Hypothermic Oxygenated Perfusion Versus Static Cold Storage in Liver Transplantation: A Meta‐ Analysis of Randomized Trials

BACKGROUND: Hypothermic oxygenated machine perfusion (HOPE) is an alternative to static cold storage (SCS) for liver graft preservation, aiming to reduce ischemia-reperfusion injury (IRI) and improve post-transplant outcomes. METHODS: We systematically reviewed randomized controlled trials (RCTs) comparing HOPE with SCS in adult liver transplantation (MEDLINE, EMBASE, CENTRAL to July 2026). Outcomes included early allograft dysfunction (EAD), primary non-function (PNF), major postoperative complications, biliary complications, including non-anastomotic strictures (NAS), graft survival, and retransplantation. RESULTS: Eight RCTs (984 patients; HOPE 461; SCS 523) met inclusion criteria. HOPE significantly reduced EAD (17.8% vs. 33.5%; RR 0.54, 95% CI 0.43-0.68; p < 0.00001) and PNF (0.4% vs. 3.6%; RR 0.26, 95% CI 0.09-0.75; p = 0.01). HOPE was associated with fewer major complications (Clavien-Dindo ≥ III) (41.2% vs. 50.7%; RR 0.80, 95% CI 0.70-0.93; p = 0.003), lower overall biliary complications (18.9% vs. 27.7%; RR 0.72, 95% CI 0.58-0.90; p = 0.004) and reduced NAS (3.3% vs. 7.6%; RR 0.43, 95% CI 0.23-0.82; p = 0.01). One-year graft survival was comparable, while retransplantation was reduced after HOPE (RR 0.35, 95% CI 0.14-0.84, p = 0.02). CONCLUSION: HOPE improves early graft outcomes and reduces biliary morbidity and retransplantation compared with SCS, supporting its use to mitigate IRI.