Carotid endarterectomy is the most common procedure used in the prevention of stroke. A subcommittee of the American Academy of Neurology (AAN) reviewed articles on carotid endarterectomy to assess the effectiveness of the procedure in preventing stroke in patients with internal carotid artery stenosis. The review was published in the September 27, 2005, issue of Neurology.
The AAN found good evidence to support carotid endarterectomy in patients with 70 to 99 percent internal carotid artery angiographic stenosis that has been symptomatic in the previous six months. Endarterectomy may be considered in patients with 50 to 69 percent symptomatic stenosis, but it is not indicated for patients with less than 50 percent symptomatic stenosis. Consideration of carotid endarterectomy is reasonable in selected patients with 60 to 99 percent asymptomatic stenosis.
Physicians should consider patient variables and radiologic factors when deciding whether carotid endarterectomy should be performed. For example, the procedure was of no clear benefit in women with 50 to 69 percent symptomatic stenosis; was of more benefit in patients with hemispheric transient ischemic attack (TIA) or stroke than in those with retinal ischemic events; was of no benefit in patients with asymptomatic stenosis and contralateral occlusion; and was of persistent benefit (although it increased risk) in patients with symptomatic stenosis and occlusion. The procedure is of greater benefit in patients whose last TIA or mild stroke occurs within two weeks of the operation.
Because the benefit of carotid endarterectomy is seen only after several years, the AAN recommends that patients undergoing the procedure have at least five years' life expectancy and that the perioperative stroke or death rate be less than 6 percent in patients with symptomatic stenosis. The AAN found good evidence that endarterectomy can reduce the future stroke rate if the perioperative stroke or death rate is kept below 3 percent.
Carotid endarterectomy should be performed without delay in patients with severe stenosis and a recent TIA or nondisabling stroke, preferably within two weeks after the last symptomatic event. The benefit of the procedure within four to six weeks after a moderate to severe stroke is unclear.
Low-dose aspirin (i.e., 81 to 325 mg) should be administered before and for at least three months after the procedure because this reduces the rates of stroke, myocardial infarction, and death. Aspirin should be continued indefinitely in the absence of contraindications.
Data regarding the value of emergent carotid endarterectomy in patients with a progressing neurologic deficit were insufficient for the AAN to make a recommendation.