Introduction: Limited data suggests that ex-vivo normothermic liver perfusion (ENLP) may improve the outcomes of donation after cardiac death (DCD) liver transplants compared to static cold storage (SCS).

Methods: All adult, DCD liver transplants performed between 2016-2021 were identified in the United Network of Organ Sharing (UNOS) database. Cox proportional hazards analysis was used to evaluate the impact of ENLP (vs SCS) on graft survival. To more effectively balance baseline covariates and minimize treatment selection bias, an inverse probability of treatment weighting (IPTW) approach using the propensity score was employed, which accounted for multiple donor and recipient factors.

Results: Between 2016 and 2021, 65 ENLP and 3079 SCS DCD liver transplants were performed in the U.S. Only 20/101 centers utilized ENLP DCDs.  Compared to SCS DCDs, recipients of ENLP DCDs had lower MELD scores at transplant (16.5 v. 18.8, P=0.033), longer wait-times (468±720 v. 246±467 days; P<0.001), and received livers from donors with a greater BMI (29.2 v. 27.5; P=0.008).  ENLP preservation was associated with improved graft survival (HR 0.15 vs SCS, 95% CI:0.04-0.60, P=0.01). As a majority of the ENLP DCDs were performed in the context of multicenter trials, we conducted a sub-analysis restricting to the 20 centers performing ENLP, encompassing 946 SCS DCDs. Results were largely unchanged: HR 0.16 vs SCS (95% CI: 0.04-0.62, P=0.01).

Conclusion: In this retrospective analysis of the early U.S. DCD ENLP experience, there may exist a graft survival benefit to transplants performed with ENLP compared to SCS.  Future analyses will require a more robust dataset with longer-follow-up.