ABSTRACT
Stentless heart valve designs, which omit sewing rings and struts, should provide optimal bioprosthetic graft haemodynamic function, more like that of heart valve homografts. Presently, two stentless porcine bioprostheses are being developed at CryoLife Inc. to take advantage of the lower expected transvalvular gradients and larger orifice size predicted for stentless valves. The design of the CryoLife-O’Brien 300 glutaraldehydefixed heart valve (Figure 29.1) incorporates the novel approach of forming a composite valve from three geometrically and size-matched non-coronary leaflets and wall derived from three separate porcine aortic valves to provide symmetrical leaflet opening. The second of these stentless bioprostheses is the Ross pulmonary heart valve, a glutaraldehyde-fixed porcine pulmonary root (Figure 29.2). The native porcine pulmonary valve does not have a singular muscle bar on its leaflets, and with its thinner and more pliable leaflets, it should share with the CryoLife-O’Brien 300 valve the potential to maximize functional valve orifice area. In fact, excellent haemodynamic function has been demonstrated for aortic valve replacements utilizing fixed pulmonary roots.1
