ABC of Vascular Disease

Carotid Artery Disease

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1. What is the carotid artery?
The carotid arteries are the main arteries that supply blood to the head and brain.  The carotid arteries run either side of the windpipe in the front of the neck just under the muscles, one on the right and one on the left.

2. What is carotid artery disease?
Carotid artery disease is like occlusive arterial disease elsewhere in the body.  Carotid artery disease behaves a bit differently to arterial disease elsewhere because the carotid artery supplies blood to the brain.

3. What symptoms does carotid artery disease cause?
In most people it doesn't cause any symptoms.  In a few people carotid artery disease causes a sudden onset of altered brain function which resolve in a few minutes (transient ischaemic attack or TIA).  Small pieces of debris from the carotid artery disease are shed into the blood and carried into the brain.  The debris gets  stuck in one of the small branches that supply the brain and the blood flow in that branch is stopped (cerebral ischaemia).  The part of the brain supplied by this artery stops working and depending on which bit is affected the patient will notice different symptoms.  Some patents notice weakness or numbness in a part of the body, others notice a change in the speech.  It is not typical to blackout or suffer a headache.  Usually the blockage is only temporary, the blood flow is restored, the brain starts to work again and the symptoms resolve.  Occasionally the debris passes into the artery that supplies the eye and this results in a sudden, but temporary, blindness in one eye (amaurosis fugax).

4. Why is carotid artery disease important?
If disease in the carotid artery is severe then two complications may occur, both of which are irreversible.  First, a large chunk of debris can be dislodged and block a large artery in the brain. Alternatively the carotid artery may block completely and the blood supply to that side of the brain may be reduced drastically.  These types of arterial occlusion do not resolve spontaneously and the brain may be permanently damaged (cerebral infarction). Other names for this event are a cerebrovascular accident (CVA) or a stroke.  Once a stroke has occurred the brain damage is irreversible.

5. How is carotid artery disease diagnosed?
If a patient has had a transient ischaemic attack (TIA) then there is a good chance of there being significant carotid disease.  An ultrasound scan of the neck is required to detect this and to measure the severity of the disease.  Occasionally it is necessary to obtain an angiogram of the carotid arteries and this is done just like any other angiogram.

6. What can be done to prevent a stroke if carotid artery disease is found?
Firstly it is important to note that only a few people with carotid artery disease will actually suffer a stroke.  The risks of a stroke are greater if

bulletThe carotid artery is more than three-quarters blocked.
bulletThe most recent transient ischaemic attack was less than 6 months ago.
bulletThe transient ischaemic attacks are frequent.
bulletThe patient is taking no medication to thin the blood.

If severe carotid artery disease is found then the current recommendations are:

bulletTake a drug like aspirin that makes the blood less "sticky"
bulletConsider an operation to "clean out" the carotid artery and reduce the risk of  a future stroke.

7. Is carotid artery disease the only cause of strokes?
No, it only accounts for about one stroke in six.  The other common causes are high blood pressure (hypertension), problems with the small arteries in the brain, and heart disease.  Cleaning out a carotid artery will unfortunately not prevent a stroke from the other causes.

8. What does the operation involve?
The operation is called a carotid endarterectomy and is normally carried out under a full (general) anaesthetic.  The vascular surgeon will expose the affected artery in the side of the neck, clamp the artery to prevent it bleeding, then open the artery and clean out the arterial disease.  The artery is then stitched up and the clamps removed to restore the blood flow.  The vast majority of patients tolerate this operation very well and are only in hospital about 4 days.

9. What are the risks of a carotid endarterectomy?
The most serious complications are a stroke, a heart attack or bleeding from the artery.  These complications are unusual and your surgeon will discuss these before the consent form can be signed.  Like other operations, there is a balance of risk.  If you have severe carotid artery disease the risk of having a stroke if the operation is not done is actually much higher.

10. What happens after the operation?
Most patients have no problems following the surgery and feel much better because the constant treat of a stroke has been lifted.  As with all arterial disease, lifelong reduction of risk factors is very important. It is very unusual for carotid artery disease to come back, and even less common to require further surgery. 

S.R.Dodds 2006

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