Background:
A most severe complication of infrarenal aortic and lower extremity major arterial reconstructions is an acute renal failure. The underlying mechanism an ischaemia-reperfusion injury of a vast mass of muscle tissues, and a consequential metabolic and haemodynamic upset. The aim of the study was to apply (ischaemic) postconditioning and also the mitochondrial K+ATP-channel agonist levosimendan, as a “pharmacological postconditioning”, and investigate their effects on the muscle ischaemia-reperfusion injuries and the corollary renal dysfunction.

Material and Methods:
Male Wistar rats underwent bilateral lower limb 180min ischaemia followed by reperfusion. Postconditioning consisted of 6 cycles of 10s aortic reocclusion and 10s declamping. Intravenous levosimendan was administered continuously (0,02μg/bwkg/h) throughout the whole course of ischaemia and the first 3h of reperfusion. Results of the pretreatment groups were compared with sham-operated and ischaemia-reperfusion control groups. Hemodynamic monitoring was performed by invasive arterial blood pressure registering and a kidney surface laser Doppler flowmetry. After 4h and 24h of reperfusion serum, urine and histological samples were collected.

Result:
Muscle viability studies showed no significant improvement with the use of postconditioning, on the other hand levosimendan administration resulted in significantly preserved viability. At the same time renal functional laboratory tests and kidney histology demonstrated significantly less expressed kidney injury in both treated groups. Systemic hemodynamics improved only in the postconditioned group after reperfusion, but kidney microcirculation was significantly less impaired in both treatment groups.

Conclusion:
The results claim a protective role for postconditioning and also levosimendan “pharmacological postconditioning” in major vascular surgeries to prevent renal complications.