Comparison of thermal variations in post‐retrieval graft conditioning on rat livers

Abstract

Background: Machine perfusion was found an effective tool to recover organ grafts from ischemic insults during preservation. It could be observed that organ integrity is significantly affected by abrupt temperature shifts during hypothermic storage and implantation periods. Studies showed that a gentle and controlled rise of the temperature during oxygenated machine perfusion prior to implantation can protect the tissue from reperfusion injury. Now, the possible role of temperature kinetics upon retrieval of the graft and prior to later cold storage should be investigated.Methods: Rat livers were retrieved after cardiac arrest and subjected to a brief ex situ machine perfusion with either hypothermic resuscitation (HR) at 8°C, near-normothermic resuscitation (NR) at 30°C or progressive resuscitation with lowering the temperature in a controlled fashion from 30°C to 8°C (PR). After cold storage (CS), liver functional parameters were evaluated by an established ex vivo reperfusion system.Results: NR and PR resulted in significantly lower release of hepatic enzymes and less production of tumor necrosis factor upon reperfusion compared to CS while HR had a far less protective effect. An increase in bile production was only observed in the PR group, which also significantly increased the recovery of tissue adenosine triphosphate, the amount of which was, however, nearly paralleled by the NR protocol. Conclusion:Within the limitations of this model, it seems that normothermic recirculation appears to be a superior approach for the restitution of warmischemically injured liver grafts than immediate hypothermic machine perfusion.

Role of perfusion medium in rewarming machine perfusion from hypo‐ to normothermia

“…8 However, the main purpose of this investigation was to evaluate the suitability of the intracellular type Belzer MPS solution to be used as a perfusate for the controlled oxygenated rewarming of cold stored organs. The extracellular type Steen solution, that has successfully been used so far in this context, 31,32 should serve as a positive reference.…”

Focusing on Ischemic Reperfusion Injury in the New Era of Dynamic Machine Perfusion in Liver Transplantation

“…This depletion leads to the failure of transmembrane ionic pumps and the subsequent development of edema. Furthermore, the absence of perfusion in the affected tissue can result in erythrocyte aggregation and microthrombus formation, which, when combined with the flushing of preservation solution, may further disrupt microcirculation during ischemic transport, potentially compromising tissue viability [22].…”