What Is a Carotid Artery Blockage?
Carotid artery stenosis can be caused by a variety of reasons, and the characteristics of carotid stenosis caused by different causes are also different.
- Western Medicine Name
- Carotid stenosis
- Affiliated Department
- Surgery-Neurosurgery
- Disease site
- Carotid artery
- Main cause
- Atherosclerosis, carotid dissection
- Contagious
- Non-contagious
| Li Meng | (Chief physician) | Department of Neurosurgery, Xuanwu Hospital, Capital Medical University |
| Jiao Liqun | (Deputy Chief Physician) | Department of Neurosurgery, Xuanwu Hospital, Capital Medical University |
| Ma Yan | (Resident) | Department of Neurosurgery, Xuanwu Hospital, Capital Medical University |
- The carotid artery is a large blood vessel that transports blood from the heart to the head, face, and neck. It is one of the main blood vessels in the brain. According to literature reports, even if patients with severe carotid artery stenosis are controlled by effective medication, the incidence of cerebral ischemic events within 2 years is as high as 26% or more; and more than 60% of cerebral infarctions are caused by carotid stenosis and severe cerebral infarction Can lead to disability and even death. Therefore, carotid artery stenosis has become one of the "number one killers" that endanger people's health in today's society.
Causes of carotid stenosis
- Carotid artery stenosis can be caused by a variety of reasons, and the characteristics of carotid stenosis caused by different causes are also different.
Carotid stenosis atherosclerosis
- Atherosclerosis is the most common cause of carotid stenosis in middle-aged and elderly patients. Patients are often accompanied by hypertension, diabetes, hyperlipidemia, obesity, smoking and other risk factors that can lead to cardiovascular and cerebrovascular damage. Atherosclerosis is caused by the accumulation of lipid substances on the blood vessel wall, and macrophages in the blood vessel wall engulf the lipid substances to form a lipid pool. At the same time, the formation of a fibrous cap on the surface of the lipid pool, the lipid core and the fibrous cap The main constituents of atherosclerotic plaque. The plaque gradually increases and the lumen gradually narrows, or the plaque is unstable and rupture occurs. The lipid components in the plaque are exposed in the blood vessel lumen, which causes platelets to aggregate and form thrombi, and the thrombus falls off. Both can cause cerebral ischemic events. Carotid artery stenosis caused by atherosclerosis is often located at the end of the common carotid artery. The initial segment of the internal carotid artery, the siphon of the internal carotid artery, and the terminal internal carotid artery are divided into the anterior and middle cerebral arteries.
Carotid dissection
- The carotid artery is composed of an intimal layer, a smooth muscle layer, and an adventitia layer. Under normal circumstances, the layers are connected to each other as a unified whole, and blood flows in the cavity surrounded by the vessel wall. The so-called arterial dissection is, as the name implies, the separation of layers of the blood vessel wall caused by blood entering between layers of the blood vessel caused by various reasons. In community-based surveys in the United States and France, the incidence of carotid dissection is 2.5-3 per 100,000. Stroke in young patients under 45 years of age can result in carotid dissection up to 25%.
Carotid stenosis angiopathy associated with development, inflammation, or autoimmunity
- Other diseases, related to development, vascular inflammation, and autoimmunity, can also cause carotid stenosis, but the proportion is very small. Such as arteritis, fibromuscular dysplasia, and moyamoya disease. Among these patients, young patients account for a large proportion. [1]
Clinical manifestations of carotid stenosis
- Some patients with mild to moderate carotid stenosis may be asymptomatic. For those who have clinical symptoms related to stenosis, it is called "symptomatic carotid stenosis".
- The clinical manifestations of symptomatic carotid stenosis are mainly related to cerebral ischemia caused by vascular stenosis. According to the time characteristics of onset, it can be divided into transient ischemic attack and stroke, and the main difference between the two is whether the patient's ischemic symptoms can be completely relieved within 24 hours. Transient ischemic attack can be completely resolved, and stroke is not completely resolved.
- Symptoms of ischemia due to carotid stenosis include dizziness, memory, loss of orientation, disturbance of consciousness, darkness, lateral and / or limb numbness and / or weakness, tongue extension, poor speech, and inability to understand what others are saying If so, wait. [2]
Diagnosis and differential diagnosis of carotid stenosis
Carotid stenosis diagnosis
- The diagnosis of carotid stenosis is mainly based on the patient's clinical symptoms, physical examination and imaging examination. At present, the imaging methods mainly used in clinical examination mainly include the morphological examination of blood vessels and the examination of brain tissues; and the imaging research on the nature of plaques and hemorheology is the future research direction.
- Vascular imaging method
- At present, the vascular imaging methods mainly used in the carotid artery include carotid ultrasound, transcranial color Doppler, CT angiography (CTA), and digital subtraction angiography (DSA). Among them, DSA is the "gold standard" for inspection.
- Brain tissue imaging
- Ischemic changes in brain tissue caused by carotid stenosis are currently mainly used in clinical brain examinations for computed tomography (CT), nuclear magnetic resonance (MRI) plain scan, and diffusion weighted imaging (DWI).
- In addition, there are currently plaque properties examination methods based on nuclear magnetic resonance in clinical applications, which mainly refer to multi-sequence nuclear magnetic resonance imaging, using the sensitivity of different scanning sequences to different tissues to detect the main components of plaques. Features. However, it is not yet universal in clinical practice.
