Carotid Artery Disease (Stroke Prevention)

What are the carotid arteries?

The carotid artery is a large blood vessel that supplies oxygenated blood to the large, front part of the brain.  This is where thinking, speech, personality, and sensory and motor functions reside.  You can feel your pulse in the carotid arteries on each side of your neck right below the angle of the jawline.  However, do not push on these until you know they are normal and no plaque will be broken loose.

What is carotid artery disease?

Carotid artery disease is also called carotid artery stenosis.  “Stenosis” refers to a narrowing and in this case the narrowing of the carotid arteries.  This narrowing is usually caused by the buildup of fatty substances and cholesterol deposits called plaque.  Carotid artery occlusion refers to complete blockage of the artery.  When the carotid arteries are obstructed, you are at an increased risk for a stroke, the third leading cause of death in the United States.

If you have a normal carotid artery on each side of the front of your neck, each supplies 40 percent of the blood to your brain.  The two vertebral arteries in the back of your neck that form the basilar artery supply a total of 20 percent of the blood flow to your brain.  Carotid arteries and basilar artery go to the circle of Willis, the circular artery under your brain.  This artery will usually supply enough blood flow to your brain when the carotid arteries are blocked, but this circle may be incomplete in 10 to 20 percent of people.

How does carotid artery disease happen?

The carotid arteries, just like the coronary arteries that supply blood to the heart and the arteries that supply blood to the legs, can also develop atherosclerosis, or “hardening of the arteries,” on the inside of the vessels.  Over time, the buildup of fatty substances and cholesterol narrows the carotid arteries.  This decreases blood flow to the brain and increases the risk of a stroke.  A piece of the plaque may break off and go to the brain causing a stroke.  The plaque may also degenerate forming an ulcer (deep sore).  Blood clots may form at the ulcer.  Pieces of the blood clot may then break off and go to your brain and this is the most common cause of TIAs and strokes.

What are the risk factors for carotid artery disease?

The risk factors for carotid artery disease are those things that stress your arteries and increase the risk of injury, buildup of plaques and include:

  • Age
  • Smoking
  • Hypertension (high blood pressure) which is the most important treatable risk factor for stroke
  • High cholesterol or abnormal lipids
  • Diet high in saturated fats
  • Diabetes
  • Obesity
  • Sedentary lifestyle (lack of exercise)
  • Family history of atherosclerosis

What is a stroke?

A stroke is similar to a heart attack.  It occurs when blood flow is cut off from part of the brain.  A stroke can occur if:

  • The artery becomes extremely narrowed
  • There is a rupture in an artery to the brain that has atherosclerosis and a piece of plaque breaks off and travels to the smaller arteries of the brain
  • The blood clot forms in the ulcer and may break off and go to the arteries around your brain.

Strokes can occur as a result of other conditions besides carotid artery disease.  For example, sudden bleeding in the brain, called intracerebral hemorrhage, can cause a stroke.  Other possible causes include:

  • Sudden bleeding in the spinal fluid space (subarachnoid hemorrhage)
  • Atrial fibrillation (irregular/irregular heartbeat)—clots in it that can break from your heart breaks off and go to your brain
  • Cardiomyopathy (disease of the heart muscles) in which they do not contract appropriately such as ischemia and congestive heart failure
  • Myocardial infarction—blood clots may form on the injured heart muscle (heart attack) and a clot may break off
  • Blockage of tiny arteries inside the brain, premature aging from atherosclerosis or diabetes mellitus

You may have heard someone speak of a “ministroke” or TIA (transient ischemic attack).  This happens when you have a temporary shortage of blood flow to a region of your brain such as from a small blood clot.  A ministroke lasts less than 24 hours.  This means you seek medical attention immediately to see if you have a problem that can be corrected before you have a permanent stroke that occur in hours, days, weeks or months.  You may not get a second chance.

The artery to your eye is the first branch to the artery to your brain after it goes inside your skull.  A transient episode of blindness in one eye like someone pulling a curtain over the eye, can be blood clots breaking loose and the next one can be to your brain and cause a permanent stroke or death.  You could also permanently lose the vision in that eye and then a blood clot to your brain’s speech center may cause you to not be able to speak clearly or not at all.  You should seek medical attention immediately.

What are the signs and symptoms of a stroke?

In its early stages, carotid artery disease often does not produce any signs or symptoms.  You and your doctor may not know you have carotid artery disease until it is serious enough to deprive your brain of blood thus causing a stroke or TIA.  For that reason, it is important that you schedule a routine physical examination and as a part of that exam your doctor will check your carotids by listening to them with a stethoscope.  He may hear a bruit (a “swooshing” sound) which is the sound characteristic of a narrowed artery.  When the artery becomes 95 to 99 percent blocked it may not make any noise and cannot be heard with a stethoscope.

If you hear your pulse swishing in your ear, tell your doctor.

