Determining the critical graft-to-recipient weight ratio threshold for safety in full-right/full-left split liver...

Split liver transplantation addresses organ shortage; however, the outcomes of and risk factors for full-right/full-left split liver transplantation (FR/FLSLT) require validation using multicenter data. This retrospective multicenter study included 132 FR/FLSLT recipients from 5 Chinese centers (May 2016 to November 2024). Risk factors affecting survival were analyzed, stratified by graft-to-recipient weight ratio (GRWR) and risk factors. The overall 3-year recipient and graft survival rates were 84.1% and 81.8%, respectively. Recipients with a GRWR ≤1.15 exhibited significantly lower 3-year survival vs GRWR >1.15 (58.1% vs 91.7% recipient survival; 55.3% vs 89.8% graft survival; P < .001). Multivariate analysis identified recipient age >52 years and model for end-stage liver disease score >15 as independent mortality risk factors. In patients without risk factors, no mortality or graft-loss events were observed in the GRWR ≤1.15 group, but the small sample size (n = 3) limits the interpretation. However, with ≥1 risk factor, a GRWR ≤1.15 significantly increased mortality (hazard ratio 8.81, P < .001) and graft loss (hazard ratio 7.50, P < .001). FR/FLSLT with GRWR >1.15 demonstrated favorable outcomes. GRWR ≤1.15 grafts may be considered for recipients without identified risk factors (age ≤52 years, model for end-stage liver disease score ≤15), and this requires further multicenter validation.