Differential diagnosis of carotid stenosis
- The differential diagnosis of carotid stenosis mainly includes the identification of symptoms and the identification of sites. Symptoms are mainly related to other brain diseases such as intracranial mass, seizures and other cerebrovascular diseases. Differential identification mainly refers to the need to determine whether carotid artery stenosis is the "responsible blood vessel" that causes ischemia of the brain when combined with other vascular stenosis diseases. [3]
Carotid artery stenosis treatment
- The treatment of carotid stenosis mainly includes the control of risk factors, drug treatment, surgical treatment and interventional treatment.
Control of risk factors for carotid stenosis
- Atherosclerotic carotid stenosis is often part of systemic vascular disease. Therefore, controlling the risk factors that can cause vascular atherosclerosis is the basis of carotid stenosis treatment. Mainly include: proper exercise, weight control, avoid obesity, quit smoking, drink less alcohol, reasonable control of blood pressure, blood sugar, blood lipids, etc.
Carotid artery stenosis medication
- Drug treatment mainly includes stabilization of atherosclerotic plaques and anti-platelet aggregation drugs. Clinically used are statin lipid-lowering drugs and aspirin and / or clopidogrel. In addition, drug treatment also includes drug treatment for risk factors such as hypertension and diabetes. Drug therapy can only serve the purpose of stabilizing atherosclerotic plaques, minimizing thrombosis, and slowing the progression of atherosclerosis, thereby reducing the occurrence of cerebral ischemic events, and cannot fundamentally remove plaque or achieve Purpose to restore blood flow to brain tissue.
Carotid stenosis surgery
- Surgical treatment mainly refers to carotid endarterectomy (CEA). It is currently the only method that can remove atherosclerotic plaques and reconstruct normal lumen and blood flow. By the 1980s, many centers in Europe and the United States began to carry out systematic research on CEA. A number of multicenter large sample randomized controlled studies have shown that CEA is significantly better than drug treatment for severe carotid stenosis and symptomatic moderate carotid stenosis. Now, CEA in North America can reach 170,000 a year, which has become the first choice for treating carotid stenosis. Is the "gold standard" for carotid artery stenosis.
Carotid artery stenosis intervention
- After the 1990s, with the advancement of equipment and instruments, Carotid Stenting Angioplasty (CAS) was gradually developed and popularized, and there is a tendency to replace CEA. Carotid stent is mainly based on intravascular interventional technology, using a balloon or stent to expand the narrow part of the carotid artery, so as to achieve the purpose of reconstructing carotid blood flow.
- In 1998, the United Kingdom took the lead in designing and conducting a comparative study of CEA and CAS for symptomatic carotid stenosis, but was terminated by the safety committee because CAS technology is still immature. In 2001, the CAVATAS study published its findings. During the trial, a total of 253 CEA and 251 carotid stenosis endovascular treatments were completed. The results showed that the incidence of major prognostic events was similar within 30 days, and cranial neuropathy was significantly higher in the surgery group. Many local hematomas are rare in the endovascular treatment group, and severe stenosis is more common in the endovascular treatment group after one year. It is concluded that the effectiveness and safety of the two are similar, and endovascular treatment can reduce minor complications. Later, from 2003 to 2010, CARESS research, SAPPHIRE research, EVA-3S research, SPACE research, ICSS research, and CREST research all reported different results. Among them, SAPPHIRE research believes that the two are in terms of effectiveness and safety. There are no significant differences, but it seems that CAS treatment is more suitable for special populations at high risk of surgery; EVA-3S, SPACE, and ICSS studies are more inclined to CEA treatment; CREST research is by far the largest group of international multicenter, randomized Controlled clinical trials involving 108 research centers in the United States and 9 research centers in Canada to compare the therapeutic effects of CEA and CAS in carotid stenosis of the extracranial segment. A total of 2,522 patients were enrolled from 2000 to 2008 and entered the final clinical trial. The analysis included 1,262 patients in the CAS group and 1,240 patients in the CEA group, with an average follow-up time of 2.5 years. There was no significant difference between the two groups in the CAS and CEA groups (7.2% vs 6.8%, P = 0.51). The main endpoint was the perioperative event. In terms of incidence, there was no significant difference between the two groups of CAS and CEA (5.2% vs 4.5%, P = 0.38). Further stratified statistics showed that there was no significant difference between the two groups of CAS and CEA in perioperative mortality ( 0.7% vs 0.3%, P = 0.18), CAS is significantly higher than CEA in the incidence of perioperative stroke (4.1% vs 2.3%, P = 0.01), but CAS is lower in the incidence of perioperative myocardial infarction CEA (1.1% vs 2.3%, P = 0.03). Other subgroup analyses also suggest that older people are more suitable for CEA treatment.
- Based on the results of the above-mentioned foreign studies for more than 20 years, CEA is now clearly identified as the preferred treatment for carotid atherosclerotic stenosis in the United States and European stroke prevention guidelines, and it is suggested that CAS can be similar or better in special populations. the result of. Earlier this year, 14 professional associations in the United States jointly published the "Guidelines for the Management of Extracranial Carotid and Vertebral Artery Diseases: A Joint Guide for Multiple Scientific Committees", which emphasized the CEA's preferences and relaxed the indications for CAS, not only as part of As an alternative to CEA, and for patients with asymptomatic carotid stenosis (angiographic stenosis is more than 60%, Doppler ultrasound is 70%), in the high choice, it is recommended to consider preventive CAS; meanwhile, again Emphasize the perioperative safety of CEA and CAS. The perioperative stroke or mortality must be less than 6%. [4]