Impact of ABO incompatibility on adult deceased donor liver transplantation outcomes: A 20-year retrospective study...

ABO-incompatible (ABOi) deceased donor liver transplantation (DDLT) is seldom used due to concerns regarding postoperative outcomes, derived from predominantly older cohorts with small sample sizes. The aim of this study is to assess the impact of ABO incompatibility on outcomes of DDLT in a large, contemporary cohort.

Adult DDLT patients were included from the Scientific Registry of Transplant Recipients (SRTR) database who underwent transplant from 2004 to 2024. Demographics and complications were compared between ABOi and ABO-compatible (ABO-c) cohorts. Multivariate Cox proportional hazards models were generated to assess the impact of ABO incompatibility on 5-year outcomes.

A total of 125,997 patients were included, with 1371 (1.1%) being ABOi. The ABOi cohort tended to be younger (53.0 ± 11.9vs54.5 ± 11.0,p < 0.001) but with severe disease requiring preoperative ICU care (24.4%vs14.1%,p < 0.001) and with higher MELD scores (25.6vs21.9,p < 0.001). Multivariate survival modelling showed that ABOi is not associated with graft loss (defined as mortality or retransplant; aHR 1.00, 95%CI 0.84-1.18) or mortality (aHR 0.83, 95%CI 0.68-1.01), but with increased likelihood of retransplant (aHR 2.08, 95%CI 1.42-3.06). Results were similar when A2 to O incompatible transplants were excluded.

ABOi DDLT is associated with increased likelihood of retransplant but did not show an association with mortality, supporting its use in highly selective unwell patients requiring urgent transplant.