Stents are usually placed to widen a vessel narrowed by cholesterol deposits. They have been widely used in vessels of the heart, as well as the carotid arteries and other areas of the body to improve blood flow, and are very successful. In October, a French study revealed that the stents posed a greater risk of stroke to the patient, than simply "cleaning out" the vessel, a procedure known as endartarectomy. Other studies have disputed these French findings, so studies in tne US are currently underway.