How does angiodysplasia appear at endoscopy?
At endoscopy angiodysplasia appears as a dense macular, reticular network of vessels (vascular tuft) which is typically 2 to 8 mm wide and is composed of intensely bright, red lesions resulting from the presence of oxygenated, “arterialized” blood within vessels directly supplied by an artery without an intervening capillary. Without capillaries the oxygen attached to hemoglobin is not released and the veins are not deoxygenated. A prominent feeding artery or draining vein is occasionally noted. Angiodysplasias are differentiated from mucosal erosions or hemorrhages from endoscopic trauma because angiodysplasias, unlike traumatic lesions, have a fine internal vascular structure often resembling a starburst, stellate, or arachnoid network.