Transcatheter aortic valve replacement (TAVR) is a minimally invasive procedure to replace a narrowed aortic valve that fails to open properly (aortic valve stenosis). In this procedure, doctors insert a catheter into the leg or chest and guide it to the heart. A replacement valve is inserted through the catheter and guided to the heart. A balloon is expanded to press the valve into place. Some TAVR valves are self-expanding.