CAS for Stenosis With High-risk Features for CEA

This trial is a prospective, multicenter, single-group target-value study to evaluate the safety and efficacy of the carotid artery stent system in patients with high-risk features for carotid endarterectomy. The primary outcome is a composite outcome that includes stroke or death within 30 days after enrollment or after a revascularization procedure for the qualifying lesion during the follow-up period or ischemic stroke in the territory of the qualifying artery between day 31 and the end of the follow-up period.

Inclusion criteria

• Age ≥ 18 years, male or female;
• 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;
• 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;
• The vessel diameter of the target lesion is between 3.0 mm and 9.0 mm;
• Voluntary participation in this trial and provision of written informed consent.

Inclusion criteria

for high-risk features for carotid endarterectomy:

Comorbidity factors:

• Age ≥ 75 years at the time of enrollment;
• Patients with congestive heart failure (New York Heart Association Class III/IV);
• Patients with unstable angina pectoris;
• 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;
• Patients with left ventricular ejection fraction ≤ 30%;
• Patients with recent myocardial infarction (within 2 to 6 weeks);
• Patients with coronary artery disease with ≥ 70% stenosis in two or more major vessels;
• Planned coronary artery bypass grafting or valve replacement surgery within 31 to 60 days following the procedure.

Anatomical factors:

• Lesions located at or above the level of the second cervical vertebra (C2) or lesions that are surgically inaccessible below the clavicle;
• History of radical head and neck surgery or radiotherapy;
• Patients with limited cervical spine mobility;
• Patients with tracheostomy;
• History of vocal cord paralysis or laryngectomy;
• Patients with contralateral recurrent laryngeal nerve palsy;
• Patients with restenosis following previous carotid endarterectomy;
• Patients with severe stenosis or occlusion of the contralateral carotid artery;
• Severe tandem lesions that can be covered by a single stent.

Exclusion criteria

• Target lesions caused by carotid arteritis;
• Target lesions located at the origin of the common carotid artery;
• Target lesions with extensive calcification or excessive tortuosity that preclude stent delivery;
• Target lesions attributable to asymptomatic complete occlusion or the presence of a "string sign";
• Target lesions adjacent to significant acute or subacute thrombus, or arteriovenous malformation;
• 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;
• History of intracranial hemorrhage or progressive stroke within 3 months before the procedure;
• History of an extensive hemispheric stroke within 2 weeks before the procedure;
• History of bradycardia (heart rate < 40 bpm) before the procedure;
• History of paroxysmal atrial fibrillation within the past 6 months, or paroxysmal atrial fibrillation requiring long-term anticoagulation therapy;
• 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);
• Patients with a known intracranial aneurysm requiring surgical intervention that cannot be treated before the procedure;
• Patients with known coagulation disorders (APTT > 3 times the upper limit of normal) or abnormal bleeding disorders;
• Patients with known contraindications to heparin or antiplatelet agents;
• Patients with a platelet count < 100×10^9/L;
• Patients with known allergies to any components of the investigational product, contrast agents;
• 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);
• Patients with known uncontrolled severe hypertension (persistent systolic blood pressure ≥ 180 mmHg or diastolic blood pressure ≥ 110 mmHg);
• Patients with a pre-procedure mRS score > 3;
• Patients with extensively metastatic malignancy;
• Patients concurrently enrolled in another drug or medical device clinical trial;
• Female patients who are currently pregnant or breastfeeding, or who plan to conceive within 1 year;
• Lesions inaccessible by endovascular approach (including severe tortuosity of aortic arch branches with no suitable access artery, or special aortic arch anatomy);
• According to the judgment of the investigator, patients with an expected survival of less than 12 months;
• According to the judgment of the investigator, other situations that are not suitable for enrollment.