Rescue of the Cold Preserved Rat Liver by Hypothermic Oxygenated Machine Perfusion

Abstract

The aim of the study was to investigate whether hypothermic oxygenated liver perfusion after cold liver preservation resuscitated metabolic parameters and whether this treatment had a benefit for liver viability upon reperfusion.We preserved rat livers either by cold storage (UW) for 10 h, or by perfusion for 3 h (oxygenated modified UW) after 10 h cold storage. We assessed viability of livers after preservation and after ischemic rewarming + normothermic reperfusion ex vivo. Ten hour cold storage reduced mitochondrial cytochrome oxidase and metabolically depleted the livers. Oxygenated perfusion after cold storage resulted in uploaded cellular energy charge and oxidized mitochondrial cytochrome oxidase. Reperfusion after 10 h cold storage increased formation of superoxid anions, release of cytosolic LDH, lipid peroxidation, caspase activities and led to disruption of sinusoidal endothelial cells. In contrast, reperfusion after 10 h cold storage + 3 h hypothermic oxygenated perfusion resulted in no changes of lipid peroxidation, bile flow, energy charge, total glutathione, LDH release and of caspase activation, as compared to fresh resected livers. This study demonstrates, that a metabolically depleted liver due to cold storage can be energy recharged by short-termed cold machine perfusion. The machine perfused graft exhibited improved viability and functional integrity.

Hypothermic Oxygenated Perfusion (HOPE) Downregulates the Immune Response in a Rat Model of Liver Transplantation

“…As expected from previous studies, 6,8 HOPE reduced reperfusion injury within the first 24 hours after OLT, confirmed by minimal 8-OHdG, HMGB-1, and AST release and decreased activation of Kupffer and endothelial cells (Figs 1, 2). Furthermore, HOPE treatment prevented infiltration of CD3-positive T cells in liver grafts (Fig.…”

“…5 The perfusion technique consisted of a short-term hypothermic oxygenated perfusion (HOPE) after conventional organ procurement and cold storage and was shown to protect effectively from ischemia-reperfusion (I/R) injury despite long donor warm ischemia times. [6][7][8] We have also reported, in several experimental studies, that such effects of HOPE depend on oxygenation of the perfusate 6 with decreased downstream activation of numerous inflammatory pathways. 6,7 On the basis of these findings, the aim of the current study was to analyze effects of HOPE treatment on the immune response in a model of acute rejection, using incompatible rat strains for OLT.…”

“…14 We used 50 mL of recirculating modified starch-free UW solution as perfusate. 7,8 Perfusion box and perfusate were maintained at 4…”

Reply to ‘Is single portal vein perfusion the best approach for machine preservation of liver grafts?’

“…The hypothermic perfusion setting, however, fundamentally differs from normothermic physiological conditions. During cold machine liver perfusion, oxygen consumption of any liver cells, including the extrahepatic bile duct, is dramatically reduced, and we convincingly reported that single portal vein perfusion with high oxygen tension enables sufficient liver ATP reload in the cold before graft implantation (6)(7)(8).To support our observation, recent human application of single portal vein HOPE in extended DCD livers displayed a significant reduction of biliary complications with robust graft survival benefit, compared to matched unperfused DCD livers (9).…”

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“…In the last decade, experimental studies have shown that continuous perfusion of the liver during preservation can improve graft viability and challenge the limits of the current static storage. 8,9 However, the mode of oxygen supply remains unclear. Optimization of oxygen delivery during hypothermic preservation is essential.…”