The carotid arteries are the two large arteries on either side of the neck which supply blood to the brain. Stenosis refers to a blockage in the artery caused by a build-up of cholesterol and fatty tissue. When the artery becomes about 60-70% blocked, we call this a significant stenosis that places the patient at risk of having a stroke.
A stroke is usually caused by a blood clot that forms around the blockage in the carotid artery. If the blood clot enlarges enough to totally shut off the flow of blood the part of the brain supplied by that blood vessel is destroyed and the typical results of a stroke (numbness, weakness of one side, difficulty speaking) are seen.
Treatment of carotid artery stenosis includes both medical and surgical options. Medical treatment involves the taking of aspirin to prevent blood clots, treatment of high cholesterol and high blood pressure, and stopping smoking. Surgical treatment consists of an operation called an "endarterectomy" in which a small incision is made into the clogged artery and the blockage is removed.
A patient with a significant blockage of a carotid artery has up to a 25% chance of having a stroke within 5 years. With medical therapy, this risk is reduced to about 10%. An endarterectomy will reduce this risk to about 5%.
Whether to choose medical or surgical treatment for carotid artery stenosis is controversial. All physicians would agree that any patient with warning signs of a stroke called TIA's (transient ischemic attacks) and carotid stenosis should have an endarterectomy. The asymptomatic patient with a carotid artery stenosis might choose surgery or medical treatment depending upon such factors as patient age, underlying health status, and the availability of a high quality vascular surgeon.
In general, I would recommend that younger patients with otherwise good health undergo carotid endarterectomy. However, each case is unique and decisions regarding medical or surgical treatment should be made after careful consideration and discussion.