coronary stent

Think of a tiny scaffold that holds open a collapsing tunnel. A coronary stent is a small mesh tube, usually made of metal, that is placed inside a narrowed heart artery to prop it open and keep blood flowing after the vessel has been widened.

The stent is crimped onto a balloon and threaded to the diseased segment. When the balloon inflates, it expands the stent against the artery wall, where it locks in place permanently. Over the following weeks the body’s own lining (endothelium) grows over the metal struts, embedding the stent into the vessel wall. This is why patients take antiplatelet medicines for a period afterward — to keep clots from forming on the fresh metal surface.

Two broad types exist: bare-metal stents and drug-eluting stents, the latter releasing medication to curb re-narrowing. A known limitation is in-stent restenosis, where scar-like tissue regrows inside the stent, and rarely stent thrombosis, a sudden clot. Drug-eluting designs have greatly reduced restenosis, making them the default choice today.