Carotid Artery Disease (Carotid Stenosis)
Carotid artery disease is a narrowing of the main neck arteries (carotid arteries) caused by atherosclerotic plaque. It reduces blood flow to the brain and raises the risk of ischemic stroke; it is often silent, and fragments breaking off the plaque can block downstream vessels.
最終更新: 2026-06-07
Definition
Carotid artery disease is a vascular condition marked by progressive narrowing (stenosis) of the internal carotid artery due to atherosclerotic plaque, with a resulting reduction in cerebral blood flow. The most common site is the carotid bifurcation, where the common carotid divides into internal and external branches; turbulent flow there promotes plaque formation. It accounts for a significant share of ischemic strokes, and its frequency increases with age.
Causes and Risk Factors
Atherosclerosis underlies the disease. Major risk factors include hypertension, high cholesterol (elevated LDL), diabetes, smoking, advanced age, family history and obesity. Plaque consists of a lipid core and a fibrous cap; vulnerable plaques with a thin cap and large lipid core are more prone to rupture and to forming clots within the vessel.
Symptoms
A large proportion of carotid stenosis is asymptomatic and is detected by a bruit heard on examination or as an incidental imaging finding. Symptomatic cases may present with a transient ischemic attack (TIA): transient weakness or numbness of the opposite arm and leg, speech disturbance, or transient loss of vision in one eye (amaurosis fugax). Ischemic stroke with persistent deficits is a medical emergency.
Pathophysiology
Symptoms arise through two main mechanisms. The first is artery-to-artery embolism, in which clot fragments forming on a vulnerable plaque surface travel to the brain and occlude smaller vessels. The second is hypoperfusion, in which a severe stenosis leaves cerebral blood flow inadequate, particularly during episodes such as low blood pressure, leading to watershed (border-zone) infarcts.
Diagnosis
The first-line study is carotid Doppler ultrasonography, a non-invasive and widely available test whose flow velocities help estimate the degree of stenosis. CT angiography or MR angiography is used for detailed assessment. Digital subtraction angiography (DSA) is the most sensitive method but, being invasive, is reserved for selected cases. The degree of stenosis is graded to guide the treatment decision.
Treatment
Medical therapy is the foundation for all patients: antiplatelet agents, a statin, blood pressure and diabetes control, smoking cessation and lifestyle change. Revascularization is considered for symptomatic high-grade stenosis and for selected asymptomatic cases. The two principal methods are surgical carotid endarterectomy and endovascular carotid stenting; the choice is individualized by age, anatomy and surgical risk.
Prognosis
Prognosis depends on the degree of stenosis and the presence of symptoms. Asymptomatic mild-to-moderate stenosis can be followed on medical therapy with a low annual stroke risk. In symptomatic high-grade stenosis the stroke risk is markedly higher and can be substantially reduced with early treatment. Restenosis may develop after treatment, so regular follow-up is important. Outcomes vary by patient and none is guaranteed.
参考文献
- Greenberg MS. Greenberg's Handbook of Neurosurgery. 10th ed. Thieme; 2023:1548-1568.
- Winn HR, ed. Youmans Neurological Surgery. 6th ed. Saunders; 2011:3621-3640.
- Spetzler RF, Kalani MYS, Nakaji P, eds. Neurovascular Surgery. 2nd ed. Thieme; 2015:1203-1213.
- North American Symptomatic Carotid Endarterectomy Trial (NASCET) Collaborators. N Engl J Med. 1991.
- Brott TG, et al. Stenting versus Endarterectomy for Carotid Stenosis (CREST). N Engl J Med. 2010.
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