age, standard values for the maximum diameter of the common bile duct in each age group appear appropriate for accurate evaluation of the presence of bile duct dilatation [20][21][22].…”

“…Cholecystectomy and resection of the extrahepatic bile duct (flow-diversion surgery) is an established standard for the surgical treatment of congenital biliary dilatation [3,22]. Internal drainage operations have been abandoned because of the high risk of postoperative carcinogenesis.…”

“…HCPBD appears to represent an intermediate clinical condition that is both morphologically and functionally difficult to differentiate clearly from PBM. We consider that HCPBD should currently be managed as a disease entity independent of PBM in terms of the appropriate therapeutic strategies [1,22].…”

Anomalous union of the pancreaticobiliary duct without choledochal cyst: is cholecystectomy alone sufficient?

“…Many studies have demonstrated that biliary tract cancers preferentially develop at sites where there is stasis of activated pancreatic enzymes. Thus, it is generally perceived that the likelihood of the development of both bile duct cancer and gallbladder cancer increases in AUPBD patients with choledochal cyst, whereas there is a significant predilection for gallbladder cancer to occur in AUPBD patient without choledochal cyst [8][9][10]. As a result, prophylactic flow-diversion surgery consisting of extrahepatic bile duct resection and bilioenteric anastomosis along with cholecystectomy is acknowledged as the treatment of choice for AUPBD patients with choledochal cyst [8].…”

Biliary carcinogenesis in pancreaticobiliary maljunction

“…As most biliary tract cancers that develop in patients with PBM without biliary dilatation are gallbladder cancers, only prophylactic cholecystectomy is performed in many institutions. However, in some institutions, because of a perceived risk of bile duct cancer, the extrahepatic bile duct is excised together with the gallbladder [1,4,26,35].…”