Where to Draw the Line in Ex-Situ Split Liver Transplantation for Adult Recipients? – A Benchmarking Analysis

Abstract

Abstract Background A comprehensive outcome analysis of ex situ right split liver graft transplantation (RSLT) is currently lacking. Aims Benchmarking outcomes of RSLT against best achievable results from whole LT offers a novel comparative approach. Methods This retrospective study includes all consecutive ex-situ RSLT for adult recipients performed from 2014-2019 at 4 high volume transplant centers (>70 LT/year). Outcomes including overall morbidity expressed by the comprehensive complication index (CCI) and graft related complications were compared to the published benchmark cutoffs for whole graft LT. Results We included 129 ex-situ RSLT with 76% H45678 (n=98) and 24% (n=31) H5678 grafts. The median follow-up was 4.8 years. Overall and severe 1-year morbidity expressed by the CCI were within established whole graft LT benchmarks. Biliary complication rates were slightly higher than the benchmark due to the occurrence of cut-surface leaks. The arterial thrombosis rate was outside the benchmark cutoff (7% vs ≤4.4%) leading to a higher retransplantation rate. However, overall 1-year graft and recipient mortality were well within the benchmark cutoffs, resulting in a 5-year overall recipient survival of 88.5%. Selecting benchmark cases for RSLT defined by low-risk recipient-donor criteria including static cold storage time ≤10h and recipient MELD≤20 points, did not significantly reduce overall morbidity nor arterial complication rate. In contrast, the type of split graft (H45678 vs.H5678) did impact on both arterial and biliary complications. Conclusions This large multicenter series of ex-situ right split grafts disclosed an overall 1-year morbi-mortality comparable to the best achievable results in whole graft LT. The results show that the main morbidity burden in adult RSLT is related to technical criteria rather than graft-recipient matching.