Suitability of livers for transplantation when treated by normothermic machine perfusion

Many factors may compromise the functional recovery of a harvested potential liver for engraftment. Normothermic machine perfusion (NMP) can revive hepatic metabolism ex vivo enabling subsequent transplantation. In this study, we evaluated the recovery of 11 discarded livers' function utilizing NMP.

Eleven consecutive discarded livers underwent NMP for 6 hours. Liver function recovery was defined by lactate levels of ≤3 mmol/L and continuous bile production.

Ten of 11 livers perfused were fatty. The median percentage of macrosteatosis (MaS) and microsteatosis (MiS) was 40% (10%-90%) and 40% (20%-50%), respectively, based on a review of paraffin-embedded sections of preperfusion biopsies. A discarded "amyloid" liver from an HIV-positive donor was also studied. Recovery of liver function was observed in 4 livers, including that with the amyloid deposition. These livers sustained shorter cold ischemia times and seemed to have increased portal and arterial blood flow. No significant change in MiS or MaS was observed before and after perfusion.

Our results suggest that some discarded grafts might have been salvaged for transplantation. Further studies utilizing NMP with subsequent transplantation would validate this strategy.