Finite element investigation of stentless pericardial aortic valves: relevance of leaflet geometry.
Recent developments in aortic valve replacement include the truly stentless pericardial bioprostheses with single point attached commissures (SPAC) implantation technique. The leaflet geometry available for the SPAC valves can either be a simple tubular or a complex three-dimensional structure molded using specially designed molds. Our main objective was to compare these two leaflet designs, the tubular vs. the molded, by dynamic finite element simulation. Time-varying physiological pressure loadings over a full cardiac cycle were simulated using ABAQUS. Dynamic leaflet behavior, leaflet coaptation parameters, and stress distribution were compared. The maximum effective valve orifice area during systole is 633.5 mm(2) in the molded valve vs. 400.6 mm(2) in the tubular valve, and the leaflet coaptation height during diastole is 4.5 mm in the former, in contrast to 1.6 mm in the latter. Computed compressive stress indicates high magnitudes at the commissures and inter-leaflet margins of the tubular valve, the highest being 3.83 MPa, more than twice greater than 1.80 MPa in the molded valve. The molded leaflet design which resembles the native valve exerts a positive influence on the mechanical performance of the SPAC pericardial valves compared with the simple tubular design. This may suggest enhanced valve efficacy and durability.
Xiong
Fang Li
FL
School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
Goetz
Wolfgang A
WA
Chong
Chuh Khiun
CK
Chua
Yeow Leng
YL
Pfeifer
Stefan
S
Wintermantel
Erich
E
Yeo
Joon Hock
JH
D001021:Aortic Valve / Q000502:physiology* / Q000601:surgery; D001705:Bioprosthesis; D004333:Drug Administration Routes; D006350:Heart Valve Prosthesis; D010496:Pericardium / Q000601:surgery*