title: Fully coupled fluid-structure interaction model of congenital bicuspid aortic valves: effect of asymmetry on hemodynamics.
abstract: A bicuspid aortic valve (BAV) is a congenital cardiac disorder where the valve consists of only two cusps instead of three, as in a normal tricuspid valve (TAV). Although 97 % of BAVs include asymmetric cusps, little or no prior studies have investigated the blood flow through a three-dimensional BAV and root. The aim of the present study was to characterize the effect of asymmetric BAV on the blood flow using fully coupled fluid-structure interaction (FSI) models with improved boundary conditions and tissue properties. This study presents four FSI models, including a native TAV, asymmetric BAVs with or without a raphe, and an almost symmetric BAV. Cusp tissue is composed of hyperelastic finite elements with collagen fibres embedded in the elastin matrix. A full cardiac cycle is simulated by imposing the same physiological blood pressures for all the TAV and BAV models. The latter have significantly smaller opening areas compared with the TAV. Larger stress values were found in the cusps of BAVs with fused cusps, at both the systolic and diastolic phases. The asymmetric geometry caused asymmetric vortices and much larger flow shear stress on the cusps which could be a potential initiator for early valvular calcification of BAVs.
authors.affiliation: School of Mechanical Engineering, The Fleischman Faculty of Engineering, Tel Aviv University, 6997801 Tel Aviv, Israel. maromgil@eng.tau.ac.il
authors.forename: Gil
authors.initials: G
authors.lastname: Marom
authors.forename: Hee-Sun
authors.initials: HS
authors.lastname: Kim
authors.forename: Moshe
authors.initials: M
authors.lastname: Rosenfeld
authors.forename: Ehud
authors.initials: E
authors.lastname: Raanani
authors.forename: Rami
authors.initials: R
authors.lastname: Haj-Ali
mesh_terms: D001021:Aortic Valve / Q000002:abnormalities* / Q000033:anatomy & histology / Q000473:pathology / Q000503:physiopathology; D000082882:Bicuspid Aortic Valve Disease; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D020342:Finite Element Analysis; D006349:Heart Valve Diseases / Q000473:pathology* / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D008955:Models, Cardiovascular; D013599:Systole