What is carotid stenosis? 

Carotid stenosis refers to narrowing of the carotid artery. The Carotid artery supplies blood to the brain. The narrowing is usually caused by plaque in a blood vessel. Plaque forms when cholesterol (fat) and other substances build up in the inner lining of an artery. This process is called atherosclerosis.

 Carotid stenosis can be dangerous if parts of the plaque dislodge. These can move upward with the flow of blood towards the brain and can block brain blood flow. This blockage (interrupting the supply of nutrients and oxygen to the brain) is one of the causes of stroke.

Carotid stenosis is caused by smoking, high blood pressure, high cholesterol, obesity, and a sedentary lifestyle. Another risk factor is diabetes. Carotid stenosis becomes common as people age. Patients can have carotid stenosis without any symptoms (asymptomatic) or with symptoms (symptomatic). Most people with carotid artery stenosis usually have no symptoms. Transient symptoms such as partial paralysis, blindness, or numbness can occur and may indicate there is great risk of a stroke. Symptoms of stroke include paralysis of an arm or leg, vision and speech problems. Carotid artery stenosis can also cause transient ischemic attacks (TIAs), also called “mini strokes.” In a TIA the blood supply to the brain is temporarily blocked which results in stroke-like symptoms such as blindness in one eye, numbness and tingling of the skin, and weakness of an arm or a leg. TIAs usually last from a few seconds to several minutes. These symptoms are temporary and reversible, but people who have TIAs are more likely to have a later stroke.

Treatments

The standard procedure (“Carotid Endarterectomy” - CEA) involves surgery, often under a general anaesthetic, to unblock the narrowed part of the artery in the neck. We know that this operation involves some immediate risk, but that it does provide long-term protection against the narrowing causing a stroke. A newer procedure (“Carotid Artery Stenting” - CAS) can now be used instead of CEA. This involves inserting a tube inside the narrowed part of the artery to hold it open. CAS avoids operating on the neck, as the tube is inserted via an artery some distance away (usually in the leg), using a local anaesthetic. CAS might be safer and as effective as CEA at preventing stroke, but currently there is not enough information to know this reliably.