Live and let die: challenges and opportunities of long-term liver graft preservation

Abstract

Ex vivo graft preservation is a major determinant of clinical outcome following liver transplantation. The traditional method of static cold storage (SCS) maintains graft viability only for a limited period, and prolonged SCS is associated with adverse outcomes. Consequently, efforts are being made not only to preserve but also to assess and potentially improve organ function before transplantation. This narrative review highlights available literature regarding long-term ex vivo preservation of liver grafts. Special emphasis is given to landmark experimental studies, clinical trials, prospective cohort studies, and review articles relevant to long-term liver preservation and machine perfusion. Liver machine perfusion (LMP) is increasingly being used in clinical practice and transplantation research. Characterized by different operating temperatures, normothermic (NMP), sub-normothermic (SNMP), and hypothermic machine perfusion (HMP) facilitate not only graft preservation but also allow extensive viability testing and therapeutic interventions. Innovative preservation methods have the potential to substantially extend the duration of ex vivo graft preservation. However, their safety and efficacy, particularly for prolonged preservation, have not yet been fully validated in randomized clinical trials.