Experimental ischemic colitis in dogs.

Experimental ischemic colitis was produced in 42 dogs by either ligation (ligation group, n=18) or temporary occlusion of the mesenteric vessels (temporary occlusion group, n=24) and changes in the local blood flow in the bowel were measured by the hydrogen clearance method. Tissue damage similar to damage seen in patients with ischemic colitis were produced in both of these groups. There was a close correlation between the severity of the ischemia and the ensuing tissue damages. In the ligation group, the tissue damages ranging from erosions or minute ulcerations to diffuse ulcerations occurred when the local blood flow was measured at 30 minutes after the ligation and was below 50 per cent of the basal flow. In the temporary occlusion group, the tissue damages were observed when the local blood flow was below 40 per cent of the basal flow and the occlusion was maintained for over two hours.