Normothermic ex-vivo liver perfusion and the clinical implications for liver transplantation

Abstract

Despite significant improvements in outcomes after liver trans-plantation, many patients continue to die on the waiting list, while awaiting an available organ for transplantation. Organ tshortage is not only due to an inadequate number of available organs, but also the inability to adequately assess and evaluate these organs prior to transplantation. Over the last few decades, ex-vivo perfusion of the liver has emerged as a useful technique for both improved organ preservation and assessment of organs prior to transplantation. Large animal studies have shown the superiority of ex-vivo perfusion over tcold static storage. However, these studies have not, necessa-rily, been translatable to human livers. Small animal studies have been essential in understanding and improving this tech-nology. Similarly, these results have yet to be translated into clinical use. A few Phase 1 clinical trials have shown promise and confirmed the viability of this technology. However, more robust studies are needed before ex-vivo liver perfusion can be iwidely accepted as the new clinical standard of organ preser-vation. Here, we aimed to review all relevant large and small animal research, as well as human liver studies on normother-mic ex-vivo perfusion, and to identify areas of deficiency and opportunities for future research endeavors.