Impact of Hypothermic Oxygenated Machine Perfusion on Early Outcomes in Kidney Transplantation from Uncontrolled Donors

Background: Kidney transplantation from uncontrolled donation after circulatory death (uDCD) donors is associated with a high incidence of delayed graft function (DGF) due to ischemia–reperfusion injury. Machine perfusion has emerged as a promising strategy to improve graft preservation and early outcomes.
Methods: We performed a retrospective study of 63 kidney transplants from uDCD donors between January 1, 2024 and January 31, 2025. Recipients were divided into two groups based on graft preservation method: static cold storage (n=28) and machine perfusion (n=35). Machine perfusion was performed using a locally developed device designed for ex vivo hypothermic perfusion of kidney grafts at Botkin Hospital. Outcomes assessed included early graft function (immediate function, DGF, primary non-function [PNF]), serum creatinine at discharge, estimated glomerular filtration rate (eGFR) at last follow-up, length of hospital stay, number of hemodialysis sessions, and cold ischemia time (CIT). Continuous variables were analyzed using the Mann–Whitney U test and are presented as median (IQR). Categorical variables were compared using the Fisher–Freeman–Halton exact test.
Results: Baseline characteristics, including recipient age, serum creatinine, eGFR, hospital stay, and dialysis requirements, were comparable between groups (p>0.05). Cold ischemia time was significantly longer in the machine perfusion group: 1083 (950–1200) vs 780 (640–920) minutes (p=0.002), which is attributable to the additional time required for ex vivo perfusion. Machine perfusion was associated with a higher rate of immediate graft function (25.7 % vs 14.3%) and a lower incidence of DGF (65.7% vs 78.6%); however, these differences were not statistically significant (p=0.56). No significant differences were observed in serum creatinine at discharge (p=0.82) or eGFR at last follow-up (p=0.27).
Conclusion: Machine perfusion in uDCD kidney transplantation is associated with a trend toward improved early graft function despite significantly prolonged cold ischemia time. The absence of statistically significant differences may be related to limited sample size. Further studies are warranted.