Currently, stroke is one of the leading causes of death in China. Stroke-induced deaths account for 20% and 19% of the total mortality in urban and rural areas, respectively. The ratio between ischemic and hemorrhagic lesions is 4:1, with carotid stenosis being very closely related to cerebral ischemic diseases (especially stroke), with about 30% of ischemic strokes caused by extracranial carotid stenosis. This category refers to stenosis and/or occlusion of the common and internal carotid arteries that can cause stroke or transient ischemic attack (TIA), and if left untreated, the 2-year stroke rate is as high as 26% in patients with >70% symptomatic carotid stenosis. The main cause of stroke due to carotid stenosis is the dislodgement of plaque or thrombus to form emboli that cause embolism of the intracranial arteries, resulting in ischemic infarction of the corresponding brain tissue. Therefore, the aim of treatment is to remove the lesion that can cause the embolus to dislodge, or to prevent the embolus from dislodging. Treatment of carotid artery stenosis includes surgical and pharmacological treatment. Surgical treatment mainly includes traditional carotid endarterectomy (CEA, Figure 1) and carotid stenting (CAS, Figure 2), which has been widely performed in recent years. Since carotid surgery is a technically difficult and risky operation, in order to obtain good surgical results and reduce the incidence of perioperative complications, the indications for surgery must be strictly defined and observed. 1. In-depth knowledge of carotid endarterectomy The current clinical indications for CEA are established mainly based on the results of large-scale multicenter prospective randomized trials including the North American Symptomatic Carotid Endarterectomy Trial (NASCET), the European Carotid Surgery Trial (ECST) Veterans Administration Symptomatic Carotid Endarterectomy Trial (VACS), and based on the recent The details have been partially revised in light of recent research advances. 1.1. Absolute indications for CEA One or more TIAs within 6 months with ≥70% carotid stenosis; one or more mild non-disabling strokes within 6 months with symptoms or signs lasting more than 24 hours and ≥70% carotid stenosis. In short, the patient is symptomatic and has ≥70% carotid stenosis. 1.2. Relative indications for carotid endarterectomy Asymptomatic carotid stenosis ≥ 70%; symptomatic stenosis of 50% to 69%, asymptomatic carotid stenosis < 70%, but angiography or other tests suggest that the stenotic lesion is in an unstable state. It is also required that the total perioperative stroke incidence and mortality rate be <6% in symptomatic patients and <3% in asymptomatic patients, and that the patient's life expectancy be >5 years. It is important to emphasize that whether the plaque is stable or not is very important because if it is unstable, even if the stenosis is not severe, the plaque is extremely easy to dislodge and can cause embolization of the corresponding vessels in the brain. 1.3. Timing of CEA surgery It is currently recommended that surgery is safer after 6 weeks of acute cerebral infarction onset, but for those with recent symptoms and imaging suggestive of unstable plaque, surgery can be chosen within 2 weeks; in case of bilateral lesions, the time interval between surgery on both sides is at least 2 weeks, with the severe stenosis and/or symptomatic side being given priority; if the patient has complete occlusion of the carotid artery, surgery does not reduce the risk of stroke because there is no embolus to continue If the patient is completely occluded, surgery does not reduce the incidence of stroke, so surgery is not recommended. The former requires a lower position of the carotid bifurcation, while the latter does not require incision of the carotid sinus and can avoid stenosis after longitudinal incision and suturing, and can shorten the overlong carotid artery at the same time, which has a lower incidence of restenosis than the longitudinal incision. The overall results of the two procedures are not significantly different, and the decision of which procedure to use can be made on a case-by-case basis. For patients with small carotid artery diameters (<4 mm), a patch can be added to prevent carotid artery narrowing after the traditional longitudinal procedure. 1.5. Indications for the application of a diverter Most scholars believe that the application of a diverter can reduce the ischemic time of the cerebral hemisphere on the operated side during surgery. The indications include: (i) imaging evidence suggesting preoperative stroke; (ii) complete occlusion of the contralateral internal carotid artery; (iii) carotid regurgitation pressure <50 mmHg; (iv) intraoperative inability to tolerate carotid block test; (v) intraoperative brain function test reveals abnormalities; (vi) intraoperative transcranial Doppler (TCD) test shows reduced cerebral blood flow; (vii) incomplete compensation of the intracranial cerebral artery ring (Willis ring). 