header

A Detailed Mechanical and Microstructural Analysis of the Ovine Tricuspid Valve Leaflets

33 Pages Posted: 23 Sep 2019 First Look: Accepted

See all articles by William Meador

William Meador

University of Texas at Austin - Department of Biomedical Engineering

Mrudang Mathur

University of Texas at Austin - Walker Department of Mechanical Engineering

Tomasz Jazwiec

Spectrum Health - Cardiothoracic Surgery; Medical University of Silesia - Department of Cardiac, Vascular, and Endovascular Surgery and Transplantology

Marcin Malinowski

Spectrum Health - Cardiothoracic Surgery; Medical University of Silesia - Department of Cardiac Surgery

Matthew R. Bersi

Vanderbilt University - Department of Biomedical Engineering

Tomasz A. Timek

Spectrum Health - Cardiothoracic Surgery

Manuel K. Rausch

University of Texas at Austin - Department of Biomedical Engineering; University of Texas at Austin - Walker Department of Mechanical Engineering; University of Texas at Austin - Department of Aerospace Engineering and Engineering Mechanics

Abstract

The tricuspid valve ensures unidirectional blood flow from the right atrium to the right ventricle. The three tricuspid leaflets operate within a dynamic stress environment of shear, bending, tensile, and compressive forces, which is cyclically repeated nearly two billion times in a lifetime. Ostensibly, the microstructural and mechanical properties of the tricuspid leaflets have mechanobiologically evolved to optimally support their function under those forces. Yet, how the tricuspid leaflet microstructure determines its mechanical properties and whether this relationship differs between the three leaflets is unknown. Here we perform a microstructural and mechanical analysis in matched ovine tricuspid leaflet samples. We found that the microstructure and mechanical properties vary among the three tricuspid leaflets in sheep. Specifically, we found that tricuspid leaflet composition, collagen orientation, and valve cell nuclear morphology are spatially heterogeneous and vary across leaflet type. Furthermore, under biaxial tension the leaflets' mechanical behaviors exhibited unequal degrees of mechanical anisotropy. Most importantly, we found that the septal leaflet was stiffer in the radial direction and not the circumferential direction as with the other two leaflets. The differences we observed in leaflet microstructure coincide with the varying biaxial mechanics among leaflets. Our results demonstrate the structure-function relationship for each leaflet in the tricuspid valve. We anticipate our results to be vital toward developing more accurate, leaflet-specific tricuspid valve computational models. Furthermore, our results may be clinically important, informing differential surgical treatments of the tricuspid valve leaflets. Finally, the identified structure-function relationships may provide insight into the homeostatic and remodeling potential of valvular cells in altered mechanical environments, such as in diseased or repaired tricuspid valves.

Keywords: biaxial, mechanobiology, growth and remodeling, second harmonic generation, collagen, morphology, nuclei

Suggested Citation

Meador, William and Mathur, Mrudang and Jazwiec, Tomasz and Malinowski, Marcin and Bersi, Matthew R. and Timek, Tomasz A. and Rausch, Manuel K., A Detailed Mechanical and Microstructural Analysis of the Ovine Tricuspid Valve Leaflets. Available at SSRN: https://ssrn.com/abstract=3455083

William Meador (Contact Author)

University of Texas at Austin - Department of Biomedical Engineering ( email )

2317 Speedway
Austin, TX 78712
United States

Mrudang Mathur

University of Texas at Austin - Walker Department of Mechanical Engineering

United States

Tomasz Jazwiec

Spectrum Health - Cardiothoracic Surgery

United States

Medical University of Silesia - Department of Cardiac, Vascular, and Endovascular Surgery and Transplantology

Poland

Marcin Malinowski

Spectrum Health - Cardiothoracic Surgery

United States

Medical University of Silesia - Department of Cardiac Surgery

Poland

Matthew R. Bersi

Vanderbilt University - Department of Biomedical Engineering

Nashville, TN 37232-0685
United States

Tomasz A. Timek

Spectrum Health - Cardiothoracic Surgery

United States

Manuel K. Rausch

University of Texas at Austin - Department of Biomedical Engineering

2317 Speedway
Austin, TX 78712
United States

University of Texas at Austin - Walker Department of Mechanical Engineering ( email )

United States

University of Texas at Austin - Department of Aerospace Engineering and Engineering Mechanics ( email )

United States

Register to save articles to
your library

Register

Paper statistics

Abstract Views
110
Downloads
17