We wanted to know how many segmental portal branches were born from the primary branches of the hepatic portal vein in the porta hepatis, in order to determine the number of portal segments in human liver. We studied 286 human livers, age groups ranging from fetuses to octogenarians, both sexes and all races, using dissection, colored acrylic injection and reconstituted tomographic images. We found the porta hepatis channel formed by each and every portal segment; we found seven segmental terminal pedicles for seven portal segments, three planes of vertical and three planes of horizontal portal fissures. There are seven terminal portal pedicles that are formed in the porta hepatis from the right and left branches of the hepatic portal vein. The only variation was portal branch V emerging from the right branch in 79 % of cases or from the left branch in 21 %. The definition of hepatic portal segment is: Portion of parenchyma irrigated by terminal branches of the portal vein and the hepatic artery proper, isolated from the other segments by planes of portal fissures and forms the parenchymal channel of the porta hepatis where it receives its vascularization. We propose a new and simple portal segmentation based on the previous definition.
KEY WORDS: Seven segmental pedicles; Seven portal segments.