Carotid artery disease, also known as carotid artery stenosis, occurs when the carotid arteries become narrowed or obstructed. This is usually due to atherosclerosis, or the build-up of plaque in the blood vessel. Plaque is a substance, usually hard on the outside and soft on the inside, which is composed of fatty material, cholesterol, calcium, and cellular waste products. Carotid artery disease can cause a stroke.
An artery is a blood vessel that takes blood away from the heart. The carotid arteries are paired blood vessels that take oxygenated blood from the heart to the frontal brain tissue. The right common carotid arteries branches from the brachiocephalic trunk in the neck extends up the right side of the neck and the left common carotid artery originates at the aortic arch in the thorax, or chest, and extends up the left side of the neck. When a pulse is taken from the neck, it is typically measuring the pulse in the carotid arteries.
Several factors can put a patient more at risk for developing carotid artery disease. High blood pressure, age, obesity, diabetes, smoking, high content of “bad” cholesterol or low content of “good” cholesterol, high saturated fat diet, lack of exercise, and family history of carotid artery disease can all increase a patient’s risk. The most serious complication of the disease is a stroke, or the loss of brain function due to impaired blood flow to the brain.
Normally, the carotid arteries are elastic and allow blood to pass freely, but as carotid artery disease advances and plaque builds along the walls of the artery, the vessel hardens and narrows. This on its own can cause a stroke if the atherosclerosis becomes so advanced that vessels are extremely narrowed and the brain can no longer get enough blood to function. A stroke can also be caused by the rupture of a plaque deposit. Disc-like blood clotting agents known as platelets rush to the site of the rupture in an effort to repair the vessel. The platelets clump together and can cause a block sufficient to cause a stroke. Also, if the plaque ruptures and a piece of the plaque drifts off and becomes lodged in a smaller artery of the brain, a stroke may occur.
Carotid artery disease frequently goes unnoticed until the event of a stroke, because it often presents no symptoms. If a patient is about to have a stroke, however, he may experience blurriness of vision, weakness or numbness in the arm, face, or leg on one side of the body, trouble comprehending and speaking, dizziness, inability to walk straight, and difficulty swallowing. These symptoms mean the patient is having a mini-stroke, or transient ischemic attack (TIA). A TIA is a medical emergency and the patient should receive immediate medical attention to prevent fatality or permanent brain damage.
Because carotid artery disease presents no symptoms until the event of a stroke, it is important to have routine physicals and tell doctors of any risk factors a patient may have. Doctors may listen for abnormal sounds in the carotid arteries with a stethoscope and perform imaging procedures to examine whether the arteries may be blocked. Carotid artery disease is often treated with lifestyle changes, such as healthy diet, exercise, and quitting smoking and alcohol consumption. Blood thinning medications are also prescribed to all patients with carotid artery disease to prevent blood clotting.
Carotid endarterectomy is the standard surgical procedure to repair carotid artery disease. The surgeon makes an incision at the site of the obstruction, removes the plaque and the damaged section of the artery, and sews the vessel back together. Surgeons may also try using a balloon to widen the artery and implanting a stent to hold the vessel open. This method is still under research.