Intestinal Ischemia
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.
Causes
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.
Types
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.
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.
Risk factors
Just like any form of blood vessel disease, factors that increase the risk of developing chronic mesenteric ischemia include:
Smoking
Diabetes
Hypertension (high blood pressure)
High lipid values (cholesterol, LDL, triglycerides)
Symptoms
Acute Mesenteric Ischemia
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
Chronic Mesenteric Ischemia
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)
Diagnosis
Acute Mesenteric Ischemia
An arteriogram is used to diagnose 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.
Chronic Mesenteric Ischemia
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).
Treatment
Acute Mesenteric Ischemia treatment
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 treatment
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.