In medicine, stenosis refers to the narrowing of a hollow organ, such as blood vessels or the spinal canal. When the carotid artery (arteria carotis, carotis) or its branching vessels narrow, doctors refer to this as carotid stenosis.
The carotid artery supplies the brain with oxygen-rich blood. Carotid stenosis leads to an insufficient supply of oxygen to the brain—ultimately posing a risk of a life-threatening stroke.
Carotid stenosis refers to the narrowing of the carotid artery @ songkram /AdobeStock
The most common cause of this narrowing is atherosclerosis (“hardening of the arteries”). In this condition, the following substances gradually accumulate on the inner walls of the vessel:
connective tissue, thrombi (blood clots), blood lipids, and/or calcium. These deposits narrow the vessel’s cross-section.
The following factors can contribute to the development of carotid stenosis:
- High blood pressure
- Elevated blood lipid levels
- Smoking, and
- Advanced age
- Other medical conditions (e.g., vasculitis)
The narrowing of the carotid artery can lead to an embolism (blockage of a blood vessel) or reduced blood flow. This results in insufficient oxygen supply to the brain.
Carotid stenosis can go unnoticed for a long time.
However, it can also lead to neurological deficits, such as:
Occasionally, the following symptoms may also occur:
These symptoms are considered warning signs of an impending stroke, which can cause permanent damage to the brain. It is essential that you seek medical attention to determine the cause of these symptoms.
In addition to a stroke, other complications may also occur:
- Transient ischemic attacks (TIA, temporary neurological deficits) and
- Amaurosis fugax (temporary vision loss)
The symptoms may already provide an initial indication of carotid stenosis. This suspected diagnosis can be confirmed by examining the carotid artery using ultrasound (color-coded Doppler sonography).
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Doppler sonography is a painless diagnostic method that measures the speed and direction of blood flow @ Pepermpron /AdobeStock
With this ultrasound examination, the doctor can assess the narrowings in the blood vessels. It is completely painless and safe for the patient.
The doctor obtains further information using the following procedures:
These procedures are often used to plan an appropriate treatment.
There are three treatment options for carotid stenosis.
The prerequisite for medical therapy of carotid stenosis is that it is not yet causing any symptoms. Medical treatment is intended to reduce risk factors (e.g., high blood pressure) as well as the risk of complications (e.g., stroke).
In open surgery, doctors surgically remove the narrowed sections of the carotid artery. One example is the well-established carotid thromboendarterectomy.
This procedure is performed by vascular surgery specialists. During this operation, doctors open the carotid artery and remove the narrowed sections.
Stent implantation is performed endovascularly: Specialists dilate the narrowed area during a minimally invasive procedure using a balloon catheter. They then insert a stent (vascular support) to keep the narrowed area open.
Specialists in carotid stenosis are typically:
Further examinations are performed by specialists in radiology or nuclear medicine. Any necessary surgeries are performed by specialists in vascular surgery.
Facilities specializing in the treatment of carotid stenosis include clinics for vascular surgery or vascular medicine, neurology, and angiology.
What are the main causes of carotid stenosis?
The primary causes of carotid stenosis are deposits (plaques) of calcium, fats, and connective tissue that form over time on the walls of the carotid arteries. This calcification leads to a progressive narrowing of the artery, particularly the internal and common carotid arteries. Risk factors such as high blood pressure, smoking, diabetes mellitus, elevated blood lipid levels, and an unhealthy lifestyle contribute to the development of these stenoses. Early diagnosis is important to slow the progression of the disease and reduce the risk of a stroke.
When is surgery necessary for carotid stenosis?
Surgery is usually unavoidable in cases of symptomatic carotid stenosis, especially when the stenosis is severe. Typical symptoms such as visual disturbances, dizziness, or brief episodes of paralysis indicate reduced blood flow to the brain. In these cases, vascular surgeons recommend treating carotid stenosis through surgical debridement (thrombendarterectomy) or stent placement. For asymptomatic patients, conservative medical therapy is often sufficient to control the risk of stroke.
What happens during carotid artery surgery?
Surgical treatment is usually performed under general anesthesia or—for certain procedures—under local anesthesia. During the procedure, the surgeons open the affected artery, remove the plaque deposits, and, if necessary, stabilize the arterial wall with a patch. Alternatively, if the anatomy is suitable, a stent can be implanted to widen the narrowed artery. Both procedures have the same goal: to restore an adequate blood supply to the brain and reduce the risk of stroke.
What role does lifestyle play in prevention and follow-up care?
A healthy lifestyle can play a significant role in preventing the progression of atherosclerosis and the formation of new stenoses. After successful treatment, it is therefore advisable to consistently reduce risk factors such as smoking, obesity, and physical inactivity. A balanced diet, regular exercise, and monitoring blood pressure and diabetes are also part of guideline-based follow-up care. These lifestyle changes can improve life expectancy and reduce the risk of another ischemic stroke.
How do symptomatic and asymptomatic carotid stenoses differ?
In symptomatic carotid stenosis, clinical signs such as visual disturbances, speech problems, or brief episodes of loss of function are already present, indicating reduced blood flow to the brain. This form usually requires surgical treatment. Asymptomatic carotid stenosis, on the other hand, is often discovered incidentally—for example, during an ultrasound examination—and can initially be treated conservatively with medication. The decision depends on the degree of stenosis and the overall vascular condition, particularly that of the internal and external carotid arteries.
How does carotid stenosis affect life expectancy?
If left untreated, carotid stenosis can significantly increase the risk of stroke and thus reduce life expectancy. However, early diagnosis, guideline-based treatment, and lifestyle modifications can significantly reduce the risk of ischemic events. With timely treatment by experienced vascular surgeons, the prognosis and long-term quality of life for patients are very good.