The more common signs and symptoms of a stroke may include:

  • Sudden numbness and weakness in the face or limbs often on only one side of the body
  • Trouble speaking (called aphasia) or understanding what is said
  • Sudden dizziness and/or confusion
  • Sudden difficulty walking, loss of balance or lack of coordination
  • Problems with memory
  • Difficulty swallowing (called dysphagia)
  • Sudden loss of vision, blurred vision, double vision or difficulty in seeing out of one or both eyes.
  • A sudden, severe headache with no known cause

What should I do if I have risk factors or think I’ve had a stroke or TIA?

Talk to your doctor if you have risk factors for carotid artery disease.  Your doctor may do some tests to check the health of your arteries such as test your strength, memory and speech.  Even if you do not have any signs or symptoms, your doctor may recommend aggressive management of your risk factors to protect you from having a stroke.  Seeing your doctor immediately improves your chances of detecting carotid artery disease and having it treated before a disabling stroke occurs.  Your doctor will determine which testing is necessary and best for you.  Possible tests include:

  • Carotid duplex Doppler (ultrasound)  This is ultrasound visualization of the artery plus Doppler examination of arterial flow.  This is a noninvasive, painless screening test that uses high-frequency soundwaves to view the carotid arteries. It looks for plaques and blood clots and determines whether the arteries are narrowed or blocked.  A carotid duplex Doppler (ultrasound) and with color flow Doppler shows the movement of blood through the blood vessels.  Ultrasound imaging does not use ionizing radiation (X-rays).
  • Magnetic resonance angiography (MRA)  This newer imaging technique uses radio waves and a powerful magnet to gather accurate information about the brain and arteries. Then a computer uses this information to generate high-resolution images.  An MRA can often detect even small strokes in the brain. 
  • Computerized tomography angiography (CTA)  More detailed than an X-ray, a CT uses X-rays and computer technology to produce cross sectional images of the carotid arteries. Images of the brain can be collected as well. With this imaging test, the scan may reveal areas of damage on the brain.  The contrast (dye) is usually injected in a vein in the arm like starting an IV.
  • Cerebral angiography (carotid angiogram) This procedure is considered the gold standard for imaging the carotid arteries. It is an invasive procedure that lets a doctor see blood flow through the carotid arteries in real time. Cerebral angiography allows the doctor to see narrowing or blockages on a live X-ray screen as contrast dye is injected in the carotid arteries. The procedure provides the best information. It does carry a small risk of serious complications.  It is usually done through an artery in your groin but can be done through an artery in your arm.

What is the treatment for carotid artery disease?

Your doctor will most likely recommend one or more of the following to treat carotid artery disease:

  • Taking medications as prescribed
  • Considering a procedure  (angioplasty or surgery) to improve blood flow, if your doctor believes it could help
  • Change in lifestyle habits (Prevention)

Which drugs can reduce the risk of stroke?

Your doctor may recommend antiplatelet medications such as aspirin or Plavix to decrease the risk of stroke due to blood clots.  Your doctor may also prescribe medications to lower your cholesterol or medication for your high blood pressure.  A blood thinner may also be prescribed.

What medical procedures treat carotid artery disease?

The goal in treating carotid artery disease is to prevent a stroke or another stroke.  The method of treatment depends on how narrow your arteries have become.

 When you have mild to moderate blockage of your arteries, the following recommendations may be sufficient:

  • Make lifestyle changes  Healthy changes in your behavior can help reduce the stress on your arteries and slow the progression of atherosclerosis.  Such changes include quitting smoking, losing weight, eating healthy foods, reducing the amount of salt you eat and exercising regularly.
  • Manage chronic conditions  It is also key to manage any chronic conditions you have, such as high blood pressure, excess weight or diabetes.  With your doctor, you can form a plan to specifically address these conditions by managing your blood pressure, maintaining a healthy weight, controlling your blood sugar levels and lowering your cholesterol.
  • Use medications  Your doctor may ask you to take a daily aspirin or another blood-thinning medicine to avoid the formation of dangerous blood clots.  Your doctor may also recommend medications to control your blood pressure, such as angiotensin-converting enzyme (ACE) inhibitors or calcium channel blockers, or a statin medication to lower your cholesterol.

When you have severe blockage of your arteries and especially if you have already had a TIA or a stroke related to the blockage, it is best to open the artery and remove the blockage or dilate it with a balloon and put in a stent.  There are two ways of doing this:

  • Carotid endarterectomy  This surgical procedure is the most common treatment for severe carotid artery disease.  The procedure is done under either local or general anesthesia.  After making an incision along the front of your neck, your surgeon opens the affected carotid artery and removes the plaques.  The artery is repaired with either stitches or possibly a patch to make it wider.  Studies have also shown that the surgery is low risk in most otherwise healthy people, has lasting benefit and helps prevent strokes.
  • Carotid angioplasty and stenting  A carotid endarterectomy is not recommended when the location of the narrowing or blockage is too difficult for the specialist to access directly or when you have other health conditions that make surgery too risky. In such cases, your doctor may recommend a procedure called carotid angioplasty and stenting.  While you are under local anesthesia, a tiny balloon is threaded by catheter to the area where your carotid artery is clogged.  The balloon is inflated to widen the artery, and a small wire mesh coil called a stent is inserted to keep the artery from narrowing again.  Usually a fine net or basket is placed between the blockage and your brain to collect any debris that may break loose when the artery is dilated and stented.  This trap is then removed with the debris in it.

