DALLAS, April 3 -- Women and certain other groups of patients who undergo carotid endarterectomy -- a common procedure used to clear blockages in the blood vessels to the brain -- may have a higher risk for death or stroke following the surgery, according to a study in this month's Stroke: Journal of the American Heart Association.
A carotid endarterectomy is the most common surgical procedure used to clear the fatty buildup in the carotid arteries that can lead to an ischemic stroke, which results when blood flow to the brain is blocked. In 1995, 132,000 carotid endarterectomies were performed in the United States. The procedure can help prevent strokes in people who have 70 percent or more blockage of their carotid arteries, according to the results of the North American Symptomatic Carotid Endarterectomy Trial.
Researchers from Duke University examined 463 people from 12 academic medical centers. These people had endarterectomies performed, but had no pre-existing symptoms or warning signs for stroke such as difficulties when speaking or moving their arms or legs.
The scientists found that 2.8 percent of the patients in the study either died or had a stroke while hospitalized after undergoing the endarterectomy.
They compared these results to those from Asymptomatic Carotid Atherosclerosis Study (ACAS). In ACAS, which demonstrated the usefulness of the operation when performed in people who also did not have symptoms related to the blockage, the complication rate was just 1.5 percent.
"In controlled trials such as ACAS, there were very rigid quality controls that are carried out and the surgeons involved had to have done a prescribed volume of procedures before they were selected," says the study's lead author Larry B. Goldstein, M.D., of the Duke University Medical Center, Durham, N.C. "In the 'real world,' however, these types of quality controls are probably not going on. If the operation can't be done very safely, it shouldn't be done at all."
In their study, Goldstein and his colleagues found that post-operative stroke or death was more frequent in women (5.3 percent) than men (1.6 percent), and in those age 75 years or older (7.8 percent) vs. those younger than 75 (1.8 percent). Post-operative stroke or death was more common in those with a history of congestive heart failure (8.6 percent) than in those who did not (2.3 percent) have this condition.
Regarding women's increased death rate, Goldstein notes that the ACAS scientists found a similar difference. "The question of why is a big, unanswered question. There's a variety of different hypotheses, but little to no data to support or disprove them. The mere observation alone is important," he says.
Goldstein points out that it is possible that the overall safety of carotid endarterectomy has improved since the data were gathered several years ago. However, he asserts that increased caution is important, especially when patients may exhibit pre-existing risk for complications.
In a previous study, Goldstein and his colleagues found that most physicians referring patients for the operation are not aware of the surgeon's complication rates.
"Basically, only 20-30 percent of general internists or primary care physicians say that they know what these complication rates are," says Goldstein. "This information is absolutely critical to determining who should and who should not perform an endarterectomy. There needs to be a greater awareness of this among medical professionals and systems put in place to monitor these rates objectively."
Co-authors are Gregory P. Samsa, Ph.D.; David B. Matchar, M.D.; and Eugene Z. Oddone, M.D.
Media advisory: Dr. Goldstein can be reached at (919) 684-3801. (Please do not publish telephone number.)