Angioplasty is a medical procedure to remove obstructions from clogged arteries. It is less invasive than coronary bypass surgery. The idea is to introduce into the artery a flexible tube called a catheter with a small, inflatable balloon attached to one end.
The progress of the guiding catheter is followed on a control screen (this is called interventional radiology). After the catheter has reached the site of the atheromatous plaque, the balloon is inflated and deflated several times.
If the odds that the artery will become obstructed again are considered high, the catheter and balloon are used to deploy a small spring, called stent or stent graph. The stent will prop the artery open after the withdrawal of the catheter.