Enhancing the Usability of older DCD donors through strategic approaches in liver transplantation in the US

Background: The use of older donors after circulatory death(DCD) for liver transplantation(LT) has increased over the past decade. This study examined whether outcomes of LT using older DCD(≥50 y) have improved with advancements in surgical/perioperative care and normothermic machine perfusion(NMP) technology. Method: 7,602 DCD LT cases from the UNOS database(2003-2022) were reviewed. The impact of older DCD donors on graft survival(GS) was assessed using Kaplan-Meier and hazard ratio(HR) analyses. Results: 1,447 LT cases(19.0%) involved older DCD donors. Although there was a decrease in their use from 2003-2014, a resurgence was noted post-2015 and reached 21.9% of all LT in the last four years(2019-2022). Initially, 90-day and one-year GS for older DCDs were worse than younger DCDs, but this difference decreased over time and there was no statistical difference after 2015. Similarly, HRs for graft loss in older DCD have recently become insignificant. In older DCD LT, NMP usage has increased recently, especially in cases with extended donor-recipient distances, while the median time from asystole to aortic cross-clamp has decreased. Multivariable Cox regression analyses revealed that in the early phase, asystole to cross-clamp time had the highest HR for graft loss in older DCD LT without NMP, while in the later phases, the CIT(>5.5 h) was a significant predictor. Conclusion: LT outcomes using older DCD donors have become comparable to those from young DCD donors, with recent HRs for graft loss becoming insignificant. The strategic approach in the recent period could mitigate risks, including managing CIT(≤5.5 h), reducing asystole to cross-clamp time, and adopting NMP for longer distances. Optimal use of older DCD donors may alleviate the donor shortage.