A novel oxygenated machine perfusion system for preservation of the liver.

Machine perfusion (MP) is a potential method to increase the donor pool for organ transplantation. However, MP systems for liver grafts remain difficult to use because of organ-specific demands. Our aim was to test a novel, portable MP system for hypothermic preservation of the liver. A portable, pressure-regulated, oxygenated MP system designed for kidney preservation was adapted to perfuse liver grafts via the portal vein (PV). Three porcine livers underwent 20 h of hypothermic perfusion using Belzer MP solution. The MP system was assessed for perfusate flow, temperature, venous pressure, and pO2 /pCO2 during the preservation period. Biochemical and histological parameters were analyzed to determine postpreservation organ damage. Perfusate flow through the PV increased over time from 157 ± 25 mL/min at start to 177 ± 25 mL/min after 20 h. PV pressure remained stable at 13 ± 1 mm Hg. Perfusate temperature increased from 9.7 ± 0.6°C at the start to 11.0 ± 0.0°C after 20 h. Aspartate aminotransferase and lactate dehydrogenase increased from 281 ± 158 and 308 ± 171 U/L after 1 h to 524 ± 163 and 537 ± 168 U/L after 20 h, respectively. Blood gas analysis showed a stable pO2 of 338 ± 20 mm Hg before perfusion of the liver and 125 ± 14 mm Hg after 1 h perfusion. The pCO2 increased from 15 ± 5 mm Hg after 1 h to 53 ± 4 mm Hg after 20 h. No histological changes were found after 20 h of MP. This study demonstrated the feasibility of a portable MP system for preservation of the liver and showed that continuous perfusion via the PV can be maintained with an oxygen-driven pump system without notable preservation damage of the organ.