To investigate the effect of normothermic machine perfusion (NMP) on preservation and repair of discarded human donor livers.

Three discarded human donor livers after cardiac death (DCD) from March 2015 to February 2016 in the First Affiliated Hospital of Sun Yat-sen University were treated with NMP for 6 hours. Glucose, lactate, urea, aspartate transaminase (AST), alanine transaminase (ALT), total bilirubin (TBIL), albumin (ALB), adenosine triphosphate (ATP), hourly bile production and total bilirubin, bicarbonate, gamma glutamyl transferase (γ-GGT) in bile were recorded during NMP. And the change of liver histology, cell apoptosis, oxidative stress markers after NMP were also analyzed.

AST/ALT and TBIL initially increased and then remained at a stable level. ALB increased from 6.00 (4.00-8.00) g/L to 23.33 (17.00-27.00) g/L during the perfusion and glucose increased to 12.07 (10.60-13.90) mmol/L at the end of perfusion, as well as urea increased to 262.3 (216.0-325.0) mg/L. The level of ATP in the liver increased from 56.95 (44.21-70.89) μmol/g tissue to 311.85 (276.61-358.08) μmol/g tissue. However, lactate concentration decreased to 2.5 (0.3-5.4) mmol/L, which reflecting active metabolism. With time prolongation of perfusion, the bile production raised gradually, with total amount of 8.87 (7.30-10.30) ml during all 6 h perfusion. The bile is dark and viscous, accompanied by increased concentration of TBIL and bicarbonate in the bile during the perfusion. γ-GGT, which is a marker of bile injury, decreased to 64.96 (38.5-107.5) U/L at the end of perfusion. The liver histological results showed a well-preserved liver morphology without injury before and after perfusion. The apoptotic cell number decreased and the oxidative stress (high mobility group box-1 protein and 8-hydroxy-2′-deoxyguanosine levels) and inflammatory cytokine (interleukin-6 and interleukin-8) concentration were maintained at a relatively low level after the perfusion.

NMP help to assess the DCD donor liver before transplantation and provides a new approach of donor selection, treatment interventions, and pretreatment. It not only improves organ quality and function but also provides a new way to expand the donor liver.