Percutaneous aortic valve implantation has become an alternative technique to surgical valve replacement in patients with high risk for surgery. This technique is at its beginning and stents used for valve prostheses remain standard vascular stents. These stents are, however, not designed to undergo heart valve stress. They do not match the aortic environment geometry, and induce exaggerated tissue traumatism. Reduced implant lifetime may therefore be expected. The purpose of this work is to evaluate in vitro the technical feasibility of noninvasive aortic valve replacement with a novel more specific stent. This stent is especially adapted to its implantation environment, with a design that matches the shape of the aortic root while respecting the valve function. To optimize the device's geometry, the influence of the design parameters on static and dynamic performances is studied in detail. For that purpose, the interaction between the stent and the aortic root is first studied theoretically, to highlight which parameters are relevant for further in vitro experiments. Static and dynamic regurgitation measurements are then performed to set the design parameters so as to optimize the behavior of the device implanted in a mock aortic root.
(c) 2009 Wiley Periodicals, Inc.