Demonstration of the right-side boundary of the caudate lobe in a liver cast

There have been historical arguments about the boundary of the caudate lobe of the liver. Kumon M first advocated the definition of the caudate lobe based on the portal segmentation of the liver in 1985, and classified it into three parts, Spiegel lobe, paracaval portion and caudate process. Prof. Couinaud defined the dorsal liver as a union of segments I and IX in 1994, based on the spatial position to the major hepatic veins, hilar plate and inferior vena cava. In Couinaud's classification, right-side of the dorsal liver is supplied by the branches from the posterior and anterior sections. In the present study using a liver cast, we found a paracaval branch of the portal vein branching from the right portal vein on the dissecting plain along the Rex-Cantlie's line. We also found several branches from the posterior portal vein to the right-side of the paracaval portion, but they should be defined to belong to the posterior sections.