Mesenteric artery ischemia

Mesenteric artery ischemia occurs when there is a narrowing or blockage of one or more of the three major arteries that supply the small and large intestines. These are called the mesenteric arteries.

Causes

The arteries that supply blood to the intestines run directly from the aorta, the main artery from the heart.

Hardening of the arteries occurs when fat, cholesterol, and other substances build up in the walls of arteries. This problem is more common in smokers and in people with high blood pressure or high blood cholesterol.

When this hardening occurs in the mesenteric arteries , the end result is narrowed blood vessels and reduced blood flow to the intestines. Like every other part of the body, blood brings oxygen to the intestines. When the oxygen supply is slowed, symptoms may occur.

The blood supply to the intestines may be suddenly blocked by a blood clot ( embolus ). The clots most often come from the heart or aorta. These clots are more commonly seen in people with abnormal heart rhythms such as atrial fibrillation .

Symptoms

Symptoms caused by gradual hardening of the mesenteric arteries:

• Abdominal pain after eating
• Diarrhea

Symptoms of sudden (acute) mesenteric artery ischemia due to a traveling blood clot:

• Diarrhea
• Sudden severe abdominal pain
• Vomiting

Exams and Tests

When symptoms begin suddenly or become severe, blood tests may show a higher than normal white blood cell count and changes in the blood acid level. There may be bleeding in the GI tract.

A Doppler ultrasound or CT angiogram scan may show problems with the blood vessels and the intestine.

A mesenteric angiogram is a test that involves injecting a special dye into your bloodstream to highlight the arteries of the intestine. Then x-rays are taken of the area. This can show the location of the blockage in the artery.

Treatment

When blood supply is blocked to a part of the heart muscle, the muscle will die. This is called a heart attack. A similar type of injury can occur to any part of the intestines.

When the blood supply is suddenly cut off by a blood clot, it is an emergency. Treatment can include medicines to dissolve the blood clots and open up the arteries.

If you have symptoms due to hardening of the mesenteric arteries, there are things you can do to control the problem:

• Stop smoking. Smoking narrows the arteries, decreases the blood's ability to carry oxygen, and increases the risk of forming clots (thrombi and emboli).
• Make sure your blood pressure is well-controlled.
• If you are overweight, reduce your weight.
• If your cholesterol is high, eat a low-cholesterol and low-fat diet.
• Monitor your blood sugar level if you have diabetes, and keep it under control.
• Surgery may be performed if the problem is severe.
• Surgery may involve removing the blockage and reconnecting the arteries to the aorta. A bypass around the blockage is another procedure. It is usually done with a plastic tube graft.
• Insertion of a stent. A stent may be used to as an alternative to surgery to enlarge the blockage in the artery or to deliver medicine directly to the affected area. This is a new technique and it should only be done by experienced health care providers. The outcome is usually better with surgery.
• At times, a portion of your intestine will need to be removed.

Outlook (Prognosis)

The outlook for chronic mesenteric ischemia is good after a successful surgery. However, it is important to make lifestyle changes (such as a healthy diet and exercise) to prevent hardening of the arteries from getting worse.

People with hardening of the arteries that supply the intestines often have the same problems in blood vessels that supply the heart, brain, kidneys, or legs.

People with acute mesenteric ischemia often do poorly because portions of the intestine may die before surgery can be done. However, with prompt diagnosis and treatment, acute mesenteric ischemia can be treated successfully.

Possible Complications

Tissue death from lack of blood flow (infarction) in the intestines is the most serious complication of mesenteric artery ischemia. Surgery may be needed to remove the dead portion.

When to Contact a Medical Professional

Call your provider if you have:

• Changes in bowel habits
• Fever
• Nausea
• Severe abdominal pain
• Vomiting

Prevention

The following lifestyle changes can reduce your risk for narrowing of the arteries:

• Getting regular exercise
• Following a healthy diet
• Treating heart rhythm problems
• Keeping your blood cholesterol and blood sugar under control
• Quitting smoking