A procedure in which doctors scrape out a partially clogged artery in the neck may be too risky for people who have had no signs of a stroke, researchers suggested today in the New England Journal of Medicine.
A stroke occurs when a clot blocks the flow of blood to the brain. There is no question that scraping out a clogged carotid artery â€” a procedure called an endarterectomy â€” can help prevent strokes in people who have already had one.
But the study casts doubt on the value and the safety of endarterectomy in people who have no symptoms.
In an endarterectomy, a surgeon opens up the neck, clamps the artery around the blockage, scrapes out the fat that is blocking it, then sews head and neck back up.
The study looked at 1,820 patients who had a partially blocked carotid artery but were otherwise symptom-free. Half of them were given the operation, the other half only medicine. A total of 122 people later had strokes caused by blood clots in the area of the brain fed by the clogged artery.
But in 45 percent of those strokes, the blocked carotid artery was not the source of the clot: The clots had formed in the heart or in small blood vessels within the brain. And those strokes cannot be prevented by endarterectomy.
The study was led by Dr. Henry J.M. Barnett of the John P. Robarts Research Institute in London, Ontario.
The group treated with medicine had a 6.6 percent risk that the artery blockage would cause a stroke, compared with a 3.1 percent risk for patients who had the operation. But Barnett said the improved outlook for those patients is outweighed by the risk of endarterectomy itself.
Medicare figures indicate that endarterectomy itself carries about a 2.5 percent risk of death. That does not include patients who suffer strokes shortly after the operation; the rate of such strokes is at least double the risk of death, Barnett said.
That makes the danger from having the operation greater than the danger of not having it, he said. Until further research, ``the scales are tipped against the routine use of endarterectomy in patients who have no symptoms.''
Dr. Karen L. Furie, a neurologist at Massachusetts General Hospital, took issue with the conclusion. Rather than ruling out surgery in all such cases, doctors should use ultrasound to see which patients are most at risk, she said.
On the Net:
National Institute of Neurological Diseases and Stroke information guide: http://www.ninds.nih.gov/patients/Disorder/STROKE/strokehp.htm
National Stroke Association: http://www.stroke.org/index.html