RESUMO
INTRODUCTION: Surgical treatment for acute limb ischemia is revascularization or - when the limb is in a critical stage - amputation. Correct staging of the disease is relatively difficult, therefore complication and mortality rates are extremely high. Our aim was to invesitigate acute critical ischemia in rats and to test postconditioning on this model. METHODS: Experiment I: male Wistar rats underwent 4, 6, 8 hours of bilateral lower limb ischemia without reperfusion. Experiment II: suspected critical ischemia was followed by 2 hours of reperfusion with or without postconditioning. Histological samples were collected for routine staining and nitroblue-tetrazolium (NBT) enzyme-histochemistry. In Experiment II the microcirculatory changes were measured by laser Doppler flowmetry and blood samples were collected for laboratory testing (kreatin-kinase, CK). RESULTS: Experiment I: After an eight-hour-obstruction, severe ischemic lesions were detectable, with rutine and NBT stainings, therefore 8 hours of ischemia was chosen for further testing. Experiment II: The CK levels showed significant (p < 0.05) drop, quantitative evaluation of enzyme-histochemisty resulted in significantly (p < 0.001) less viability depletion and microcirculation showed significant (p < 0.05) amelioration of the reperfusion parameters in the postconditioned group compared to the control. CONCLUSIONS: Eight hours of lower limb ischemia is a suitable model to investigate acute critical ischemia in rats. Postconditioning could be a feasible technique to reduce IR injury associated with acute lower limb ischemia.
