The mesenteric arteries are the three major arteries that supply blood to the stomach, small intestine, and large intestine. The word "ischemia" means decrease in oxygen supply. Mesenteric ischemia is a condition in which the mesenteric arteries do not deliver enough blood and oxygen to the small and large intestines. This makes it difficult for the intestines to digest food and can cause segments of the intestine to die.
Mesenteric artery ischemia is often seen in those with hardening of the arteries elsewhere in the body, such as that associated with coronary artery disease or peripheral vascular disease. The condition is more common in smokers and in patients with high cholesterol.
Mesenteric ischemia may also be caused by a blood clot (embolus) that moves through the blood and suddenly blocks one of the mesenteric arteries. The clots usually come from the heart or the aorta. These clots are more commonly seen in patients with heart arrhythmias such as atrial fibrillation.
Signs and Symptoms
Chronic mesenteric ischemia caused by atherosclerosis is commonly associated with chronic abdominal pain after eating, and occasionally, diarrhea. Acute mesenteric ischemia due to an embolus is frequently associated with sudden onset severe abdominal pain, vomiting, and diarrhea.
Angiography is the gold standard for diagnosis of this condition. An angiogram is a test where dye is injected into the blood vessels of the intestines to look for narrow areas. The dye is usually injected through a catheter placed into an artery in the groin. The dye can cause allergic reactions or damage to the kidneys, but these are rare. Because of the risks of angiograms, chronic mesenteric ischemia may be evaluated by other less invasive screening tests first. Regardless of the screening test performed, an angiogram is usually necessary to determine the best treatment for chronic mesenteric ischemia. Our preferred screening test is duplex sonography, which employs sound waves to obtain pictures of the intestinal arteries.
Prevention includes following lifestyles changes that reduce your risk for atherosclerotic disease. This includes:
·Follow a healthy diet
Chronic mesenteric ischemia is usually treated with surgery. The narrow or blocked portion of the arteries may be removed and the arteries are then reconnected to the aorta. Or, the blocked part of the artery may be bypassed, with a piece of vein or a plastic tube. Acute mesenteric ischemia is treated with emergency surgery. It is extremely important to restore the blood supply to the intestine as quickly as possible by removing the blockage from the artery. Portions of the intestine may have to be removed if the lack of blood has caused any of the tissue to die.
Nonocclusive mesenteric ischemia is treated medically, while acute and chronic ischemia is correctable with surgery. The first step in treating nonocclusive ischemia is identifying the underlying cause and, once found, correcting it. For instance, if a patient is found to have vasospastic disease, direct injection of papaverine into the SMA may resolve the vasospasm. If resolution with papaverine occurs, start an infusion of 30-60 mg/h.
A baloon is threaded through the artery and is inflated at the location of the blockage to restore blood flow.
Medicines that dilate the arteries, such as papaverine, is given intravenously to open the clot.