Current status on stentless aortic bioprosthesis: a clinical and experimental perspective.

Introduction of stentless valves into clinical practice has not replaced stented valve prosthesis as expected a decade ago. With respect to clinical parameters such as transvalvular pressure differences, left ventricular mass regression as well as a possible survival benefit, there are many contradictory studies published. The overall dilemma is the absence of large randomized studies. This review, therefore, focuses on two issues: Experimental research in order to disclose design advantages or drawbacks and clinical trials expressing the real benefit or risk for the patient. In general, both clinical and experimental studies show that stentless valves have several biomechanical and haemodynamic benefits when compared with stented valves though new generation pericardial valves have excellent blood flow profiles. However, stentless and stented valves seem to perform equally well when it comes to various clinical parameters. In most cases, a stented valve is therefore preferable because of the simpler implantation technique. In order to gain a more widespread clinical use, the design of the stentless valve needs to be improved in order to simplify the implantation.