What Is Mesenteric Artery Ischemia?
Mesenteric artery ischemia is a condition that restricts blood flow to your intestines. There are three main arteries that supply blood to your small and large intestines. These are called the mesenteric arteries. Narrowing or blockage of the arteries reduces the amount of blood that travels to your digestive tract.
When your intestines do not receive enough oxygen-rich blood, it can lead to serious health problems—including cell death and permanent damage. It can even be life threatening. Luckily, the disease is very rare, accounting for less that 0.1 percent of hospital visits every year (Tessier, 2011).
Causes of Mesenteric Artery Ischemia
People of any age can develop mesenteric artery ischemia (MAI), but it is most common in adults older than 60.
MAI may be related to cardiovascular disease, according to the National Institutes of Health (NIH, 2012). The mesenteric arteries that deliver blood to your intestines branch off from the aorta, the heart’s main artery. Heart disease caused by atherosclerosis or the buildup of plaque (an accumulation of fatty deposits) in the vessel walls is usually associated with the same changes in the aorta and the vessels that branch off of the aorta.
High cholesterol contributes to the ischemia because it causes your arteries to become lined with plaque. This plaque buildup (called “atherosclerosis”) causes narrowing of the vessels and reduces the blood flow to your intestines. You are more likely to develop atherosclerosis if you smoke, have high blood pressure, or have high cholesterol.
Blood clots can block the mesenteric arteries and reduce blood flow to the digestive tract. A blood clot is a group of blood cells that stick together. Blood clots can also increase your risk of stroke if they travel to the brain. Birth control pills and other medications containing estrogen can increase your risk of developing blood clots.
Cocaine and methamphetamine use can also lead to ischemia in some people (Mayo Clinic, 2012). These drugs cause your blood vessels to narrow.
Surgery involving the blood vessels is another possible cause of ischemia. Surgery can create scar tissue that narrows the arteries.
Symptoms of Mesenteric Artery Ischemia
Mesenteric artery ischemia is divided into two types: acute and chronic. The acute form of the disease appears suddenly and with severe symptoms. The chronic type of MAI has a more gradual onset. For most people, blood clots cause acute ischemia, while atherosclerosis is usually the cause of chronic ongoing symptoms.
- abdominal pain and tenderness
- bloating or a sense of fullness
You may also have a sudden urge to have frequent bowel movements during an acute case of MAI. Blood in the stool is a common symptom.
Stomach pain after eating is also a symptom of chronic ischemia. You may develop a fear of eating due to the expectation of pain. This can cause unintended weight loss.
Diagnosis of Mesenteric Artery Ischemia
Your doctor will take your medical history and perform a physical exam to diagnose MAI. Imaging tools can confirm a narrowing of one or more mesenteric arteries. These include:
Computed Tomography (CT) Scans
CT Scans use X-rays to produce cross sectional images of body structures and organs.
This imaging tool is a sonogram that uses high-frequency sound waves to create images of body organs.
MRI (magnetic resonance imaging) uses a magnet and radio waves to look at body organs.
An MRA (magnetic resonance angiography) is an MRI exam of the blood vessels.
This is a procedure that uses X-rays and a special dye to look at the inside of blood vessels.
Treatment for Mesenteric Artery Ischemia
Acute blockages in the intestines must be treated immediately to prevent tissue death. Usually, in the case of an acute ischemia attack, surgery is performed to remove blot clots, scar tissue, and parts of the intestines that have already died. Your doctor may prescribe blood-thinning medications to prevent future blood clots.
Angioplasty is another treatment option for arteries that have narrowed. A mesh tube called a stent can be placed into the narrowed artery to hold it open. In cases of total blockage, sometimes the blocked artery is bypassed altogether.
Chronic mesenteric artery ischemia may be treated with surgery, if needed. Surgery is not always necessary if intestinal ischemia progresses slowly. Lifestyle adjustments may help reverse atherosclerosis naturally. Lifestyle changes can include following a low-fat and low-sodium diet to reduce your cholesterol and blood pressure levels. Daily exercise can also lower cholesterol, regulate blood pressure, and increase heart health.
These medications also play a role in treating mesenteric artery ischemia:
- antibiotics (if infection has caused a blockage in the intestinal arteries)
- blood thinners to prevent future blood clots, such as heparin or warfarin
- vasodilator drugs to widen your blood vessels, such as hydralazine
Most people with chronic mesenteric artery ischemia recover well with treatment and lifestyle changes, according to the NIH.
The outlook for those with acute intestinal ischemia is less positive. The American Journal of Roentgenology reports that the death rate for acute mesenteric artery ischemia patients can be higher than 60 percent. (Shih & Hagspiel, 2007). The high mortality rate mainly stems from treatment that occurs too late, after intestinal tissue has already died.