T.E. Maksimuk1, S. Bakhtiyar2, N. Mott2, J. Schold3, J.R. Hoffman4, Y.J. Bababekov3 1University Of Colorado Denver, School Of Medicine, Aurora, CO, USA 2University Of Colorado Denver, Department Of Surgery, Aurora, CO, USA 3University Of Colorado Denver, Department Of Surgery, Division Of Transplant, Aurora, CO, USA 4University Of Colorado Denver, Department Of Surgery, Division Of Cardiothoracic Surgery, Aurora, CO, USA
Introduction: Donation after circulatory death (DCD) liver transplantation (LT) is rapidly evolving given the rise of new procurement and perfusion techniques such as normothermic regional perfusion (NRP), direct procurement (DP), normothermic machine perfusion (NMP), and hypothermic machine perfusion (HMP). While existing literature compares survival outcomes between donation after brain death (DBD) and DCD allografts, a comprehensive analysis of survival outcomes stratified by these new methods is needed.
Methods: Using the Organ Procurement and Transplantation Network registry, we identified adult (≥18y) LT recipients between 09/2021-03/2024. Recipients were grouped by DBD or DCD, with the DCD group further classified as—either NRP or DP—based on the time from circulatory standstill to aortic cross-clamp. Perfusion modality was categorized as static cold storage (SCS), NMP, or HMP. Two-year posttransplant survival is presented as Kaplan-Meier curves for each group. Risk-adjusted hazards of mortality were calculated using Cox proportional hazards models and are reported as hazard ratios(HR) with 95% confidence intervals(CI).
Results: Of the 21,036 liver transplant patients, 2,576 (12%) were in the DCD group, with 349 (14%) procured using NRP and 2,227 (86%) using DP. Within the NRP group, 274 (79%) were in the NRP/SCS cohort, 74 (21%) in the NRP/NMP group, and 1 (0.3%) in the NRP/HMP group. In the DP group, 983 (44%) were in the DP/NMP cohort, 53 (2.4%) in the DP/HMP group, and 1,191 (53.5%) in the DP/SCS group. The frequency of DCD LT increased from 721(9%) in 2022 to 1313(15%) in 2023 and 361(15%) in the first 3 months of 2024(Figure 1A). Similarly, the number of transplant centers performing DCD LT increased from 59/117 in 2021 to 93/123 in 2023 with 76/118 centers performing DCD LT in the first 3 months of 2024. Regional variation in DCD technique is shown in Figure 1B. Compared to DBD recipients, NRP/SCS recipients were older (59vs56y,P<0.001), more often male (74vs61%,P<0.001), and on average had a lower MELD (18vs26,P<0.001). Similarly, DP/NMP recipients were older (58y,P<0.001), and had a lower MELD (19,P<0.001) versus their DBD counterparts. Compared to DBD, both NRP/SCS and DP/NMP recipients spent more time on the waitlist (80 and 71d, respectively, vs 30d,P<0.001). After adjusted analysis, 2-year posttransplant survival was equivalent for DBD versus NRP/SCS (HR0.59,CI 0.3-1.3) and DP/NMP (HR0.74, CI 0.5-1.1)(Figure 1C).
Conclusion: DCD LT is becoming increasingly common in the US. We report similar 2-year posttransplant outcomes between DBD, and both DCD cohorts (NRP/SCS and DP/NMP). These findings highlight the importance of broader DCD LT utilization to expand the donor organ pool and reduce waitlist mortality.