BACKGROUND: Postconditioning - using alternating brief cycles of reperfusion/reocclusion applied just at the very beginning of reperfusion - has recently been described as a potent therapeutic technique, attenuating ischaemia-reperfusion injury. In vascular surgery, certain elective interventions involve cross-clamping of major arteries, resulting in temporary ischaemia in large peripheral organs, which thus suffer ischaemia-reperfusion injury. Patients undergoing these operations may develop also serious systemic complications such as multiple distant organ dysfunctions, SIRS, detrimental redistribution of the circulation or even shock, a phenomenon called reperfusion-syndrome. We studied the effects of postconditioning on reperfusion-syndrome in a rodent experimental model. MATERIAL AND METHODS: Anaesthetized male Wistar rats underwent 180 minutes of bilateral lower limb ischaemia and 4 hours of reperfusion using an infrarenal cross-clamping of the abdominal aorta. Control animals underwent no additional intervention. Postconditioning consisted of 6 cycles of 10-second aortic occlusion/10-second declamping starting at the beginning of reperfusion. Haemodynamic parameters were observed with invasive arterial manometer, microcirculation of the lower limb was detected with laser-Doppler-flowmeter. After 4 hours of reperfusion serum, urine, and histological samples were collected. RESULTS: 180-minute ischaemia resulted in significant haemodynamic changes after reperfusion. Postconditioning affected the character of the microcirculatory flow curves, the limb circulation stabilized with hyperaemia after reperfusion. Postconditioning caused a significant reduction in systemic inflammatory response (TNF-alpha, oxygen-derived free radicals). The laboratory and histological samples implied a significant decrease in remote organ (lung and renal) dysfunctions after postconditioning. CONCLUSION: Postconditioning proves to be capable in conferring protection against different organ injuries caused by longer circulatory occlusions during elective major vascular surgeries.
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