Hepatic hypoxia in donation after circulatory death: Physiology, clinical relevance, and future directions

Donation after circulatory death (DCD) has increased hepatic graft supply but is plagued by complications that arise from hypoxic injury. There is a lack of understanding regarding donor physiology during DCD and how this contributes to hepatic dysfunction in transplantation. Herein, we outline the current DCD process and the concept of donor warm ischemic time. We then discuss physiologic mechanisms of hepatic blood flow and oxygenation, and how these are relevant to donor warm ischemic time and DCD. We discuss the pathophysiology of hepatic ischemia-reperfusion injury and relevant insights that can be derived from studies of other hepatic conditions. Lastly, we touch on emerging technologies such as machine perfusion. We hope that our review unites concepts of hepatic physiology with DCD practice and enlightens readers to envision novel areas of study in this field.