THURSDAY, Sept. 23 (HealthDay News) -- For people whose carotid
arteries have become narrowed, restricting blood flow to the brain,
having a surgical procedure to widen them reduces the risk of
stroke over a 10-year period, British researchers report.
The carotid artery -- one on either side of the neck -- supplies
blood carrying oxygen to the head, so a procedure to widen it helps
restore blood flow to the brain. However, the operation, called a
carotid endarterectomy, has about a 3 percent risk of causing an
immediate stroke, the researchers cautioned.
For some elderly patients, this risk may outweigh any long-term
benefit. But older, healthy patients will likely benefit from the
procedure, the study authors noted.
However, Dr. Larry B. Goldstein, professor of neurology and
director of the Duke Stroke Center at Duke University Medical
Center, who was not involved in the study, suggested that the
benefits might be smaller than they appeared in the study.
"Recent studies suggest that the rate of stroke in patients with [narrowed carotid arteries without symptoms] is lower than the rates found in this trial," he said. Although the study found the rate of stroke in patients without a carotid endarterectomy to be 1.8 percent a year over a 10-year period, Goldstein noted that "the rates are thought to be about 1 percent a year, but may be as low as around 0.5 percent a year."
The lower rates of stroke, he said, "are thought to be due to
advances in medical treatment such as blood pressure control,
antiplatelet drugs and more widespread use of statins."
The report is published in the Sept. 25 issue of
In the Asymptomatic Carotid Surgery Trial, a research team led
by Dr. Alison Halliday of the John Radcliffe Hospital, the
University of Oxford, randomly assigned 3,120 patients with
narrowed carotid arteries to surgery or to no surgery until their
condition required it.
Some of the patients originally assigned to the "no surgery"
group did undergo the operation during the study, the researchers
A total of 1,979 operations were performed. Among these the risk
of stroke within 30 days was 3 percent, including 26 minor and 34
disabling or fatal strokes, Halliday's team reported.
Over an average of five years of follow-up, 4.1 percent of those
who underwent the procedure suffered a stroke, compared with 10
percent of those who did not have the operation.
At 10 years, 10.8 percent of those who had the operation had
suffered a stroke, compared with 16.9 percent of those who were not
operated on, the researchers found.
The study authors noted that both groups included patients
receiving blood pressure-lowering and anti-clotting drugs.
In addition, over the years of the study, patients in both
groups were also taking cholesterol-lowering drugs. Even these
medications did not affect the benefit of the surgery, the
The benefit of the operation was seen for people who had the
surgery before they were 75, but not among patients older than
that, Halliday's group found.
"This trial took more than 15 years to complete, because we wanted to know about the long-term effects of surgery," Halliday said in a statement.
"The finding that successful carotid artery surgery can substantially reduce the stroke risk for many years is remarkable, because it means that most of the risk of stroke over the next five years in patients with a narrowed carotid artery is caused by that single carotid lesion. The definite benefits that we have found will be of practical value to doctors and patients deciding in the future whether to take the immediate risk of having such surgery," she said.
Overall, the study found benefit of endarterectomy in selected
patients, Goldstein said.
The rates of stroke were reduced from about 2.2 percent a year
to 1.4 percent a year over five years and from 1.8 percent a year
to 1.3 percent a year over 10 years, he said.
"Decisions regarding whether or not to perform the operation must consider the overall small, but significant, benefit found in the study, the possibility that the benefit may be further reduced with modern medical therapy, individual patient characteristics, the surgeons' experience and complication rates, and patient preferences," he added.
This modest reduction in risk and the number of patients needed
to treat to prevent one stroke may not be enough to justify
performing the surgery on most patients, Goldstein said.
"This means that 24 operations would need to be performed to prevent one stroke over five years, or 22 operations to prevent one stroke over 10 years. This includes a 3 percent risk [of stroke from] the operation," he said, adding that there was no reduction in total mortality.
In a comment published with the study, Pierre Amarenco of Bichat
Hospital in Paris, France, and colleagues wrote: "... it should be
investigated further why the net benefit is not significant in
patients older than 75 years, to distinguish whether some older
patients could still benefit. Until then, decision making for these
patients can only be on the basis of medical judgment for
individual patients with in-depth discussions with the
For more information on stroke, visit the
U.S. National Library of Medicine.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © EBSCO Publishing. All rights reserved.