To collect clinical outcome and device performance data on the FDA 510(k)-cleared Emboshield® BareWire™ Rapid Exchange Embolic Protection System and FDA-approved Xact® Rapid Exchange Carotid Stent System when used under commercial use conditions by a broad group of physicians entering the study with differing carotid artery stenting experiences.

This is a multi-center, observational, single arm, post-approval study enrolling the following study population:

• Subjects with neurological symptoms and >= 50% stenosis of the common or internal carotid artery by ultrasound or angiogram (visual estimate), or
• Subjects without neurological symptoms and >= 80% stenosis of the common or internal carotid artery by ultrasound or angiogram (visual estimate)
• The endpoint for the 1500 subjects enrolled will be a 30-day composite of death, stroke and myocardial infarction (MI).
• For the 500 subjects with 12 month follow-up, the endpoint will be a composite of stroke, death and MI at 30 days and ipsilateral stroke at 12 months (31-365 days).

Inclusion Criteria:

• Subjects who agree to participate in this study and have signed the IRB approved informed consent form.
• Subjects who are willing to have the Emboshield and/or the Xact inserted into the their vasculature.

Exclusion Criteria:

• There are no exclusion criteria for this study.