Carotid Artery Disease, Endarterectomy and Stenting
Carotid endarterectomy is the surgical removal of fatty plaque build up from any of the four carotid arteries that supply blood to the neck. Carotid endarterectomy is a preventive measure to prevent strokes. Carotid endarterectomy is usually recommended following a series of strokelike attacks called transient ischemic attacks (TIAs) that suggest a full-scale stroke is about to happen. Strokes can result in brain damage, disability and death.
Transient ischemic attacks (TIAs) produce stroke symptoms but resolve within 24 hours. Most TIAs resolve within an hour of onset. People that have TIAs are at increased risk for peripheral and coronary artery disease and a later heart attack or stroke.
Anatomy of the Carotid Arteries
There are two main blood vessels, the left and right common carotid artery, that are the main blood supply to the neck and head. The left carotid arises directly from the aortic arch (the major artery of the heart) and the right from the brachiocephalic artery. The two common carotids divide to form the external and internal carotid arteries. Arteries are blood vessels that carry oxygenated blood.
The external carotid supplies blood to the head. It branches from the top of the common carotid and goes behind the mandible towards the rear of the parotid gland. The internal carotid supplies blood to much of the cerebral hemisphere, the eye and the orbit. It begins about the level of the trachea (windpipe) and runs up the neck and into the base of the skull.
Carotid Artery Disease
Carotid atherosclerotic disease is associated with 15% of ischemic strokes. Carotid artery disease is when the carotid arteries get clogged with fatty deposits, called plaque. Plaques are made of cholesterol, calcium, fibrous tissue and other cellular debris that build up in the artery. The process of fatty materials depositing on the artery walls (plaque build up) is called atherosclerosis. The amount of plaque depends on your family history (heredity), age and/or your lifestyle. Other factors like smoking, high cholesterol, high blood pressure, and diabetes can worsen the build up of plaque on the artery walls causing stenosis or narrowing of the arteries.
The blockage usually develops slowly and there are no signs until you have a transient ischemic attack (TIA) also called a ministroke. The milder form of stroke, a TIA , is caused by a lesser narrowing of the arteries so the blood supply to the brain is partially reduced.
Eventually, the blockage of the carotid arteries can lead to stroke (cerebrovascular accident). A stroke is when the blood supply to the brain is either reduced or completely stopped due to severe blockage (stenosis) in the carotid artery.
Treatment for carotid artery disease is often a combination of lifestyle changes (stopping smoking and changes in diet), and taking medicine to prevent or reduce the plaque build up. In severe cases, treatment can include surgery to remove the plaque and fatty deposits or place stents in the arteries to open up artery to increase the blood flow to the brain.
Signs and Symptoms of Carotid Artery Disease
Carotid artery disease doesn’t produce any signs or symptoms in its early stages. You may not know you have it until your arteries have narrowed enough to cause a TIA or stroke.
The symptoms of a TIA or Stroke:
• Fainting spells, lightheadedness or blackouts.
• Sudden and/or persistent severe headache. People with stroke often say they have the worst headache of their life.
• Difficulty speaking such as slurring or total loss of speech.
• Problems with your vision or blindness.
• Confusion or difficulty in understanding.
• Loss of balance, trouble walking.
• Sudden numbness/weakness and/or paralysis of the face, arm and leg which usually affects only one side of the body.
If you have any of these symptoms you might be having a stroke—you should get medical help right away. Even if they go away, don’t ignore the symptoms. Getting medical help may prevent a stroke.
Usually the symptoms last less than an hour, in which case you should see your doctor; a TIA is a sign that you are at high risk for a stroke and you should get treatment.
Risk Factors for Carotid Artery Disease
• Age. As we get older, our arteries become less elastic and more prone to injury.
• High blood pressure. High blood pressure is an important risk factor for carotid artery disease. Too much pressure on the artery walls can weaken them and make them easier to damage.
• Smoking. Nicotine can irritate the inner lining of your arteries. It can increase your heart rate and raise your blood pressure.
• Too much fat in your blood. High levels of low-density lipoprotein (LDL) cholesterol and triglycerides can cause plaque to build up faster.
• Diabetes. Diabetes affects your ability to handle sugar and your ability to process fats putting you at a higher risk for high blood pressure and atherosclerosis.
• Obesity. Carrying around too much weight increases your risks for high blood pressure, atherosclerosis and diabetes. Being overweight can also make you less active and more prone to injuries exercise injuries.
• Heredity. A family history of atherosclerosis or coronary artery disease increases your risk of carotid artery disease.
• Not enough exercise. Lack of exercise contributes to many health problems, including high blood pressure, diabetes and obesity.
The more of these factors you have, the more likely you are to develop carotid artery disease.
Diagnosis of Carotid Artery Disease
Before starting treatment, your doctor has to determine how much narrowing and blockage you have. Stenosis can be found during a physical examination by using a stethoscope to check the sound of the blood flow in the carotid artery. When there is narrowing of the artery, the blood rushes through the artery which makes a sound called a “bruit.”
If you have symptoms or a history of a TIA or stroke your doctor can more easily identify the stenosis and plan treatment. If you have not had a TIA or stroke, other tests are done to find out how much stenosis you have. These tests include:
Doppler ultrasound – Ultrasound waves are sent to the tissues and the blood flowing in the arteries, which bounce back as echoes and translated into images.
Oculoplethysmography (OPG) – This is an indirect process, where the pulse of the arteries behind the eyes is measured the amount of blockage in the carotid artery.
Computed tomography (CT) scan or computer-assisted tomography (CAT) scan – This is a process of taking many cross-sectional x-rays of the head and brain. This scan also an indirect process as the test does not identify blockage or stenosis, instead it eliminates other problems that cause similar symptoms.
