What is carotid stenosis (carotid artery disease)?
The carotid arteries are the two main blood vessels that carry blood and oxygen to the brain. When these arteries become narrowed, it’s called carotid artery disease. It may also be called carotid artery stenosis. The narrowing is caused by atherosclerosis. This is the buildup of fatty substances, calcium, and other waste products inside the artery lining. Carotid artery disease is similar to coronary artery disease, in which buildup occurs in the arteries of the heart. It can cause a heart attack.
Carotid artery disease reduces the flow of oxygen to the brain. The brain needs a constant supply of oxygen to work. Even a brief pause 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 that blood flow is blocked. If a piece of plaque breaks off it can also block blood flow to the brain. In either case, a stroke occurs. Fifteen to 30% of strokes are related to carotid artery disease.
Atherosclerosis causes most carotid artery disease. In this condition, fatty deposits build up along the inner layer of the arteries forming plaque. The thickening narrows the arteries and decreases blood flow or completely blocks the flow of blood to the brain.
Who is at risk for carotid artery disease?
Risk factors associated with atherosclerosis include:
- Older age
- Family history
- Genetic factors
- High cholesterol
- High blood pressure
- Diet high in saturated fat
- Lack of exercise
Although these factors increase a person's risk, they do not always cause the disease. Knowing your risk factors can help you make lifestyle changes and work with your doctor to reduce chances you will get the disease.
What are the symptoms of carotid artery disease?
Carotid artery disease may have no symptoms and they may look like other medical conditions or problems. Always consult your doctor for a diagnosis.
Sometimes, the first symptoms are those of a transient ischemic attack (TIA) or so-called “mini-stroke." A transient ischemic attack (TIA) is a sudden, temporary loss of blood flow to an area of the brain. It usually lasts a few minutes to an hour. You may have short term weakness on one side of your body, or your vision may change suddenly. Symptoms go away entirely within 24 hours, with complete recovery. Stroke symptoms.
If you or a loved one has TIA or stroke symptoms, call 9-1-1 right away. While TIAs generally do not cause permanent brain damage, they are a serious warning sign that a stroke may happen in the future and should not be ignored. TIAs do not precede all strokes, however.
How is carotid artery disease diagnosed?
In addition to a complete medical history and physical exam, tests for carotid artery disease may include:
- Listening to the carotid arteries. For this test, your doctor places a stethoscope over the carotid artery to listen for a sound called a bruit (pronounced brew-ee). This sound is made when blood passes through a narrowed artery. A bruit can be a sign of atherosclerosis. But, an artery may be diseased without producing this sound.
- Carotid artery duplex scan. This test is done to assess the blood flow of the carotid arteries. A probe called a transducer sends out ultrasonic sound waves. When the transducer (like a microphone) is placed on the carotid arteries at certain locations and angles, the ultrasonic sound waves move through the skin and other body tissues to the blood vessels, where the waves echo off of the blood cells. The transducer sends the waves to an amplifier, so the doctor can hear the sound waves. Absence of or faintness of these sounds may mean blood flow is blocked. A carotid artery duplex scan lets the physician know if there’s blockage and what the blood flow is, as well as its speed.
This test is recommended especially if you have had a "mini-stroke."
- MRI scan. This procedure uses a combination of large magnets, radiofrequency, and a computer to make detailed images of organs and structures in the body. For this test, you lie inside a big tube while magnets pass around your body. It’s very loud.
- Magnetic resonance angiography (MRA). This procedure uses a combination of magnetic resonance technology (MRI) and intravenous (IV) contrast dye to make the blood vessels visible. Contrast dye causes blood vessels to appear solid on the MRI image so the doctor can see them.
- CT scan. This test uses X-rays and computer technology to make horizontal, or axial, images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general X-rays. Like an MRI, it’s sometimes done with IV contrast injected into your veins.
- Angiography. This test is used to assess the how blocked the carotid arteries are by taking X-ray images while a contrast dye is injected. The contrast dye helps the doctor see the shape and flow of blood through the arteries as X-ray images are made. MRA and CT angiogram both allow the doctor to get a more clear view of the blockage and to better assess the area.
How is carotid artery disease treated?
Your healthcare provider will figure out the best treatment for you based on:
- How old you are
- Your overall health and past history
- How sick you are
- How well you can handle specific medicines, procedures, or therapies
- How long the condition is expected to last
- Your opinion or preference
Carotid artery disease is very correctible
If a carotid artery is less than 50% narrowed, it is often treated with medicine and lifestyle changes. If the artery is between 50% and 70% narrowed, medicine or surgery may be used, depending on your case.
Medical treatment for carotid artery disease may include:
- Quit smoking. Quitting smoking can reduce the risk for carotid artery disease and cardiovascular disease. All nicotine products, including electronic cigarettes, constrict the blood vessels. This decreases blood flow through the arteries.
