Extended hypothermic oxygenated machine perfusion enables ex situ preservation of porcine livers for up to 24 hours

JHEP Rep. 2020 Feb 17;2(2):100092. doi: 10.1016/j.jhepr.2020.100092. eCollection 2020 Apr.


Background & aims: End-ischemic hypothermic oxygenated machine perfusion (HOPE) of the donor liver for 1-2 h mitigates ischemia-reperfusion injury during subsequent liver transplantation. Extended preservation time may be preferred to facilitate difficult recipient hepatectomy or to optimize logistics. We therefore investigated whether end-ischemic dual HOPE (DHOPE) could extend preservation time for up to 24 h using a porcine liver reperfusion model.

Methods: Following 30 min warm ischemia, porcine livers were subjected to 2 h static cold storage (SCS), followed by 2 h, 6 h, or 24 h DHOPE (n = 6 per group). Subsequent normothermic reperfusion was performed for 4 h using autologous blood. Two livers preserved by 24 h SCS served as additional controls. A proof of principle confirmation was carried out in 2 discarded human livers subjected to extended DHOPE. Hepatocellular and cholangiocyte injury and function were assessed. Oxidative stress levels and histology were compared between groups.

Results: Perfusion flows remained stable during DHOPE, regardless of duration. After normothermic reperfusion, livers perfused for 24 h by DHOPE had similar lactate clearance, blood pH, glucose, and alanine aminotransferase levels, and biliary pH, bicarbonate, and LDH levels, as livers perfused for 2 h and 6 h. Levels of malondialdehyde and high-mobility group box 1 in serum and liver parenchyma were similar for all groups. Histological analysis of bile ducts and liver parenchyma revealed no differences between the groups. Extended DHOPE in discarded human livers preserved hepatocellular and cholangiocyte function and histology after reperfusion. In contrast, livers preserved by 24 h SCS were non-functioning.

Conclusion: Extended end-ischemic DHOPE enabled successful preservation of porcine and discarded human donor livers for up to 24 h. Extended DHOPE enables safe extension of preservation time, which may facilitate allocation and transplantation from a logistical perspective, and further expand the donor pool.

Lay summary: It has been suggested that preserving liver grafts with a technique called (dual) hypothermic oxygenated machine perfusion ([D]HOPE) leads to better outcomes after transplantation than if livers are stored on ice, especially if an organ is of lesser quality. In this study, we showed that DHOPE could be used to preserve liver grafts for up to 24 h. This extended procedure could be used globally to facilitate transplantation and expand the donor pool.

Keywords: 8-OHdG, 8-hydroxydeoxyguanosine; ALT, alanine aminotransferase; DCD, donation after circulatory death; DHOPE, dual hypothermic oxygenated machine perfusion; ECD, extended criteria donor; HMGB-1, high-mobility group box 1; HMP, hypothermic machine perfusion; HOPE, hypothermic oxygenated machine perfusion; HPF, high-powered field; IL-6, interleukin 6; LDH, lactate dehydrogenase; MDA, malondialdehyde; NMP, normothermic machine perfusion; SCS, static cold storage; SEM, standard error of the mean; TNFα, tumor necrosis factor-alpha; UW, University of Wisconsin; VWF, von Willebrand factor; cfDNA, cell-free DNA; donation after circulatory death; extended preservation; hypothermic machine perfusion; liver preservation; sTM, soluble thrombomodulin.