Carotid artery stent for people with carotid narrowing who are high risk for surgery

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.