Transplantation of older DCD livers in the machine perfusion era: a U.S. cohort study

Donation after circulatory death (DCD) livers increasingly use machine perfusion (MP). This study evaluates MP's impact on older DCD livers based on data from the United Network for Data Sharing, covering all first adult DCD liver transplants (2016-2025). The cohort, divided into pre-MP and MP eras (separated by the FDA approval of the first normothermic MP platform in 2021), showed accelerated growth in DCD liver transplants during the MP era. Donors ≥60 rose 7.8-fold, including donors ≥70 (a USA first). By 2025, DCD livers accounted for 43.2%, with 61.35% from donors ≥50. Normothermic regional perfusion (NRP) (3.0%-16.5%), NMP (2.1%-38.9%), and sequential NRP-NMP (0.1%-10.7%) increased significantly (p < 0.001). The MP era was associated with a decrease in median waitlist time from 112 to 62 days (p < 0.001). Early graft survival was similar across ages. For ages 50-59, 1- and 3-year survivals were 87.9%/78.4% pre-MP and 90.1%/78.8% in the MP era. For 60-69, survival was 85.0%/80.6% pre-MP and 90.0%/71.3% in the MP era. DCD LTs for ≥70 were limited to the MP era with 87.8% 1-year survival. Multivariable Cox regression showed that static cold storage (HR = 1.29), donor age 50-69 versus 18-49, and recipient age (HR = 1.01) increased the risk of graft loss after adjustment. MP is associated with an increased number of older DCD liver transplants and acceptable early graft survival.