Rescue by Hypothermic Oxygenated Machine Perfusion for Unexpected Long Prolongation of Cold Preservation Time in Expanded Criteria Donor Kidneys Can Achieve Favorable 2‐Year Outcomes

Background: Hypothermic oxygenated machine perfusion (HOPE) is occasionally used to overcome logistical issues and allow longer cold preservation time (CPT); however, reports regarding these situations in older brain-dead donors are lacking. Methods: Retrospective analysis of kidney transplants (KTs) performed between January 1, 2015, to December 31, 2023, from extended criteria donors (ECDs) switched to HOPE after a median time of 17.1 h in static cold storage (SCS) for unexpected logistic reasons and with a median total CPT of 28.6 h (25.3–32.0) (n = 44, HOPE ECDs), compared with a control group of KTs (n = 44, L-ECDs) maintained in SCS alone with a low CPT (median, 10.4 h; range, 7.1–11.1) and matched for age, sex, donor age, donor eGFR, pre-emptive transplant, and cPRA. Results: No primary nonfunction was observed, and both death-censored graft survival (DCGS) and renal function progressively improved, remaining satisfactory and superimposable between groups up to two years post-transplant (97.7% of DCGS with mean eGFR 46.5 mL/min/1.73 m2 [36–55.65] in HOPE-ECDs) versus 97.7% with 42.0 (30.2–48.2) in L-ECDs with similar KDPI (67% [49.75–86.5] vs. 72.5% [60.5–87.75], p = 0.475). These results were achieved in patients with HOPE-ECDs, who experienced higher rates of DGF (31.8% vs. 11.4%, p = 0.036). No differences were noted in infection or rejection rates. Conclusion: Rescue by HOPE after SCS in ECDs with a very long CPT can achieve midterm outcomes similar to those with a low CPT in SCS alone, paving the way for its safe implementation in clinical practice.