2005

Carotid Angioplasty With Stent Placement Is an Effective Alternative for High-Risk Carotid Endarterectomy Patients

Points to Remember

• Stroke is the third-leading cause of death in the industrialized world, and carotid artery occlusive disease is an important causal factor.
• Carotid endarterectomy (CEA) is a successful treatment, but some patients are at high risk for this surgery.
• Carotid angioplasty with stent (CAS) placement is an effective alternative to CEA in high-risk patients. Mayo Clinic has been successfully performing CAS placement since 1996.
• Mayo Clinic is currently enrolling patients in the Carotid Revascularization Endarterectomy Versus Stent Trial (CREST), a National Institutes of Health-sponsored, multicenter study evaluating CAS placement.

Scope of Problem

Stroke is the third-leading cause of death in the industrialized world. In the United States each year, an estimated 750,000 people experience a new or recurrent stroke, which contributes to approximately 160,000 deaths. Carotid artery occlusive disease is an important cause of stroke. When carotid artery stenosis causes symptoms of transient ischemic attack (TIA) and the vessel lumen is narrowed by 70%, the chance of a stroke occurring is approximately 26% over 2 years if surgery is not performed to open the artery. This risk is reduced to 9% if the artery narrowing is treated surgically.

Standard Treatment

After TIA or stroke occurs, the patient is evaluated to determine the cause. If symptoms are evident in the distribution of the carotid arteries, imaging studies such as carotid ultrasonography or magnetic resonance angiography (MRA) are used to determine if the narrowing of the arteries is severe. When the degree of carotid narrowing is severe, lifestyle changes and medical therapy are generally the first-line treatments. These include controlling hypertension and diabetes, treating elevated lipids, quitting smoking, moderating alcohol intake, increasing exercise, and using antiplatelet drugs, anticoagulants, or both.

If the narrowing of the carotid arteries is severe, further intervention may be needed. Carotid endarterectomy (CEA), which has been used successfully for decades, is the standard surgical treatment. However, it is not appropriate for all patients. Some patients considered for CEA have cardiopulmonary or other medical conditions that place them at high surgical risk. Likewise, previous neck irradiation, extensive neck surgery, or CEA may increase the risk of surgical complications. Patients with these conditions are candidates for carotid angioplasty with stent (CAS) placement.

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A New Approach: CAS Placement

Mayo Clinic neuroradiologists began using CAS in high-risk patients in 1996. The Mayo Clinic experience with CAS placement suggests that, when performed by an experienced, multispecialty team on carefully selected patients, the procedure is approximately equal to CEA in terms of effectiveness, risks, and complications.

If carotid ultrasonography or MRA shows severe carotid artery stenosis, the patient is thoroughly examined by a Mayo Clinic multidisciplinary team.

If CAS placement is deemed the best treatment option, the patient undergoes carotid angiography. During the evaluation, the patient is sedated but awake. A small plastic catheter is put into a groin artery and tracked through the aorta to the carotid arteries. Next, dye is injected into the artery to delineate the anatomy. If the angiogram confirms severe narrowing that could be best treated with CAS placement, the procedure begins:

• A protection device is deployed distally in the carotid artery to catch material that may break free when the angioplasty is performed.
• The angioplasty balloon is brought across the plaque and inflated to push the plaque aside and open the artery.
• The stent is brought up to keep the artery from narrowing again.
• The procedure ends with the withdrawal of the distal protection device and the catheter. Patients are typically discharged from the hospital the next day. Most can quickly resume normal activities when they return home. Clopidogrel and aspirin are required for 1 month after CAS placement to prevent blood clot formation at the CAS site. Aspirin alone is taken indefinitely thereafter.

Potential Disadvantages of CAS

Because the interventionist is working within the artery, the procedure carries with it a small risk of stroke. How this risk compares with that of CEA is under evaluation. Risk of recurrent narrowing in the months and years after CAS compared with the risk after CEA is also under evaluation.

The NIH Study of CAS

In recognition of Mayo Clinic's experience and skill with CAS placement, Mayo Clinic has been selected to participate in the Carotid Revascularization Endarterectomy Versus Stent Trial (CREST), a multicenter, National Institutes of Health-sponsored study. The study compares CAS placement and CEA in terms of therapeutic value and durability, as well as risks and complications posed to the patient.