A stent is a wire mesh stainless steel tube that holds an artery open and keeps it from closing again. It becomes a permanent part of your artery. Fatty deposits can block blood flow through arteries and cause pain. A piece may break off, form a clot, and cause a heart attack or stroke. A stent opens the blockage and keeps it open, which allows blood to flow smoothly. Good blood flow reduces pain and risks of clots forming.