What is the best bioprosthetic operation for the small aortic root?: allograft, autograft, porcine, pericardial? Stented or unstented?

Durability is assessed with regard to valve position, patient age, and the techniques of graft preparation for each of the tissue valves. Design affects both durability and the effective orifice area. It is assessed for each of the available devices, with particular emphasis on the stentless porcine valve. The effect that differences between this glutaraldehyde fixed device and the allograft valve may have on techniques of implantation is analyzed. On the basis of this information, an attempt is made to grade the currently available tissue valves with a satisfactory intermediate-term performance for use in the small aortic root.