Background : Living donor liver transplantation (LDLT) is a critical solution for organ shortages, but its success is challenged by the variable anatomy of liver grafts. The impact of graft anatomy on post-transplant outcomes remains unclear, highlighting the need for further study.

Methods : A retrospective review of LDLT performed at Severance Hospital from July 2005 to December 2022 was conducted, analyzing a cohort of 908 adult patients. The cohort was divided into complex-graft (n=418) and control groups (n=490), based on the presence of multiple anatomical structures in the graft. Kaplan-Meier and Cox proportional hazards regression models assessed the association between graft complexity and long-term survival.

Results : Before and after propensity score matching (PSM), graft survival rates between recipients of complex and standard grafts did not significantly differ (p=0.162 pre-PSM; p=0.274 post-PSM). Complex graft recipients, however, experienced a statistically significant increase in vascular complications (12.8% vs. 7.7%, p=0.013) and a higher likelihood of bile duct complications, with a risk ratio of 1.26 (p=0.042). In subgroup analysis, grafts with multiple hepatic arteries were associated with a non-significant reduction in survival (p=0.059), whereas grafts with two or more hepatic veins significantly improved survival outcomes (p=0.016).

Conclusions : The anatomical complexity of liver grafts does not significantly alter overall survival outcomes in LDLT. However, it is associated with an increased risk of specific postoperative complications. These findings underscore the importance of considering graft complexity in preoperative planning and risk assessment to optimize LDLT outcomes.