The Benefit of Sequential Normothermic Regional Perfusion and Hypothermic Machine Perfusion in Kidney Transplantation from Donation after Circulatory Death Donors.

BACKGROUND:Normothermic regional perfusion (NRP) is associated with improved posttransplant outcomes in donation after circulatory death (DCD) kidney transplantation. It remains unknown whether hypothermic machine perfusion (HMP) offers additional benefits over static cold storage (SCS) during transport. METHODS:All adult kidney-only transplantations from DCD donors procured by NRP in the OPTN data (10/1/2020-6/30/2025) were identified. Primary exposure was preservation method during transport: NRP combined with HMP (NRP+HMP) or SCS (NRP+SCS). One-to-two propensity score matching (PSM) was performed on fifteen donor and recipient factors. Primary outcomes included delayed graft function (DGF), posttransplant length of stay (LOS), and estimated glomerular filtration rate (eGFR) at 6 months posttransplant. Secondary outcomes were one-year graft and patient survival. RESULTS:Among 4792 NRP cases, HMP was utilized in 85.1%, with its use increasing over time. After 1:2 PSM (685 NRP+SCS matched to 1262 NRP+HMP), NRP+HMP was associated with significantly lower DGF (23.3% vs. 30.5%, p < 0.01). Median LOS (4.0 days in both groups, p = 0.07), 6-month eGFR (58.5 vs. 60.1 mL/min/1.73m2, p = 0.46), one-year graft survival, and one-year patient survival were not significantly different. The association between HMP and lower DGF was observed across KDPI strata, heart recovery status, and cold ischemia time categories, with no significant interactions detected. CONCLUSION:The adoption of HMP after NRP has increased substantially in the United States and was associated with reduced DGF, but no difference was observed for LOS, 6-month eGFR, graft survival, and patient survival. These findings support the routine use of HMP after NRP.