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The aortic valve microstructure: effects of transvalvular pressure
M S Sacks1, D B Smith, E D Hiester
1Department of Biomedical Engineering, University of Miami, Coral Gables, Florida 33124-0621, USA. msacks@coeds.eng.miami.edu
Journal of Biomedical Materials Research
|June 26, 1998
Summary
The aortic valve cusp
Area of Science:
- Cardiovascular biomechanics
- Tissue engineering
- Biomaterials science
Background:
- Understanding aortic valve cusp mechanics is crucial for bioprosthetic heart valve design.
- Previous studies lack quantitative data on microstructural responses to pressure loading.
Purpose of the Study:
- To quantitatively assess the microstructural response of aortic valve cusps to varying transvalvular pressures.
- To investigate fiber alignment and orientation changes within different cusp layers under pressure.
Main Methods:
- Small-angle light scattering (SALS) was employed to analyze fiber structure in porcine aortic valves.
- Valves were subjected to transvalvular pressures ranging from 0 to 90 mmHg.
- Fibrosa and ventricularis layers were analyzed separately and together.
Main Results:
- Fiber preferred directions consistently aligned circumferentially.
- Significant changes in fiber alignment occurred between 0-1 mmHg, with stabilization beyond 4 mmHg.
- The fibrosa layer showed higher initial orientation than the ventricularis, with layers becoming more similar at higher pressures.
Conclusions:
- Aortic valve cusp structure exhibits a complex, heterogeneous response to pressure.
- The ventricularis layer may contribute to diastolic stiffness at high pressures, preventing over-distention.
- Future bioprosthetic heart valve designs must replicate this intricate fiber-level response.