Sellers, Marty

Background and Objectives: Normothermic regional perfusion (NRP) is an effective technique to improve recipient outcomes. However, no valid methods for determining liver viability exist. Identifying relevant biological markers with clinical correlation to liver viability and recipient clinical outcomes is imperative to improve decision-making. Materials and Methods: Fifty-four donors undergoing NRP and their recipients were included. FMN was measured at the start, 1 h, and end of NRP. Lactate was measured at the start, 30, 60, and 90 min of NRP. Primary outcomes were early allograft function using the early allograft dysfunction (EAD) criteria and the model for early allograft function (MEAF). Secondary outcomes included the association with donor warm ischemia time (DWIT), stratified by 30 min. Spearman’s rho assessed correlations. Results: Forty (74%) livers were transplanted, with 5 (12.5%) recipients developing EAD and the mean MEAF score was 3.13 (1.49). FMN at all time points was significantly greater in the EAD group compared to the non-EAD group and was significantly correlated with the MEAF score (Peak FMN: rho = 0.507, p = 0.001). FMN during perfusion did not differ between DWIT < and ≥30 min. Lactate levels were similar across all groups and did not discriminate for adverse allograft outcomes. However, lactate levels during perfusion were higher in the DWIT ≥ 30 min group. Conclusions: These findings suggest that during NRP, elevated FMN, but not lactate, is associated with early allograft function.

Normothermic regional perfusion (NRP) adoption for donation after circulatory death (DCD) liver transplantation in the United States has been growing, but there remains a higher rate of non-utilization of NRP DCD liver grafts as compared with donation after brain death liver grafts. Six transplant centers and 1 organ procurement organization (OPO) with substantial NRP liver procurement experience performed retrospective reviews of all NRP procurement attempts from September 1, 2021, until March 1, 2024, identifying opportunities for utilization. Five of the 6 transplant centers had prospectively collected data on all accepted livers with NRP intent. The transplant center's intention to utilize DCD donors included 329 livers accepted for transplantation before withdrawal, 252 (76.6%) potential donors expired within the hospital timeframe for donation, and 168 (66.7%) livers were transplanted. Fifty-seven opportunities for utilization were identified by transplant centers, plus 11 from the OPO: most were due to exceeding a functional warm ischemic time limit (n=26), other reasons (n=17), and functional assessment (n=16). The lessons learned by centers in this study provide guidance for newer NRP centers and for OPOs in identifying opportunities for utilization of NRP DCD grafts that have historically been declined.