A stent is a device that supports an opening in the heart's blood vessel to provide better blood flow. Typically, stents are placed in narrowed vessels immediately after angioplasty to help maintain the opening. Stents are made of stainless steel wires and closely resemble ballpoint pen springs. Stents come in different sizes and lengths for all different types of vessels.

You can imagine a stent being the steel structure that keeps the roof of the artery from collapsing, and thus, keeps the blood flowing freely through the restored blood vessel.