Carotid Artery Stenosis
The brain is an organ that is supplied with a dense network of small arterioles. However, there are only two pairs of arteries bringing the oxygenated blood towards the brain - two relatively carotid arteries located relatively superficially in the neck and two vertebral arteries that run deeply along the vertebral column.
Carotid arteries are relatively large and they may be easily palpated. Narrowing of the arteries is relatively common in older people and it is usually caused by the process of atherosclerosis (cholesterol deposits in the walls of blood vessels).
Narrowing of carotid arteries has initially no symptoms. The brain is a sufficient blood supply by four main blood vessels and even total gradual obstruction of a single carotid artery may cause no harm. However, in some people the narrowing can cause symptoms in conditions that impair the blood flow into the brain (low blood pressure, dehydration, sepsis, etc.). These symptoms may include confusion, dizziness and other neurological manifestations. Narrowed carotid artery also increases risk of ischemic stroke. The stroke is caused not by the narrowing itself, but by increased risk of a sudden blood clot formation in the narrowed artery. The blood clot may loosen and travel with the bloodstream into a smaller brain artery, which gets obstructed, causing acute local ischemia.
The narrowing can be suspected even during physical examination when listening with a stethoscope. Blood flow through the narrowed area manifests with a characteristic murmur. Accurate diagnosis can be done by Doppler ultrasound of the affected carotid. This examination not only confirms the narrowing, but it also helps us to evaluate its severity. More invasive examination is for example the local angiography.
There are two therapeutic options – conservative and invasive (endovascular or surgical). The decision, which procedure to choose, is individual and depends on the decision of a neurologist, angiologist and vascular surgeon.
The conservative therapy means therapy of atherosclerosis which means regular administration of hypolipidemic agents (usually statins), anticoagulants (usually drugs containing acetylsalicylic acid) and antihypertensives when there is simultaneously present high blood pressure.
Endovascular approach is a more invasive solution, which consists of therapeutic angiography, dilation of the narrowed area (angioplasty) and its support by a tube-shaped stent that prevents restenosis.
Surgical treatment is the most invasive option. It is a relatively demanding procedure, in which the inner layer of the arterial wall is removed in the narrowed area. However, this operation is a little bit risky by increased risk of a stroke during- or after the procedure.