The accurate placement of the valve is facilitated by a radiopaque center marker that allows alignment with the native valve. The preloaded prosthesis is positioned over a three-armed, self-centering system (Figure 1). An additional so-called “adaptive seal” at the lower part of the prosthesis skirt helps to conform to irregular surfaces of the native anatomy and to further reduce periprosthetic AR. The Sadra Lotus system is delivered percutaneously over an 18-Fr introducer Inhibitors,research,lifescience,medical sheath. In 2011, the REPRISE CE Mark trial with two valve sizes, 23 mm and 27
mm, was initiated in Germany, France, the United Kingdom, and Australia. Figure 1 Sadra Medical Inhibitors,research,lifescience,medical Lotus™ aortic valve.Courtesy of Sadra Medical, Inc./Boston Scientific, Natick, Massachusetts. Direct Flow Medical Aortic Valve The Direct Flow Medical Aortic Valve (Direct Flow Medical,
Santa Rosa, California) consists of a bovine pericardial tissue valve that is mounted between two inflatable polyester rings (Figure 2). These two rings are able to adapt to the native aortic annulus and the left-ventricular outflow tract to prevent periprosthetic AR. The device is delivered over an 18-Fr catheter-based, four-armed system after balloon valvuloplasty (BAV) Inhibitors,research,lifescience,medical of the native aortic valve. To better visualize the prosthesis under fluoroscopy for optimal positioning, the polyester rings of the prosthesis are filled with a mix of saline and contrast dye. Before final deployment of the valve, this fluid is exchanged Inhibitors,research,lifescience,medical against a hardening medium to firmly anchor the prosthesis in the native annulus. If necessary, the rings
can be fully deflated and the valve prosthesis can be retrieved Inhibitors,research,lifescience,medical with a net basket. The selleck screening library profile size has been reduced from 22 Fr to 18 Fr with the second-generation transcatheter heart valve. CE Mark approval is anticipated at the end of 2012. Figure 2 Direct Flow Medical aortic valve.Courtesy of Direct Flow Medical, Inc., Santa Rosa, California. Symetis Acurate TA™ Aortic Bioprosthesis The Symetis Acurate valve (Symetis, Lausanne, Switzerland) consists Bay 11-7085 of an aortic stentless porcine valve that is mounted and sutured in a self-expanding nitinol alloy stent (Figure 3) with a Dacron interface at the lower part of the stent frame. This transcatheter heart valve comes in three sizes and can accommodate native annulus sizes of 21-27 mm. After BAV, device deployment begins with the release of the stabilization arches and the upper crown of the valve in the ascending aorta. Two radiopaque markers help deploy the valve in a proper axial position. After the upper crown has engaged the cusps of the native leaflets, the lower crown is fully expanded and anchors the new valve in the native annulus. During release, the stabilization arches self-position the device with axial alignment.