Double common bile duct: A case report and a review of the Japanese literature

Background. A double common bile duct (DCBD) is a rare congenital anomaly. We report the case of a 60-year-old Japanese female, whose common bile duct divided into 2 channels and both channels Opened individually into the second portion of the duodenum. This is the fourth reported case of DCBD with a choledochal cyst and pancreaticobiliary malfunction (PBM). Methods. A review of the literature revealed that DCBD is more frequently diagnosed in Oriental people. We reviewed 4 7 cases of DCBD reported in the Japanese literature. Results. Among these, cholelithiasis was found in 27.7%, a choledochal cyst in 10.6%, PBM in 29.8%, and cancers in 25.5%. Cancer and PBM were the 2 most serious concomitant conditions. The incidence and type of complicating cancer and PBM varied according to the site of the opening of the accessory common bile duct (ACBD). Concomitant gastric cancer was frequently noted when the ACBD opened into the stomach, whereas cancer of the biliary system was common when the ACBD opened into the second portion of the duodenum Or the pancreatic duct. PBM was observed only in those patients in whom the ACBD opened into the second portion of the duodenum or the pancreatic duct. Therefore the treatment and prognosis of DCBD is influenced by the site of opening of the ACBD. Conclusions. In DCBD, the opening site of the ACBD was considered to have close implications for the type of concomitant cancer and concomitant PBM that would appear.