Stroke Prevention: Extra-Cranial Carotid Artery Therapy
Nearly 800,000 strokes occur each year in the United States, and over 120,000 Americans die
annually from stroke. Atherosclerotic carotid artery disease is the leading cause of
non-cardioembolic ischemic strokes.
Carotid plaque most often causes cerebrovascular events due to plaque rupture with
atheroembolization, rather than carotid artery occlusion (<20% of ischemic strokes) with thrombosis.
The risk of stroke related to carotid artery stenosis is strongly related to
the presence or absence of preceding symptoms (transient ischemic attack (TIA), or stroke).
Symptomatic patients have a much greater risk of stroke when compared to
asymptomatic patients, but the ratio asymptomatic to symptomatic patients undergoing
carotid revascularization is 2.5:1.4 A TIA is an important warning
sign associated with a 30% risk of stroke within 6-months.
Digital subtraction angiography is the gold standard for defining carotid anatomy
with the North American Symptomatic Carotid Endarterectomy Trial (NASCET)
method of stenosis measurement the most widely accepted methodology.
However, invasive cerebral catheter-based angiography carries a risk of
cerebral infarction of 0.5% to 1.2%; therefore, non-invasive
imaging should be the initial strategy for evaluation.
Carotid doppler ultrasound (duplex) imaging, computed tomography angiography (CTA), and magnetic resonance angiography (MRA) are the non-invasive methods of stenosis assessment. Duplex
imaging is the best initial choice given its safety profile, low-cost, and wide availability.
Neuro Open J. 2019; 6(1): 13-20. doi: 10.17140/NOJ-6-132