Hypothermic oxygenated perfusion in liver transplantation: a meta-analysis of randomized controlled trials and matched studies

Int J Surg. 2024 Jan 1;110(1):464-477 doi: 10.1097/JS9.0000000000000784.

Hypothermic oxygenated machine perfusion (HOPE) is a novel organ-preservation technology designed to optimize organ quality. However, the effects of HOPE on morbidity and mortality after liver transplantation remain unclear. This meta-analysis evaluated the potential benefits of HOPE in liver transplantation.


The Embase, Web of Science, PubMed, Cochrane Library, and Scopus databases were searched for articles published up to 15 June 2023 (updated on 12 August 2023). Mean differences (MDs), risk ratios (RRs), and 95% confidence intervals were calculated.


Eleven studies encompassing five randomized controlled trials and six matched studies were included, with a total of 1000 patients. HOPE did not reduce the incidence of major postoperative complications (RR 0.80), primary non-function (PNF) (RR 0.54), reperfusion syndrome (RR 0.92), hepatic artery thrombosis (RR 0.92), renal replacement therapy (RR 0.98), length of hospital stay (MD, -1.38 days), 1-year recipient death (RR 0.67), or intensive care unit stay (MD, 0.19 days) after liver transplantation. HOPE reduced the incidence of biliary complications (RR 0.74), non-anastomotic biliary strictures (NAS) (RR 0.34), early allograft dysfunction (EAD) (RR 0.54), and acute rejection (RR 0.54). In addition, HOPE improved the retransplantation (RR 0.42) and 1-year graft loss rates (RR 0.38).


Compared with static cold storage (SCS), HOPE can reduce the incidence of biliary complications, NAS, EAD, and acute rejection and retransplantation rate after liver transplantation and improve the 1-year graft loss rate. These findings suggest that HOPE, when compared to SCS, can contribute to minimizing complications and enhancing graft survival in liver transplantation. Further research is needed to investigate long-term outcomes and confirm the promising advantages of HOPE in liver transplantation settings.

CET Conclusion
Reviewer: Prof Simon Knight, Centre for Evidence in Transplantation, Nuffield Department of Surgical Sciences University of Oxford
Conclusion: This systematic review and meta-analysis includes randomised controlled trials and matched cohort studies comparing static cold storage with hypothermic oxygenated machine preservation (HOPE) of the deceased donor liver. The authors identified 5 RCTs and 6 matched studies with over 1,000 patients. They demonstrate significant reductions in incidence of biliary complications including non-anastomotic strictures and acute rejection with HOPE, along with improved 1-year graft survival and a reduction in risk of early allograft dysfunction. The review is well designed, conducted and reported, and very comprehensive in terms of studies included and outcomes evaluated. The authors misinterpret the findings of their subgroup analyses slightly, stating that the effects of HOPE on risk of biliary complications, acute rejection and graft loss appear greater in the DCD subgroup, whereas in fact none of the tests for interaction demonstrate statistical significance. Overall, the results agree with the findings of a number of recent systematic reviews in this area, making the findings robust if not particularly novel.
Study Details
Aims: This study aimed to determine the benefits of hypothermic oxygenated machine perfusion (HOPE) in liver transplant recipients.
Interventions: Five databases including Embase, Web of Science, PubMed, Cochrane Library, and Scopus were searched. Study selection and data extraction were perfomed by two reviewers. Risk of bias was assessed using the Cochrane Collaboration’s risk-of-bias tool 2.
Participants: 11 studies were included in the review.
Outcomes: The main outcomes included total biliary complications, major complications, hepatic artery thrombosis, non-anastomotic biliary strictures, primary non-function, early allograft dysfunction, acute rejection, post-reperfusion syndrome, retransplantation rates, renal replacement therapy rates, 1-year graft loss, 1-year recipient death, hospital stay, intensive care unit stay and hospitalisation costs.
Follow Up: N/A
Funding: Non-industry funding
Publication type: Meta-Analysis, Systematic Review
Trial registration: PROSPERO - CRD42023435615
Organ: Liver
Language: English
Author email: zhourongxing@vip.163.com
MeSH terms: Humans; Liver Transplantation; Tissue Donors; Randomized Controlled Trials as Topic; Graft Survival; Perfusion; Organ Preservation; Liver