Language
Country/Area
No result found
Carotid Artery Stenosis: Why is it the Silent Killer of Stroke?
Carotid stenosis refers to narrowing or compression of any part of the carotid artery, usually caused by arteriosclerosis. This type of stenosis often has no obvious symptoms but can be a silent killer of stroke. This article will provide an in-depth look at the symptoms, pathophysiology, diagnosis, and treatment of carotid stenosis to help readers better understand this condition and its potential risks.
Signs and symptoms of carotid artery stenosis
The carotid arteries are mainly divided into internal carotid arteries and external carotid arteries. The internal carotid arteries are the main arteries that supply blood to the brain, while the external carotid arteries supply blood to the face. The accumulation of arteriosclerosis often forms plaque where the carotid arteries bifurcate, a phenomenon that leads to a narrowing of the blood vessel lumen known as stenosis.
These plaques may be stable and asymptomatic, or they may be a source of blood clots. When plaque ruptures, emboli may develop, which can enter the circulation and travel to the brain, eventually causing blockage of blood flow.
This ischemia may be temporary, causing a transient ischemic attack (TIA), or permanent, causing a thrombotic stroke. By definition, a transient ischemic attack lasts less than 24 hours and usually presents with weakness or loss of sensation in one limb or loss of vision in one eye (leukotropia). Less common symptoms such as arterial sounds (murmurs) or tinnitus may also occur.
Pathophysiology
Arteriosclerosis causes plaque to form in the walls of the carotid arteries, usually where the carotid arteries bifurcate. When plaque proliferates to a certain extent, it can cause arterial narrowing, which is the so-called carotid stenosis. When plaque ruptures, it releases arteriosclerotic fragments or blood clots into the arteries. Certain parts of these substances can break off and enter the brain with the blood flow, causing obstruction of the blood supply and possibly causing ischemic stroke.
Statistically, symptomatic stenosis carries a high risk of stroke within the next two days.
Although asymptomatic carotid artery stenosis also increases the risk of stroke, the risk is lower than that of symptomatic patients. The annual stroke rate in asymptomatic patients is reported to be between 1-2%, while the risk of surgery can range from 1% to 10%.
Diagnostic methods
The diagnosis of carotid stenosis mainly relies on color flow ultrasonography of the neck. This examination method does not require radiation, needles, and contrast agents, and has good sensitivity and specificity for the examination of cardiovascular diseases. Generally speaking, ultrasonography is the most common method used to evaluate carotid artery stenosis.
If the stenosis is not near the bifurcation of the carotid artery, further imaging may be needed, such as computed tomography angiography (CTA) or magnetic resonance angiography (MRA). Each of these tests has advantages and disadvantages, which will be determined based on clinical needs and available imaging technology.
Screening recommendations
Per recommendations from the U.S. Preventive Services Task Force (USPSTF), routine screening is not recommended for patients without symptoms. However, screening is recommended for people with risk factors, such as those with peripheral arterial disease or cardiovascular disease.
Screening should also be considered when a doctor hears a carotid murmur during a physical exam.
Treatment methods
The main goal of treating carotid stenosis is to reduce the risk of stroke. The choice of treatment depends on the severity of the disease and includes the following aspects:
- Lifestyle changes: include quitting smoking, eating healthily, reducing sodium intake, weight control, and regular exercise.
- Control medications such as high blood pressure and blood lipids.
- Surgical intervention: such as carotid angioplasty.
Medication management
Occupational health guidance recommends that all patients with carotid artery stenosis need medications to control cardiovascular risk factors, such as medications to control high blood pressure, antiplatelet medications (eg, aspirin or clopidogrel), and cholesterol-lowering medications (eg, statins) wait.
Vascular reconstruction surgery
For symptomatic patients, it is recommended that patients with acute ischemic stroke who have experienced a transient ischemic attack or non-severe disability undergo surgical intervention when possible. Although all interventional procedures carry a risk of stroke, for those patients at higher risk, surgery may provide benefits
Conclusion
Carotid artery stenosis is one of the important risk factors for stroke, and it is important to understand its symptoms and preventive measures. How should we guard against this potential health threat in our daily lives?
