Role of oxygenation in hypothermic machine perfusion of kidneys from heart beating donors.

Unlabelled: Dynamic preservation of organ grafts by hypothermic machine perfusion (HMP) has regained broader interest to provide better outcome after transplantation. One pivotal aspect still under debate is the role of oxygenation during HMP. The present study investigates functional and molecular aspects of active oxygenation during HMP of kidneys from heart beating donors.

Methods: Kidneys were retrieved from Landrace pigs (25-30 kg body weight) and preserved by pulsatile HMP for 21 hr. All kidneys were randomly assigned to either anoxic perfusion (MPanox) or active oxygenation of the perfusate (MPox). All grafts were then autotransplanted, and the remaining native kidney was removed at the same time. Renal integrity and function was evaluated during perfusion and for 1 week after the transplantation and the removal of the remaining native kidney.

Results: Oxygenation during HMP resulted in lower endischemic vascular resistance and slightly elevated free radical-mediatedtissue injury during HMP. After reperfusion, radical mediated lipid peroxidation was twofold higher in the MPanox group. Renal clearance of creatinine was found significantly better during the first 2 days after transplantation after MPanox than after MPox. Molecular expression of erythropoietin was increased threefold to baseline levels after MPanox, indicating renal hypoxia during preservation, but was remained unchanged after MPox. Gene expression of sodium-glucose transporter reflected similar functional outcome in both groups. Fractional excretion of Na(+), proteinuria, or serum levels of lactate dehydrogenase were similar in both groups.

Conclusion: The present data do not support the use of active oxygenation during hypothermic perfusion of kidneys from donors with intact circulation.