Diagnosis and management of aneurysms involving the superior mesenteric artery and its branches--a report of four cases.

Aneurysms of the superior mesenteric artery (SMA) are an uncommon but lethal entity, which must be treated expeditiously to avoid mortality and high incidence of ischemic small bowel complications. In the past 7 years the authors have treated 4 patients with a variety of types of aneurysms involving the SMA and its branches at a university-based teaching hospital. The first was a mycotic SMA aneurysm as a result of septic mitral valve, the second a jejunal aneurysm in a patient with pancreatitis, the third a spontaneous dissection distal to a small SMA aneurysm with thrombus partially occluding the distal vessel, and the fourth an SMA aneurysm associated with the diagnosis of mesenteric insufficiency. All patients presented with abdominal pain. The diagnosis was made initially in 1 patient on plain abdominal films with a calcified aneurysm, on duplex scan in the second, and on computed tomography (CT) scans in the remaining 2. Treatment consisted of bowel resection and ligation of mycotic aneurysm in the first patient, of catheter embolization of jejunal aneurysm in the patient with pancreatitis, and of vein graft bypass in the patient with a large SMA aneurysm. The patient with SMA aneurysm and distal dissection with partially occluding thrombus received anticoagulation and is being followed up with serial CT scans. There were no deaths. One patient required bowel resection, which did not result in short gut syndrome. Improved abdominal duplex scanning and CT technology facilitates the diagnosis of mesenteric aneurysm. The broad spectrum of etiologies mandates that treatment be tailored to the individual patient, and it varies from endovascular techniques to traditional bypass surgery. Prompt diagnosis and treatment results in the lowest mortality rate and minimizes the prevalence of intestinal infarction.