Stents are metal scaffolds used to prevent arteries from recoiling after angioplasty.

“So after you mentioned these stents, these little metal scaffolds, they developed back in the 1990s as a means of treating stable angina. So if somebody came in and they were having stable angina, so they said, God, you know, doc, I'm walking up the hill and I get this, you know, burning in my chest and I sit down and it goes away and I can't now I'm just not able to walk anywhere. So what can we do? Well, people realize that if you went in there, you blow up the balloon, this angioplasty thing, but if you wrap a metal scaffold around, it's almost like a slinky around the balloon. When you blow up that balloon, you leave that behind and that helps to keep the artery from recoiling back down.”