Evolution of lesions in intestinal ischemia.

Intestinal ischemia was produced in dogs by ligation and division of a branch of the superior mesenteric artery that supplied a selected segment of bowel. The bowel lesions included patchy mucosal necrosis, ulceration, and stenosis. The development of these changes was studied, and it appeared that ulceration was accompanied by severe submucosal inflammation in uniform appearance. Healing was accomplished by regeneration of mucosa and widespread submucosal fibrosis. Villi developed in the regenerated mucosa about 30 days after the onset of ischemia. Focal disruption of muscularis mucosa and loss of ganglion cells were common, although muscularis propria remained largely intact.