The Impact of Normothermic Machine Liver Perfusion on Early Renal Outcomes After Simultaneous Liver-kidney Transplantation: A Propensity Score–Matched Analysis

Background. No study has assessed the effect of end-ischemic normothermic machine perfusion (NMP) on renal function in simultaneous liver-kidney (SLK) transplantation. We hypothesized that by mitigating liver ischemia/reperfusion injury, NMP exerts a renoprotective effect on kidney allografts. This study compares renal outcomes in SLK transplant recipients receiving NMP versus static cold storage (SCS) livers. Methods. We analyzed deceased-donor SLK transplant recipients (January 2019–July 2024) with at least 6 mo follow-up (n = 85). Primary outcomes included delayed graft function (DGF) and functional-DGF (f-DGF; failure of serum creatinine to decrease 10% daily for 3 d in the first week). Liver Core Outcome Sets were reported. NMP recipients (n = 17) were propensity score–matched 1:2 to SCS controls (n = 34). Kidneys underwent hypothermic machine perfusion in both groups. Results. Cohorts were well matched, although NMP had more donation after circulatory death donors ( P = 0.006). f-DGF was significantly lower in NMP versus SCS (35% versus 68%, P = 0.025); this persisted in the hepatorenal syndrome subcohort (27% versus 65%, P = 0.03). Post–reperfusion syndrome was lower in NMP ( P = 0.041). NMP demonstrated superior renal function: lower peak creatinine (2.58 versus 3.03 mg/dL, P = 0.031), higher lowest postoperative estimated glomerular filtration rate (25 versus 19 mL/min/1.73 m 2 , P = 0.021), and reduced 6-mo dialysis requirement (6% versus 32%, P = 0.036). Conclusions. In this cohort, NMP was associated with improved early renal recovery in SLK transplant recipients, characterized by lower rates of f-DGF and higher estimated glomerular filtration rate. These findings suggest that mitigating liver ischemia via NMP may provide secondary benefits to the simultaneous kidney allograft.