Is 2 h of Hypothermic Machine Perfusion for Pancreas Preservation Effective in Improving Graft Reperfusion?

Abstract

Background: Static cold storage (SCS) remains the standard method for organ preservation. The development of parenchymal edema during prolonged hypothermic machine perfusion (HMP) was a major barrier to the introduction of this technique for the preservation of pancreases. A short period of HMP could optimize the pancreas for reperfusion while minimizing the side effects related to perfusion. Our objective is to evaluate the impact of short-term HMP on the pancreatic reperfusion.

Methods: A preclinical study using a controlled donation after circulatory death porcine model was conducted. After procurement, the pancreases were preserved under hypothermic conditions for 2 h either by SCS (n = 4) or HMP (n = 4). After these 2 h of preservation, the pancreases were reperfused using a normothermic machine perfusion (NMP) for 2 h. During NMP, oxygenation, perfusion parameters, biochemical analyses, a glucose stimulation insulin secretion test, and an evaluation of ischemia/reperfusion injury by photoacoustic tomography were assessed.

Results: During NMP, resistance indices were significantly lower in the HMP group compared with the SCS group, even after 2 h of reperfusion. The tissue oxygen partial pressure was higher throughout NMP after HMP preservation. Lactate and amylase levels were equal between the 2 groups. Lipase levels were higher in the HMP group. The glucose stimulation test showed no difference between the 2 groups. Photoacoustic tomography assessment showed no endothelial damage in either group.

Conclusions: Our study suggests that a short-term HMP applied to pancreases for 2 h is effective in reducing resistance indexes and improving oxygenation.

Graphical abstract

FIGURE 1.

Experimental protocol. Porcine pancreases were procured in a cDCD model (30 min warm ischemia). Pancreases were then preserved under cold ischemia for 2 h according to statical cold storage or hypothermic machine perfusion. Finally, reperfusion and evaluation of the pancreas were conducted for 2 h using normothermic perfusion technique with autologous blood. cDCD, controlled donation after circulatory death.

FIGURE 2.

In tissue partial pressure of oxygen during hypothermic preservation according to static cold storage or hypothermic machine perfusion. Values expressed as median ± interquartile range. *P < 0.05; **P < 0.01; ***P < 0.001. ns, not significant.

FIGURE 3.

Resistance index during hypothermic preservation during hypothermic machine perfusion. Values expressed as median ± interquartile range. **P < 0.05; **P < 0.01; ***P < 0.001. ns, not significant.

FIGURE 4.

In tissue partial pressure of oxygen during normothermic reperfusion with normothermic machine perfusion. Values expressed as median ± interquartile range. *P < 0.05; **P < 0.01; ***P < 0.001. ns, not significant.

FIGURE 5.

Resistance index during normothermic reperfusion with normothermic machine perfusion. Values expressed as median ± interquartile range. *P < 0.05; **P < 0.01; ***P < 0.001. ns, not significant.

FIGURE 6.

Concentration of lactate (A), lipase (B), and amylase (C) during normothermic reperfusion with normothermic machine perfusion. Values expressed as median ± interquartile range. *P < 0.05; **P < 0.01; ***P < 0.001. ns, not significant.

FIGURE 7.

Insulin concentration after glucose stimulation (13.5 mM) at 15 min during normothermic reperfusion. Values expressed as median ± interquartile range. *P < 0.05; **P < 0.01; ***P < 0.001. ns, not significant.

FIGURE 8.

Photoacoustic tomography assessment of pancreases preserved for 2 h before normothermic reperfusion. The photoacoustic signal intensity indicates the amount of hemoglobin. Different colors represent measurement depth, aiding in the visualization of the 3-dimensional structure. HMP, hypothermic machine perfusion; SCS, static cold storage.