A Cadaveric study on Branching Patterns of the Right Intrahepatic Bile Ducts at the Hepatic Hilum

Objective: Comprehensive anatomical knowledge in branching patterns of intrahepatic bile ducts at the hepatic hilum is useful in liver resection and transplantation. This study was aimed on the anatomical relation of the right anterior and posterior segmental branches to the formation of the right hepatic duct and on the variants of their drainage. Methods: From the year 2022 to 2023, 25 fresh liver specimens were dissected. The extrahepatic bile duct was identified initially. Then the right hepatic duct identified followed by the right anterior and posterior segmental branches were delineated via liver parenchymal dissection. Results: In our study, 19/25 (76%) of liver specimens had the right posterior duct ran posterior to the right anterior duct and fused it from a left (medial) sided approach to form the right hepatic duct. An ectopic drainage of the right anterior segmental duct into the common hepatic duct was noted in 3/25 (12%). A variant of “triple confluence”, was encountered in 1/25 (4%). Drainage of the right posterior hepatic duct into the left hepatic duct before its confluence with the right anterior duct was presented in 1/25 (4%). The direct drainage of the right posterior duct into the common hepatic duct was present in 1/25 (4%). There was no ectopic drainage of the right anterior duct into the left hepatic ductal system, and an ectopic drainage of the right posterior duct into the cystic duct. Conclusion: Variations of the right hepatic duct confluence were less. However, two most common variations were the ectopic drainage of the right anterior duct into the common hepatic duct and the triple confluence.