Effects of Carotid Stent Design on Cerebral Embolization

Stroke is responsible for more than 10% of all deaths and much severe disability in developed
countries. In the United States, approximately 600,000 new strokes are reported annually, of
which 150,000 are fatal, and more than 4,000,000 surviving stroke victims are affected by
significant disability. Seventy-five percent of strokes occur in the distribution of the
carotid arteries and are considered of a thromboembolic etiology, most of which originate in
carotid lesions. Carotid artery stenting (CAS) with cerebral embolic protection is currently
the preferred treatment of carotid stenosis in high risk surgical patients, i.e., those with
significant comorbidities or a hostile neck from previous surgical procedures or radiation.
Although several predictors of adverse outcomes after CAS have been identified, the effects
of device characteristics, including stent design, on neurologic adverse events have not been
established.

The proposed study will be a randomized prospective controlled trial designed to test the
hypothesis that the implantation of closed-cell stents for carotid lesions in high-risk
patients will be associated with a reduced perioperative cerebral microembolization, as
detected by transcranial Doppler and diffusion-weighted magnetic resonance imaging of the
brain, and reduced 30-day stroke, myocardial infarction, and death rates when compared with
the implantation of open-cell stents.

Inclusion Criteria:

- Subject is at high risk for carotid endarterectomy due to either anatomic or co-morbid
conditions; AND

- Symptomatic patients (TIA or non-disabling stroke within 6 months of the procedure),
with carotid stenosis ≥ 50% as diagnosed by angiography, using NASCET methodology
(50); OR

- Asymptomatic patients with carotid stenosis ≥ 80% as diagnosed by angiography, using
NASCET methodology

Exclusion Criteria:

- Conditions that interfere with the evaluation of endpoints

- Subject has anticipated or potential sources of cardiac emboli

- Subject plans to have a major surgical procedure within 30 days after the index
procedure.

- Subject has intracranial pathology that makes the subject inappropriate for study
participation.

- Subject has a total occlusion of the ipsilateral carotid artery (i.e., CCA).

- Severe circumferential lesion calcification that may restrict the full deployment of
the carotid stent.

- Carotid stenosis located distal to the target stenosis that is more severe than the
target stenosis.