Machine Perfusion Ameliorates Nonanastomotic Strictures After Liver Transplantation: A Systematic Review and Meta-analysis of Randomized Controlled Trials

INTRODUCTION Machine perfusion (MP) technology may reduce the incidence of biliary complications (BCs) by reducing ischemia-reperfusion injury (IRI). This meta-analysis aims to compare the effects of MP and static cold storage (SCS) on the incidence of BCs, non-anastomotic stricture (NAS), and anastomotic stenosis (AS) after liver transplantation (LT).

METHODS Randomized controlled trials (RCTs) comparing the effects of MP versus SCS on BCs, NAS, or AS after LT were included for the systematic review in October 2024. Random-effects models were used to perform pooled analyses to calculate risk ratios (RRs) with 95% confidence intervals (CIs).

RESULTS A total 9 RCTs including 6 hypothermic oxygenate perfusion (HOPE) and 3 normothermic machine perfusion (NMP) were eligible for inclusion. Compared to SCS, MP technology seemed to reduce the incidence of BCs (HOPE: RR 0.77, 95% CI 0.62 to 0.97, P = 0.03; NMP: RR 0.67, 95% CI 0.44 to 1.00, P = 0.05). In addition, MP technology could explicitly reduce NAS incidence (HOPE: RR 0.40, 95% CI 0.19 to 0.84, P = 0.01; NMP: RR 0.39, 95% CI 0.19 to 0.83, P = 0.01). However, MP technology was likely unable to reduce the incidence of AS (HOPE: RR 0.89, 95% CI 0.63 to 1.26, P = 0.51; NMP: RR 0.99, 95% CI 0.53 to 1.85, P = 0.99).

DISCUSSION This meta-analysis confirmed that MP technology could reduce the incidence of NAS, which might further lead to a reduction in the incidence of BCs. However, it did not seem to improve AS incidence.