Abdominal Normothermic Regional Perfusion Versus Normothermic Machine Perfusion of DCD Kidneys Aged 50 Years or Older: A Propensity Score Matched Analysis

Introduction The use of donor kidneys from older donation after circulatory death (DCD) donors is limited due to increased susceptibility to ischemia–reperfusion injury, resulting in delayed graft function (DGF) and graft loss. While hypothermic machine perfusion (HMP) with oxygen (HMPO 2 ) offers some benefit, clinical outcomes remain suboptimal. Emerging normothermic preservation techniques, such as abdominal normothermic regional perfusion (aNRP) and normothermic machine perfusion (NMP), may enhance graft viability in high‐risk transplants. This study compares post‐transplant outcomes of aNRP versus NMP in DCD donors over 50 years of age. Materials and Methods Data were collected from two clinical trials (NMP group) and a national registry (aNRP group). The primary outcome was the incidence of DGF. Secondary outcomes included primary non‐function (PNF), acute rejection, death‐censored graft and patient survival, and longitudinal kidney function (eGFR) until three years after transplantation. Results The outcomes of 85 kidneys that underwent aNRP were compared to 29 kidneys that underwent NMP. No significant difference was observed in the incidence of DGF (aNRP: 46% vs. NMP: 52%, p = 0.82), PNF (aNRP: 8% vs. NMP: 7%, p = 0.87) or acute rejection (25% vs. 31%, p = 0.67). Death‐censored graft and patient survival was similar in the aNRP and NMP group. At three years post‐transplant, median eGFR was 38 (±2.1) mL/min/1.73 m 2 in the aNRP group and 33 (±3.8) mL/min/1.73 m 2 in the NMP group. Conclusion The findings of this study demonstrate that both aNRP and NMP provide similar graft outcomes in older DCD kidney transplantation, potentially increasing the acceptance of high‐risk donor kidneys by transplant centers. The interpretation of the results of this study is limited by its non‐randomized design and small sample size.