Liver transplant outcomes of deceased donor types following normothermic machine perfusion: A meta-analysis

Livers from donation after circulatory death (DCD) are less frequently utilized than those from donation after brain death (DBD). Normothermic machine perfusion (NMP) offers the opportunity to assess high-risk grafts before transplantation; however, the predictive value for each respective donor type remains unclear. The aim of this meta-analysis was to compare outcomes between DBD and DCD livers subjected to NMP.

Studies on clinical liver NMPs published in four databases up to March 2025 were reviewed. A random-effects meta-analysis using Cohen's D and log odds ratios to calculate effect sizes (ES) was conducted.

Sixteen studies were included, encompassing 568 livers (297 DBD, 271 DCD) subjected to NMP. Following the viability assessment, the utilization rate was 91% for DBD and 74% for DCD livers (ES: 0.59, p=0.10), despite exposure of DBD grafts to worse donor risk factors such as higher age (ES: 0.36, p=0.006), and longer CIT (ES: 0.33, p=0.015). Stringency in viability assessment, such as the inclusion of cholangiocyte criteria and lactate clearance within 2 hours, resulted in 20-22% lower DCD utilization rates, compared to DBD. Post-transplantation, DBD and DCD grafts had 3.6% and 12% non-anastomotic strictures (ES: -0.69, p=0.053), and 95% and 90% one-year death-censored graft survival (ES: 0.56, p=0.41).

Presumed high-risk DBD and DCD grafts achieve excellent transplant results after viability assessment during NMP. Stringency of viability criteria correlated with lower DCD utilization rates. More research is needed to elucidate evidence-based assessment criteria that correlate directly to transplant outcomes.