With the patient under general anaesthesia, access to the heart is usually made through a full- or mini‑sternotomy, or right anterior thoracotomy. Once cardiopulmonary bypass and cardioplegia are established, the diseased aortic valve is accessed and removed through a cut in the aorta. Bulky calcifications around the native aortic annulus are removed to achieve a smooth round annulus for valve implantation. The valve prosthesis with self‑expanding or balloon expanding frame, loaded into a special delivery device, is deployed into the native annulus. Once in position the valve is released. The exact deployment method varies between the different devices available for this procedure and with some devices; one or more temporary guiding or securing sutures may be used. Balloon dilatation of the new valve may be used to maximise the area of contact between the prosthesis and the aortic annulus. Once the valve is deployed, the delivery system is removed and the aortotomy is closed. All of the devices used in this procedure contain material derived from animal sources.