About the disease
Carotid artery stenosis is a narrowing of neck artery which carries blood to brain. In most cases carotid artery stenosis develops as a result of atherosclerosis. Atherosclerosis is an extremely complex degenerative disease. Scientists do not know the cause of atherosclerosis, however, they are aware of many components that contribute to growth of atherosclerotic lesions. It is mostly believed that atherosclerosis develops because of injury of arterial wall. Factors that contribute to arterial wall injury include mechanical traumas, hypertension, and low elasticity of the wall. Also nicotine and other harmful chemicals can provoke development of atherosclerosis. Typically carotid stenosis develops few years later after coronary artery was damaged. Carotid artery stenosis can also occur because of plaques, which are fatty deposits that accumulate in artery. Patients who have artery stenosis must always beware of stroke risk, because this is most common death cause in the world. Stroke happens when there is not sufficient supply of blood and oxygen to brain cells. Stenosis of carotid, which blocks supply of blood to the brain by 50-60%, can contribute to emergence of stroke. According to News.Medical, which is a medical magazine, approximately 25% of all strokes are caused by this disease.
As it was mentioned above, carotid stenosis in most cases is caused by atherosclerosis, which is accumulating of plaques in artery. Basically, such fat deposits appear because of unhealthy lifestyle and excessive body weight. Stenosis can also be caused by tobacco consumption when clots form in artery because of nicotine and its harmful effects on body. If a person has troubles sleeping at night, if he suddenly wakes up and experiences shortness of breath, it can be a sign of sleep apnea, which is another cause of artery stenosis. It happens because during sleep apnea a person usually sits and pushes his head up very suddenly, that's why there could be a microscopic damage to carotid artery, which can later grow into clots. Some surgeries on neck or face can also contribute to development of stenosis. If a person never exercises, his muscles become stiff. It happens especially if he works at office where he sits the whole day without moving his neck. Such constant stiffness of neck can contribute to appearance of plaques which would decrease amount of blood transferred to the brain. A person who has sedentary lifestyle is usually advised to move his neck in both sides and rotate his head as often as possible. Neck massage and swimming can also be a good solution.
Factors that increase risk of carotid artery stenosis include:
- Family history
- Age. Risk of developing carotid artery stenosis increases with age, particularly after 75 years of age
- Tobacco consumption
- High blood pressure
- Excessive weight
- Sedentary lifestyle
Transient ischemic attack (called "mini-stroke") is the most common symptom of carotid stenosis. Transient ischemic attacks occur when "clot" blocks for a short time an artery which is supplying blood to brain. Other symptoms can occur suddenly and last for several minutes or even hours. Those are:
- Sudden loss of vision, which can occur in one or both eyes
- Weakness or numbness in face, leg or hand
- Slurred speech
- Difficulty comprehending what others are saying or questioning
- Severe headache
- Loss of balance and coordination
- Difficulty and pain during swallowing
Transient attack is medical emergency, as it is impossible to predict whether it is ischemic stroke or carotid artery stenosis.
- Diagnostic tests mainly include Doppler ultrasound of neck vessels to investigate if vessels are narrowed. Angiography of carotid arteries injects catheter into arm or leg to assess carotid artery. This method determines degree of narrowing or blockage of carotid artery to determine risk of stroke and assess need for further treatment. Magnetic angiography (MRA) is also an effective imaging technique, which uses magnetic radio waves to provide an image of carotid arteries. This method may also provide important information about degree of stenosis.
- Computed tomography (CT scan of the brain) may be performed if there is suspicion of stroke or transient attack. This test may identify areas, where there was damage in the brain.
- Computed tomography angiography is method, which uses advanced CT technology to produce 3D images of carotid artery with high resolution.
- Transluminal angioplasty and stenting are used if there is high risk of stroke. Angioplasty and stenting is performed without general anesthesia and in this case sedation is used. During this procedure balloon catheter is inserted into a blood vessel. Once in carotid artery, balloon is inflated for several seconds to open and expand artery. During stenting instead of balloon doctors use a stent (small mesh tube) corresponding with the size of the artery. Stent stays in artery permanently to prevent narrowing in future. Studies have shown that carotid stenting is more safe and effective than carotid angioplasty.
- Thromboendarterectomy is a traditional carotid artery stenosis surgery. This procedure is recommended for patients with stenosis level of 50 percent or more. Carotid endarterectomy can be generally performed under anesthesia with intravenous sedation. During surgery, a doctor makes an incision in neck to remove clots if they are there and to restore blood flow to brain.