Ruptured abdominal aortic aneurysm presenting as an obstruction of the left colon.

The clinical presentation of an abdominal aortic aneurysm can be misleading. The typical triad of abdominal pain, pulsate mass, and hypotension may be absent. Delay in diagnosis is associated with a high mortality. Described in the article is a case of a ruptured abdominal aneurysm presenting as a large bowel obstruction. When found at surgery, the aneurysm had ruptured and was sealed by overlying colonic mesentery, along with retroperitoneal fascia. Elderly male patients who are smokers are believed to be at higher risk for atypical presentations from ruptured abdominal aortic aneurysms. This is thought to result from a generalized defect in collagen combined with diffuse atherosclerotic vascular disease. The diagnosis requires maintenance of a high clinical suspicion, in particular for those patients with higher risk factors.