Do stentless valves make a difference?

Stentless glutaraldehyde-preserved bioprosthetic valves for the aortic position were introduced into clinical practice in 1988. Their introduction coincided with the publication of several long-term observational studies of aortic homografts, which showed superior freedom from structural valve damage compared to the first generation stented porcine bioprosthesis. There followed 10 years of intensive investigation into the haemodynamic characteristics of stentless valves. These studies have demonstrated superior haemodynamic features in terms of transvalvular pressure gradients, effective orifice area, and more complete regression of left ventricular hypertrophy. Despite these advantages, stentless valves have yet to be adopted widely. This review seeks to explain this paradox.