Feasibility of Reduced-size Orthotopic Liver Transplantation with Fatty Grafts and its Potential Regeneration in Rats

Background and Aims ertook this study to determine the minimum necessary volume of various grades of fatty liver grafts in reduced-size orthotopic liver transplantation (ROLT) and to elucidate the property of fatty liver regeneration. s ified two-cuff technique, ROLT of different rats was performed with various grades and volumes of fatty liver grafts. The survival rate, graft-to-recipient body weight ratio (GRWR), standard liver volume (SLV) and liver function were detected to determine appropriate steatotic grafts that could be safely adopted in ROLT. s de II macrovesicular steatosis (MaS) grafts, the 1-week survival rate of 70% ROLT was significantly worse (25%). In grafts with microvesicular steatosis (MiS) undergoing 70%, 60%, and 50% ROLT, 7-day survival decreased according to the graft volume (75%, 75%, and 33.3%). Proliferating cell nuclear antigen (PCNA) and 5-bromo-2′-deoxyuridine (BrdU) labeling index in normal liver graft reached the highest on postoperative day (POD) 3, whereas in fatty grafts the expression peak was on POD 7. Liver regeneration ratios of normal liver graft were higher than mild MaS graft, but grade II MaS grafts hardly regenerated. When compared with moderate MaS grafts B2 (70% ROLT) and mild MaS grafts A3 (60%) groups, the disparities of alanine aminotransferase and total bilirubin were significant. sions cessful and long-term survival of rat ROLT, MiS or grade II MaS livers could be safely used as grafts only when their GRWR >2.29 ± 0.20 (or 2.28 ± 0.12) % and SLV >60%; MaS livers in grade II should not be used as grafts. Hepatic regeneration potential of mild MaS or MiS with any grade graft is not obviously impaired after ROLT, but delayed proliferative peak and prolonged cell proliferative cycle are shown.