Blocked carotid could lead to stroke
Dear Dr. Roach: What could precipitate a need to check an 83-year-old man’s carotid arteries for blockage? What percentage of blockage would necessitate surgery?
W.M.
Answer: There are two carotid arteries, running on either side of the neck, bringing blood to the head.
They provide a great deal of the blood flow to the brain, and blockages of either can lead to a stroke.
The symptoms that would make a doctor want to check for blockages in the artery are stroke and transient ischemic attack.
TIA is a loss of blood and oxygen flow in the brain, leading to temporary symptoms that look very like a stroke.
If, when checked, the carotid artery has blockages on the same side that the TIA or stroke was on, then not only is medical therapy begun to reduce risk of another event, but surgery is considered as well.
If the blockage is not very extensive, surgery is not any more beneficial than medical therapy, including dietary changes and exercise counseling.
However, for more extensive blockages, surgery can help. Men have been proven to see a benefit when the artery is 50% to 99% blocked; with women, only those with 70% to 99% blockages benefit from surgery.
The short-term risk of dying from the surgery is significant.
In large studies, the overall risk was just about 3%, although newer surgical techniques may have brought that number down a bit since those studies were published in the 1990s.
Carotid surgery is not to be undertaken lightly, especially since medical therapy is much better than it used to be as well.
There are newer and more powerful drugs to reduce the risk of stroke. Surgery should be considered only in someone who is pretty healthy otherwise and who is likely to live at least five more years, since the risk of dying around the time of surgery is significant.
I do not recommend screening for blockages in the carotids in people with no symptoms.
It’s more important to identify people who are at risk for stroke and reduce that risk by better lifestyle and medications if needed.