What are intestinal ischemic syndromes?
Intestinal ischemic syndromes -- also called visceral or mesenteric ischemic syndromes -- occur when blood flow to the bowel or gastrointestinal system (intestines) is decreased because of a blood vessel blockage.
The three major abdominal blood vessels that may become blocked include the celiac artery, superior mesenteric artery or inferior mesenteric artery. Usually two or three of these arteries must be narrowed or blocked to cause intestinal ischemic syndromes.
What causes these syndromes?
In most cases, intestinal ischemic syndromes are caused by atherosclerosis (buildup of fatty matter and plaque on the blood vessel walls), leading to narrowing or blockage of the vessel. The conditions also can be caused by blood clots or aneurysms (an abnormal enlargement or bulging) in the vessels.
Are these conditions more common at a certain age?
Intestinal ischemic syndromes are more common after age 60 but can occur at any age.
Types of Intestinal Ischemic Syndromes
Intestinal ischemic syndromes can occur suddenly (acute) or over time (chronic).
Acute Mesenteric Ischemia: The arteries supplying oxygen-rich blood and nutrients to your intestines can become narrowed from atherosclerosis in the same way that coronary (heart) arteries become narrowed in heart disease. Mesenteric ischemia can develop if the narrowing or blockage become severe.
Another cause of acute mesenteric ischemia is a blood clot. If a blood clot forms or travels to the narrowed artery, the blood supply to the intestine is suddenly interrupted. The tissues below the blocked vessel will be starved for oxygen-rich blood and die. This event is a life-threatening condition.
Prompt diagnosis and treatment are necessary to save the patient’s intestine and life.
Early signs and symptoms of acute mesenteric ischemia include:
- Severe abdominal pain, concentrated in one area of the abdomen
- Nausea and/or vomiting
- Bloody stools
- History of chronic atrial fibrillation or cardiovascular disease
An arteriogram is used to diagnosis acute mesenteric ischemia. An arteriogram is an invasive test of the blood vessels in which dye is injected and x-ray pictures are obtained.
Abdominal computed tomography (CT) scans and chest X-rays, as well as other tests, may be performed first to rule out other conditions that may have similar symptoms, such as a bowel obstruction.
Emergency surgery may be performed to remove the blood clot (embolectomy) or bypass the blocked vessel and restore blood flow to the intestines. The surgeon may use autologous bypass grafts (patient’s own blood vessels) or artificial grafts. In some cases, the surgeon may need to remove a portion of the intestine if tissue death has occurred.
Another option is the use of a “clot busting” medication. With the aid of an arteriogram, a clot- busting medication may be injected to break up the clot in the artery.
Chronic Mesenteric Ischemia
Chronic mesenteric ischemia is characterized by narrowing of the blood vessels that supply the intestines with nutrients and oxygen-rich blood. This narrowing also is caused by atherosclerosis (buildup of fatty matter and plaque on the blood vessel walls). Chronic mesenteric ischemia is more common in women than men, and occurs after age 60.
Just like any form of blood vessel disease, factors that increase the risk of developing chronic mesenteric ischemia include:
- Hypertension (high blood pressure)
- High lipid values (cholesterol, LDL, triglycerides)
The organs of the gastrointestinal system are responsible for the digestion of food. Therefore, decreased blood supply to these organs cause symptoms related to eating or after-meal digestion, including:
- Abdominal pain after meals
- Weight loss
- Fear of eating or change in eating habits due to post-meal pain
- Nausea and/or vomiting
- Constipation or diarrhea
- History of cardiovascular disease (such as peripheral arterial disease, stroke, coronary artery disease or heart attack)
Abdominal computed tomography (CT) scans, gastrointestinal X-rays and other tests may be performed first to rule out other conditions that may have similar symptoms, such as a bowel obstruction.
Once chronic mesenteric ischemia is suspected, an arteriogram is used to confirm the diagnosis and to evaluate atherosclerosis inside the arteries.
Other tests may include ultrasound, CT scan or magnetic resonance arteriography (MRA).
How is chronic mesenteric ischemia treated?
Treatment for chronic mesenteric ischemia is important to reduce the risk of blood clot formation or other damage to the intestines. Treatment options include:
- Anticoagulant medications, such as Coumadin (warfarin - a blood-thinner), to reduce the risk of blood clots.
- Angioplasty and stenting: A balloon catheter is used to attempt to open the artery and a small stent is placed inside the artery to keep it open.
- Surgery may be performed to remove plaque (endarterectomy), bypass the blocked vessel to restore blood flow to the intestines, or remove or repair an aneurysm. The surgeon may use autologous bypass grafts (patient’s own blood vessels) or artificial grafts during the bypass procedure.
In addition to following a low-fat diet, eating small, frequent meals is recommended for patients with chronic mesenteric ischemia. Regular exercise, as well as managing blood pressure, cholesterol and diabetes, also are recommended.
If you’re prescribed Coumadin (warfarin):
- You will need to have frequent blood tests, called the PT-INR, to evaluate how well the medication is working. Please keep all scheduled lab appointments so you response to the medication can be monitored. Your medications may be changed or adjusted based on the results of this test.
- You should order and wear a medical identification bracelet so you can receive proper medical care in an emergency situation.
- You may bleed or bruise more easily when you are injured. Call your doctor if you experience heavy or unusual bleeding or bruising.
- Certain nonprescription (over-the-counter) medications affect the function of anticoagulants. Do not take any other medications without first consulting with your doctor.
- Ask your doctor for specific dietary guidelines when taking warfarin. Certain foods, such as foods high in vitamin K (found in brussel sprouts, spinach and broccoli) can affect the way the medication works.
- You should not take warfarin if you’re pregnant or planning to become pregnant. Ask your doctor about switching to a different type of anticoagulant medication.