Atherosclerosis is a hardening of the arteries that supply blood to the head and neck (carotid and vertebral arteries), thus causing narrowing and eventually blockage of these vessels. Atherosclerosis of the carotid arteries often cause transient ischemic attacks (TIAs or ministrokes) because pieces of the material that forms the blockage (plaque) and blood clots that form on the plaque break off and are carried into the head where they can block vessels supplying blood the brain.
If there is blockage of a larger vessel or the blockage doesn’t break up right away, a stroke results. The symptoms of blockage of these vessels may get better and worse, or they may suddenly appear if a stroke occurs. Extracranial atherosclerosis should be treated when it is found. If there are reasons why medical therapy or surgery is not recommended (such as a severe narrowing (especially in a location that cannot be safely reached by the surgeon), poor health, or previous radiation therapy to the neck), angioplasty and possibly stenting may be recommended. A catheter is placed into an artery (usually in the leg, similar to an angiogram of the heart) and threaded up to the vessel with the blockage. A small catheter with a balloon on the tip is inserted at the site of the blockage and inflated to open the vessel; occasionally a stent (a metal tube designed to keep the vessel open) is placed. Blood thinners are given during the procedure and for a short time after to prevent blood clots as it starts to heal.