Angioplasty is a collection of different procedures to mechanically widen narrowed or obstructed blood vessels (often as a result of atherosclerosis). Typically, a tightly folded balloon is inserted through a large artery to the location where the blood vessel is obstructed. Then, the balloon is inflated to press the plaque against the walls of the artery, opening the narrowed location. To keep the artery open after an angioplasty procedure surgeons insert an expandable metal mesh tube (stent) at the site of the blockage. Angioplasty was developed by Andreas Gruentzig and was performed for the first time in 1977 in Zurich, Switzerland.