Is the 0.80%graft-to-recipient weight threshold still relevant in modern adult living donor liver transplantation?OA

The graft-to-recipient weight ratio(GRWR)threshold of 0.80%has long been used to guide graft selection in adult living donor liver transplantation(LDLT)as a pragmatic surrogate for graft adequacy.However,expanding use of donor-sparing left liver grafts and advances in perioperative management have challenged the universality of this cutoff.This review re-examines the relevance of the 0.80%GRWR threshold in modern adult LDLT,focusing on the evolving pathophysiology of small-for-size syndrome,the role of portal hyperperfusion and secondary hepatic arterial hypoperfusion mediated through the hepatic arterial buffer response,and the clinical impact of hemodynamic monitoring and inflow modulation.We summarized surgical and pharmacologic strategies to optimize portal and arterial inflow and proposed practical hemodynamic targets(e.g.,portal venous flow<5 mL/min per gram graft and portal venous pressure<20 mmHg with preserved hepatic arterial inflow).To provide real-world context,the authors integrated original data from their institutional left-graft LDLT cohort(n=202,median GRWR 0.72%,range 0.39%-1.48%),including recipients with GRWR<0.80%(n=152,75.2%)and<0.60%(n=44,21.8%).Small-for-size syndrome occurred in 56.9%of recipients.GRWR<0.80%was not associated with the incidence of small-for-size syndrome(60.5%vs.46.0%,P=0.102)or in-hospital mortality(8.6%vs.6.0%,P=0.765),and long-term survival was comparable across GRWR groups when portal inflow was controlled and hepatic arterial perfusion preserved.Overall,GRWR remains useful for risk stratification but should not function as an absolute cutoff,rather a physiology-driven,hemodynamic-guided strategy may better define graft adequacy in modern adult LDLT.