Evaluation of the Ton-bridge Carotid Stent for Carotid Artery Stenosis

Inclusion Criteria: * Patient is 18-80 years old and of any sex; * Patient is diagnosed with carotid atherosclerotic stenosis by imaging. The lesion site is located in the extracranial segment of carotid artery and is suitable for endovascular treatment. Patient is either symptomatic with carotid stenosis≥50% or asymptomatic with carotid stenosis≥70% as determined by digital subtraction angiography (DSA) using NASCET methodology. * Symptomatic is defined as non-disabling ischemic stroke (mRS≤2) or transient cerebral ischemia (TIA, including cerebral hemispheric neurological events and amaurosis fugax) associated with the carotid stenosis within the past 6 months. * The target vessel reference diameter ranges from 3.5mm to 9mm. * Patient has been informed of the nature of this trial, understood the purpose of this clinical investigation, and volunteered to participate and sign the informed consent form. Exclusion Criteria: * Evolving stroke within 3 months before index procedure, disabling stroke (mRS≥3) before the procedure, or massive cerebral infarction (area of infarction is \>1/3 of the ipsilateral middle cerebral artery territory) within 30 days before the procedure. * Myocardial infarction within 30 days prior to index procedure. * Severe heart, lung, liver, or renal insufficiency. * Patient has known bleeding diathesis, or contraindication to heparin or antiplatelet therapy. * Patient has a known allergy to contrast media or nickel-titanium material. * Disturbance of consciousness, dementia, or severe neurological deficits (NIHSS≥15 or mRS≥3) * Severe hypertension (Systolic blood pressure≥180mmHg and/or diastolic blood pressure≥110mmHg) difficult to be controlled. * Patient has known risk factors for embolization. * Patient has had any major surgical procedure (i.e., intraabdominal or intrathoracic surgery, any surgery or interventional procedure involving cardiac, cerebral or vascular system) within 30 days before index procedure. * Patient has had any intracranial surgery or intracranial hemorrhage within 1 year before index procedure. * Patient has other known neurological diseases such as intracranial tumor, which may confound the neurological assessments. * Intracranial aneurysm or arteriovenous malformation, which requires treatment. * Patient has other known vascular lesion requiring intervention at the same time or within 30 days after index procedure. * Patient has other carotid diseases such as vasculitis, carotid dissection, carotid aneurysm and fibromuscular dysplasia. * Ipsilateral intracranial artery severe stenosis (≥70%), occlusion or dissection; stenosis(≥50%) or occlusion of ipsilateral common carotid artery opening or brachiocephalic artery; any previously placed stent in the ipsilateral carotid artery or brachiocephalic artery; the target lesion is a restenosis after a previous carotid endarterectomy (CEA). * The target lesion vessel has intraluminal filling defect, thrombosis, occlusion or subtotal occlusion ("string sign"). * Severe tortuous anatomy or other anatomic factors that prohibit the safe placement of the catheter or stent systems. * Pregnant or lactating female. * Patient is participating in an investigational drug or device study where the primary endpoint has not yet been completed or that will clinically interfere with the endpoint of this investigation. * Other circumstances which the investigator considers unsuitable for participating in this investigation.