Stentless Devices : A bioprosthesis mounted on a stent reduces the effective orifice area (EOA). The newer version (third generation) stentless gluteraldehyde preserved porcine valves are now available for clinical use. The

commonly used one is Toronto stentless prosthetic valve (SPV) made by St. Jude Medical. The other type is Medtronic free style porcine bioprosthesis. Both are preserved in gluteraldehyde. It can be implanted in the sub-coronary position in the aorta or as a full aortic root replacement with reimplantation of corollary arteries. Usually the cusps remain free of calcium at six years and 85 per cent have freedom from structural deterioration at the end of nine years.