Relationship between right portal and biliary systems based on reclassification of the liver

Background Although the anatomy of the right portal and biliary systems and their interrelationships must be understood to safely and satisfactorily perform left-sided resection of hilar cholangiocarcinoma or right-lobe living donor liver transplantation, the anatomies of the right portal and biliary systems are extremely difficult to understand. Methods A total of 60 patients with normal liver underwent computed tomography during both portography and cholangiography to evaluate relationships between the right biliary and portal systems based on reclassification of the liver to divide the right liver into 3 segments. Results All ventral and posterior ducts constantly join medially to the anterior portal trunk. In contrast, some dorsal ducts join the ventral duct medially and others join the posterior duct lateral to the anterior trunk. Conclusions Reclassification of the liver to divide the right liver into 3 segments facilitates an understanding of relationships between the right portal and biliary systems.