What treatment should I expect?

If you have carotid artery disease, treatment is determined by weighing a number of factors that are individualized.  Some of the factors include:

  • Percent of stenosis (narrowing)
  • Your symptoms of TIA or stroke, if any
  • Other associated health problems
  • Smoking history is important
  • Cholesterol management is important if you do not yet have high-grade stenosis or symptoms

The most important thing you can do is quit smoking.

The following guidelines are some general guidelines about percent of stenosis and symptoms that may apply to you based on your findings.  Ask your physician if these apply.

General Guidelines Based on % of Stenosis
% of StenosisAsymptomaticSymptoms (if any)
1 to 49 %Medical management including anti-platelet therapyMedical management—anti-platelet therapy
50 to 69 %Medical management and anti-platelet therapy but surgery may be considered (percutaneous balloon angioplasty and stenting)Surgery (percutaneous balloon angioplasty and stenting)
70 to 99 %Surgery (percutaneous transluminal angioplasty and stenting)
       85 to 99 %This is the percent of stenosis when symptoms really begin to increase.  If you cannot tolerate a procedure of any form, you may need anticoagulation.Surgery (percutaneous transluminal angioplasty and stenting)
100 %Nothing can be done to open this blockage because the artery blocks all the way into your skull.  Narrowing in the opposite carotid becomes even more critical because that side has to increase flow to make up for part of the decreased flow from the blocked side and depends on the complete circle of Willis and also the contribution of the vertebral basilar arteries from the back of your neck.  Fortunately, the circle is relatively complete in around 90% of people.

If you have had a screening done somewhere and you have been told that you have some disease, you must follow-up with your local physician and treatment of risk factors must really be aggressive.  You must have formal follow-up at six-months to two-year intervals.  They will also talk with you about heart disease.  These findings, like PAD, are warnings that you have problems elsewhere in your body and particularly your heart.

If you are over 80 years of age, surgery so far seems to be having better outcome than with percutaneous transluminal angioplasty and stenting.  The studies of this age group are still evolving.

There are certain conditions involving the vertebral arteries in the back of your neck that supply blood flow to the base of the brain that may need to be treated.  These two arteries that form the basilar artery supply 20% of the total blood flow to your brain (remember each carotid artery supplies 40%).  The vertebral arteries arise off the artery that goes to each arm.  If the artery to your arm becomes blocked, flow may not go to the base of your brain from the good arm but may actually go up where these two arteries go together to form the basilar artery but blood flow turns around and goes back down to the opposite arm (steals it from your brain).  If you are right-handed and do heavy repetitive work with your right arm and the artery to your right arm is blocked, you may get brain symptoms with exercise of that arm.  Under this circumstance, a procedure may need to be done to improve the flow to the bad artery to the bad arm.

If the artery to one arm is blocked, the blood pressure in this arm will be lower.  Your true blood pressure is the pressure in the artery to the arm with the highest blood pressure and this is the side that you must monitor in controlling blood pressure.  If you know one side is lower, tell your physician so they, too, will check the correct arm when monitoring your blood pressure.

Coronary artery disease has a high instance with these problems and needs to be evaluated.

In summary, your treatment may be more complicated than the above problems.  Always discuss your symptoms and health problems in detail with your physician.

If you do not have bad problems but are bad enough to require intervention, there are some things that absolutely must be done:

  • Stop smoking
  • Control cholesterol
  • Control diabetes
  • Control blood pressure
  • Have repeat duplex Doppler (ultrasound) of your arteries at nine months to two-to-three-year intervals to monitor the severity of your narrowing (stenosis). 

The first symptoms you experience could be a permanent stroke without warning.  Do not miss an appointment for follow-up.  The fact that you are feeling well does not mean that all is well.

Prevention

Making healthy choices in your daily lifestyle can help prevent or slow the progression of carotid artery disease and help prevent the occurrence of a TIA or a stroke.  Here are some suggestions:

  • Quit smoking.
  • Control chronic conditions such as diabetes, weight and high blood pressure.  Remember high blood pressure is silent, so know your blood pressure numbers and know your goal blood pressure.
  • Have regular check-ups with your doctor.
  • Have your doctor check your cholesterol and triglycerides and get treatment if necessary.
  • Eat foods low in saturated fats, trans fats, cholesterol and salt.
  • Eat a variety of fruits and vegetables.
  • Eat only enough calories to maintain a healthy weight and avoid weight gain.
  • Limit salt (sodium) intake
  • Increase exercise to at least 30 minutes of physical activity most days of the week.
  • Limit alcohol consumption

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We hope the information on these pages is both informative and helpful, but it is intended for education only.  Please do note that no web site, no matter how much information is shared, can replace a consultation with your doctor and a vascular specialist.  Medical technology and treatment are continually improving and evolving so before making any decision on treatment, it is always advisable to see your doctor first for a comprehensive evaluation of your vascular disease and other medical conditions.

At the Vascular Center of Wichita Falls, we work closely with your other physicians.  If you have concerns about your arteries or veins, contact us.  A referral is not necessary to make an appointment.