Stroke is the fourth and fifth leading cause of death in the UK and US, respectively, and the leading cause of disability in both countries. Carotid artery stenosis causes approximately 10% to 15% of all ischaemic strokes.
Atherosclerotic plaque in the cervical carotid artery is the most common cause. Plaque disruption and atheroembolisation into the intracranial circulation is the most common mechanism for stroke.
The majority of carotid artery stenoses are mild or moderate, and asymptomatic.
Duplex ultrasonography is a commonly used mode of diagnosis; computed tomography angiography or magnetic resonance angiography are alternatives that also help to define the anatomy if intervention is indicated.
Most patients with carotid artery stenosis should receive antiplatelet therapy, and all should receive risk factor modification.
Carotid revascularisation of moderate- or high-grade recently symptomatic carotid artery stenosis prevents future stroke.
The benefit of revascularisation for asymptomatic stenosis is less certain.
Carotid artery stenosis is a narrowing of the lumen of the carotid artery. Atherosclerotic plaque in the cervical carotid artery is the most common cause. The unique haemodynamics at the carotid bifurcation predisposes this area to atherosclerosis. The majority of patients have mild- or moderate-sized plaques, while some develop high-grade stenoses. A small percentage of plaques may rupture and embolise to occlude intracranial arteries, causing a transient ischaemic attack or stroke, or occlude retinal arteries to cause transient monocular blindness (amaurosis fugax) or retinal strokes.
History and exam
Key diagnostic factors
- cervical bruit
- focal neurological deficit lasting >24 hours (i.e., stroke)
- focal neurological deficit lasting <24 hours (i.e., transient ischaemic attack [TIA])
Other diagnostic factors
- transient visual symptoms
- older age
- history of hypertension
- history of cardiovascular disease
- history of hypercholesterolaemia
1st investigations to order
- duplex ultrasonography
- computed tomography angiography (CTA) of head, neck, and chest
Investigations to consider
- magnetic resonance angiography (MRA) of head, neck, and chest
- cervical angiography
- CT brain
- MRI brain
asymptomatic carotid stenosis <70%
asymptomatic carotid stenosis ≥70%
bilateral carotid stenosis
- Carotid dissection or subintimal haematoma
- Thrombotic occlusion of the carotid artery resulting from plaque rupture
- Fibromuscular dysplasia
- 2017 ESC guidelines on the diagnosis and treatment of peripheral arterial diseases
- Management of atherosclerotic carotid and vertebral artery disease
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