Asymptomatic Carotid Bruit/Carotid Artery Stenosis

Abstract

Stroke used to be the third leading cause of death in the United States, behind coronary artery disease and cancer. However, a 2011 report states that stroke has now dropped to the fourth leading cause of death. Nearly 80% of strokes are ischemic, but only 15% of stroke patients have warning transient ischemic attacks. The management of patients with asymptomatic carotid stenosis is controversial; in this review, a stepwise approach to the management of asymptomatic carotid bruit/extracranial carotid artery stenosis is provided. Specifically, this review covers clinical evaluation, carotid bruits, vascular risk evaluation, imaging modalities, natural history of asymptomatic carotid artery disease, carotid plaque progression, natural history of asymptomatic carotid stenosis with evidence of clinically silent cerebral emboli, recommendations for carotid intervention/medical therapy, level 1 evidence supporting carotid endarterectomy in asymptomatic patients, and decision making for medical therapy alone versus intervention. Figures show color Doppler image with Doppler sampling from the right common carotid artery (CCA) and internal carotid artery (ICA), color duplex image with Doppler sampling of the distal left CCA and proximal ICA, color duplex ultrasound image of a plaque at the carotid bifurcation, magnetic resonance angiography showing severe stenosis of the right ICA and occluded left ICA, computed tomographic angiography showing severe stenosis of the left ICA with calcification, diagram for management of patients with both carotid stenosis and coronary artery disease, and protocol of management of asymptomatic bruit/carotid artery stenosis. Tables list the annual risk of stroke, prevalence of carotid stenosis in patients with bruits and in healthy volunteers, duplex velocity criteria for carotid stenosis, consensus criteria, validation of consensus criteria: duplex ultrasonography versus angiographic stenosis, risk factors for stroke, ranking of modifiable stroke risk factors, asymptomatic randomized trials comparing medical with medical and surgical treatment (stenosis > 60%), and a summary of specialty/societal guidelines. This review contains 7 highly rendered figures, 9 tables, and 91 references