A retrospective study investigating the risk of graft loss in living donor liver transplant cases where size mismatching is predicted from graft-to-recipient weight ratio

Background/purpose: Living donor liver transplantation (LDLT) is vital for pediatric end-stage liver disease due to organ shortages. The graft-to-recipient weight ratio (GRWR) preoperatively measured predicts the outcomes of LDLT. We typically target between 0.8 and 3.0–4.0%, but the ideal GRWR remains controversial. We compared the outcomes of LDLT according to the GRWR to examine whether the criteria could be expanded while ensuring safety. Methods: We retrospectively reviewed 99 patients who underwent LDLT in our department by dividing them into three groups according to their GRWR: Group S, with GRWR values lower than the normal range (GRWR < 0.8%); Group M, with GRWR values in the normal range (GRWR ≥ 0.8 to < 3.5%); and Group L, with GRWR values above the normal range (GRWR ≥ 3.5%). Results: In Groups S and L, 46.2 and 44.4% of patients underwent splenectomy and delayed abdominal wall closure, respectively. After these intraoperative adjustments, there were no significant differences between the groups in 5-year patient survival, 5-year graft survival, or the occurrence of post-transplantation thrombosis. Conclusion: When the GRWR is beyond the normal threshold, the risk of complications associated with graft size might be reduced by adjustments to provide appropriate portal blood flow and by delayed abdominal wall closure.