Atherosclerotic plaque buildup in the carotid arteries can block blood flow to the brain or can break off into small floating particles that can result in transient ischemic attack (TIA, or mini-stroke) or permanent stroke.
The surgical removal of the inner lining of a carotid artery that contains plaque deposits is called carotid endarterectomy.
Carotid endarterectomy is an effective, safe, and long-lasting treatment that has been proven to prevent stroke.
The two common carotid arteries bring oxygenated blood from the heart through the neck to each side of the head. Each main artery branches off into the external carotid and internal carotid arteries. The internal carotid artery is the important branch because it continues into the brain. The external carotid artery is one of many arteries that supply blood to the face and scalp.
As people age, plaque can build up inside their arteries. Over time, these plaques collect on arterial walls as cholesterol circulates in the blood. As the plaques enlarge, the arteries become narrow and stiff, a process called atherosclerosis or 'hardening of the arteries.' Plaque buildup is typically seen in the carotid artery at the point where it branches into the internal and external carotid arteries and in the origin, or lower part, of the internal carotid artery.
Blood clots forming on the plaque can cause an occlusion or blockage, preventing the flow of blood to the brain. The blockage can create an ischemia, or lack of oxygen caused by insufficient blood flow, which can cause an ischemic stroke if the blood flow is blocked long enough.
Atherosclerotic plaques in the carotid arteries can also increase a person's risk of an arterial embolism, the sudden blocking of an artery by a small piece of loose plaque or a loose blood clot.
Endarterectomy is a treatment for carotid arteries that are partially blocked by atherosclerotic plaque, and is usually only done when the amount of partial blockage is severe enough to threaten a stroke. Endarterectomy is the most commonly performed vascular surgery procedure. When experienced, competent surgeons perform the procedure, its risks and benefits are well known for people with or without transient ischemic attack (TIA) symptoms.
Left, an angiogram shows an internal carotid artery that is sufficiently narrowed by plaque buildup to threaten a stroke. Right, the angiogram shows the same carotid artery after physicians performed a carotid endarterectomy.
WHEN IS THE PROCEDURE INDICATED?
Physicians perform endarterectomy based on assessments of the blockage caused by plaque in a carotid artery and by considering other factors, such as history of TIA or prior stroke and the status of other vessels supplying blood to the brain in each person.
Common indications for carotid endarterectomy include:
Persons who have had a TIA or mild or moderate stroke within the past six month and have carotid artery stenosis (blockage) between 50 and 69 percent; or
The presence of severe degrees of blockage even without any warning symptoms.
Carotid endarterectomy may also be recommended prior to heart surgery if there is severe blockage or combined with required coronary artery bypass graft surgery.
Endarterectomy may be inappropriate for people for whom surgery poses a significantly increased risk, such as:
People of very advanced age or who have a serious disease, such as uncontrolled cancer;
People with surgically inaccessible atherosclerotic plaques; and
People with problems with other blood vessels in the head, such as cerebral aneurysm.
Prior to the endarterectomy, a physician may order the following tests to assess the plaque buildup inside the arteries:
Magnetic Resonance Arteriography.
WHAT TO EXPECT
Before the operation, the physician cleans and shaves the skin on the neck to help prevent infection. The patient may be given a general anesthesia, or the patient may remain awake and given a local anesthetic to numb the neck area.
The surgeon makes an incision along one side of the neck and carries the incision down to expose the blocked carotid artery. Then the surgeon retracts, or draws back, the jugular vein, as well as nerves that lead to the ear, tongue and vocal cords. The sections of the common, external, and internal carotid arteries affected by plaque buildup are separated from surrounding tissue and are clamped to temporarily stop blood from flowing through them.
Once the arteries are clamped, the surgeon makes an incision, called an arteriotomy, directly into the section of the carotid artery that is blocked by plaque. During the time the carotid artery is open and clamped, blood does not flow through the artery. A temporary bypass (called a shunt) is often used to carry blood flow around the section of the artery that is being repaired. During the procedure, the brain gets its blood supply from the common carotid on the other side of the neck and other blood vessels.
The surgeon then removes or peels out the entire carotid plaque by removing the inner lining of the diseased section of artery. Once all plaque deposits are removed from the carotid arteries, the arteriotomy is closed. The closure may be made either with sutures that pull the edges of the arteriotomy together, or with a patch, a prosthetic material or a piece of vein that is stitched into the space made by the arteriotomy, slightly widening the artery. The artery clamps are removed and the surgeon stops any bleeding. The neck incision is then closed and the endarterectomy is complete.
The procedure typically takes about two hours.
POST TREATMENT GUIDELINES
Following the procedure, the patient may spend one or two days in the hospital. During this stay, the physician will monitor the patient to ensure normal brain functioning, maintain blood pressure, and watch for any sign of bleeding from the neck area.
After discharge, physicians recommend that the patient:
Limit physical activity for several weeks;
Avoid driving a car; and
Report any change in brain function, severe headaches, or swelling in the neck.
The patient is usually able to resume normal activity several weeks following the operation.
Restenosis, or re-blockage of the carotid artery, occurs in approximately six percent of patients. To help prevent restenosis, the physician recommends lifestyle changes, which include:
Maintaining an ideal weight;
Exercising regularly; and
Avoiding foods that are high in cholesterol and saturated fat.
Although carotid endarterectomy is effective in reducing the likelihood of future strokes, there is a risk of serious complications such as stroke during the procedure. This risk can range between one and three percent.
Another recognized risk of carotid endarterectomy is injury to the nerves on the neck. In most cases, nerve dysfunction may be temporarily caused by swelling or stretching and clears up on its own within two weeks.
Factors that increase the risk of complications include:
Extensive arterial blockage in other blood vessels;