Artery Problems of the Intestines

Patients who have atherosclerosis affecting the arteries to their intestines can present with acute or chronic symptoms. If there is a sudden closure of an artery which supplies blood to a major portion of the intestine, patients can present with extremely severe, acute, abdominal pain. The clinical situation is frequently one in which a blood clot travels from the heart (in a patient with atrial fibrillation, for example) and lodges in a major artery of the intestine. There is a group of patients however, who have a chronic lack of circulation to the intestine. This is called chronic mesenteric ischemia and their symptoms are sometimes referred to as "mesenteric angina". This is caused by a gradual buildup of atherosclerotic plaque in the arteries supplying the intestine. Patients typically complain of severe abdominal pain, approximately one hour after eating. The increased demand for circulation to the intestine, which occurs in response to eating a meal, cannot be met by the arteries supplying blood to the intestine because those arteries are partially blocked. This results in the typical mesenteric ischemic pain ("mesenteric angina"). Patients typically will avoid eating because of the pain associated with having a meal. As such, patients with chronic mesenteric ischemia typically have lost a significant amount of weight before the diagnosis is ultimately determined. Many times, patients with chronic mesenteric ischemia have undergone multiple tests before the diagnosis is made. Not infrequently, patients will have undergone ultrasonography and CT scan of the abdomen, colonoscopy and upper endoscopy before the diagnosis of mesenteric ischemia is considered.

There are three major arteries supplying blood to the intestine. The celiac axis, superior mesenteric artery, and inferior mesenteric artery. If only one artery is heavily diseased, it is rare for a patient to have symptoms. When a patient has symptoms of chronic mesenteric ischemia, they are typically found to have blockage of at least two of the major arteries to the small and large intestine. If the diagnosis is suspected, patients should usually undergo ultrasound evaluation in an attempt to "image" the arteries to the intestine in a non-invasive manner. If it is suggested by this test that there is a narrowing in the arteries, a conventional angiogram may be recommended at that point. If a significant narrowing (greater than 75%) is identified in the celiac axis and/or the superior mesenteric artery, treatment options including balloon angioplasty and stenting of these arteries or bypass around the blocked artery. After successful revascularization, patients usually will become symptom free and begin to re-gain the weight lost during the time that the circulation to the intestine was compromised.

Superior Mesenteric Artery Syndrome

Superior mesenteric artery (SMA) syndrome is a rare cause of abdominal pain and duodenal obstruction caused by compression of the transverse duodenum between the SMA and the aorta. It is usually thought that this condition occurs in individuals who have had a severe, rather sudden, loss of weight. In patients with severe weight loss, it is thought that the loss of retroperitoneal fat causes a change in the individual's anatomy and this results in obstruction of the duodenum by compression of this structure between the SMA and the Aorta. The diagnosis can be made by CT scan using oral and intravenous contrast agents. Treatment depends on the cause. Patients with severe weight loss may respond to nutritional support and weight gain. Some patients may require surgical treatment.