Effect of Intraoperative Dexmedetomidine Use on Postoperative Liver Function and Graft Outcomes in Laparoscopic Living Donor Hepatectomy: A Propensity Score–Matched Study

<b>Background/Objectives:</b> Laparoscopic living donor hepatectomy may compromise hepatic microcirculation and exacerbate ischemia-reperfusion injury. Evidence regarding the effects of dexmedetomidine on donor liver injury and graft outcomes in laparoscopic living donor liver transplantation (LDLT) remains limited. <b>Methods:</b> We conducted a retrospective cohort study of adult donor-recipient pairs undergoing purely laparoscopic living donor hepatectomy with the Pringle maneuver, categorized by intraoperative dexmedetomidine administration. Primary outcomes were postoperative donor liver function and lactate dynamics. Secondary outcomes included recipient postoperative liver function, perioperative lactate dynamics, early allograft dysfunction (EAD), and graft failure. A 1:1 propensity score matching was performed, and longitudinal laboratory trends were analyzed using linear mixed-effects models. <b>Results:</b> Among 395 donor-recipient pairs, 168 matched pairs (84 per group) were analyzed after PSM. Donors receiving dexmedetomidine had significantly lower postoperative peak aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels (both <i>p</i> < 0.01), with significant group-by-time interactions (AST <i>p</i> < 0.001; ALT <i>p</i> = 0.013). Lactate trajectories differed significantly between groups in both donors and recipients (<i>p</i> for interaction < 0.001). In recipients, there were no significant differences between the two groups in EAD (2.4% vs. 8.3%; OR, 0.31; 95% CI, 0.07-1.35; <i>p</i> = 0.168) and one-year graft survival (1.2% vs. 4.8%; HR, 0.36; 95% CI, 0.04-7.20; <i>p</i> = 0.251). <b>Conclusions:</b> Intraoperative dexmedetomidine administration in living liver donors was associated with reduced biochemical evidence of hepatocellular injury and improved perioperative metabolic profiles. These findings suggest a potential donor-level protective effect without demonstrable early clinical benefit in recipients, supporting the need for prospective studies to clarify its clinical significance.