2. In-depth knowledge of carotid stenting The endovascular treatment of carotid stenosis has gone through three stages of development, from simple balloon dilation, balloon dilation combined with stent placement, to stent placement under cerebral protection, and its indications have also been expanding. The current indications for CAS are based on the results of several large-scale multicenter prospective randomized trials (e.g., CAVATAS, SAPPHIRE, EVA-3S, SPACE, etc.) in combination with other trials (e.g., NASCET and ECST, etc.). 2.1. Indications for CAS Patients with symptomatic carotid stenosis >50% and requiring a stroke and death rate of ≤6% from all causes and ≤2% from disabling stroke or death within 30 days of surgery in the previous year at the operator’s site; asymptomatic carotid stenosis >60% and requiring a stroke and death rate of ≤3% from all causes within 30 days of surgery in the previous year at the operator’s site and the incidence of disabling stroke or death ≤1%. The decision to perform CEA or CAS in patients with carotid stenosis should be based not only on operator proficiency (which reduces the incidence of perioperative complications), but also on patient specificity. CAS should be considered when the following conditions are present: (1) congestive heart failure (New York Heart Association class III or IV) and/or various known severe left heart insufficiencies; (2) open heart surgery within 6 weeks; (3) recent history of myocardial infarction (within 4 weeks); (4) unstable angina (Canadian Cardiovascular Society class III or IV); (5) contralateral carotid artery stenosis. grade); ⑤ contralateral carotid artery obstruction; ⑥ carotid artery stenosis secondary to myofiber dysplasia. 2.2.2 Patients with the following special conditions: ① contralateral recurrent laryngeal nerve palsy; ② history of cervical radiotherapy or post-radical cervical surgery; ③ restenosis after CEA; ④ lesions difficult to reveal surgically, high carotid bifurcation or common carotid artery stenosis below the clavicular plane; ⑤ severe pulmonary disease [e.g. COPD with exertional expiratory volume in 1 second (FEV1) <20%]; ⑥ age > 80 years ; ⑦ Refusal to undergo CEA. 2.3. Because of the characteristics of CAS endoluminal operation, which requires the use of contrast agent and digital subtraction angiography (DSA) machine, there are corresponding contraindications. 2.4. Relative contraindications to CAS Intracranial vascular malformations, subacute cerebral infarction, contraindications to angiography (severe contrast reactions, chronic renal failure), severe calcific lesions, and difficult vasodilation. 2.5. Absolute contraindications to CAS intracarotid appendage thrombosis, lesions inaccessible by intraluminal methods (severe distortion of aortic arch branches, absence of a suitable introducing artery, special anatomy of the aortic arch), severe stenosis (>99%), lesions near carotid aneurysms. 2.6. Application of cerebral protection devices Clinical studies have confirmed that cerebral protection devices (EPDs) can significantly reduce the incidence of perioperative stroke, which is consistent with the clinical follow-up results at the author’s hospital. For patients with common carotid stenosis, a distal filtration EPD (including filters and vascular umbrellas) is recommended. In patients with severe carotid stenosis, proximal blocking EPD may be considered if the distal filtering EPD cannot be passed 3. However, the long-term efficacy of surgery cannot be maintained without medical medication, especially oral antiplatelet agents and statins. The most commonly used antiplatelet agents are aspirin and clopidogrel. The former is inexpensive and effective, while the latter has better antiplatelet aggregation effect, but is more expensive. Those who have the condition can take oral clopidogrel for a long time, while those who do not have the condition can combine clopidogrel and aspirin for 3 months and then change to aspirin monotherapy. The significance of statins in the postoperative treatment of carotid stenosis is not only to lower lipids, but also to stabilize plaque and prevent restenosis. Therefore, routine oral administration of this drug is recommended for patients who are eligible. Surgical treatment of carotid artery stenosis has been performed for half a century, with definite clinical efficacy. With the increasing incidence of carotid stenosis in the country, its surgical treatment is increasing year by year. In order to obtain good results, clinicians must be familiar with the pathophysiology of carotid stenosis, strictly grasp the indications for surgery, and continuously carry out clinical practice in order to improve the treatment level of carotid stenosis in China.