Disruption of the middle hepatic vein is not crucial for liver regeneration of the remnant liver after right hemihepatectomy for hepatic tumors

Background: To clarify the role of the middle hepatic vein (MHV) in liver regeneration of the remnant liver after right hemihepatectomy for hepatic tumors, we reviewed 29 patients to evaluate liver regeneration for up to 12 postoperative months. Methods: Volume regeneration of the remnant liver was investigated by computed tomography at 3, 6, and 12 postoperative months. The remnant liver was divided into the following three areas: the medial section (segment IV), the lateral section (segments II and III), and segment I. The patients were divided into two groups: group A (n = 17), in which the MHV was preserved in the remnant liver, and group B (n = 12), in which the MHV was removed. Results: Volume regeneration of each area continued until 6 postoperative months but did not increase thereafter. On univariate analysis, differences in the volume regeneration of each area between the groups were not significant at any measured time point. Furthermore, disruption of the MHV was determined to not be crucial to the volume regeneration of any liver area on multivariate analysis. Only the resection volume (percentage) significantly affected liver regeneration of the remnant liver. Conclusions: Disruption of the MHV does not decisively affect liver regeneration of remnant liver after right hemihepatectomy for hepatic tumors.