Oxygen saturation during donor warm ischemia time and outcome of donation after circulatory death (DCD) liver transplantation with static cold storage: A review of 1114 cases

The donor operation and the hemodynamics during declaration resulting in donor warm ischemia time have been linked to the outcomes in donation after circulatory death (DCD) liver transplantation (LT). Scrutiny of the donor hemodynamics at the time of withdrawal of life support concluded that a functional donor warm ischemia time may be associated with LT graft failure. Unfortunately, the definition for functional donor warm ischemia time has not reached a consensus-but has almost always incorporated time spent in a hypoxic state. Herein, we reviewed 1114 DCD LT cases performed at the 20 highest volume centers during 2014 and 2018. Donor hypoxia began within 3 minutes of withdrawal of life support for 60% of cases and within 10 minutes for 95% of cases. Graft survival was 88.3% at 1 year and 80.3% at 3 years. Scrutinizing the time spent under hypoxic conditions (oxygen saturation ≤ 80%) during the withdrawal of life support, we found an increasing risk of graft failure as hypoxic time increased from 0 to 16 minutes. After 16 minutes and up to 50 minutes, we did not find any increased risk of graft failure. In conclusion, after 16 minutes of time in hypoxia, the risk of graft failure in DCD LT did not increase. The current evidence suggests that an over-reliance on hypoxia time may lead to an unnecessary increase in DCD liver discard and may not be as useful for predicting graft loss after LT.