title: Engineering analysis of the effects of bulging sinuses in a newly designed pediatric pulmonary heart valve on hemodynamic function.
abstract: The purpose of this study was to examine the hemodynamic characteristics of expanded polytetrafluoroethylene (ePTFE) pulmonary valves with bulging sinuses quantitatively in a pediatric pulmonary mechanical circulatory system designed by us, in order to propose the optimal design for clinical applications. In this study, we developed a pediatric pulmonary mock circulation system, which consisted of a pneumatic right ventricular model, a pulmonary heart valve chamber, and a pulmonary elastic compliance tubing with resistive units. The hemodynamic characteristics of four different types of ePTFE valves and a monoleaflet mechanical heart valve were examined. Relationships between the leaflet movements and fluid characteristics were evaluated based on engineering analyses using echocardiography and a high-speed video camera under the pediatric circulatory conditions of the mock system. We successfully performed hemodynamic simulations in our pediatric pulmonary circulatory system that could be useful for quantitatively evaluating the pediatric heart valves. In the simulation study, the ePTFE valve with bulging sinuses exhibited a large eddy in the vicinity of the leaflets, whereas the straight tubing exhibited turbulent flow. The Reynolds number obtained in the valve with bulging sinuses was calculated to be 1667, which was smaller than that in the straight tubing (R (e) = 2454).The hemodynamic characteristics of ePTFE pediatric pulmonary heart valves were examined in our mock circulatory system. The presence of the bulging sinuses in the pulmonary heart valve decreased the hydrodynamic energy loss and increased the systolic opening area. Based on an in vitro experiment, we were able to propose an optimal selection of pulmonary valve design parameters that could yield a more sophisticated pediatric ePTFE valve shape.
authors.affiliation: Graduate School of Biomedical Engineering, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, Japan. ichiro-rifle@pop02.odn.ne.jp
authors.forename: Ichiro
authors.initials: I
authors.lastname: Suzuki
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Shiraishi
authors.forename: Shota
authors.initials: S
authors.lastname: Yabe
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Tsuboko
authors.forename: Telma Keiko
authors.initials: TK
authors.lastname: Sugai
authors.forename: Ken
authors.initials: K
authors.lastname: Matsue
authors.forename: Takeyoshi
authors.initials: T
authors.lastname: Kameyama
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Saijo
authors.forename: Takashi
authors.initials: T
authors.lastname: Tanaka
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Okamoto
authors.forename: Zhonggang
authors.initials: Z
authors.lastname: Feng
authors.forename: Takako
authors.initials: T
authors.lastname: Miyazaki
authors.forename: Masaaki
authors.initials: M
authors.lastname: Yamagishi
authors.forename: Makoto
authors.initials: M
authors.lastname: Yoshizawa
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Umezu
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Yambe
mesh_terms: D002648:Child; D006321:Heart / Q000502:physiology*; D006350:Heart Valve Prosthesis; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008422:Materials Testing; D008955:Models, Cardiovascular; D011138:Polytetrafluoroethylene; D011673:Pulsatile Flow / Q000502:physiology
chemical_list: D011138:Polytetrafluoroethylene