Stroke is the number one cause of severe disability and death in China. Stroke includes ischemic stroke (caused by narrowing or occlusion of the blood supplying arteries to the brain) and hemorrhagic stroke (rupture of blood vessels caused by aneurysms, vascular malformations, etc.). Scientific studies have shown that 20% to 30% of ischemic strokes are caused by carotid artery stenosis or occlusion. Therefore, early treatment of carotid artery stenosis can effectively reduce the incidence of ischemic strokes. The treatment of carotid artery stenosis includes surgical (carotid endarterectomy, CEA) and interventional (carotid stenting, CAS) methods. In terms of safety and efficacy of treatment, the two are roughly equivalent. However, CAS is less invasive and has a wider range of indications. Some symptomatic thromboembolic or hypoperfusion complications can be easily observed and treated with timely interventions, as the procedure is performed under local anesthesia and in a conscious state. Therefore, treatment of carotid artery stenosis has been increasingly treated with stentoplasty. Carotid stenting will play an important role in stroke prevention in patients with carotid stenosis. With the development of stent materials, the use of distal embolic protection devices can reduce the operative risk associated with intraoperative embolic dislodgement due to manipulation of the plaque. At the same time, improvements in endovascular manipulation techniques and standardization of perioperative drug therapy have greatly improved and increased the surgical safety and reduced the rate of perioperative complications in CAS. Indications: The main indicators of suitability for stent-forming therapy are symptomatic stenosis (stenosis ≥ 50%), or asymptomatic stenosis (stenosis ≥ 60%), and the nature of the lesion is atherosclerotic. Non-atherosclerotic lesions are not a contraindication, but the long-term efficacy is not very certain. The term “symptomatic” refers to a transient ischemic attack (TIA) or a non-significant disabling infarction in the relevant blood supply area within 6 months. In addition, CAS is recommended in cases of severe carotid stenosis prior to coronary artery bypass grafting, post-surgical restenosis, or if the patient refuses surgical treatment. Contraindications: All conditions with active bleeding are absolute contraindications; recent surgical procedures; inability to take antiplatelet medications (e.g., with gastric ulcer); severe hepatic, renal and pulmonary insufficiency; infarction exceeding 1/3 of the area of the blood supply area within 1 month; contrast allergy; abnormal thyroid function; inability of the guidewire to pass through the lesion; etc.; and the presence of intracranial aneurysm or AVM requiring treatment. Complications: Complications are are adverse events that occur intraoperatively and 30 days after the procedure.The main complications that can occur intraoperatively and postoperatively with CAS include new infarcts, intracranial and other bleeding and heart attacks, and deaths caused by them. There are also intra-stent thrombosis, transient vasospasm, bleeding at the puncture site, contrast allergy, impairment of renal function, vagal reflexes (sudden drop in heart rate and blood pressure), and postoperative in-stent restenosis or even occlusion. The perioperative complication rate of stentoplasty increases with age, and is 1.7%, 1.3%, 5.3%, and 12.1% for <60, 60-69, 70-79, and >80 years of age, respectively. The chance of intraoperative new infarcts has been greatly reduced by the use of protective devices. The current international average for the incidence of new infarcts is around 4%, the incidence of intracranial hemorrhage <1%, mortality <1%, and infarction <1.1%. The overall incidence is higher in patients with symptomatic stenosis than in asymptomatic patients. The incidence rates in our center were all below 1%. Other morbidity rates were vasovagal reflexes in 5-17%, contrast allergy <1%, in-stent thrombosis <1%, transient vasospasm 10-15%, restenosis rate 3-13%, and vascular injury at the puncture site 5%. For these complications, appropriate preventive and treatment measures are generally available, and the chance of causing disabling and fatal complications is small.