Postconditioning of the Lower Limb-Protection Against the Reperfusion Syndrome

Background. Postconditioning-alternating brief cycles of reperfusion/reocclusion applied at the beginning of revascularization-is a potent therapeutic technique, attenuating ischemia-reperfusion injury. Vascular surgery on the lower limb with ischemia-reperfusion injury may give rise to serious systemic complications [organ dysfunction syndrome (MODS), systemic inflammatory response syndrome (SIRS)], a phenomenon called reperfusion-syndrome. Material and Methods. We studied the effects of postconditioning on reperfusion-syndrome in a rodent experimental model. Wistar rats underwent 180 min of bilateral lower limb ischemia using an infrarenal crossclamping of the abdominal aorta. Postconditioning consisted of six cycles of 10-s aortic occlusion/10-s declamping at the beginning of reperfusion. Microcirculation of the lower limb was detected with laser Doppler flowmeter. After 4 h of reperfusion, plasma, urine, and histologic samples were collected. Results. One hundred eighty-minute ischemia resulted in significant hemodynamic changes after reperfusion. Postconditioning affected the character of the microcirculatory flow, the limb circulation stabilized with hyperemia during reperfusion. Postconditioning caused a significant reduction in systemic inflammatory response (TNF-alpha, oxygen-derived free radicals). The laboratory and histologic samples implied a significant decrease in distant organ (lung and renal) dysfunctions after postconditioning. Conclusion. Postconditioning proves to be capable of conferring protection against different organ in-juries caused by longer circulatory occlusions during elective major vascular operations. (C) 2011 Elsevier Inc. All rights reserved.