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 20h of hypothermic perfusion using Belzer MP solution. The MP system was assessed for perfusate flow, temperature, venous pressure, and pO(2)/pCO(2) 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 20h. PV pressure remained stable at 13 +/- 1 mm Hg. Perfusate temperature increased from 9.7 +/- 0.6 degrees C at the start to 11.0 +/- 0.0 degrees C after 20h. Aspartate aminotransferase and lactate dehydrogenase increased from 281 +/- 158 and 308 +/- 171 U/L after 1h to 524 +/- 163 and 537 +/- 168 U/L after 20h, respectively. Blood gas analysis showed a stable pO(2) of 338 +/- 20 mm Hg before perfusion of the liver and 125 +/- 14 mm Hg after 1h perfusion. The pCO(2) increased from 15 +/- 5 mm Hg after 1h to 53 +/- 4 mm Hg after 20h. No histological changes were found after 20h 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.