Prolonged time from cross-clamp until normothermic machine perfusion start is associated with an increased risk of...

There is a paucity of data on the impact of cold ischemia time before the initiation of normothermic machine perfusion (NMP), particularly in more susceptible organs such as livers from donation after circulatory death (DCD) donors. The present analysis aimed to investigate the impact of prolonged time from cross-clamp until NMP start on early allograft dysfunction and other peri-liver transplant (LT) outcomes. All DCD LT performed and placed on NMP at Mayo Clinic Arizona, Florida, and Rochester from January 2022 to March 2024 were included. The decision was made a priori to divide the population into 2 groups based on terciles: typical cross-clamp to on-pump time (lower 2 terciles) versus prolonged cross-clamp to on-pump time (upper tercile; >2 h 45.6 min). Three hundred eighty-four DCD LT undergoing NMP met the inclusion criteria. The rate of early allograft dysfunction was significantly higher in the prolonged cross-clamp to on-pump group (51.2%) compared to the typical cross-clamp to on-pump group (37.6%) ( p = 0.01). The prolonged cross-clamp to on-pump group also had higher rates of acute kidney injury and the number of packed red blood cells transfused during LT. No significant difference in ischemic cholangiopathy (2.4% vs. 3.1%; p = 0.68) or graft survival at 12 months was seen between the prolonged cross-clamp to on-pump and typical cross-clamp to on-pump group, respectively. Following cross-clamp, DCD liver grafts should be placed on the NMP pump as quickly as is safely and logistically possible. In cases where delays are unavoidable, such as waiting for biopsy results or liver reallocation with another center, acceptable results can still be achieved, and therefore, livers with prolonged times should still be used.