Carotid ArteryEdit
The carotid arteries are the main vessels in the neck that deliver arterial blood to the head and brain. The two primary channels are the left and right common carotid arteries, which ascend beside the trachea and larynx and then divide into the internal carotid artery and external carotid artery. The internal carotid artery carries blood into the cerebral circulation, including pathways that feed the circle of Willis and major brain regions, while the external carotid artery supplies the face, scalp, and neck. Because the brain depends on a steady supply of oxygenated blood, any narrowing or blockage of these vessels can have serious consequences.
Most clinically significant disease of the carotid arteries arises from atherosclerosis, a long-term buildup of plaque that narrows the vessel lumen and raises the risk of downstream ischemia. In many people, this process remains asymptomatic for years, but when plaques become unstable or embolic fragments break free, they can trigger a sudden event such as a ischemic stroke or a transient ischemic attack (TIA). Accordingly, management emphasizes risk-factor modification, appropriate imaging, and, in select patients, procedures that restore patency and improve cerebral perfusion. The overall approach blends personal responsibility—mitigating smoking, controlling blood pressure and lipids, maintaining a healthy weight—with medical and, when indicated, surgical or endovascular care.
Anatomy
Common and internal carotid arteries
The two main vessels begin as the left and right common carotid arteries. Each common carotid artery travels upward in the neck and then bifurcates into an internal carotid artery and an external carotid artery. The internal carotid artery enters the skull and feeds the anterior and middle cerebral circulations, contributing significantly to the blood supply of the brain. The external carotid artery runs toward the face and scalp, giving off branches that nourish facial structures and the scalp. See common carotid artery, internal carotid artery, and external carotid artery.
Bifurcation, sinus, and body
The bifurcation point is a clinically important landmark because the carotid sinus at this region houses baroreceptors that help regulate blood pressure, while neighboring chemoreceptors in the carotid body help sense blood gas levels. These sensors influence cardiovascular and respiratory reflexes. Additional branches in the neck and skull contribute to regional perfusion before the blood reaches the intracranial arteries, including the ophthalmic, anterior cerebral, and middle cerebral arteries via the intracranial circulation.
Physiology and function
The carotid arteries contribute to cerebral perfusion, the process by which the brain maintains a relatively constant blood flow across a wide range of systemic pressures. Autoregulation mechanisms in the brain adapt to changes in blood pressure, ensuring neurons receive sufficient oxygen and nutrients under most conditions. Disruption of flow, whether from severe stenosis, dissection, or acute thrombosis, can precipitate neurologic symptoms and, if not promptly managed, can lead to brain injury. The anatomy of these vessels also supports collateral pathways, such as connections in the circle of Willis, which can partially compensate when one pathway is compromised.
Pathology
Carotid artery disease
Atherosclerotic disease in the carotid arteries (carotid artery disease) narrows the vessel lumen and increases the risk of embolization to cerebral vessels. Risk factors include age, smoking, hypertension, diabetes, and dyslipidemia. Clinically significant stenosis may be evident through symptoms like TIAs or strokes, though many cases are discovered incidentally on imaging performed for other reasons. Management hinges on risk-factor control and, in selected cases, procedural intervention. See atherosclerosis and ischemic stroke.
Dissection and other etiologies
Carotid dissection involves a tear in the arterial wall that can create a false channel or propagate a clot, potentially causing sudden neurologic symptoms. Less common causes include congenital abnormalities, trauma, and aneurysms of the carotid system. See carotid dissection.
Diagnostics and imaging
Diagnosis of carotid disease uses a staged approach designed to balance accuracy, invasiveness, and cost. Noninvasive screening and assessment typically begin with duplex ultrasonography, which estimates flow velocity and plaque burden. If needed, further detail is provided by CT angiography (CT angiography) or MR angiography (magnetic resonance angiography). In some cases, invasive catheter-based angiography is performed, often to plan or confirm a surgical or endovascular intervention. See duplex ultrasonography, CT angiography, and MR angiography.
Treatment and management
Medical management
Most patients benefit from aggressive cardiovascular risk-factor modification. This includes antiplatelet therapy where appropriate, statin therapy to manage cholesterol, blood pressure control, diabetes management, smoking cessation, and lifestyle changes that promote vascular health. These measures aim to slow progression of atherosclerosis and reduce the risk of embolic events. See antiplatelet therapy and statin.
Interventions: endarterectomy and stenting
For certain patients with high-grade carotid stenosis, particularly if symptoms are present or if imaging shows substantial narrowing, surgical or endovascular intervention can reduce the risk of stroke. The most established surgical option is carotid endarterectomy (carotid endarterectomy), which removes plaque from the narrowed segment. An alternative approach is carotid artery stenting (carotid artery stenting), a less invasive endovascular method that places a scaffold to keep the artery open. Selection depends on anatomy, comorbidities, and patient preferences, and guidelines emphasize individualized decision-making. See carotid endarterectomy and carotid artery stenting.
Controversies and debates
There is ongoing debate about the benefits of screening and intervention in asymptomatic individuals. Proponents of targeted, evidence-based screening argue that identifying high-risk patients and offering timely interventions can prevent strokes while avoiding unnecessary procedures. Critics contend that routine screening in broad populations leads to overdiagnosis and overtreatment, with costs and risks that may outweigh benefits in low-risk groups. From a policy and practice perspective, many healthcare systems emphasize risk-based imaging and shared decision-making, rather than blanket screening. The discussion often centers on the balance between proven benefit in select groups (e.g., symptomatic high-grade stenosis) and the risks, costs, and resources involved in widespread screening and treatment. For those following the technology and device landscape, long-term outcomes of carotid stenting versus endarterectomy remain a key point of comparison, with trials and real-world data informing best practices. See NASCET and carotid endarterectomy.