Methylene Blue Administration Reduces Acute Kidney Injury After Living Donor Liver Transplantation: A Single‐Center Retrospective Study

ABSTRACT Background and Aims The efficacy of methylene blue (MB) in preventing acute kidney injury (AKI) in liver transplant recipients remains unclear. In this study, we hypothesized that pre‐reperfusion administration of MB decreases the incidence of postoperative AKI in living donor liver transplantation (LDLT). Methods We retrospectively analyzed data from 415 patients who underwent LDLT between January 2018 to June 2023. The MB group received a bolus of 1–1.5 mg/kg of MB just prior to graft reperfusion, and the control group did not receive MB. The primary outcome was the incidence of postoperative AKI for each stage, as defined by the Kidney Disease Improving Global Outcomes guidelines. Secondary outcomes included post‐reperfusion hemodynamics, hospital length of stay (LOS), the incidence of early allograft dysfunction (EAD), and mortality at 30‐days, 6‐months, and 1‐year. Results The incidence of postoperative AKI all stage and AKI stage 1 was significantly lower in the MB group compared to the control group (AKI all stage: 40.8% vs. 30.0%, p = 0.049, AKI stage 1: 34.7% vs. 23.3%, p = 0.03). In multivariable analysis, MB administration was independently associated with the incidence of AKI stage 1 (OR 0.59, 95% CI 0.36‐0.99, p = 0.046). Hemodynamics during post‐reperfusion period were similar among the groups. The incidence of EAD is significantly lower in MB group compared to control group, but hospital LOS and mortality at 30‐days, 6‐months, and 1‐year were similar in both groups. Conclusion The administration of MB just prior to graft reperfusion was associated with decreased incidence of postoperative AKI stage 1 in LDLT. MB administration was also associated with reduced incidence of EAD.