A stent is a wire mesh tube used to prop open an artery that’s recently been cleared using angioplasty. The stent is collapsed to a small diameter and put over a balloon catheter. It’s then moved into the area of the blockage. When the balloon is inflated, the stent expands, locks in place and forms a scaffold. This holds the artery open. The stent stays in the artery permanently, holds it open, improves blood flow to the heart muscle and relieves symptoms (usually chest pain).