Role of normothermic machine perfusion in liver transplantation: Current trends and outcomes.

Background: Liver transplantation is the only known curative treatment option for end-stage liver diseases and failure; however, there is an imbalance between the number of available liver organs for transplant and the number of patients as recipients due to a shortage of suitable organs. In recent years, ex vivo liver machine perfusion has been introduced to liver transplantation to expand the donor organ pool. Studies showed that using normothermic machine perfusion can increase the pool of transplantable discarded livers and is a promising strategy to improve graft resilience and performance further. Methods: A systematic literature search of PubMed and ClinicalTrials.gov registry was performed. A three-stage independent screening method was applied. Inclusion criteria for this review were published prospective, retrospective, clinical trials, and systematic reviews studies using normothermic machine perfusion devices. Results: Twenty-two articles on normothermic liver machine perfusion with patients and graft survival rate were identified. These studies have demonstrated the safety and efficacy of normothermic liver machine perfusion for discarded liver preservation in both standard and expanded criteria donors following patients and graft follow-ups. The overall number of livers that went under NMP was 568 in all the studies in which 503 of the livers were transplanted (88.6%). The 30,90,180 days and 1-year patients and grafts survival rates were promising. Conclusion: Normothermic machine perfusion is a novelty method recently being used in liver transplantation and can lead to the expansion of the liver donor pool by revitalizing discarded livers. Our study was able to show the promising outcomes for both patients and grafts, which were achieved in many human clinical studies around the world using normothermic machine perfusion as a method of liver preservation and revitalization.