Branching patterns of the main portal vein: effect on estimated remnant liver volume in preoperative evaluation of donors for liver transplantation.

OBJECTIVES

To compare estimated remnant liver volume (ERLV) ratios among the major main portal vein (MPV) variants.

METHODS

Eighty-five potential donors underwent multidetector CT examination. Arterial, portal and hepatic venous phase images were obtained. CT volumetric measurements were performed by using summation-of-area method. MPV variants were classified into three groups. In type 1 (group 1), the MPV branches into the right portal vein (RPV) and the left portal vein (LPV). In type 2 (group 2), the MPV trifurcates into the right anterior portal vein (RAPV), right posterior portal vein (RPPV) and LPV. In type 3 (group 3), the RPPV arises from the MPV as a first branch, and the RAPV emerges directly from the LPV.

RESULTS

No differences were observed between groups 1 and 2 with respect to ERLV ratios. However, significant differences were discovered between groups 1 and 3 and between groups 2 and 3 (p<0.001 and p<0.05, respectively).

CONCLUSIONS

The ERLV proportions in the donors with a type 3 MPV variation were significantly lower than those in the donors with type 1 and type 2 MPV variations and six (31.6%) donors in group 3 presented an ERLV percentage below 30% of the total liver volume.