摘要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 chal-lenged the universality of this cutoff.This review re-examines the relevance of the 0.80％GRWR thresh-old 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 ar-terial 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.