In addition, in nine patients, a total of 15 accessory portal sectors were present, each arising directly from the portal bifurcation or the right portal trunk. Further subdivision of the portal sectors showed marked individual variability, with no prevailing branching pattern. In 24 patients, portal branches crossed the plane of the right hepatic vein. No transverse scissura could be seen in the anterosuperior or posteroinferior sector. The right hemiliver could be divided into anterosuperior and posteroinferior sectors in all patients studied.
Many patients have accessory sectors.
Further subdivision into portal segments can be described only after the individual portal branching pattern has been studied. The right hepatic vein is an inaccurate indicator of the position of the right scissura. No clear transverse scissura can be seen in the right hemiliver.