Carotid artery stenosis
Carotid artery stenosis is atherosclerotic narrowing of the extracranial internal carotid artery that raises ischemic stroke risk, graded by percent luminal narrowing on duplex ultrasound. Symptomatic stenosis of at least 50% warrants urgent revascularization; asymptomatic stenosis under 80% is managed with best medical therapy alone, including a high-intensity statin and antiplatelet agent.
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What this article covers
- Overview
Definition: carotid artery stenosis is narrowing of the extracranial internal carotid artery lumen caused by atherosclerotic plaque, most often at or just distal to the carotid bifurcation, that…
- Epidemiology
Common substrate of stroke: symptomatic extracranial internal carotid artery stenosis from large-artery atherosclerosis is associated with a high risk of recurrent stroke after a transient ischemic…
- Risk factors
Hypertension: chronic elevated arterial pressure accelerates atherosclerotic plaque formation and progression.
- Pathophysiology
Plaque formation: atherosclerotic plaque accumulates at the carotid bifurcation and proximal internal carotid artery, a site of turbulent flow and low shear stress that favors endothelial injury and lipid deposition.
- Clinical features
Asymptomatic stenosis: most patients have no symptoms directly referable to the carotid lesion; the stenosis is often discovered incidentally on exam (carotid bruit) or on imaging for another indication.
- Differential diagnosis
Carotid artery dissection: an acute wall tear rather than chronic plaque, typically in a younger patient, presenting with pain and a partial Horner syndrome rather than a slowly progressive bruit…
- Diagnosis
Established by percent luminal narrowing on vessel imaging: the diagnosis and severity grading of carotid artery stenosis is established by quantifying percent stenosis, most commonly with carotid duplex ultrasonography.
- Management
Initial step in symptomatic patients presenting with acute stroke: follow standard acute ischemic stroke protocols, including intravenous thrombolysis or mechanical thrombectomy when eligibility…
- Complications
Ischemic stroke: the principal complication of untreated or progressive high-grade stenosis, from plaque rupture with artery-to-artery embolism.
- Prognosis
Asymptomatic stenosis under 80%: low annual stroke risk, likely under 1%, with medical therapy alone.
- Prevention
No general population screening: the U.S.
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Carotid artery dissection is a tear in the wall of the internal carotid artery creating an intramural hematoma, typically presenting with unilateral head, face, or neck pain, partial Horner syndrome, and ischemic stroke or transient ischemic attack in a young or middle-aged patient. Diagnosis is by MRA or CTA of the neck, and most patients are treated with antiplatelet or anticoagulant therapy.
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