Valve-in-valve implantation using a novel supravalvular transcatheter aortic valve: proof of concept

Abstract

Background: Transcatheter valve implantation within degenerated bioprostheses is a potentially promising treatment for high-risk surgical patients. Clinical experience is limited; however, we have shown in vitro that currently available transcatheter aortic valve sizes did not provide acceptable hemodynamics in small bioprostheses. The objective of this study was to develop a new transcatheter valve that would provide good hemodynamics within degenerated bioprostheses.

Methods: Supravalvular transcatheter valves were created using a Dacron covered stainless steel stent at the base and trileaflet pericardial leaflets in an open stent above the bioprosthesis. The transcatheter valves were implanted within 19-, 21-, and 23-mm Carpentier-Edwards Perimount bioprostheses with simulated degeneration using BioGlue to achieve a mean pressure gradient of 50 mm Hg. Hemodynamics of valve-in-valve implantation were studied in a pulse duplicator.

Results: Supravalvular transcatheter valves successfully relieved bioprosthetic stenosis. Acceptable hemodynamics were achieved with a significant reduction in mean pressure gradient of 54.0 +/- 3.5 to 9.2 +/- 6.3 mm Hg in 23-mm bioprostheses (p < 0.001), from 49.3 +/- 3.1 to 14.4 +/- 4.7 mmHg (p < 0.001) in 21 mm, and from 53.9 +/- 3.8 to 28.3 +/- 9.8 mm Hg (p = 0.013) in 19-mm bioprostheses. Effective orifice area after valve-in-valve implantation increased significantly and was comparable to rereplacement with the same size bioprosthesis.

Conclusions: Valve-in-valve implantation was performed using a novel supravalvular transcatheter valve, which successfully relieved bioprosthetic stenosis. The hemodynamics were comparable with standard surgical valve replacement. Further studies are required to assess device safety and efficacy in patients.