The effects of ischemia and reperfusion were studied in the small colon of 12 horses. Under general anesthesia, arterial pressure and arterial hemoglobin oxygen saturation values were maintained constant and within the normal physiological range. After celiotomy, the small colon was exposed and three segments were demarcated. Total arterial venous ischemia was induced in two segments during 90 (group A) and 180 (group B) minutes. The third segment was the control group. Full-thickness biopsy specimens, for histopathology, were obtained at the end of the ischemia periods and at 90 (groups A and B) and 180 minutes (group A) of reperfusion. The mucosa and the submucosa were evaluated by semiquantitative morphological assessment such as epithelial detachment, edema and hemorrhage, and by quantitative morphological assessment such as percentual depth of mucosal loss (ML) and mucosal crypt:interstitium ratio (C:I). After ischemia, lesions such as ML, C:I, epithelial detachment and mucosal edema were more intense in group B when compared to group A. In both groups after reperfusion there were significant increases in ML, C:I, epithelial detachment and submucosal edema. The results showed aggravation of the mucosal lesions in the reperfusion period in equine small colon, and the model was considered adequate for experimental purposes.
Equine; ischemia; reperfusion injury; small colon; acute abdomen
