Angioplasty is a procedure done to open a partially blocked blood vessel so that blood can flow through it more easily. It is most often done on arteries that deliver blood to the heart (coronary arteries) when they are narrowed by plaque buildup (atherosclerosis) or blood clots.

During the angioplasty procedure, a thin flexible tube (catheter) is inserted through an artery in the groin, arm, or wrist and is carefully guided into the artery that is narrowed. After the tube reaches the narrowed artery, a small balloon at the end of the tube is inflated. The balloon may remain inflated for a short time. The pressure from the inflated balloon presses fat and calcium deposits (plaque) against the wall of the artery to improve blood flow.

After the fat and calcium buildup is compressed, a small, expandable tube called a stent is sometimes inserted into the artery to hold it open. The artery is less likely to get narrow again (restenosis) after angioplasty with stenting than after angioplasty alone.