Carotid artery stenosis overview

# Overview
Carotid arterial stenosis is a narrowing of the lumen of the carotid artery, usually by atheroma (a fatty lump or plaque causingatherosclerosis). Atheroma's may cause transient ischemic attacks (TIAs) and cerebrovascular accidents (CVAs) as it obstructs the bloodstream to the brain.  It also has the potential to generate emboli (blood clots) that obstruct the cerebral arteries. The narrowing can either be asymptomatic (causing no medical problems) or presents with symptoms such as TIAs and CVAs.

# Pathophysiology
Embolism of atherosclerotic lesions in the carotid is the most common mechanism of stroke in patients with carotid artery disease. Thrombosis of the cerebral arteries is also a possible, less common cause of stroke.

# Causes
The most common cause of carotid artery stenosis is atherosclerosis.  The process of atherosclerotic plaque formation starts in the early adulthood but it takes years for it to cause symptoms.  Uncommon causes include Marfan's syndrome and fibromuscular dysplasia.

# Risk Factors
Risk factors for carotid artery stenosis are almost similar to those for cerebrovascular accident (CVA), coronary heart disease (ACS) and peripheral vascular disease (PVD).  Common risk factors include hypertension, smoking, advanced age and abnormal cholesterol levels including lowered HDL levels in the blood.

# Screening
Screening for carotid disease is done before cardiac surgery.

# Diagnosis

## Electrocardiogram
The EKG may show evidence of an old infarct or myocardial ischemia. The most common cause of death post-CEA is a myocardial infarction.

## CTA
CTA can be used for further imaging to assess whether the artery is still patent, in order to further assess for treatment options.

## MRA
If there is doubt whether the narrowing is still patent (open to blood flow) and the patient is to be assessed for treatment, the next imaging option would either be computed tomography angiogram (CTA) or a magnetic resonance imaging angiogram (MRA). MRA tends to over-estimate the stenosis, but can be used in collaboration with duplex to evaluate the carotid stenosis.

## Echocardiography or Ultrasound
Carotid stenosis is usually diagnosed by ultrasound scan of the neck arteries.  This is the first imaging option and usually used for follow up and observation as it involves no radiation and no contrast agents that may cause allergic reactions.

# Treatment

## Medical Therapy
Medical therapy for carotid artery stenosis includes; antihypertensives to control blood pressure, antiplatelet agents, management of lipids, and management of diabetes through tight control of blood glucose levels. Management also includes assessment of the global cardiovascular risk, as well as a yearly surveillance ultrasound, and educating the patient about the symptoms of TIA and stroke.

## Surgery
Carotid endarterectomy and stenting are two methods of surgical treatment for carotid artery stenosis.

## Secondary Prevention
Secondary prevention for carotid artery stenosis include the cessation of smoking. Other preventative methods which can also be treatment measures are tight control of blood pressure, management of diabetes, and management of lipids.