Liver resection that is less extensive than segmentectomy for hepatocellular carcinoma focused on the fourth branch of the portal vein

The optimal location of the portal branch to be removed by liver resection that is less than a segmentectomy for patients with hepatocellular carcinoma (HCC) is elusive. This study examines the impact of removing the fourth branch on postsurgical outcomes. HCC patients who underwent liver resection less extensive than segmentectomy (2015–2022) were included. The impact of removing the fourth branch of the tumor-bearing portal vein (PVR) on recurrence was evaluated using Gray and Fine-Gray methods, adjusted for confounding factors. Overall survival was assessed via the Kaplan-Meier method and log-rank test. Of the 89 patients eligible for this study, 47 were in the PVR group, and 42 were in the non-PVR group. The PVR group had a significantly lower median level of total bilirubin; however, other covariates related to liver function were comparable to those in the non-PVR group. Additionally, oncological and operative covariates were comparable between the two groups. The 1-, 3-, and 5-year cumulative incidences of recurrence were significantly lower in the PVR group than in the non-PVR group (10.9 %, 34.1 %, and 43.2 % vs. 21.6 %, 59.1 %, and 71.1 %, respectively; P = 0.01). The overall survival rates were comparable between the groups. Bivariable analysis was adjusted for recurrence using significant covariates identified by the univariable analysis and revealed that non-PVR surgery was associated with a significantly greater risk of HCC recurrence with any combination of other significant factors. The risk of short-term intrahepatic recurrence may be reduced by liver resection via removal of the fourth branch of the portal vein.