Normothermic Machine Perfusion vs. Static Cold Storage in Liver Transplantation: A Systematic Review and Meta-Analysis

Background: Normothermic machine perfusion (NMP) represents an alternative to prolong liver preservation and reduce organ discard rates. We performed an updated systematic review and meta-analysis to compare NMP with static cold storage (SCS) in liver transplantation. Methods: MEDLINE, Embase, and Cochrane were searched for randomized controlled trials (RCTs) or observational studies. Risk ratios (RR) and mean differences were calculated. p < 0.05 was considered significant. A random-effects model was applied for all outcomes. PROSPERO ID: CRD42023486184. Results: We included 1295 patients from 5 RCTs and 6 observational studies from 2016 to 2023. 592 (45.7%) underwent NMP. A subgroup RCT analysis favored NMP for non-anastomotic strictures (RR 0.4; 95% CI 0.2, 0.9), postreperfusion syndrome (RR 0.4; 95% CI 0.27, 0.56), and early allograft dysfunction (RR 0.6; 95% CI 0.4, 0.9). NMP favored higher organ utilization rates (RR 1.1; 95% CI 1.02, 1.18). No significant differences between NMP and SCS were observed in graft survival or patient survival at 12 months, primary non-function, serious adverse events, overall biliary complications, AST, or bilirubin levels peak within the first 7 days, ICU or hospital length of stay. Conclusion: Our findings suggest that NMP is associated with lower non-anastomotic biliary stricture rates, postreperfusion syndrome, early allograft dysfunction, and higher organ utilization in the RCT subgroup analysis, without increasing adverse events.