Fig. 1

Preoperative images during the first hepatectomy. a Tumor 1 was located in segment 8 near the caval confluence (white arrowhead). The borders between the tumor and the right or the middle hepatic veins were unclear. b Tumor 2 was located in the left lobe and had invaded the umbilical portion of the portal vein (white arrow). c Tumor 1 decreased in size after chemotherapy but was still attached to the RHV (white arrowhead). d Tumor 1 (white arrowhead) and tumor 2 (white arrow) were visualized by three-dimensional volumetric software. The volumes of the left liver, the non-congested area, and the congested area were estimated at 19.6% (green-colored area), 26.3% (brown-colored area), and 53.1% (blue-colored area) of the total liver volume, respectively