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TEXTBOOK PRESENTATION
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Bleeding from angiodysplasia can look like any other cause of lower GI bleeding. It is seen almost exclusively in older adults and can present with anything from hematochezia to occult blood loss. In general, hemorrhage from angiodysplasia tends to be less brisk than bleeding from diverticula.
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Angiodysplasias, also called arteriovenous malformations, are dilated submucosal veins that are most commonly seen in the right colon of adults over age 60.
Present in < 5% of patients over age 60.
Most patients with angiodysplasias do not bleed and those that do tend to have occult blood loss rather than brisk, overt hemorrhage.
Angiodysplasia has historically been associated with various diseases (eg, aortic stenosis, cirrhosis) but only a relationship to end-stage renal disease seems definite.
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EVIDENCE-BASED DIAGNOSIS
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As in diverticular hemorrhage, colonoscopy, tagged red blood cell scan, and angiography are all used in the diagnostic evaluation.
Colonoscopy is the most common tool. It allows good visualization of the cecum, which is the site of most angiodysplasias.
If suspicious vascular patterns are seen during colonoscopy, angiography can provide evidence of a diagnosis even without active bleeding.
As in diverticular hemorrhage, the diagnosis is often presumptive, made on the basis of visualizing nonbleeding angiodysplasia in a patient with GI bleeding.
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Both acute and chronic bleeding is generally treated endoscopically with thermal or laser ablation. This method can be repeated for recurrent bleeding.
Angiographic intervention, with vasoconstrictor agents or embolization, is rarely used.
Surgical management (right hemicolectomy) is sometimes required for frequent, recurrent bleeding.
Hormonal therapy with estrogen has been used to prevent recurrent bleeding in angiodysplasia, but recent studies suggest that this is not very effective.
Whenever possible, long-term antiplatelet therapy should be discontinued.
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ALTERNATIVE DIAGNOSIS: COLON CANCER
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