Arteriography – Also called Digital Subtraction Angiography (DSA). In this process a dye is injected into the patient’s vascular system and then xrays are taken of the carotid arteries. This process has risks since it is an invasive procedure, but it gives an accurate diagnosis.
Magnetic Resonance Angiography (MRA) – With the help of computer software and a powerful magnetic field, a detailed image of the arteries is created. An MRI is not an invasive procedure but is a very accurate one.
Treatment of Carotid Artery Disease
How your doctor treats the disease will depend on how narrow your arteries are the symptoms you’re having. If your arteries have mild narrowing, your doctor will likely treat you with lifestyle changes and medicine to prevent further plaque build up.
• Lifestyle changes. Stop smoking, lose weight if you need to and exercise are all changes you can make to lower your risk and stop the progression of carotid artery disease. It is also very important that you manage a chronic health condition, especially high blood pressure, high cholesterol and diabetes.
• Medicine. Daily aspirin therapy or other blood thinning medicines can help keep blood clots from forming. Blood pressure medicine may be needed if losing weight and exercise are not enough.
If the narrowing in your arteries is severe enough to cause TIAs or a stroke, then surgery to remove the blockage will be recommended. Your doctor may recommend a vascular surgeon for a carotid endarterectomy or angioplasty with a stent implant. Carotid endarterectomy is the most common treatment for severe narrowing. There is low risk with this surgery if you are otherwise healthy.
If the blockage of the artery is located in an area that the surgeon can’t get to with surgery, then angioplasty and stenting may be recommended.
If your disease requires surgery a vascular surgeon will likely perform the operation. Tests are often done to find out if there is stenosis in other arteries and whether your have other health problems related to high blood pressure or heart diseases. If these tests show that the risks of surgery are too high, the surgeon may postpone surgery.
If you are OK for surgery routine blood and urine tests will be done. You may also have an EKG and chest xray to see if you are otherwise healthy enough for surgery and anesthesia.
The surgery begins with an incision on the neck down to the carotid artery. A temporary rerouting of the artery is done while the surgery is in process. The plaque and fatty deposits are removed from the walls of the arteries. The arteries are stitched back into position. Sometimes arteries need to be patched with either artificial materials or with a vein graft taken from the patient’s leg. When the surgery is finished the neck incision is closed.
How long you stay in the hospital depends on your overall health before surgery, how well you tolerated the surgery and how soon you recover enough to go home.
After Carotid Endarterectomy
After surgery, the patient usually stays in the hospital for a couple of days to watch for complications. Then the patient is discharged with instructions to avoid strenuous activities and slowly increase the level of activity as tolerated. The patient is also given instructions for a low-sodium, low-fat diet, to do moderate exercise, and quit smoking as these lifestyle changes will help avoid the risk of the artery becoming blocked again.
This procedure is relatively new and is still evolving. A long thin tube is inserted in the groin and moved up the aorta, behind the heart and to the carotid artery using xrays as a guide; instruments are moved through the artery inside the tube to the blocked area. An angiogram (xrays with dye) is taken of the artery. A filter is used to keep the plaque from breaking off and going to the brain and causing a stroke. With angioplasty and stenting a catheter with a balloon is inserted in to the narrowed artery and inflated to open up the artery. Then the balloon is deflated and removed. Then a stent (a small wire mesh) is fed up the artery with a catheter into the opened up area with a guide wire and left inside the artery to keep the artery open. The catheter is taken out leaving the stent in place. A balloon opens the stent further and widens the artery. The balloon is removed leaving the stent in place to hold the artery open. An after angiogram is taken and compared to the before angiogram. If the result is good, the filter and instruments are removed and the puncture site in the groin is closed.
When you get home:
• Take blood thinner medications as prescribed to prevent blood clots from forming on the stent. These medications can make you to bruise more easily.
• Shower instead of taking tub baths for a few days.
• Don’t lift anything over 10 pounds for a few days.
• Take it easy, but get back to your normal routine as much as you can.
• Talk to your doctor before driving, returning to work, and other activities you are concerned about.
Call your doctor if you have:
• swelling, redness, bleeding, warmth, leaking of fluids, or increasing pain at the incision site in your leg
• a cold or painful leg or foot
• a severe headache
Call 911 if you have any of these symptoms of a stroke:
• Paralysis or weakness on one side of the body
• Numbness or tingling on one side of the body
• Difficulty speaking
• Blindness in one eye
• One side of the face is drooping
Risks and Complications
All surgery has risks and sometimes complications (like bleeding, infection, scarring, complications from anesthesia, etc.), carotid endarterectomy can have its own complications of the esophagus (food pipe), trachea (air tube), vocal cords and even the nerves of the face, mouth or tongue. Because these are very close to the surgical site, although rare, there is always a possibility of damaged during surgery.
There is also the possibility of a that a blood clot from the endarterectomy may block another artery causing an embolism or even a stroke.
The severity of the complications depends on the patient’s age and their overall health.
Preventing Carotid Artery Disease
In order to prevent a stroke, the risk factors for stroke should be eliminated or controlled. These risk factors include:
• high blood pressure
• high blood sugar
• heart disease
When these factors are controlled, the chances of a stroke can be significantly reduced.
Certain nutritional supplements are known to reduce the homocysteine level (an amino acid that is one of the causes of plaque formation), increase the oxygen level in the blood and improve the blood circulation. These are folic acid; vitamins B6, B12, C and E; angelica (a herb known for its anticoagulant or blood thinning properties). Ask your doctor if you should take these supplements or a daily vitamin.
Though carotid endarterectomy is a safe and effective procedure to remove plaque from the carotid arteries, it is always better to do what you can to prevent plaque from forming.
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