Carotid artery stenting (CAS) is a procedure that can be used to open narrowed carotid arteries. It is also called carotid angioplasty and stenting.

There are two carotid arteries-one on each side of the neck-that supply blood to the brain. Fatty build-up (plaque) can narrow or block these arteries (stenosis). When one or both of your carotid arteries are narrowed, it can make it hard for blood to flow to the brain. Carotid artery stenting may improve blood flow to your brain and lower your risk of having a stroke.

During carotid artery stenting, a small, expandable tube called a stent is permanently inserted into the carotid artery.

To insert the stent, the doctor uses another tube called a catheter.

The doctor inserts the catheter into a large artery-most often the femoral artery in the groin-and threads it through other arteries to the carotid artery. The doctor will put dye into the catheter. The dye will make your carotid artery show up on X-ray images so that the doctor can find the narrowed or blocked section of the artery.

A very thin guide wire is inside the catheter. The guide wire is used to move a balloon and the stent into the carotid artery. The balloon is placed inside the stent and inflated. This opens the stent and pushes it into place against the artery wall. The balloon is then deflated and removed, leaving the stent in place. Over time, the cells lining the blood vessel will grow through and around the stent to help hold it in place.