A stent assembly adapted to carotid arterial placement that includes a self-expanding support element comprising metal struts constructed to be positioned in a body lumen and expanded from a retracted state to an expanded state, and a knitted cover disposed over an exterior of the support element and along an entire length thereof, wherein the knitted cover comprises a single polymer fiber having a diameter of at least 40 nanometers to 30 microns, wherein the self-expanding support element and knitted cover together have apertures sized 20 microns to smaller than 100 microns in diameter to block larger debris when the stent assembly is placed in a carotid artery and expanded to the expanded state. Methods of stenting a carotid artery by applying the stent assembly to the carotid artery of a patient in need of treatment and expanding the stent assembly in situ are disclosed.
