1.What is a stroke?
Stroke, commonly known as stroke, is one of the three leading causes of death in the elderly. It is a disease in which the main symptoms are sudden fainting, unconsciousness, distortion of the mouth and eyes, unfavorable speech, hemiplegia or sudden hemiplegia without fainting. There are two types of stroke: hemorrhagic stroke and ischemic stroke. Hemorrhagic strokes are mainly caused by the hardening and rupture of blood vessels in the brain. Ischemic stroke is a clinical manifestation of insufficient or blocked blood supply to the brain, mainly due to atherosclerotic plaques or ulcers in the extracranial or intracranial blood vessels supplying the brain, resulting in significant narrowing or occlusion of the lumen.
The vast majority of patients will have some manifestations before the stroke such as suddenly dropping chopsticks when eating, suddenly having a black eye when reading the newspaper, unconsciously drooling when speaking, unconsciously wetting their pants, etc. These manifestations are collectively referred to as mini-stroke by the common people.
Medically known as transient ischemic attack, it has several characteristics.
(1) Transient in nature, usually not exceeding 24 hours.
(2) Reversible, the symptoms can return to normal.
(3) Recurrent attacks.
2. What is the relationship between stroke and carotid artery stenosis?
Blood to the brain is supplied by four vessels outside the skull: two carotid arteries and two vertebral arteries. A lesion in any of these four arteries can lead to cerebral ischemia and cause a stroke. In ischemic stroke, carotid artery stenosis causes about 80% of all strokes. As the body ages and blood vessels harden, atherosclerotic plaques can form in arteries throughout the body, causing arterial stenosis. The bifurcation of the carotid artery is the most common site. These plaques grow in size and can become calcified, hemorrhagic, necrotic and detached, resulting in occlusion of the carotid artery and embolism of the brain. Statistics show that about 2/3 of cerebral infarcts in stroke patients are related to carotid artery stenosis. In our clinical practice there are many patients with severe carotid artery stenosis detected by carotid ultrasound, which is in the high incidence of stroke, but due to the lack of proper understanding of the benefits and harms of treating carotid artery stenosis and stroke, the patients failed to deal with it in time, and as a result, ipsilateral stroke and hemiplegia occurred.
3.Who are prone to carotid stenosis?
Men over middle age and postmenopausal women, people with long-term hypertension, diabetes, hyperlipidemia, smoking, and obesity are prone to carotid stenosis. These people are prone to deep fatty degeneration and cholesterol deposition in the arterial intima, forming atherosclerotic plaques and various secondary lesions that narrow or even occlude the arterial lumen, with the carotid artery being the commonly affected area. Since atherosclerosis is a disease that affects the whole body, patients suffering from coronary heart disease or lower limb atherosclerosis-occlusive disease should be alert to whether they also suffer from carotid artery stenosis.
4.What are the main symptoms and signs to be alerted for carotid stenosis?
The most common symptom in patients with carotid stenosis is transient ischemic attack, which is characterized by sudden onset of dizziness, weakness or numbness of one side of the face or limb, or short period of speech difficulty, blackness in front of the eyes (often a transient blackness of one eye), or transient loss of consciousness or amnesia. These symptoms last for a short period of time, usually minutes or hours, and often recover completely within 24 hours without sequelae. However, the symptoms are recurrent, more often than not, several times a day, and less often, once every few weeks, months or years. Carotid stenosis should be suspected in cases of sudden onset of limb numbness, weakness and visual disturbances, incomplete hemiparesis and sensory disturbances of unknown etiology, as well as in cases of sequelae of previous strokes. Carotid artery stenosis should also be considered in cases where a carotid murmur is found on physical examination but there are no symptoms.
5.What diagnostic methods can be used to determine carotid stenosis at an early stage?
Generally speaking, patients with no symptoms or mild symptoms cannot know for themselves whether they have carotid stenosis. However, with the development of various diagnostic methods, the detection of asymptomatic carotid stenosis has become more and more common, providing a reliable basis for active prevention of stroke.
Carotid Doppler ultrasound is currently the simplest and most commonly used diagnostic method, which is non-invasive, less expensive, and 97% sensitive. It can be used as an adjunct to screening. We can initially understand whether there is carotid artery stenosis and its degree of stenosis, determine the composition of the stenotic plaque and whether there are ulcers on the surface, and whether there is bleeding within the plaque. For those who have risk factors for atherosclerosis as mentioned above, and those who are suspected of having carotid stenosis, it can be the first choice of examination.
In addition, carotid angiography and digital silhouette (DSA), carotid CT angiography (CTA) and magnetic resonance angiography (MRA) can provide more visualization of the degree and location of carotid stenosis and blood flow, and provide accurate information for surgical treatment, but they are relatively expensive and invasive. It is generally suitable for patients with carotid artery stenosis who are considering surgery, and requires an experienced physician to choose according to the patient’s specific situation.
Transcranial Doppler ultrasound (TCD): not only can we understand the carotid artery stenosis, but also whether there are lesions in the intracranial vasculature, which can help in the selection of surgery and evaluation of the results.
6.How is carotid stenosis treated?
Treatment of carotid stenosis is currently divided into non-surgical treatment and surgical treatment.
