1 A catheter, with a balloon at the tip, is threaded into the patient through the femoral artery in the groin until it reaches the clogged artery. The balloon is expanded, opens the artery, and is removed.
2 A catheter, now with a stent at the end with a balloon inside, is inserted. When it reaches the artery, the balloon is inflated, propping open the stent. The catheter and balloon are removed, leaving the stent in place.
3 Over time, the drug sirolimus, which is coated onto the stent, is released into the blood vessel wall. It acts to block the creation of excessive amounts of scar tissue that could reclog the artery.