Coronary stent. Coloured computed tomography (CT) scans of the coronary arteries of a 59-year-old patient with a coronary stent. The coronary artery with the stent in it has been highlighted (orange) by the injection of an iodine contrast medium. This allows the surgeons to assess how successful the operation has been. The stent is a tubular mesh that is expanded inside an artery at a point where it is blocked or partially blocked, and it is intended to unblock and strengthen the artery. Here, the implantation of a stent restores blood flow to the heart muscle. The blockage is often due to a condition such as atherosclerosis, where arteries harden and become blocked by fatty deposits.