Atherosclerosis is known as hardening of the arteries. It refers to lipids or fats, such as cholesterol, being deposited into the artery wall making it rigid. Also, during this process a plaque forms. This plaque can break lose and cause a blockage of an artery down stream. Stenosis is a related condition that literally means narrowing of the arteries. This narrowing is a result of the plaque and fatty build up in the arterial wall. A narrowing can cause decreased blood flow to the area supplied by that artery.
The carotid arteries are two arteries on either side of the neck that supply blood to the brain. These are the arteries you can use to take your pulse. If any plaque breaks loose, it is called an embolus; it can flow toward the brain and block blood from getting to the brain. The embolus can be small or large. A significant narrowing, or stenosis, of the carotid artery results in decreased blood flow to the brain.
Sometimes carotid atherosclerosis and stenosis is asymptomatic. It becomes symptomatic with any sign of ischemic episode such as a TIA or stroke. Eighty percent of strokes come without warning. At a doctor’s visit, the doctor listens to either side of the neck over the carotid arteries to see if there is a carotid bruit. A bruit is a rushing sound that the blood makes as it squeezes through a narrow portion of the artery.
Evaluation of the carotid arteries may include an ultrasound, MRA, or a CT-angiogram; all of these tests are noninvasive. Conventional cerebral angiography may also be needed at times; while an invasive study, it is relatively low risk, and provides the best high-resolution pictures of the arteries.
Sometimes a stenosis, particularly if asymptomatic, can be managed without surgical intervention. Typically, a physician will recommend very important measures, including medications, to control blood pressure and lower cholesterol. Smoking cessation is also very important, as it contributes to this disease. ‘Blood-thinning’ medications called anti-platelet agents are typically prescribed to prevent embolic strokes; these include drugs such as Aspirin and Plavix. If the stenosis is significant, surgical intervention may be recommended. This typically entails one of two procedures: carotid endarterectomy or carotid angioplasty with stenting. Carotid endarterectomy entails an open surgery of the neck during which the surgeon opens the carotid artery and physically cleans out the plaque, sewing it closed at the end. Carotid angioplasty and stenting entails performing an angiogram during which a balloon is advanced within the artery and inflated to open the narrowing in the artery from the inside. A stent is then left in place to keep the artery open. Both treatments are useful; a surgeon who performs these operations can help determine which is most appropriate for each patient.
Lindsey Parker PA-C and Justin F. Fraser M.D.