title: Development of a stent-biovalve with round-shaped leaflets: in vitro hydrodynamic evaluation for transcatheter pulmonary valve implantation (TPVI).
abstract: This study evaluates a newly designed autologous heart valve-shaped tissue with a stent [stent-biovalve (SBV)] for transcatheter pulmonary valve implantation using the "in-body tissue architecture" technology. In the previously developed SBV with flat-shaped leaflets (FS-SBV), the valve could not close rapidly, because the leaflets were fixed in the open position, which induced regurgitant volume in the closing phase. Therefore, a novel mold to fabricate an SBV with round-shaped leaflets (RS-SBV) was developed, and its hydrodynamic performance with different valve diameters was evaluated in this study. A specially designed, self-expandable, stent-mounted, acrylic mold, which has 3 hemispheres, was placed in dorsal subcutaneous pouches of goats for 2 months. After extraction, the acrylic mold was removed from the implant, and a tubular tissue impregnated with the stent strut was obtained. Half of the tubular tissue with 3 hemispheres was completely folded in half inwards. The acrylic mold was designed, such that the folded half of the tubular tissue became the round-shaped leaflets. The 3 commissure parts were connected to form 3 leaflets, resulting in the preparation of the RS-SBV (internal diameter 25 mm). The RS-SBV closed more rapidly than the FS-SBV in a pulsatile mock circulation circuit under the pulmonary circulation conditions. The regurgitant fraction of the RS-SBV was approximately 6 %, which was lower than that of the FS-SBV. The appropriate pulmonary annulus diameter of the RS-SBV was from 24 to 25 mm based on the pressure difference and effective orifice area.
authors.affiliation: Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita-Shi, Osaka, 565-8565, Japan. sumikura@ri.ncvc.go.jp.
authors.forename: Hirohito
authors.initials: H
authors.lastname: Sumikura
authors.affiliation: Division of Medical Engineering and Materials, National Cerebral and Cardiovascular Center Research Institute, Suita-Shi, Japan.
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Nakayama
authors.affiliation: Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita-Shi, Osaka, 565-8565, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Ohnuma
authors.affiliation: Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita-Shi, Osaka, 565-8565, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Takewa
authors.affiliation: Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita-Shi, Osaka, 565-8565, Japan.
authors.forename: Eisuke
authors.initials: E
authors.lastname: Tatsumi
mesh_terms: D000818:Animals; D001705:Bioprosthesis; D006041:Goats; D006350:Heart Valve Prosthesis; D057446:Hydrodynamics; D066298:In Vitro Techniques; D011474:Prosthesis Design; D011664:Pulmonary Valve; D015607:Stents
keywords: Autologous tissue; Biovalve; Hydrodynamic evaluation; Leaflet design; Pulmonary valve