Abdominal angina is postprandial pain that occurs in the mesenteric vascular occlusive disease when blood flow to the colon cannot increase enough to meet visceral demands. This is similar to intermittent claudication in peripheral vascular disease or angina pectoris in coronary artery disease.
Ischemia of the intestine results from an imbalance of oxygen supply to and oxygen consumption by the GI tract. A decrease in blood flow results from decreased size of mesenteric vessels. Atherosclerotic disease is the most common cause of abdominal angina. It frequently involves ostia of the mesenteric vessels. In most people, it is occlusion of the superior mesenteric artery that is responsible for the abdominal symptoms.Risk factors for superior mesenteric artery atherosclerosis include smoking and hyperlipidemia.
Abdominal angina is rare and has a high mortality rate. It is more common in females and the elderly. The problem with diagnosis is that the symptoms are often vague and no work up is ever done. The average age of those affected is slightly older than 60 years although it has been reported in young individuals. Females outnumber males by approximately 3 to 1. Because of the few cases, there are no large series to determine which population is most at risk. Outside the United States, there are few cases of abdominal angina reported.
Abdominal angina diminishes blood flow as a result of the narrowing of the mesenteric vessels. The most common cause of abdominal angina is an atherosclerotic vascular disease at ostia of the mesenteric vessels. Superior mesenteric artery occlusion is usually found in patients with symptomatic occlusive mesenteric ischemia. Shortly after eating, patients with abdominal angina are unable to increase flow in the mesenteric vessels, and they develop pain.
The typical clinical presentation of abdominal angina is severe pain that is out of proportion to the physical exam. The patient usually complains of severe abdominal pain that starts after eating a meal. In most cases, the pain gradually subsides after a few hours. Because the pain is so severe, most people develop a fear of eating and hence lose weight. One should always ask about a history of smoking, claudication, and hyperlipidemia. On physical exam, marked weight loss is obvious. The abdomen is often soft and there are not peritoneal signs. An abdominal bruit may be heard in some patients. One may also find features of peripheral vascular disease with diminished pulses in the leg. The digital rectal exam is usually guaiac negative.
Laboratory tests are not helpful in the diagnosis. However, one must always rule out malignancy of the colon and stomach. Ultrasound is not sensitive to make a diagnosis of mesenteric ischemia. The gold standard is an angiogram. No laboratory test is diagnostic. A mesenteric angiogram is the standard diagnostic study. CT angiography has become the test of choice and as sensitive as an angiogram. Since these patients have atherosclerotic disease, one should work up the patient for heart and peripheral vascular disease. If they are heavy smokers, an arterial blood gas and pulmonary function tests should be ordered in case the patient is being worked up for surgery.
There is no medical treatment. Mesenteric revascularization treats abdominal angina. Surgery for abdominal angina includes removal of the obstructing lesion. Usually, the celiac artery, superior mesenteric artery, and inferior mesenteric artery are involved, and at least two vessels must be revascularized using angioplasty and stenting techniques. If the residual stenosis is present after angioplasty, a stent is placed across the narrowed region of the blood vessel. Complications of endovascular mesenteric revascularization procedures are groin hematoma, acute limb ischemia, mesenteric artery dissection, mesenteric artery rupture, and embolization of atherosclerotic plaques. If endovascular management is not an option, two types of arteriotomy can be performed: transverse and longitudinal. Other surgical options include an antegrade or retrograde bypass. There continues to be debate over the choice of a conduit. While prosthetic grafts have been used, some experts recommend using the reversed saphenous vein. For the surgeon who has never done a superior mesenteric bypass, the vessel is usually less than 2 to 3 mm and can be easily narrowed with large bites of the vessel. Failures after surgery are not uncommon because of technical problems and it behooves the surgeon to wear microloops when performing the anastomosis.
During surgery, patients need close cardiac monitoring. Some surgeons even check the patency of the repair with a tabletop Doppler.
Patients should stop smoking. No effective medical therapy exists. In addition, the patient should be treated for hyperlipidemia. A referral to a cardiologist and a vascular surgeon is prudent.
Even though many patients have significant weight loss, the role of total parenteral nutrition is also a hotly debated topic. Some surgeons use it preoperatively in select patients, but whether it actually benefits or reduces the morbidity remains unknown. Once the surgery is completed, there are no restrictions on diet.
Duplex ultrasonography is used for follow-up. The blood flow velocities are measured regularly to ensure that restenosis is not occurring. Even with treatment, a morbidity rate of 30% has been reported. The most common complications of surgery or an endovascular procedure include a hematoma, pseudoaneurysm, and thrombosis followed by bowel infarction. It is vital to tell the patient to stop smoking.
Once discharged from the hospital, the patient should be told to consume several small meals rather than one large meal. This practice requires less blood flow in the mesenteric vessels. If the surgery is not a success, the symptoms will appear immediately. A number of patients with failed surgery end up having massive bowel resection and end up with a short gut.
The presentation of abdominal angina can be non-specific but if the diagnosis is delayed, the disorder carries high morbidity and mortality. Thus, the disorder is best managed by a multidisciplinary team that includes a general surgeon, vascular surgeon, gastroenterologist, emergency department physician, radiologist and ICU nurses. Even after treatment, patients need to be monitored to ensure that there is no recurrence. Graft thrombosis and occlusion may lead to bowel ischemia and necessitate the need for emergent surgery.