CAS for Stenosis With High-risk Features for CEA

Inclusion Criteria: 1. Age ≥ 18 years, male or female; 2. Pre-procedural carotid duplex ultrasound and/or computed tomography angiography confirmed stenosis of the common carotid artery, internal carotid artery, or carotid bifurcation, and are considered suitable for endovascular treatment; 3. Intra-procedural digital subtraction angiography, using NASCET criteria, confirmed stenosis of ≥ 50% (symptomatic) or ≥ 80% (asymptomatic), and symptomatic is defined as the occurrence of one or more clinical events within 6 months prior to the procedure, including transient ischemic attack, amaurosis fugax, or minor/non-disabling stroke attributable to the ipsilateral intracranial circulation; 4. The vessel diameter of the target lesion is between 3.0 mm and 9.0 mm; 5. Voluntary participation in this trial and provision of written informed consent. Inclusion criteria for high-risk features for carotid endarterectomy: Comorbidity factors: 1. Age ≥ 75 years at the time of enrollment; 2. Patients with congestive heart failure (New York Heart Association Class III/IV); 3. Patients with unstable angina pectoris; 4. Patients with severe chronic obstructive pulmonary disease, defined as an FEV1 ≤ 50% of predicted, requirement for chronic oxygen therapy, or a resting PO₂ ≤ 60 mmHg; 5. Patients with left ventricular ejection fraction ≤ 30%; 6. Patients with recent myocardial infarction (within 2 to 6 weeks); 7. Patients with coronary artery disease with ≥ 70% stenosis in two or more major vessels; 8. Planned coronary artery bypass grafting or valve replacement surgery within 31 to 60 days following the procedure. Anatomical factors: 1. Lesions located at or above the level of the second cervical vertebra (C2) or lesions that are surgically inaccessible below the clavicle; 2. History of radical head and neck surgery or radiotherapy; 3. Patients with limited cervical spine mobility; 4. Patients with tracheostomy; 5. History of vocal cord paralysis or laryngectomy; 6. Patients with contralateral recurrent laryngeal nerve palsy; 7. Patients with restenosis following previous carotid endarterectomy; 8. Patients with severe stenosis or occlusion of the contralateral carotid artery; 9. Severe tandem lesions that can be covered by a single stent. Exclusion Criteria: 1. Target lesions caused by carotid arteritis; 2. Target lesions located at the origin of the common carotid artery; 3. Target lesions with extensive calcification or excessive tortuosity that preclude stent delivery; 4. Target lesions attributable to asymptomatic complete occlusion or the presence of a "string sign"; 5. Target lesions adjacent to significant acute or subacute thrombus, or arteriovenous malformation; 6. History of major surgery (including intra-abdominal, intrathoracic, cardiac, or vascular procedures) within 30 days before the procedure, or any such surgery scheduled within 30 days after the procedure; 7. History of intracranial hemorrhage or progressive stroke within 3 months before the procedure; 8. History of an extensive hemispheric stroke within 2 weeks before the procedure; 9. History of bradycardia (heart rate \< 40 bpm) before the procedure; 10. History of paroxysmal atrial fibrillation within the past 6 months, or paroxysmal atrial fibrillation requiring long-term anticoagulation therapy; 11. Patients with known or potential sources of thromboembolism (including previously known symptomatic patent foramen ovale, mechanical heart valves, or deep vein thrombosis treated within 6 months); 12. Patients with a known intracranial aneurysm requiring surgical intervention that cannot be treated before the procedure; 13. Patients with known coagulation disorders (APTT \> 3 times the upper limit of normal) or abnormal bleeding disorders; 14. Patients with known contraindications to heparin or antiplatelet agents; 15. Patients with a platelet count \< 100×10\^9/L; 16. Patients with known allergies to any components of the investigational product, contrast agents; 17. Patients with known severe hepatic or renal insufficiency (ALT or AST \> 5 times the upper limit of normal, or serum creatinine \> 3 times the upper limit of normal); 18. Patients with known uncontrolled severe hypertension (persistent systolic blood pressure ≥ 180 mmHg or diastolic blood pressure ≥ 110 mmHg); 19. Patients with a pre-procedure mRS score \> 3; 20. Patients with extensively metastatic malignancy; 21. Patients concurrently enrolled in another drug or medical device clinical trial; 22. Female patients who are currently pregnant or breastfeeding, or who plan to conceive within 1 year; 23. Lesions inaccessible by endovascular approach (including severe tortuosity of aortic arch branches with no suitable access artery, or special aortic arch anatomy); 24. According to the judgment of the investigator, patients with an expected survival of less than 12 months; 25. According to the judgment of the investigator, other situations that are not suitable for enrollment.