Carotid endarterectomy (CEA) and carotid artery angioplasty with stenting (CAS) are procedures performed to treat carotid artery disease in certain circumstances. Carotid artery disease, also called carotid artery stenosis, occurs when the carotid arteries, the main blood vessels that carry oxygenated blood to the brain, become narrowed.
Narrowing of the carotid arteries is most commonly related to atherosclerosis (a build-up of plaque, which is a deposit of fatty substances, cholesterol, cellular waste products, calcium, and fibrin in the inner lining of an artery). Atherosclerosis, or "hardening of the arteries," is a vascular disease (disease of the arteries and veins). Carotid artery disease is similar to coronary artery disease, in which blockages occur in the arteries of the heart, and may cause a heart attack.
Atherosclerosis is a slow, progressive, vascular disease that may start as early as childhood. However, the disease has the potential to progress rapidly. It is generally characterized by the accumulation of fatty deposits along the innermost layer of the arteries. If the disease process progresses, plaque formation may take place.
This thickening narrows the arteries and can decrease blood flow or completely block the flow of blood to the brain.
To better understand how carotid artery disease affects the brain, a basic review of the anatomy of the circulation system of the brain follows.
Carotid arteries
The main supply of blood to the brain is carried by the carotid arteries. The carotid arteries branch off from the aorta (the largest artery in the body) a short distance from the heart and extend upward through the neck carrying oxygen-rich blood to the brain.
There are six carotid arteries: the right and left carotid arteries divide to provide the right and left internal carotid arteries and the right and left external carotid arteries. One pair (external and internal) is located on each side of the neck. Just as a pulse can be felt in the wrists, a pulse can also be felt on either side of the neck over the carotid arteries.
Because the carotid arteries deliver blood to the brain, carotid artery disease can have serious implications by reducing the flow of oxygen and nutrients to the brain. The brain needs a constant supply of oxygen and nutrients in order to function. Even a brief interruption in blood supply can cause problems. Brain cells begin to die after just a few minutes without blood or oxygen. If the narrowing of the carotid arteries becomes severe enough to block blood flow, or a piece of atherosclerotic plaque breaks off and obstructs blood flow to the brain, a stroke may occur.
Unfortunately, there may be no symptoms of early carotid artery disease. An abnormal sound called a bruit (pronounced brew-ee) may be heard by a stethoscope placed on the carotid arteries in the neck. A bruit is an abnormal sound that is produced by blood passing through a narrowed artery. A bruit is generally considered a sign of an atherosclerotic artery; however, an artery may be diseased without producing a bruit. If the disease continues to progress until sufficient artery blockage exists, problems may occur, such as a stroke. Because brain tissue cannot be regenerated (replace itself), stroke prevention is the goal of treatment.
Surgical treatments of carotid artery disease
There are two procedures used to treat carotid artery disease. The standard surgical procedure is carotid endarterectomy (CEA), while the newer minimally invasive endovascular intervention is called carotid artery angioplasty with stenting (CAS).
Carotid endarterectomy. In a carotid endarterectomy, atherosclerotic plaque that has built up on the inside of the carotid artery wall is surgically removed. An incision is made on the side of the neck where the affected carotid artery is located. Under direct visualization, the artery is opened and the plaque removed. The artery is sutured back together, restoring normal blood flow to the brain. This procedure may be performed while a patient remains awake under local anesthesia or while the patient is asleep under general anesthesia.
Carotid artery angioplasty with stenting (CAS). Carotid artery angioplasty with stenting (CAS) is a minimally invasive procedure requiring only a small incision in the groin. A special catheter (long hollow tube) is inserted into the carotid artery to be treated. This catheter has a tiny balloon at its tip. The balloon is inflated once the catheter has been placed into the narrowed area of the carotid artery. The inflation of the balloon compresses the fatty tissue in the artery and makes a larger opening inside the artery for improved blood flow. A stent (a tiny, expandable metal coil) may be inserted into the newly-opened area of the artery to help keep the artery from narrowing or closing again. Because of the potential for clots (emboli) to dislodge from the plaque into the circulation of the brain and possibly cause a stroke, there are now devices called embolic protection devices (EPD) being used during CAS. One type of EPD has a filter-like basket attached to a catheter that is positioned in the artery so as to "catch" any clots or small debris that might break loose from the plaque during the procedure. This technique may help reduce the incidence of stroke during carotid angioplasty.
Your doctor will determine the most appropriate intervention for treating your carotid artery disease.
Other related procedures that may be used to diagnose carotid artery disease include carotid artery duplex scan and cerebral arteriogram. Please see these procedures for additional information.
Importance of carotid stenting
Carotid endarterectomy may be performed to treat a blockage or narrowing of the carotid arteries, thus improving blood supply to the brain. Carotid endarterectomy has been shown to be effective for preventing stroke in carotid artery disease.
Carotid artery angioplasty with stenting (CAS) is a procedure currently being used on selected patients who are at high risk for surgery. While this procedure is performed widely, the long-term effects are still being studied.
High risk conditions under which CAS may be considered include, but are not limited to, the following:
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Older age
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Coronary artery disease or pending open heart surgery
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Heart failure
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Heart valve disease
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Heart arrhythmias
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Angina or heart attack within the last six months
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Cancer
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Carotid artery disease in more than one carotid artery
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Location of the blockage in the carotid artery
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Carotid artery stenosis (narrowing) caused by radiation, previous surgery on the neck, or severe chronic obstructive pulmonary disease (COPD)
Carotid artery disease may be asymptomatic (without symptoms) or symptomatic (with symptoms). Asymptomatic carotid disease is the presence of a significant amount of atherosclerotic plaque buildup in the carotid arteries without obstructing blood flow enough to cause symptoms. Symptomatic carotid artery disease may result in either a transient ischemic attack (TIA) and/or a stroke (brain attack).
The decision to treat carotid artery disease is based on certain criteria such as, but not limited to, the following:
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Symptomatic and asymptomatic carotid artery disease with blockage greater than 70 percent in the internal carotid artery is usually treated surgically.
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Asymptomatic and symptomatic carotid artery disease with blockage of 50 percent to 69 percent (with results from diagnostic tests indicating blockage closer to 69 percent) may require surgical treatment. Risk factors associated with carotid artery disease are taken under consideration when determining the need for surgery.
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Asymptomatic and symptomatic carotid artery disease with blockage of 50 percent to 69 percent (and results of diagnostic tests indicating blockage closer to 50 percent) may be treated medically, depending on the individual situation.
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Asymptomatic and symptomatic carotid artery disease with blockage of less than 50 percent are generally treated medically.
Choice of treatment, such as carotid endarterectomy, carotid artery angioplasty with stenting, or medical treatment will be determined by your doctor.
There may be other reasons for your doctor to recommend a carotid endarterectomy or carotid artery angioplasty with stenting.