Carotid Artery Disease

The carotid arteries are the pipes (vessels) that carry oxygen and nutrient rich blood to the head. There is one of them on each side of the neck. They are essential for the blood supply to the part of the brain which controls thought, speech, personality, ability to move and our sense of smell.

Carotid artery disease is one of the commonest causes of (ischaemic) stroke. It is the narrowing (stenosis) or blockage (occlusion) of these arteries due to build-up (“furring-up”) of fat containing material (called a cholesterol rich plaque) in its walls. These plaques can then crack and form an irregular surface, which can then cause serious health problems.

This irregular surface can cause blood to become gel-like (a blood clot) and then that can break off to be carried upwards to the brain. That can then interrupt the blood flow to the smaller arteries within the brain and the way the brain works in a temporary (mini-stroke) or permanent way (stroke).

Irregular plaque removed from Carotid

When there is a temporary interruption of the brain function, the medical term used is a “Transient Ischaemic Attack” – TIA. In this case, a patient may experience speech problems, or brief weakness, clumsiness, numbness or pins and needles of the face, arm or leg on one side of the body. The eye can also be affected resulting in loss of vision in one eye (typically appears as a back curtain in your field of vision). This is a milder form of mini-stroke called “Amaurosis Fugax”.

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There are various causes, some of which cannot be changed, because the genetic make-up of the individual determines how vulnerable to the condition somebody is (a “predisposition”). An indication of this genetic predisposition is of course having a close member of your family with the same condition or the individual suffering from heart disease or peripheral arterial disease (the arteries supplying the legs may also be affected).

Fortunately, there are some “causes” which can be modified to prevent worsening of the condition or its return after treatment. The most important cause is smoking and then high cholesterol, high blood pressure and diabetes.

After your doctor will take a thorough history of your condition and examine you, the diagnosis would usually be confirmed with an ultrasound scan of the arteries in the neck (duplex, triplex or colour doppler), or sometimes after a CT or MRI scan.

Diagnosis of this condition is important because your doctor will then assess your likelihood (chances) of having a stroke in the future and advice will be given to you of measures you could take to prevent this happening.

All patients with this condition must stop smoking completely. Stopping smoking, helps make blood less “sticky” to the walls of the arteries and therefore makes it less likely it would form a blood clot. They can also benefit from taking 75 mg of aspirin (or a similar drug) a day. This drug reduces the stickiness of some circulating blood cells called platelets, which if left untreated they promote expanding the plaques and forming blood clots. Patients can also benefit from a cholesterol-lowering drug (from the family of statins) and from treatment of other factors which worsen this condition (particularly treating their blood pressure and diabetes). The statins help by lowering the circulating cholesterol which is the biggest culprit of plaques BUT they also appear to make the plaques more stable, lowering the chance they would crack, independently of their cholesterol lowering effects. Therefore, even patients with low cholesterol may benefit from these. Recent multi-national studies support lowering the LDL (bad) cholesterol to very low levels, according to the individual’s risk profile.

An operation may be necessary if your doctor believes that you would benefit from it, beyond the improvement you would expect from other conservative (non-interventional) measures, such as modifying the factors which influence the disease, and taking medication. As the main issue with carotid disease is NOT the total amount of blood flowing to the brain, but really the chance of a blood clot flaking off the plaque and blocking the smaller arteries within the brain, surgery involves cleaning the carotid artery of the plaque.

There is good evidence from studies that some patients, especially those with narrowing greater than about 70% of the diameter of the artery, may benefit from surgery called a carotid endarterectomy.

Your surgeon will advise you whether and when you need an operation. The decision making is complex and depends if you have already had “trouble” (symptoms) from the Carotids, the quality of the plaque and other aspects of your health.

It is likely that if you have had a stroke, a TIA or amaurosis fugax that you will be advised to have the operation as soon as possible (and preferably within 2 weeks of the event) to prevent a further stroke, provided the % stenosis is >50% and you fulfil other criteria for surgery.

Get immediate medical advice if you experience symptoms such as:

• Numbness, pins and needles or weakness in your face, arm or leg
• speech problems
• loss of vision in one eye (not just blurring BUT a black-curtain in your vision)