Carotid Artery Stenosis

Relationship to stroke pathogenesis

When a carotid artery is narrowed by atherosclerotic plaque so that the cross-sectional area of its lumen is reduced by 70% or more, the patient has a significantly increased risk of stroke. Narrowing of the carotid artery can be symptomatic, producing a stroke or transient ischemic attack (TIA), or asymptomatic. This depends on factors like whether the plaque surface is disrupted, increasing the likelihood of thrombus formation (a thrombus can directly block the artery or be a source of emboli) or whether there is an effective collateral circulation that supplements the blood supply to brain regions in the jurisdiction of the partially occluded carotid. 

A little about control/treatment

When a carotid artery is narrowed 70% or more, carotid endarterectomy (surgical removal of fatty deposits) is often considered. This procedure has been shown to significantly reduce stroke risk for both symptomatic and asymptomatic patients, but has associated surgical risk. Early intervention after the onset of symptoms is now often recommended. More recently, minimally invasive angioplasty with or without stenting has become available. The results of clinical trials comparing long-term outcomes and considering factors such as patient age and gender continue at this time.  Blockages ≤30% are often treated using lipid-lowering agents (statins) and antiplatelet therapy, with the combined goals of slowing atherosclerotic disease and reducing the risk of thrombus formation.