Left-sided grafts for living-donor liver transplantation and split grafts for deceased-donor liver transplantation: Their impact on long-term survival

Background: A small-for-size graft is important in living-donor liver transplantation (LDLT) and deceased-donor liver transplantation (DDLT). Subjects and methods: First, we confirmed the effect of initial graft volume on survival using a rat model of liver transplantation (LT). We then evaluated the actual long-term survival based on graft type in 1421 LTs (including 1364 LDLTs) at Kyoto University and 2000 DDLTs at the Mayo Clinic, to evaluate donor safety in LDLT and the possibility of shifting to split orthotopic liver transplantation (SOLT) in DDLT. Results: In the rat model, SOLTs with 40%- and 20%-grafts had a poor survival. A total of 697 pediatric LTs showed good long-term outcomes (survival rate was 0.764 at 21.2 years). The survival rate of 724 adult LTs was 0.664 at 17.8 years. The survival rates of auxiliary partial orthotopic liver transplantation with a left-sided graft (0.421 at 15.0 years) and SOLT with a left-sided graft (0.000 at 0.8 years) need to be improved. Although the survival rate of 1965 adult DDLTs with a whole-liver graft in the Mayo Clinic was 0.727 at 12.8 years, that of adult SOLT was 0.595 at 11.0 years. Conclusion: From the viewpoint of greater donor safety and expanded donor candidates in LDLT, the choice of a left-sided graft still remains controversial. A shift to SOLT to achieve excellent results should be established to resolve a donor shortage in DDLT.