Carotid Artery Occlusion

Carotid artery occlusion occurs when one of the major blood vessels delivering blood to your brain becomes completely blocked, significantly increasing your risk of stroke.

Table of contents

• What is carotid artery occlusion?
• Causes and risk factors
• Symptoms and warning signs
• How it is diagnosed
• Treatment options
• What to expect

What is carotid artery occlusion?

Carotid artery occlusion is a complete blockage of the internal carotid artery, one of the two large blood vessels on each side of your neck that carry blood to your brain, face, and head.^[1] When these arteries are healthy, they are smooth and open like clean pipes that allow blood to flow freely. However, when they become completely blocked, the brain may not receive enough oxygen and nutrients, which can lead to serious complications.^[2]

This condition is closely related to carotid artery stenosis, which is a narrowing of the carotid artery rather than a complete blockage. Occlusion typically develops when atherosclerosis—the buildup of fatty deposits called plaque inside the arteries—progresses to the point where blood flow is completely stopped.^[1] The blockage is usually made up of cholesterol deposits that accumulate over time.^[2]

• Carotid arteries
• Brain
• Neck blood vessels

Causes and risk factors

Carotid artery occlusion is typically a chronic condition that develops over time as people age. The primary cause is atherosclerosis, where cholesterol and other substances gradually accumulate on the artery walls.^[2] Low density lipoprotein (LDL) cholesterol plays a major role in this process. Over time, this material gets trapped inside the blood vessel and eventually forms hardened plaque that can completely block the artery.^[1]

Several factors can increase your chance of developing this condition. Some of these are factors you can change, while others you cannot:

• Smoking and using tobacco products
• Having obesity
• Sedentary lifestyle with little physical activity
• High blood pressure (hypertension)
• High cholesterol levels
• Diabetes
• Advancing age
• Genetics and family history
• Fatty diet

In some cases, patients who have had radiation treatment for head and neck cancers can develop carotid artery problems from the radiation effect rather than from plaque buildup.^[10] There are also some inflammatory conditions that can cause irregularities in the carotid arteries.

Symptoms and warning signs

In many cases, carotid artery occlusion may not cause any symptoms on its own, especially if it develops slowly and other blood vessels can compensate for the blocked artery.^[1] In fact, approximately 38% of patients with internal carotid artery occlusion are symptomatic when first discovered, with 87% of those having symptoms on the same side as the blocked artery.^[4]

The most serious symptom is a stroke, which occurs when the brain loses its blood supply. During a stroke, the brain doesn’t get oxygen and brain cells begin to die within minutes.^[1] You may also experience a transient ischemic attack (TIA), sometimes called a “mini-stroke,” which is a temporary shortage of blood flow to the brain that does not cause permanent damage.^[1] A TIA can be a warning sign that a more serious stroke may occur.

Symptoms of a stroke or TIA include:

• Sudden numbness or weakness in the face or limbs, often on one side of the body
• Drooping of one side of your face
• Slurred speech or trouble forming words and communicating with others
• Sudden trouble understanding what others are saying
• Losing vision in one eye, with the experience of a dark shade coming down over your field of vision
• Sudden dizziness or loss of balance
• Losing feeling on one side of your body
• Losing muscle strength and having weakness on one side of your body
• Sudden, severe headache with no known cause

The side of your body that experiences symptoms is very important, as symptoms typically occur on the opposite side from the blocked artery.^[10]

If you experience any symptoms of a stroke, seek emergency care immediately by calling 911 or your local emergency number. Even if the symptoms last only a short while and then you feel okay, you should still see a healthcare professional right away.^[1] With a stroke, every second of delay can result in more brain injury.^[17]

How it is diagnosed

Carotid artery occlusion is often discovered after a patient has experienced symptoms of a stroke or during an examination for other reasons.^[2] Diagnosis usually starts with a medical history and physical examination. During the exam, your doctor may use a stethoscope to listen for an abnormal sound called a bruit over the carotid artery in your neck, which can indicate narrowed or blocked blood flow.^[7]

