Convergence Process of Volumetric Liver Regeneration After Living-Donor Hepatectomy

We investigated the long-term profiles of liver regeneration after living-donor hepatectomy. Thirty-three donors participated in the study. Preoperative and postoperative liver volume was calculated using computed tomography. Volume assessment was repeated at 1 week, 2 weeks, 1 month, 3 months, 6 months, 12 months, and 4 years postoperatively. Donors were divided into the right (n = 23; residual liver volume, 42%) and left (n = 10; residual liver volume, 63%) groups according to the operative procedures. The restoration ratio to the preoperative liver volume (right vs. left groups) were 51%, 57%, 64%, 74%, 77%, 81%, and 88% vs. 69%, 72%, 76%, 79%, 83%, 84%, and 91% at 1 week, 2 weeks, 1 month, 3 months, 6 months, 12 months, and 4 years, respectively; the interindividual variation in the restoration ratio to the preoperative liver volume became narrower with time. Liver resection in humans resulted in rapid regeneration during the first 3 months, followed by a more moderate rate of regeneration thereafter, in proportion to the amount of liver mass resected. The volume of the regenerating liver appeared to converge towards the individual preoperative volume with time. However, the liver volume was not restored to the preoperative volume at 4 years after the resection.