Impact of hepatic vein dominance and interposition venous graft on postoperative liver regeneration: A CT volumetry study

To compare pre- and postoperative right hepatic venous volumes using automatic computed tomography (CT) volumetry and explore factors influencing early postoperative outcomes, such as liver regeneration. We analyzed 79 pairs of donor and recipient CT images, calculating liver territories and ratios to total liver volume. Patients were categorized as 'middle hepatic vein (MHV) dominance' or 'right hepatic vein (RHV) dominance' based on MHV territory proportion. Liver volumes were compared, and changes pre- and post-transplantation were assessed via graft regeneration ratio (GRR). Clinical and laboratory data influencing GRR were collected, analyzing with linear regression. In MHV-dominant patients (n = 41), those with or without an occluded interpositional venous graft (IVG), exhibited decreased right anterior segment (RAS) volume post-surgery (GRR = −2.87 %), with a lower increase in right liver volume than that observed in patients with an IVG connected to the MHV (GRR = 2.59 % vs. 16.63 %, respectively; p = 0.029). Conversely, in RHV-dominant patients (n = 38), the GRRs were similar regardless of the IVG connection (P > 0.05). In both groups, the graft-recipient weight ratio significantly influenced right liver regeneration (p < 0.05). Graft weight emerged as the only significant factor in the multivariate analysis, although IVG occlusion showed a trend towards decreasing right liver GRR (p = 0.073). RHV-dominant patients may not require an IVG connection because their regeneration is unaffected by patency. Conversely, MHV-dominant patients without postoperative IVG connections showed inferior regeneration of the right lobe, particularly the RAS.