Curriculum · Gastroenterology
Colonic angiodysplasia
What it is
Angiodysplasia, also written AVM, is made of small ectatic vessels in the submucosa: an arteriovenous malformation. It accounts for 5% to 20% of LGIB, is the most common cause of hemorrhage from the SB, and is the most common cause of massive LGIB from the right colon.
Causes and risk
It is common in old cardiac patients, in CRF, and in AS. When it sits alongside aortic stenosis the pair carries its own name, Heyde syndrome.
How it presents
Acute, painless LGI bleeding in older adult patients is usually caused by colonic diverticula or angiodysplasia, and chronic blood loss or acute painless hematochezia in an older adult patient points to a colonic tumor, polyp or angiodysplasia. Two features in the history move the diagnosis: aortic stenosis points to angiodysplasia as Heyde syndrome, while painless, self-limited, massive hematochezia points instead to diverticular bleeding, the most common cause overall.