Single-Arm Trial of Carotid Stenting for Carotid Stenosis (Timing Trial)

Inclusion Criteria:

General Inclusion Criteria (all must be satisfied):

1. Age ≥18 years, either sex.
2. Preoperative carotid duplex ultrasound (DUS) confirms stenosis of the common carotid artery (CCA), internal carotid artery (ICA), or carotid bifurcation, and the subject is deemed suitable for endovascular intervention.
3. Intraoperative digital subtraction angiography (DSA) confirms symptomatic carotid artery stenosis ≥50% or asymptomatic carotid artery stenosis ≥80% (measured by NASCET criteria). Symptomatic is defined as a non-disabling ischemic stroke or transient ischemic attack (TIA), including cerebral hemisphere events or amaurosis fugax, occurring within 6 months prior to the procedure.
4. Reference vessel diameter at the target lesion ranges from 3.5 mm to 9.5 mm.
5. Voluntarily participates in this trial and signs the informed consent form.

CEA High-Risk Inclusion Criteria (at least one criterion must be met):

Clinical High-Risk Factors:

1. Age >80 years.
2. Low cardiac output [left ventricular ejection fraction (LVEF) <30%].
3. Untreated or poorly controlled arrhythmia (recurrent despite standard medical therapy or other treatment).
4. Cardiac insufficiency (New York Heart Association Class III-IV).
5. Recent myocardial infarction (occurring between 72 hours and 30 days prior to the procedure).
6. Unstable angina (Canadian Cardiovascular Society Class 3-4).
7. Severe chronic obstructive pulmonary disease (COPD), defined as forced expiratory volume in 1 second (FEV1) <50% of predicted value.

Anatomic High-Risk Factors:

1. Restenosis after prior carotid endarterectomy (CEA).
2. Contralateral carotid artery occlusion.
3. Tandem carotid artery lesions.
4. Carotid artery dissection.
5. Pseudoaneurysm.

Exclusion Criteria:

1. Target lesion caused by carotid arteritis.
2. Target lesion located at the ostium of the common carotid artery.
3. Severe, long-segment calcification or severe tortuosity at the target lesion preventing adequate stent delivery.
4. Target lesion is a complete occlusion.
5. Presence of large acute or subacute thrombus, or arteriovenous malformation adjacent to the target lesion.
6. Requirement for concurrent stenting or stenting in other territories (intracranial or extracranial) within 30 days after the procedure.
7. Intracranial hemorrhage within 3 months prior to the procedure.
8. Large-scale ischemic stroke within 30 days prior to the procedure.
9. Known intracranial aneurysm that cannot be treated in advance.
10. Known coagulation disorder (activated partial thromboplastin time [APTT] >3 times the upper limit of normal) or abnormal bleeding diathesis.
11. Known contraindication to heparin or antiplatelet agents.
12. Known allergy to device components, contrast agent, or related materials.
13. Severe hepatic or renal insufficiency (alanine aminotransferase [ALT] or aspartate aminotransferase [AST] >5 times the upper limit of normal; serum creatinine >3 times the upper limit of normal).
14. Uncontrolled severe hypertension (persistent systolic blood pressure ≥180 mmHg or diastolic blood pressure ≥110 mmHg).
15. Preoperative bradycardia (heart rate <40 beats per minute).
16. Preoperative modified Rankin Scale (mRS) score ≥3.
17. Malignant tumor with extensive metastasis.
18. Currently participating in another drug or device clinical trial.
19. Pregnant or lactating women, or women planning pregnancy within 1 year.
20. Any other condition that, in the investigator's judgment, makes the subject unsuitable for participation in this trial.