Several imaging tests can be used to identify and evaluate carotid artery occlusion:

Carotid ultrasound (also called carotid Doppler) uses sound waves to create real-time pictures of the arteries and locate blockages. This test can show blood flow and pressure in the carotid arteries.^[5] All patients with internal carotid artery occlusion should have multiple ultrasound exams available for review.^[4]

Computed tomography angiography (CTA) uses a CT scanner to produce detailed views of the arteries in the neck. The test is particularly useful for patients with pacemakers or stents.^[5] These scans create images of the neck and brain after a contrast dye is injected into a blood vessel to make areas stand out.^[7]

Magnetic resonance angiography (MRA) is a noninvasive test that gives information similar to CTA without using ionizing radiation.^[5]

Cerebral angiography (also known as catheter angiography) is a more invasive test where a thin tube called a catheter is guided through an artery in the groin to the area of interest in the brain. Contrast material is injected through the tube and images are captured with X-rays.^[5] This test may help identify the type of plaque blocking the arteries.^[7]

Treatment options

Treatment for carotid artery occlusion focuses on preventing stroke and managing risk factors, since the artery is already completely blocked. Unlike carotid artery stenosis, where procedures like carotid endarterectomy or carotid stenting can be performed to remove or bypass the blockage, complete occlusion is generally not treated with these surgical interventions.^[9]

Lifestyle changes are an important part of treatment. These healthy changes can help prevent further narrowing of other arteries and reduce stroke risk:^[17]

• Eat a healthy, low-fat diet with plenty of fruits and vegetables
• Choose high-fiber foods, such as whole-grain breads, pastas, cereals, and crackers
• Eat lean meats and skinless chicken and turkey
• Eat fish twice a week, as fish is good for your arteries
• Cut back on saturated fat, cholesterol, and added salt and sugar
• Be more active—start with 10 to 15 minutes of walking per day and gradually build up to 150 minutes of exercise per week
• Stop smoking if you smoke

Medications play a crucial role in managing carotid artery occlusion. Several types of medicines may be prescribed:^[17]

Cholesterol-lowering medicines, particularly statins, help your liver produce less cholesterol and prevent plaque from building up in other arteries. A target LDL cholesterol level below 100 mg/dL is recommended, with some high-risk patients aiming for 70 mg/dL.^[11]

Blood pressure medicines help relax your blood vessels, make your heart beat slower, and help your body get rid of extra fluid, which lowers high blood pressure.^[17]

Blood-thinning medicines, such as aspirin or clopidogrel, decrease the chance of blood clots forming and help lower your risk of stroke.^[17] Aspirin works by irreversibly blocking platelet function, while clopidogrel is similar but has a lower risk of certain side effects.^[11]

These medicines can have side effects. If you notice any problems, tell your doctor, who may change the dose or type of medicine. Never stop taking medicines or take less medicine without talking to your healthcare provider first.^[17]

What to expect

Carotid artery occlusion is a risk factor for stroke and puts patients in a high-risk category.^[4] In one study that followed patients with internal carotid artery occlusion for an average of 52 months, 9% had a neurologic event during follow-up, with 86% of those events occurring on the side of the blocked artery.^[4]

Your healthcare provider will want to monitor you regularly to see how well your treatment is working. At follow-up visits, your provider may:^[17]

• Use a stethoscope to listen to the blood flow in your neck
• Check your blood pressure
• Check your cholesterol levels
• Order imaging tests to see if blockages in your other arteries are becoming worse

The development of significant narrowing or blockage of the external carotid artery on the same side as the occlusion has been associated with increased risk of death.^[4] In one study, the seven-year survival for patients who developed external carotid artery disease during follow-up was significantly worse than for those who did not.^[4]

Having carotid artery disease puts you at risk for stroke. Get help as soon as stroke symptoms occur. The sooner you receive treatment, the better your chance for recovery.^[17]