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Titolo:
A general method for estimating deformation and forces imposed in vivo on bioprosthetic heart valves with flexible annuli: In vitro and animal validation studies
Autore:
Shandas, R; Mitchell, M; Conrad, C; Knudson, O; Sorrell, J; Mahalingam, S; Fragoso, M; Valdes-Cruz, L;
Indirizzi:
Childrens Hosp, Cardiovasc Flow Res Lab, Dept Cardiol, Denver, CO 80218 USA Childrens Hosp Denver CO USA 80218 ab, Dept Cardiol, Denver, CO 80218 USA Childrens Hosp, Dept Cardiothorac Surg, Denver, CO 80218 USA Childrens Hosp Denver CO USA 80218 ardiothorac Surg, Denver, CO 80218 USA Univ Colorado, Dept Mech Engn, Boulder, CO 80309 USA Univ Colorado Boulder CO USA 80309 Dept Mech Engn, Boulder, CO 80309 USA
Titolo Testata:
JOURNAL OF HEART VALVE DISEASE
fascicolo: 4, volume: 10, anno: 2001,
pagine: 495 - 504
SICI:
0966-8519(200107)10:4<495:AGMFED>2.0.ZU;2-M
Fonte:
ISI
Lingua:
ENG
Soggetto:
ECHOCARDIOGRAPHY; RING;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Citazioni:
11
Recensione:
Indirizzi per estratti:
Indirizzo: Shandas, R Childrens Hosp, Cardiovasc Flow Res Lab, Dept Cardiol, 1056 E 19th Ave,B-100, Denver, CO 80218 USA Childrens Hosp 1056 E 19th Ave,B-100 Denver CO USA 80218 18 USA
Citazione:
R. Shandas et al., "A general method for estimating deformation and forces imposed in vivo on bioprosthetic heart valves with flexible annuli: In vitro and animal validation studies", J HEART V D, 10(4), 2001, pp. 495-504

Abstract

Background and aim of the study: The use of flexible structures within cardiovascular prostheses such as valves, stents and vascular grafts has been proposed as a means of more closely modeling native mechanics, and thereby reducing the biomechanical problems associated with rigid materials. However, the design of such materials has been hampered by the paucity of quantitative information on the in-vivo behavior of such structures. The aim of this study was to explore the use of 3D ultrasound imaging coupled with finite element analysis (FEA) as a tool to estimate deformation and forces imposed in vivo on a novel bioprosthetic valve design. Methods: The method was first tested using in-vitro static loading conditions, where good agreement between displacements seen on video and those obtained from application of the identical force within the finite element program was seen. The method was then tested in a porcine model with valves implanted in the mitral position. Images of the deforming annular ring were obtained over the cardiac cycle using 3D intravascular ultrasound; these images were fed into the FEA program for calculation of reaction forces. Results: Results in vitro showed that a force of 2.7-8.0 Newtons (N) was required to produce a deformation of between 1.0 and 3.0 mm in the radial direction. A time history of deformation and force around the ring-of the valve stent could be obtained for the in-vivo conditions. These results revealed a maximum deformation of 0.5-1.7 mm along the short axis (anteroposterior) of the mitral valve. Coupled to this, a peak reaction force of 4.4-13.9 N was found at the points corresponding to maximal deflection. Both deformation and reaction force reached maximum during atrial contraction. Conclusion This method provides an accurate means of estimating deformation and corresponding forces imposed in vivo on intracardiac prostheses. The results provide information on the dynamic behavior of the mitral valve annulus. Such information should be useful in the design of flexible cardiovascular prostheses.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/11/20 alle ore 07:10:36