Graft survival after liver transplantation using portable normothermic machine perfusion at a US center

Portable normothermic machine perfusion (pNMP) may improve outcomes of liver transplantation (LT) compared to static cold storage (SCS), though variables associated with outcomes in pNMP compared with SCS remain unclear. This single-center, retrospective study reports outcomes of LTs from donation after brain death (DBD) and donation after circulatory death (DCD) grafts by preservation type (pNMP vs. SCS) between January 2015 and December 2024. During the study period, 1723 LTs were performed on 1652 patients, including 1202 DBD SCS, 373 DBD pNMP, 41 DCD SCS, and 107 DCD pNMP grafts. Graft survival (GS) probabilities at 1 and 3 years were 88.1% (95% CI: 86.6-89.7) and 79.4% (77.3%-81.5%) overall, 88.4% and 80% for DBD SCS, 87.6% and 78% for DBD pNMP, 80.5% and 60.7% for DCD SCS, and 90.3% and 82.3% for DCD pNMP, respectively. In univariable, both with and without matching (pNMP vs. SCS), and multivariable models, DCD SCS had worse GS compared with DBD SCS, DBD pNMP, and DCD pNMP, which did not significantly differ. GS for pNMP grafts (n=407 LTs) was negatively associated with recipient MELD, liver cancer diagnosis, and lower median hepatic artery flow on pump, but not with bile production and lactate values. However, in addition to these parameters, GS for SCS grafts (n=1180 LTs) was also negatively associated with DCD donors, total preservation time, and recipient age at transplant. Overall, this study demonstrates improved GS and marginal donor utilization, and an increased number of critical recipients associated with pNMP use compared to SCS use, enabling longer preservation time and functional assessment of grafts via hepatic artery flow.