The case for normothermic machine perfusion in liver transplantation

In recent years, there has been growing interest in normothermic machine perfusion (NMP) as a preservation method in liver transplantation. In most countries, because of a donor organ shortage, an unacceptable number of patients die while awaiting transplantation. In an attempt to increase the number of donor organs available, transplant teams are implanting a greater number of high-risk livers, including those from donation after circulatory death, older donors, and donors with steatosis. NMP maintains the liver ex vivo on a circuit by providing oxygen and nutrition at 37°C. This permits extended preservation times, the ability to perform liver viability assessment, and the potential for liver-directed therapeutic interventions during preservation. It is hoped that this technology may facilitate the enhanced preservation of marginal livers with improved posttransplant outcomes by reducing ischemia/reperfusion injury. Clinical trials have demonstrated its short-term superiority over cold storage in terms of early biochemical liver function, and it is anticipated that it may result in increased organ utilization, helping to reduce the number of wait-list deaths. However, further studies are required to demonstrate longer-term efficacy and the impact on biliary complications as well as further knowledge to exploit and maximize the potential of this exciting new technology. Liver Transplantation 24 269-275 2018 AASLD.