Anatomy of the Intrahepatic Ramification of the Portal Vein in the Right Hemiliver

The ramification of the portal vein in the right hemiliver was studied by anatomic dissection in 36 formalin-fixed human livers. In 28/36 (77.8%) cases, the portal vein bifurcated into a right branch and a left branch and the right branch bifurcated into anterior and posterior segmental branches. The anterior segmental branch terminated in the anterosuperior subsegment (S(8)) in two types: bifurcated when it divided into anterior P(8) and posterior P(8 )branches towards the respective regions of S(8) (24/28 cases) and monopodal when it had a single pedicle (4/28 cases). The maximum anteroinferior subsegmental branch (P(5 )maximum) originated either from the anterior segmental branch (16/28 cases) or from the anterior P(8) branch (12/28 cases). The posterior segmental branch vascularized the posteroinferior (S(6)) and the posterosuperior (S(7)) subsegments, and was terminated in three types: fan-shaped (16/28), bifurcated (9/28) and tripodal (3/28). In 4/36 (11.1%) cases the portal vein bifurcated into a right branch and a left branch but the posterior segmental branch was not present. In 4/36 (11.1%) the right branch of the portal vein was not present. These anatomical variations are explained separately and finally all cases are considered as a whole.