| Institution: | 1. Department of Surgery, Division of Cardiac, Thoracic and Vascular Surgery, Section of Pediatric and Congenital Cardiac Surgery, New-York Presbyterian - Morgan Stanley Children's Hospital, Columbia University Medical Center, 3959 Broadway, CHN-274, New York, NY, 10032 USA;2. Department of Civil Engineering and Engineering Mechanics, Fu Foundation School of Engineering and Applied Science, Columbia University, 610 Mudd Building, 500 3. W. 120th Street, New York, NY, 10027 USA;4. Department of Mechanical Engineering, Fu Foundation School of Engineering and Applied Science, Columbia University, 220 Mudd Building, 500 5. Department of Surgery, Division of Cardiac, Thoracic and Vascular Surgery, Section of Pediatric and Congenital Cardiac Surgery, New-York Presbyterian - Morgan Stanley Children's Hospital, Columbia University Medical Center, 3959 Broadway, CHN-274, New York, NY, 10032 USA
Department of Mechanical Engineering, Fu Foundation School of Engineering and Applied Science, Columbia University, 220 Mudd Building, 500 |
| Abstract: | Currently available heart valve prostheses have no growth potential, requiring children with heart valve diseases to endure multiple valve replacement surgeries with compounding risks. This study demonstrates the in vitro proof of concept of a biostable polymeric trileaflet valved conduit designed for surgical implantation and subsequent expansion via transcatheter balloon dilation to accommodate the growth of pediatric patients and delay or avoid repeated open-heart surgeries. The valved conduit is formed via dip molding using a polydimethylsiloxane-based polyurethane, a biocompatible material shown here to be capable of permanent stretching under mechanical loading. The valve leaflets are designed with an increased coaptation area to preserve valve competence at expanded diameters. Four 22 mm diameter valved conduits are tested in vitro for hydrodynamics, balloon dilated to new permanent diameters of 23.26 ± 0.38 mm, and then tested again. Upon further dilation, two valved conduits sustain leaflet tears, while the two surviving devices reach final diameters of 24.38 ± 0.19 mm. After each successful dilation, the valved conduits show increased effective orifice areas and decreased transvalvular pressure differentials while maintaining low regurgitation. These results demonstrate concept feasibility and motivate further development of a polymeric balloon-expandable device to replace valves in children and avoid reoperations. |
