Oxygen consumption during hypothermic and subnormothermic machine perfusions of porcine liver grafts after cardiac death

The use of grafts donated after cardiac death (DCD) would greatly contribute to the expansion of the donor organ pool. Machine perfusion (MP) is a promising technology to improve DCD liver grafts. Several perfusion technologies under various temperature and oxygenation conditions have been suggested and are still debated. It is important to confirm the relationship between oxygen consumption and organ conditions during MP. In this study, we analyzed oxygen consumption during oxygenated MP of porcine DCD liver grafts under different temperature conditions: hypothermic and subnormothermic. Grafts exposed to 60 min of warm ischemia were perfused for 4 h with a modified UW-gluconate perfusate under hypothermic (HMP) and subnormothermic conditions. Oxygen consumption, pressures of the portal vein and hepatic artery, and effluent enzymes were analyzed. Oxygen consumption was strongly related to the graft temperature during MP. Effluent enzyme level of the LDH were lower in the high oxygen consumption group than in the low oxygen consumption group during MP. In summary, we found that high oxygen consumption under subnormothermic temperature conditions has several advantages over HMP for DCD liver graft preservation.