Non-surgical treatment includes control of high-risk factors and prevention of stroke. Hypertension, hyperlipidemia, hyperglycemia, smoking and advanced age are the high-risk factors for atherosclerosis. Therefore, hypertension, hyperlipidemia and hyperglycemia should be actively controlled to effectively stop the development of carotid artery stenosis. Anti-platelet drug therapy can prevent microthrombosis and thus prevent stroke. Anticoagulation therapy can be applied to patients with transient ischemic attacks who are still symptomatic during the application of antiplatelet drugs.
Surgical treatment currently consists of carotid endarterectomy (CEA) and carotid artery stenting (CAS).
7.How to choose the treatment according to the patient’s condition?
The purpose of carotid artery stenosis surgery is to prevent and treat strokes caused by carotid artery stenosis.
Therefore, patients with the following conditions need to undergo surgery.
(1) A clear history of transient ischemic attack, or symptomatic attacks even after the symptoms of cerebral infarction have stabilized.
(2) Those whose symptoms are not relieved by aggressive drug therapy.
(3) Vascular luminal stenosis of 70% or more.
Some patients have no symptoms themselves, but only carotid plaques are found on physical examination, which depends on the size of the plaque, its softness and the presence of plaque rupture and other conditions to determine the treatment plan. Small plaques, non-floating plaques that do not cause carotid stenosis can be treated without surgery for the time being, but should be followed up and observed, but antiplatelet drugs must be applied to prevent microthrombosis. If the plaque is found to be enlarged and causing carotid stenosis, surgery should be performed promptly.
If carotid artery stenosis is found on examination, appropriate treatment should be taken depending on the degree of stenosis. If the stenosis is less than 50%, it can be treated with thrombosis prevention drugs and surgery is not necessary; if the stenosis is 50% to 70%, it can be closely observed and treated with drugs if there are no symptoms, and surgery should be performed if there are symptoms; if the stenosis is greater than 70%, the hemodynamics will be significantly affected and there is a high chance of cerebral infarction, so surgery should be performed.
For patients with bilateral carotid artery stenosis, it is not advisable to solve the problem at one time, because the carotid artery has already caused a decrease in cerebral blood flow, if the sudden increase of bilateral cerebral blood flow at one time, it will lead to sudden transitional perfusion damage of brain tissue, cerebral edema, and serious life-threatening cerebral herniation, so when bilateral carotid artery stenosis occurs, the serious side of the lesion should be solved first, and then the other side of the carotid artery should be operated after at least 1~2 weeks. Surgery.
When a complete occlusion of one carotid artery is found, there is often already a better compensation of the contralateral blood flow, and if a cerebral infarction or hemiparesis does not occur at the time of the complete occlusion of the carotid artery, no further cerebral infarction will occur. As long as the contralateral side is well compensated, surgery can be avoided. However, if the contralateral carotid artery also has stenosis, then an attempt should be made to reconstruct the blood flow of the occluded side of the carotid artery first, with the aim of laying a blood flow foundation for the next reconstructive surgery of the stenotic side of the walk.
8.Which of the two surgical procedures (carotid endarterectomy or carotid stenting) should I choose? What are the surgical risks?
The decision of which procedure to choose is made by an experienced vascular surgeon based on the patient’s specific situation.
(1) Carotid endarterectomy: This is a surgical procedure to remove the plaque and thrombus from the carotid artery. This is a more traditional surgical method and the technique is relatively mature. The patient can return to normal life 1-2 days after surgery. The main and serious surgical complication of carotid endarterectomy is stroke attack, but the incidence is low, usually less than 2%. This is followed by peripheral nerve injury and cardiac accidents. Moreover, with the presence of atherosclerotic disease, carotid artery stenosis can reappear after surgery. In addition, there is a possibility of wound bleeding and hematoma because anticoagulation therapy is required after surgery.
(2) Carotid artery stenting: This is a more promising alternative therapy to carotid endarterectomy, which requires only a femoral artery puncture under local anesthesia or mild general anesthesia to implant a metal stent into the narrowed carotid artery to support the stenosis and serve the purpose of allowing blood flow. It avoids surgical incisions in the neck and its resulting complications such as cranial nerve damage and hematoma compression. Because it is less invasive and has a faster recovery, it can still be considered for patients who are too old or too ill to tolerate carotid endarterectomy. In addition, restenosis after carotid endarterectomy, carotid stenosis near the skull base that makes the procedure more difficult, and carotid lesions caused by radiation are good indications for stent implantation. However, carotid artery stenting also has its disadvantages: it is more expensive; it is also associated with stroke, hemiparesis and even life threatening; in some cases, carotid artery stenosis is too severe or completely occluded for the delivery device to pass, in which case endarterectomy is the only option. In addition, it also has problems such as restenosis.
9.What else should I pay attention to after surgery?
After carotid artery stenosis surgery, there is still a possibility of recurrence of cerebral infarction, mainly due to the progression of atherosclerosis, stenosis in other areas (such as intracranial vessels), restenosis at the site of carotid artery surgery, and thrombosis. Therefore, anticoagulant drugs should be taken for a period of time after carotid surgery, which should be administered under the guidance of a doctor and should not be increased or decreased without authorization. Oral antiplatelet medication should be taken for at least one year after carotid surgery, but long-term medication is usually required because of the presence of systemic atherosclerosis in all patients. In addition, carotid artery Doppler ultrasound should be reviewed regularly under the follow-up of the doctor for early detection of restenosis