Carotid Artery Stenosis
Carotid stenosis is a change that leads to a decrease in the caliber or even an almost total obstruction of the carotid arteries (main arteries that carry blood to the brain).
In the vast majority of cases, the obstruction of these arteries is caused by fatty and calcium plaques (atherosclerotic plaques) that accumulate on the arterial wall, leading to stenosis (decreased artery caliber). The formation and accumulation of these fatty plaques are one of the main causes of stroke in the elderly.
Stenosis of the carotid arteries or vertebral arteries can be asymptomatic and in these cases they are diagnosed in check-up tests, such as Doppler, CT angiography or magnetic resonance angiography. It is good to remember that even asymptomatic lesions can cause silent strokes.
When symptomatic, these lesions usually manifest with a picture of cerebral ischemia (CVA). Normally, this ischemia can be caused by three different mechanisms: the most common is a part of the fatty plaque breaking off and obstructing a smaller artery. Another form of stroke resulting from atherosclerotic plaques occurs when these are very bulky and obstruct the entire lumen of the artery, which can lead to very serious ischemic lesions. The third mechanism of ischemia occurs when, due to severe stenosis, the brain does not receive enough blood and some more sensitive regions receive less blood supply than necessary.
Other less common symptoms resulting from severe atherosclerotic lesions in the carotid arteries are dizziness, fainting, and impaired cognition.
Asymptomatic lesions that have never caused silent ischemia are only treated in cases of very severe stenosis (above 80%) or if they have other associated symptoms such as fainting and dizziness, without other causes.
Carotid stenosis that has already caused cerebral ischemia (stroke) should be treated when the lesion determines a reduction in the artery caliber above 50% or if the plaque shows signs of instability that can increase the chance of stroke recurrence, such as ulceration and hemorrhages. The indication for this treatment is the prevention of recurrence of cerebral ischemia.
There are two treatment modalities for carotid stenosis: Carotid angioplasty, percutaneous treatment, minimally invasive and performed under sedation, where a stent is placed in the region of the plaque that will restore normal arterial caliber. The other treatment modality is endoarterectomy, an open surgery performed under general anesthesia, where through a cut in the neck and posterior opening of the carotid, the surgical removal of the fat pad will be performed. The choice of the best treatment will depend on the characteristics of the lesion and the patient.
What causes blockage of the carotid and vertebral arteries?
The main cause of obstruction of the carotid arteries is atherosclerotic disease.
Atherosclerosis is the accumulation of fatty plaques in the vessels and can affect any artery in the body.
How is the diagnosis made?
The history and physical examination support the possibility of carotid stenosis as a cause of the patient’s symptoms.
The presence of a carotid murmur is an important suspicion on physical examination.
Carotid Doppler ultrasound is the main screening test for carotid stenosis, however, other studies may be necessary to confirm the disease and plan its treatment, such as CT angiography or angioresonance of the cervical vessels.
How is carotid stenosis prevented?
Prevention includes the identification and control of risk factors such as controlling hypertension, dyslipidemia, diabetes and smoking cessation.
Regular neurological assessment and follow-up are components of preventive treatment.
