Protected Carotid Artery Stenting in Subjects at High Risk for Carotid Endarterectomy (CEA) (PROTECT)

Inclusion Criteria Subject must be ≥ 18 years of age.

Subject has the ability to cooperate with study procedures and agrees to return for all
required follow-up visits, tests and exams.

Female subjects of childbearing potential must have a documented negative pregnancy test
within 30 days prior to the index procedure.

Subjects taking warfarin may be included if their dosage is reduced before the index
procedure to result in an INR of 1.5 or less. Warfarin may be restarted to therapeutic dose
after the index procedure.

The subject must sign a written informed consent prior to the initiation of any study
procedures, using a form that is approved by the Institutional Review Board (IRB) or
Medical Ethics Committee (EC).

The life expectancy of the subject is at least two years.

The subject has a lesion located in the internal carotid artery (ICA); the carotid
bifurcation may be involved.

The target lesion is intended to be treated with a single stent.

Target ICA vessel diameter must be visually estimated to be:

   - ≥2.5 mm and ≤7.0 for the Emboshield Pro (Gen 5)

   - ≥ 2.8 mm and ≤6.2 for the Emboshield (Gen 3)

And

   - ≥4.0 mm and ≤9.0 mm for the Xact Stent treatment area.

The subject has a carotid artery stenosis determined by ultrasound or angiography (visual
estimate) to be:

   - ≥50% for symptomatic subjects

Or

   - ≥80% for asymptomatic subjects

High-risk inclusion criteria for either anatomical or co-morbid risk factors are present.
The subject must fulfill at least one of the criteria, Category I or II risk factors,
listed below to meet the inclusion criteria.

Category I Anatomic Risk Factors

   - Previous radiation treatment to the neck or radical neck dissection

   - Target lesion is at or above the second vertebral body C2 (level of jaw)

   - Inability to extend the head due to cervical arthritis or other cervical disorders

   - Tracheostomy or tracheal stoma

   - Laryngectomy

   - Contralateral laryngeal nerve palsy

   - Severe tandem lesions

Category II Co-morbid Risk Factors

   - Previous CEA with significant restenosis (as defined for symptomatic or asymptomatic
   subjects)

   - Total occlusion of the contralateral carotid artery

   - Left ventricular ejection fraction < 35%

   - Congestive Heart failure New York Heart Association (NYHA) Functional Class III or
   higher

   - Dialysis dependent renal failure

   - Canadian Cardiovascular Society Angina Classification III or higher or unstable angina

   - Requires coronary artery bypass surgery, cardiac valve surgery, peripheral vascular
   surgery, or abdominal aortic aneurysm repair within 60 days

   •≥80 years of age

   - Myocardial infarction within previous 6 weeks

   - Abnormal stress test. Treadmill, thallium or dobutamine echo are acceptable. The
   stress tests should be sufficiently abnormal to place the subject at increased risk
   for CEA. This includes subjects with two or more proximal diseased coronary arteries
   of >70% stenosis that have not or cannot be revascularized or <30 days since
   revascularization.

   - Severe pulmonary disease, including at least one of the following: requires chronic O2
   therapy; resting PO2 ≤60 mm Hg, Hematocrit ≥50%, FEV₁ or DLCO ≤50% of normal.

Exclusion Criteria

   - The subject is participating in another investigational trial that would interfere
   with the conduct or result of this study.

   - The subject has dementia or a neurological illness that may confound the neurological
   evaluation.

   - Total occlusion of the target vessel.

   - There is an existing, previously placed stent in the target artery.

   - The subject has a known life-threatening allergy to the contrast media that cannot be
   treated.

   - Subject has history of intolerance or allergic reaction to any of the study
   medications including aspirin, Clopidogrel bisulfate (Plavix®) or Ticlopidine
   (Ticlid®), heparin or Bivalirudin (Angiomax™). Subjects must be able to tolerate a
   combination of aspirin and Clopidogrel or aspirin and Ticlopidine.

   - The subject has a GI bleed that would interfere with antiplatelet therapy.

   - The subject has known cardiac sources of emboli, including but not limited to current
   or past history of paroxysmal or sustained atrial fibrillation (treated or untreated),
   valve replacement, etc.

   - Subject has Hemoglobin (Hgb) less than 8 gm/dL (unless on dialysis), platelet count
   <50,000/mm3, or known heparin associated thrombocytopenia.

   - The subject has a history of bleeding diathesis or coagulopathy including
   thrombocytopenia or an inability to receive heparin or Bivalirudin (Angiomax™) in
   amounts sufficient to maintain an ACT of >250, or will refuse blood transfusion.

   - The subject has atherosclerotic disease involving adjoining vessels that precludes
   safe placement of the guiding catheter or sheath.

   - The subject has other abnormal angiographic findings that indicate the subject is at
   risk for a stroke due to a problem other than that of the target lesion, such as:
   ipsilateral arterial stenosis greater in severity than the target lesion, cerebral
   aneurysm, or arteriovenous malformation of the cerebral vasculature.

   - There is evidence of a carotid artery dissection prior to the initiation of the index
   procedure.

   - There is an angiographically visible thrombus.

   - There is any condition that precludes proper angiographic assessment, placement of the
   cerebral protective system or makes percutaneous arterial access unsafe, e.g. morbid
   obesity, sustained systolic blood pressure >180 mm Hg, tortuosity, occlusive disease,
   vessel anatomy, or aortic arch anatomy.

   - Occlusion (TIMI 0 flow), or string sign of the ipsilateral common or internal carotid
   artery.

   - There is evidence of bilateral carotid stenosis that would require intervention within
   30 days of the index procedure.

   - There is evidence of a stroke within the previous 30 days of the index procedure.

   - There is a planned treatment of a non-target lesion within 30 days post-index
   procedure.

   - There is a history of intracranial hemorrhage within the previous 3 months, including
   hemorrhagic transformation of an ischemic stroke.

   - There is a history of an ipsilateral stroke with fluctuating neurologic symptoms
   within one year of the index procedure.