June 2009

Treating Carotid Artery Disease Surgery or Stenting?

Michael S. Conte, M.D.
Chief of Vascular and Endovascular Surgery
UCSF Heart and Vascular Center

Carotid artery disease causes an estimated 20 to 30 percent of all preventable strokes in adults due to the development of plaque in the main arteries to the brain. In most cases, it is believed to occur when tiny pieces of plaque break free from these arteries in the neck and embolize to small vessels of the brain.

Some patients may experience a brief loss of strength, sensation, vision or speech without lasting damage, referred to as a "mini-stroke" or transient ischemic attack (TIA). These are considered warning signs of an unstable plaque. When an area of brain is irreversibly damaged, some functional deficit remains and a stroke has occurred.

Many patients with a significant condition have no symptoms, but are at risk for a stroke. A simple non-invasive ultrasound test can diagnose carotid artery disease and should be obtained in patients with TIA-like symptoms, those with prior strokes or patients with established risk factors such as age, heart disease, diabetes and hypertension.

Most patients with mild or moderate plaque in the arteries do not require a procedure, but may need medical management, lifestyle modification such as smoking cessation and close follow-up. Those with more advanced plaque, causing severe narrowing or producing symptoms, are candidates for procedures to prevent stroke.

Treatment — Surgery Versus Stenting

The optimal management of carotid artery disease continues to be the subject of debate. The only well-established medical therapy — aspirin and other aspirin-like drugs — has only a modest benefit. Based on the results of several landmark studies, including the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the Asymptomatic Carotid Atherosclerosis Study (ACAS), carotid endarterectomy (CEA) was established as the gold standard of treatment for CAD and remains so, with generally excellent outcomes and a very well established track record.

CEA is a surgical procedure performed via a 2-to-3-inch incision in the neck, in which the artery is opened and cleared of plaque. The operation is highly technical and studies have shown that best outcomes are achieved by board-certified specialists who perform the procedure in adequate volume. In competent hands, the risks of death or stroke are low — generally less than 5 percent — and the majority of patients are discharged the following day.

Some patients, however, may be at higher risk for the surgical procedure due to underlying conditions such as severe heart disease or general frailty.

The advent of a less invasive procedure, carotid artery stenting (CAS), may allow many such patients to avoid open surgery. It is important to note that technology for CAS is recently developed and continually evolving, as is physician experience with this procedure. While recent results demonstrate continued improvement in CAS outcomes, concerns remain about the safety of the procedure and the appropriate selection of patients for CAS or CEA.

Several trials have compared CEA and CAS, most notably the SAPPHIRE, EVA-3S and SPACE trials. While SAPPHIRE suggested that CAS was not inferior to CEA for high-risk patients, the other two trials both failed to prove this hypothesis. Each of these studies has been criticized for aspects of their design.

Results of the most recent and largest study to date comparing CAS and CEA, the National Institute of Health-sponsored Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) trial, will be reported this year. The long awaited results of CREST, with an enrolment of roughly 2,500 patients, will certainly play a major role in the shaping of this debate.

At present, the best defined role for CAS — and the only FDA-approved indication for the treatment outside of a clinical trial — is for patients with cerebral symptoms, such as stroke or TIA, and significant carotid artery stenosis who are at high-risk for surgery, such as those with advanced heart or lung disease, or those with anatomical features, such as prior operation, that make surgery more risky.

At present, CEA remains the preferred treatment option for carotid artery disease in standard-risk patients, who comprise the overwhelming majority of individuals likely to benefit from these procedures.

UCSF Vascular and Endovascular Surgery

UCSF's vascular surgeons, who are part of the UCSF Heart and Vascular Center, perform carotid artery surgery and are involved in CAS trials for appropriate candidates. To contact Vascular and Endovascular Surgery, please call (415) 353-2357.

For more information, contact the Physician Referral Service at UCSF Medical Center:

Phone(800) 444-2559
Email referral.center@ucsfmedctr.org

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