The Pitfalls of Left Trisectionectomy or Central Bisectionectomy for Biliary Cancer: Anatomical Classification Based on the Ventral Branches of Segment VI Portal Vein Relative to the Right Hepatic Vein.

In Ventral-P6a, the complete exposure of RHV was rare in left trisectionectomy or central bisectionectomy. Surgeons should preoperatively recognize the course of RPHA, the presence of inferior RHV, and the S6-S7angle. In Dorsal-P6a, the volume of posterior section, which tended to be overestimated using 2D images, was smaller than that in Ventral-P6a.