Risk Assessment in DCD Liver Transplantation - Which Recipient Should Be Selected?

Abstract

Obejctive: To evaluate at which donor recipient risk categories DCD livers may be used with acceptable graft survival. Background: Based on the large UNOS (USA) database, we recently developed and validated a score (balance of risk (BAR) score), which best detected unfavorable combinations between key donor and recipient factors (score>18) in liver transplantation (LT), when compared to other systems. We applied now the BAR score in DCD liver transplants of the UNOS database. Methods: We compared registered DCD and DBD liver transplants between 2002-2010 (n=1661, n=37255). Endpoint of the study was graft survival (Cox regression model adjusted for HCC, Hepatitis C). Three different risk strata were chosen (low, intermediate, high), defined by increasing BAR score (0-9, >9-18, >18). Results: Transplantation of DCD grafts in the low risk group (BAR 0-9) resulted in 5-year graft survival of >60%. However, DCD grafts used in situations with higher cumulative risk, i.e. BAR>9-18 and BAR>18 had a significant lower 5-year graft survival (45% and 29% respectively). In contrast, DBD liver grafts showed 5-year graft survival of 70% (p< 0.01) up to BAR 18. Conclusions: Analysis of cumulative risk in the UNOS database suggests that the BAR score might be useful in allocation decisions using liver grafts from donors after cardiac death. While DBD liver grafts can be considered in patients up to BAR 18, DCD livers should most likely be transplanted in lower risk situations (e.g. BAR ≤9). This study suggests a guideline for the safer use of liver grafts donated after cardiac death through patient selection and reduction of cumulative risk.