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Carotid artery stenosis

Carotid artery stenosis is a condition in which the carotid artery is narrowed. It develops as a result of atherosclerosis (hardening of the arteries) and may restrict blood flow to the brain. In most cases, people with the condition will remain asymptomatic, and as a result, the condition is usually only found during routine medical examinations.

What is carotid artery stenosis?

When arteries get clogged up by fatty deposits (atherosclerosis) as a result of diabetes, high blood pressure, smoking, obesity or genetic factors, this may result in narrowing (stenosis) of the blood vessels. While stenosis can develop anywhere, the condition has a tendency to develop at specific sites.

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Sites often affected by stenosis include the coronary arteries (coronary heart disease, KHK), ), the renal arteries, the arteries of the pelvis and lower limbs, as well as the carotid artery. Stenosis of the artery in the arm is less common, and usually affects the point at which it arises from the aorta.

 coronary heart disease

The patient's risk of stroke increases depending on the degree of narrowing present. If the degree of narrowing exceeds 80%, the annual risk of stroke is 3%. One third of all patients with stroke will have some form of permanent disability or require long-term care. Stroke is the third leading cause of death in Germany.

At a degree of stenosis exceeding 50% of the vessel's diameter, the patient will develop symptoms of poor blood flow. Stenosis affecting the carotid artery is of particular concern as narrowing of the carotid artery may result in a reduced supply of blood to the brain. The main risk of carotid artery stenosis is that it may cause a stroke. The normal supply of blood to the brain is interrupted either as a result of narrowing of the artery or due to blood clots that form as a result of this narrowing. This interruption in blood supply may cause varying degrees of tissue damage which, depending on the site and extent of this damage, may result in some loss of function.

Carotid artery stenosis, heart attack and peripheral arterial disease (PAD) are typical consequences of atherosclerosis (hardening of the arteries). As with other cardiovascular diseases, frequency of occurrence increases with age.

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to peripheral arterial disease (PAD)

What are the main symptoms?

People with carotid artery stenosis can remain asymptomatic for a long time. As a result, carotid artery stenosis is usually detected during routine medical examinations. Such routine examinations are particularly common in patients with coronary heart disease and PAD as carotid artery stenosis is seen more frequently in these patients. In many patients, an early indication of carotid artery stenosis may be a temporary loss of neurological function that resolves itself completely within a day, but can often resolve much more quickly than that (this is known as a transient ischemic attack, or TVA). Temporary symptoms that may be warning signs of a future stroke include:


These types of symptoms should be taken seriously because a longer-lasting interruption in the flow of blood may lead to tissue death (stroke). Depending on where this tissue death occurs, all of the main bodily functions may be affected. The most common symptoms are paralysis on one side of the body, slurred speech and difficulty finding the right words. Other possible symptoms include loss of vision, impaired sense of smell and hearing loss. 

Surgical removal is advisable if an ultrasound examination reveals an irregular area of narrowing (even if the degree of narrowing is less than 50%) and if the patient has previously presented with symptoms indicative of thromboembolism. It is usually only after the event that such symptoms are correctly identified as a "mini stroke". The symptoms described above may only last for a very short time, such as in the case of a transient ischemic attack (TIA) or monocular vision loss (amaurosis fugax). They may, however, last much longer. One example here is prolonged reversible ischemic neurologic deficit, which lasts for over 24 hours and is slow in clearing.

The subclavian steal phenomenon on the other hand has a very rare symptom complex. The phenomenon is caused by chronic stenosis of the subclavian artery near the point of origin of the vertebral artery. When the muscles of the arm are subjected to sustained physical activity, blood is diverted away via the vertebral artery and effectively "stolen" from the blood vessels supplying the brain. The result is vertigo. Although not dangerous, as the affected person is not at risk of stroke, this condition can be extremely bothersome. 

What are possible causes?

Just like coronary heart disease and heart attack, carotid artery stenosis is caused by atherosclerosis (hardening of the arteries).

Risk factors include:

Diagnosis of carotid artery stenosis

Diagnostic steps:

  • Many cases of narrowed carotid arteries can be identified as a result of auscultation using a stethoscope (typical sounds associated with reduced blood flow).
  • A special type of ultrasound examination known as echo color Doppler ultrasonography allows the physician to determine the degree of narrowing (stenosis) present.
  • Images of the blood vessel itself (angiogram), obtained using a contrast agent, can provide additional information.
  • If a patient is already scheduled to undergo cardiac catheterization (e.g. to assess known coronary heart disease), the procedure can be expanded to include an investigation of the carotid arteries.
Duplex-Sonographie einer hochgradigen Stenose der Arteria carotis interna. Die hohe Flussbeschleunigung mit Farbumschlag des Flusssignals in der Carotis-Stenose ist gut zu erkennen.

Treatment of carotid artery stenosis

The elimination of all known risk factors is a fundamental step and includes the following: avoidance of nicotine, weight loss, physical activity, controlling high blood pressure and diabetes, and reducing cholesterol levels.

In addition to drug treatment, there are usually two other treatment options available, both of which are aimed at eliminating carotid stenosis: 

Where can I find out more about carotid artery stenosis?

General information
Deutsche Gesellschaft für Gefäßchirurgie (German Society of Vascular Surgery):https://www.gefaesschirurgie.de/

 

General information
Deutsche Gesellschaft für Neurology (German Neurological Society):
www.dgn.org

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