Transplant Trial Watch

Does machine perfusion improve immediate and short-term outcomes by enhancing graft function and recipient recovery after liver transplantation? A systematic review of the literature, meta-analysis and expert panel recommendations.

Ramirez-Del Val, A., et al.

Clinical Transplantation 2022; 36(10): e14638.

This study aimed to examine the role of machine perfusion on immediate and short-term outcomes following liver transplantation.

A literature search was conducted using the following databases: Ovid MEDLINE, Embase, Google Scholar, Scopus, and Cochrane Central. Studies were selected for inclusion by two independent reviewers. The quality of studies and recommendations were graded using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

38 studies were included in the review.

Primary nonfunction, postreperfusion syndrome (PRS), early allograft dysfunction, need for postoperative renal replacement therapy (RRT), length of intensive care unit (ICU) stay, length of hospital stay, biochemical parameters and early complications.


CET Conclusions
In this systematic review and meta-analysis, a total of 38 studies were included in the qualitative synthesis, of those a further 28 were included in the meta-analysis. Only studies of adult deceased donor transplants were included, paediatric, split-liver or live donor related studies were excluded. The included studies compared either hypothermic machine preservation (HMP) +/- oxygenation (HOPE), normothermic machine preservation (NMP) or normothermic regional perfusion (NRP) with SCS. The focus of the study is on outcomes relating to enhanced recovery after transplantation. Overall HMP/HOPE was associated with: lower likelihood of early allograft dysfunction (EAD), decreased incidence of postreperfusion syndrome (PRS), length of hospital stay (LOS) and lower peak transaminases. No difference was found in primary nonfunction (PNF), need for renal replacement therapy (RRT) or length of ITU stay. A subgroup analysis between type of graft (DBD vs DCD) was performed and found for DCD grafts there was a higher degree of effect on reduction of EAD and PRS. The use on HMP is strongly recommended by the panel with moderate quality evidence for PRS and high quality for EAD, the greatest advantage being in DCD grafts. Overall NMP was associated with: decreased incidence of PRS, less EAD, shorter ITU stay and hospital stay as well as lower peak transaminases. No difference in PNF, need for RRT or frequency of major complications. A subgroup analysis of DBD vs DCD could not be performed. The use of NMP is strongly recommended by the panel with a moderate quality evidence in all domains apart from LOS which is low quality. Overall NRP was associated with less EAD and PNF, but compared to DBD livers there was a higher PNF rate. The use of NRP also is strongly recommended by the panel, but with a low quality evidence. The investigators performed a thorough literature search with appropriate terms and inclusion criteria, they screened 1840 articles to find their included studies. For hypothermic preservation they included mostly HOPE studies (11) and one HMP study, which are different interventions and should not be included together. For both HOPE and NMP, there is sufficient volume of evidence to support the recommendations made. For NRP was no RCT evidence considered, and only 2 prospective studies totalling 30 cases of NRP. Most of the patients included in meta-analysis (545) were from a single retrospective registry analysis, suggesting that more prospective or randomised studies with appropriate endpoints are required for NRP to be considered a beneficial intervention for the purposes of enhanced recovery.

Trial registration
PROSPERO - CRD42021237713

Funding source
Non-industry funded