Gastrointestinal vascular and ischemic syndromes.

Among the vascular disorders of the small intestine, two major categories are mesenteric ischemia and occult gastrointestinal bleeding secondary to a mucosal or muscular lesion. Mesenteric ischemia remains a clinical entity with a high mortality. Recent advances in the understanding of the pathogenesis of mesenteric ischemia have focused on the role of the neutrophil in modulating reperfusion injury. The advent of duplex scanning has provided a noninvasive method to detect hemodynamically significant stenoses in the mesenteric vessels. Effective small bowel endoscopy remains a critical requirement for endoluminal intestinal enteroscopy, and its application has proved of increasing advantage in the localization of small intestinal lesions that may be the source of occult gastrointestinal bleeding.