RESUMO
Arteriovenous malformations of the gastrointestinal tract are a source of upper and lower gastrointestinal bleeding. We studied 40 patients with arteriovenous malformations. Eighteen percent had single lesions in either the distal transverse colon or the left colon (the angiographic distribution of the inferior mesenteric artery). Seventeen percent had concomitant colonic and extracolonic arteriovenous malformations. Only 6% of those who underwent surgery for removal of arteriovenous malformations rebled. We also studied the incidence of angiodysplastic lesions of the colon of 159 patients over the age of 55 with lower gastrointestinal bleeding; associated arteriovenous malformations were present in 21%. These data suggest: that to evaluate arteriovenous malformations as a cause of gastrointestinal bleeding, one must perform inferior and superior mesenteric and celiac angiography; the incidence of rebleeding is reduced when triple-vessel selective visceral angiography precedes surgical removal of arteriovenous malformations; and the incidence of associated arteriovenous malformations approaches that of diverticulosis in elderly patients with lower gastrointestinal bleeding.