About the procedure
The advantage of local anaesthetic is it allows the surgeon to monitor brain function while you're awake. But there's no evidence that either is safer or better.
During the procedure, a 7 to 10cm (2.5 to 4 inch) cut is made between the corner of your jaw and your breastbone.
A small cut is then made along the narrowed section of artery and the fatty deposits that have built up are removed.
The artery is closed with stitches or a patch and your skin is also closed with stitches.
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What happens after the procedure
You'll usually be moved to the recovery area of the operating theatre for monitoring for about 3 hours, before returning to the vascular ward.
Most people are well enough to go home within about 48 hours of the procedure.
In most cases, the only problems experienced after the operation are temporary numbness or discomfort in the neck.
But there's a small risk of more serious complications, which can include stroke or death in 2 to 3% of cases.
Nevertheless, this risk is much lower than in people with carotid artery disease who haven't chosen to have the operation.
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Are there any alternatives?
Carotid endarterectomy is the main treatment for narrowing of the carotid arteries, but sometimes an alternative procedure called carotid artery stent placement may be available.
It's a less invasive procedure than a carotid endarterectomy because there's no need to make a cut in the neck.
Instead, a thin flexible tube is guided to the carotid artery through a small cut in the groin.
A mesh cylinder (stent) is then placed into the narrowed section of artery to widen it and allow blood to flow through it more easily.
Current guidelines recommend that a carotid endarterectomy should be the first line of treatment for most people.
This is because carotid stenting is associated with a higher risk of stroke during the procedure, particularly if it's carried out in the first few days after symptoms appear.
But it's an important alternative for some people who may otherwise be considered to be high risk because of other medical problems.