If the cardiologist discovers severe artery blockage while performing your cardiac catheterization (angiogram), he or she may decide to open the blockage with angioplasty. During this procedure, the cardiologist inserts a special balloon-tipped catheter into the blockage and inflates the balloon to open the artery. After the balloon is removed, a second catheter carrying a metal coil called a stent may often be inserted. The stent is expanded using a balloon and will remain permanently at the site of the repaired blockage.