- Lower cholesterol. Eat a low-fat, low-cholesterol diet. Eat plenty of vegetables, lean meats (avoid red meats), fruits, and high-fiber grains. Avoid foods that are processed, and high in saturated and trans-fats. When diet and exercise are not enough to control cholesterol, you may need medicines.
- Lower blood sugar. High blood sugar (glucose) can cause damage and inflammation to the lining of the carotid arteries. Control glucose levels through a low-sugar diet, and regular exercise. If you have diabetes, you may need medicine or other treatment.
- Exercise. Lack of exercise can cause weight gain and raise blood pressure and cholesterol. Exercise can help maintain a healthy weight and reduce risks for carotid artery disease.
- Lower blood pressure. High blood pressure causes wear and tear and inflammation in blood vessels increasing the risk for artery narrowing. Blood pressure should be below 140/90 for most people. People with diabetes may need even lower blood pressure.
Medicines that may be used to treat carotid artery disease include:
- Antiplatelets. These medicines make platelets in the blood less able to stick together and cause clots. Aspirin, clopidogrel, and dipyridamole are examples of antiplatelet medicines.
- Cholesterol-lowering medicines. Statins are a group of cholesterol-lowering medicines. They include simvastatin and atorvastatin. Studies have shown that certain statins can decrease the thickness of the carotid artery wall and increase the size of the opening of the artery.
- Blood pressure-lowering medicines. Several different medicines work to lower blood pressure.
When surgery is considered
If a carotid artery is narrowed from 50% to 69%, you may need more aggressive treatment, especially if you have symptoms.
Surgery is usually advised for carotid narrowing of more than 70%. Surgical treatment decreases the risk for stroke after symptoms such as TIA or minor stroke.
Surgical treatment of carotid artery disease includes:
- Carotid endarterectomy (CEA). This is surgery to remove plaque and blood clots from the carotid arteries. The patient undergoes general anesthesia and the procedure involves a cut at the neck. Surgery can take anywhere from 90 minutes to several hours. The patient remains in the hospital for one or two nights.
Surgery is usually recommended if the patient has had no symptoms but the test show 80% blockage or more, or if the patient has had symptoms and has 70% blockage or more. Endarterectomy may help prevent a stroke in people who have symptoms and a narrowing of 70% or more and reduce a patient’s risk of stroke significantly.
- Carotid artery angioplasty with stenting (CAS). This is an option for people who are unable to have carotid endarterectomy. It uses a very small hollow tube, or catheter, that is thread through a blood vessel in the groin to the carotid arteries. Once the catheter is in place, a balloon is inflated to open the artery and a stent is placed. A stent is a thin, metal-mesh framework used to hold the artery open.
The U.S. Preventative Task Force recommends against routine screening for asymptomatic patients but suggest you speak with your primary care physician if you are concerned because of your history. Your doctor may also order a carotid ultrasound based on findings during an exam.
What are the complications of carotid artery disease?
The main complication of carotid artery disease is stroke. Stroke can cause serious disability and may be fatal.
Can carotid artery disease be prevented?
You can prevent or delay carotid artery disease in the same way that you would prevent heart disease. This includes:
- Diet changes. Eat a healthy diet that includes plenty of fresh fruits and vegetables, lean meats such as poultry and fish, and low-fat or non-fat dairy products, Limit your intake of salt, sugar, processed foods, saturated fats, and alcohol.
- Exercise. Aim for 40 minutes of moderate to vigorous-level physical activity at least 3 to 4 days per week.
- Manage weight. If you are overweight, take steps to lose weight.
- Quit smoking. If you smoke, break the habit. Enroll in a stop-smoking program to improve your chances of success. Ask your doctor about prescription options.
- Control stress. Learn to manage stress in your home and work life.
When should I call my healthcare provider?
Learn the symptoms of stroke. If you think you are having symptoms of a stroke, call 911 immediately.
Key points about carotid artery disease
- Carotid artery disease is narrowing of the carotid arteries. These arteries deliver oxygenated blood from the heart to the brain.
- Narrowing of the carotid arteries can cause a stroke or symptoms of a stroke and should be treated right away.
- Risks for carotid artery disease are similar to coronary artery disease.
- Eating a low-fat, low-cholesterol diet that is high in vegetables, lean meats, fruits, and high fiber is one way to reduce the risk of carotid disease. Exercise, quitting smoking, blood pressure control, and medications can help.
- Opening the carotid arteries once they are narrowed can be done with a surgery or with angioplasty and a stent.
- Carotid artery disease may not have symptoms, but if you have significant risk factors, see your healthcare provider for screening and diagnosis.
Tips to help you get the most from a visit to your healthcare provider:
- Before your visit, write down questions you want answered.
- Bring someone with you to help you ask questions and remember what your provider tells you.
- At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you.
- If you have a follow-up appointment, write down the date, time, and purpose for that visit.
- Know how you can contact your provider if you have questions.