For Immediate Release
April 8, 1998
Contact:
Barbara Peck
(847) 692-9500
Procedure Reduces Risk of Stroke
A surgical procedure performed to remove the fatty build-up in the carotid arteries leading to the brain has proven to reduce the risk of stroke. Stenosis, or blockage, in the carotid artery narrows the pathway for blood to travel to the brain. This build up can break off and block the flow of blood to the brain completely, causing a stroke and the ensuing brain damage. Carotid endarterectomy is a procedure that removes this fatty build up from the artery walls.
Study Results
The North American Symptomatic Carotid Endarterectomy Trial (NASCET), sponsored by the National Institute of Neurological Disorders and Stroke (NINDS), is a 12- year study evaluating the effectiveness of carotid endarterectomy for preventing stroke. The study involved over 100 medical sites and compared outcomes of patients that received carotid endarterectomy and medication with those patients who received medical treatment alone - usually high blood pressure medication and aspirin to reduce the "stickiness" of the blood.
"What the study found is that patients with a carotid artery that is more than 50 percent blocked greater reduced their risk of stroke when they underwent a carotid endarterectomy in comparison to if they were treated with medications alone," said Gary Ferguson, MD, PhD, who will lead a discussion on the study at the 1998 Annual Meeting of The American Association of Neurological Surgeons in April. "This is important because there is little we can do once a stroke and the ensuing brain damage has occurred. Preventing strokes in the first place is our best defense against this devastating disease."
Over 700,000 Americans suffer a stroke each year, and it is the third leading cause of death in the United States following heart disease and cancer. Also, stroke is the leading cause of adult disability and loss of independence among the elderly. Narrowing of the carotid blood vessels is the most common cause of stroke.
The NASCET study showed that for patients with severe stenosis (over 70 percent blockage) the relative risk for stroke is reduced by approximately 65 percent, and one stroke will be prevented in 2 years for every 6 patients who undergo carotid endarterectomy. In patients with moderate stenosis (50 to 69 percent) the relative risk reduction for stroke is 30 percent, and one stroke in 5 years will be prevented for every 15 patients who undergo carotid endarterectomy
Benchmark For Treatment
"The study also showed that there is no advantage in having a carotid endarterectomy if the arteries are less than 50 percent blocked," said Dr. Ferguson, who is a Professor and Chief of the Division of Neurosurgery at the London Health Sciences Center - University Campus in London, Ontario. "This study gives surgeons a bench mark of 50 percent blockage to help evaluate whether carotid endarterectomy is in the best interest of the patient."
During a carotid endarterectomy, the carotid arteries in the neck are surgically opened and the fatty plaque build up is removed. The procedure can be done under local or general anesthesia, depending on the preference of the physician and patient. During the NASCET study, investigators reported an overall low complication rate.
"Now that we have these results, we have established that carotid endarterectomy is a safe, effective treatment to prevent stroke," Ferguson said. "The key now is identifying patients with arteries that are more than 50 percent blocked and getting these patients the appropriate treatment that they need."
Carotid artery blockage can be detected in a routine physical exam. By listening to the arteries in the neck with a stethoscope, a physician can hear if there is a disruption in the blood flow. If the doctor suspects a problem, the patient can be referred for further tests, which can include imaging of the blood vessels by Doppler ultrasound or magnetic resonance studies. If the results of these tests suggest extensive blockage, the patient can undergo a carotid angiogram. During this procedure, dye is injected into the carotid arteries and the exact amount of blockage can be seen. This is similar to the procedure used to view and identify blockage in the arteries near the heart.
The NASCET study also showed that the positive effects of the surgery are long-term. Patients in the study who had a carotid endarterectomy were followed for over 8 years and showed no significant signs of re-blockage.
"If the angiogram shows more than 50 percent blockage, the patient and the surgeon need to sit down and make some decisions on treatment," said neurosurgeon Robert E. Harbaugh, MD, Professor of Cerebrovascular Surgery at Dartmouth-Hitchcock Medical Center.
At Dartmouth-Hitchcock, the surgery takes an average of just over an hour and the patient's length of stay in the hospital averages to about 1.2 days, with 90 percent of patient's going home within 24 hours.
"Carotid endarterectomy is an evolving surgical procedure which I believe can be done safer and in a more cost-effective manner than has often been the case, " Dr. Harbaugh said. "Our patients are rapidly mobilized after surgery and are not sent to the ICU. This regimen has resulted in fewer complications, better outcomes and reduced costs to the way we did the surgery 10 years ago."
Recently, surgeons have begun to evaluate using angioplasty and stenting in the carotid arteries. These procedures are less invasive and require threading a balloon up the arteries from the groin. The balloon then pushes and compacts the fatty build up against the artery wall, opening up a larger space for the blood to flow. Stents, which are similar to a tiny cylinder, may be used to re-enforce the opening.
"Cardiologists and interventional radiologists have been successful in using this technique for coronary and peripheral arterial disease," Dr. Ferguson said. "Angioplasty and stenting may sound appealing to some patients, however, this is an experimental procedure in the carotid artery and it has not undergone an extensive clinical trial like carotid endarterectomy. The long-term effects for this procedure have not yet been proven."
To view the entire 1998 AANS Annual Meeting press kit, please visit the on-line Press Room located in the Virtual Exhibit Hall: http://server400.aans.org/VEH/mainhall2.html
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Founded in 1931 as the Harvey Cushing Society, The American Association of Neurological Surgeons is a scientific and educational association, with approximately 5,000 members in the United States, Canada, Mexico, Europe and the Pacific Rim. It is dedicated to advancing the specialty of neurological surgery in order to provide the highest quality of neurosurgical care to the public. All active members must be certified by the American Board of Neurological Surgery.
For more information on The American Association of Neurological Surgeons, please visit our Web site: www.neurosurgery.org
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