Carotid endarterectomy

The carotid arteries are the main arteries that deliver blood to the head and neck. The common carotid artery branches into the internal and external carotid arteries on each side of the neck. Carotid endarterectomy is the surgical removal of cholesterol buildup within the blood vessels from the lower part of the internal carotid artery.


Purpose
Carotid endarterectomy can help prevent strokes or transient ischemic attacks by removing plaque in the carotid artery. Transient ischemic attacks are also known as TIAs or "mini-strokes." They're caused by reduced or blocked blood flow to the brain. By definition, a TIA lasts less than 24 hours and causes no lasting neurological damage.

Indications
Many factors are considered before a carotid endarterectomy is recommended, including your risk factors for a stroke and whether you've had symptoms of TIA. The procedure is typically recommended for people who have a significant amount of carotid stenosis (narrowing or obstruction of the arteries), which increases the risk of stroke.
The symptoms of TIA are brief, temporary and may include:

weakness, tingling or numbness on one side of the body
vision loss, typically in one eye
dizziness or lightheadedness
difficulty speaking or loss of speech
loss of balance or coordination
headache, usually sudden and severe
confusion
Without proper medical evaluation and treatment, TIAs may signal an impending stroke.

Carotid endarterectomy may be recommended for people who have symptoms of a TIA and greater than 50-percent carotid narrowing. Some surgeons recommend carotid endarterectomy for people who have severe carotid narrowing with no other symptoms.

If you have atherosclerosis of the carotid arteries, you may have atherosclerosis elsewhere and be at high risk for a heart attack during and after the procedure. You'll need a careful preoperative evaluation to determine your risk of a heart attack and to start interventions that can reduce the risk. In addition to a thorough medical history and physical exam, you'll probably have an electrocardiogram (a recording of the electrical activity of the heart). A cardiac stress test may also be recommended to look for evidence of heart disease.

If you smoke, your doctor will encourage you to quit, regardless of whether you're a candidate for surgery. He or she may also prescribe medication to prevent the formation of blood clots and reduce cholesterol levels.


Diagnostic tests
Before endarterectomy, various diagnostic studies may be done to clarify the diagnosis and verify the need for surgery. For example:
Doppler ultrasound imaging uses sound waves to help the doctor study the carotid arteries. This test is also called duplex imaging.

Arteriography and digital subtraction angiography (DSA) are X-rays of the carotid artery taken after a special dye is injected into an artery in your arm or leg. These particular tests carry a very slight risk of causing a stroke.

Magnetic resonance angiography (MRA) is a diagnostic study that doesn't use dye. Through powerful magnetic fields, this tool uses enhanced magnetic resonance imaging (MRI, an imaging technique based on computer analysis of the body's response to a magnetic field) to see body tissues and blood flow characteristics.

Computed tomography (CT scan) produces a series of cross-sectional X-rays of the head and brain. This test doesn't detect carotid artery disease, but may be used to detect previous strokes and other causes of neurological symptoms, such as a brain tumor or infection.

Oculoplethysmography (OPG) measures the pulse of the arteries in the back of the eye. OPG is used to indirectly check for blockage of the carotid artery.
Often, your medical condition will require individually tailored tests.


Patient preparation
Although every surgery has its own standard procedure, your individual health history could play a role in any variation to the procedure. Discuss these issues with your doctor.
Before you're given anesthesia, you'll meet with an anesthesiologist (a doctor who specializes in the administration of anesthesia for surgeries and other procedures) to discuss any concerns you may have. You'll be asked to sign an informed consent form.


Procedure
Carotid endarterectomy is done under local or general anesthesia. An arterial line (a monitoring system made of a special tube connected to pressure tubing and an electronic monitor) may be inserted into an artery to monitor your blood gases and blood pressure. Blood may also be drawn from this line. You may also have electroencephalogram (EEG) leads placed on your scalp to monitor your brain activity during surgery.
To expose the surgical area, you'll be positioned on your back with your head slightly tilted. The surgeon will make an incision down the side of your neck to expose the carotid artery, being careful not to damage any nerves in the area.

In order to operate on the carotid artery, the surgeon must clamp the artery upstream from the surgical field. Enough blood flow adequately reaches the brain, however, through the other neck arteries. In some cases, the surgeon will use a bypass shunt (a special type of tubing placed inside the artery) to help blood flow to the brain.

Once the carotid artery is open, the surgeon will remove the plaque deposits from the arterial walls with a dissecting tool and then close the artery.


Postprocedure care
You'll be taken to a recovery room and closely monitored while the anesthesia wears off. Nausea and vomiting are possible.
During the first hour, your vital signs will be taken about every 15 minutes. Your neurological and cardiac status will also be monitored. The medical staff will check your pupils (the structure at the center of the iris, the colored part of the eye, that contracts and expands to control the amount of light entering the eye) for size equality and reaction to light. Your hand grip and extremity reflexes will also be checked. The surgical site will be watched carefully for any internal bleeding that could lead to a hematoma (a swelling or mass of blood), and the wound will be cared for according to the doctor's instructions.

When you're fully conscious, you'll be asked general questions to determine your mental status and quality of speech. For a short time, you may experience a severe headache and lightheadedness due to increased blood flow in the newly opened artery. You'll be given pain medication as needed. Beta-adrenergic blocking agents may also be prescribed to reduce the severity of symptoms related to the increased blood flow.


Benefits
Endarterectomy can help reduce the risk of initial and recurrent TIAs or strokes.

Risks
Complications may vary greatly depending on the surgeon's expertise and your general health. Possible risks include:
stroke
heart attack
postoperative hypertension (increased blood pressure) or hypotension (decreased blood pressure)
injury to a cranial nerve (one of 12 pairs of nerves originating in the brain)
wound hematoma (a swelling or mass of blood near the wound)
If there's any arterial blockage, you may develop facial paralysis (such as drooping of the corner of your mouth). This paralysis may resolve on its own with time. In extreme cases, the procedure may lead to fatal complications.


Considerations
Ask your surgeon about his or her success record for carotid endarterectomy and postoperative complications.
Risk factors for carotid blockage include:

high blood pressure
previous cardiovascular disease
obesity
diabetes
smoking
high cholesterol
If your lifestyle contributes to carotid blockage, your doctor may recommend lifestyle changes such as quitting smoking, eating less food high in cholesterol and saturated fat, and exercising regularly.


Pregnancy-specific information
If you have significant carotid stenosis, you'll need medication and close supervision throughout your pregnancy. Depending on your medical condition, you may need specialty care from a neurologist.

Senior-specific information
The risk of developing atherosclerosis, an underlying cause of carotid artery stenosis, increases with age. This is one of the reasons why the risk of having a stroke also increases with age. Discuss individual risk factors and treatment options with your doctor.