CGUARDIANS III IDE Pivotal Trial

This study is a prospective, multi-center, single arm pivotal study. The study shall not be blinded prior to, during or following the procedure. Patients undergoing transcarotid artery revascularization will be screened against the study inclusion/exclusion criteria. If the patient meets study eligibility requirements, they shall be invited to participate, provided informed consent and shall subsequently be assigned a study ID number.

Enrollment will be 103 pivotal patients. A maximum of 20% of patients will be enrolled at any single site. The total enrollment accounts for an estimate that up to 2 patients will exit the study prior to the 30-day primary endpoint assessment.

An additional roll-in cohort of up to 2 patients per primary physician operator at each study site may also be accrued (maximum of 50 roll-in patients total, assuming one primary physician operator per site).

This study does not duplicate any current knowledge existing today on use of the SwitchGuard NPS when used in conjunction with the CGuard Prime™ 80cm in the United States.

Inclusion criteria

• Patient is willing and able to provide appropriate study-specific informed consent, follow protocol procedures, and comply with follow-up visit requirements.
• Patient is diagnosed with carotid artery disease treatable with a Carotid Artery Stent via a Transcarotid Artery Revascularization approach and is either symptomatic or asymptomatic, defined as:

Symptomatic carotid stenosis ≥ 50%. Symptomatic is defined as amaurosis fugax, transient ischemia attack (TIA) or stroke within the last 6 months ipsilateral to the side of the stenosis OR asymptomatic carotid stenosis ≥ 80%

• High Risk condition for CEA: at least one, as shown below:

Comorbid conditions:

Age ≥ 70 (maximum 82 years) CCS angina class 3-4 or unstable angina Congestive Heart Failure (CHF) NYHA class III-IV Left ventricular ejection fraction (LVEF) ≤ 35% MI ≥ 72 hours and < 6 weeks pre-procedure Multi-vessel CAD (≥ 2 vessels >70% stenosis) and history of angina Chronic Obstructive Pulmonary Disease (COPD) with FEV1<50 Permanent contralateral cranial nerve injury/paralysis Restenosis from previous carotid endarterectomy (CEA) Planned coronary artery bypass grafting (CABG) or valve replacement surgery between 31-60 days after CAS Abdominal aortic aneurysm surgical repair or Endovascular repair is planned between 31 to 60 days after CAS

Anatomic conditions:

Occlusion of the contralateral CCA or ICA Prior radiation treatment to the neck or a radical neck dissection Severe bilateral ICA stenosis requiring treatment Target lesion at or above the level of the jaw (C2) or below the clavicle Severe tandem lesions Inability to extend the neck due to cervical disorders Laryngeal palsy or laryngectomy Prior head and neck surgery in the region of the carotid artery Tracheostomy or tracheostoma Spinal immobility of the neck

Exclusion criteria

• Patient had or will have an interventional procedure or surgery of the carotid, coronary or peripheral arteries within 30 days before or after the index carotid procedure
• Patient had or will have open heart surgery or valvular intervention (percutaneous or surgical), or any major operation, within 30 days before or after the index carotid procedure
• Vascular anatomy that would preclude safe sheath insertion or deliverability of stent
• Previously placed stent in the ipsilateral ICA or CCA
• Total occlusion or presence of a "string sign" of the ipsilateral ICA or CCA
• Presence of a filling defect of the target lesion
• Tandem lesions, which cannot be covered by a single CGuard Prime stent
• Stenosis of the innominate artery or proximal CCA requiring revascularization
• Open neck stoma
• History of bleeding diatheses or coagulopathy
• Hypercoagulable state
• Alternative source of cerebral embolus, including but not limited to:

Chronic atrial fibrillation Episode(s) of paroxysmal atrial fibrillation within the past 6 months or history of paroxysmal atrial fibrillation requiring chronic anticoagulation Knowledge of cardiac sources of embolus (e.g. left ventricular aneurysm, intracardiac filling defect, cardiomyopathy, aortic or mitral prosthetic heart valve, calcific aortic stenosis, endocarditis, mitral stenosis, atrial septal defect, atrial septal aneurysm, or left atrial myxoma) Recently (<60 days) implanted heart valve (either surgically or endovascularly) as a known source of emboli as confirmed on echocardiogram, Abnormal angiographic findings: ipsilateral intracranial or extracranial arterial stenosis (as determined by angiography or CTA/MRA 6 months prior to index procedure) greater in severity than the lesion to be treated; cerebral aneurysm > 5mm; AVM (arteriovenous malformation) of the cerebral vasculature, or other abnormal angiographic findings Known sensitivity or allergy to nickel or titanium.