In a porcine liver transplant model, a brief period of oxygenated hypothermic machine perfusion (HMP) at the end of simple cold storage (SCS) has been shown to improve the viability of damaged liver grafts. To test the clinical validity of this strategy, we randomized SCS-discarded human liver grafts to either 4 hours of HMP (n = 13) or an additional 4 hours of SCS (n = 14). All livers were then warm reperfused to mimic ischemia-reperfusion injury ex vivo. The settings for HMP were: portal vein: 3 mm Hg, 300 mL/min and hepatic artery: 20 mm Hg, po(2): 300 mm Hg. Perfusion used Kidney Machine Perfusion Solution at 4 degrees C to 8 degrees C. During warm reperfusion, aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) values were higher (P