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ABSTRACT Despite the frequent failure of aortic valves and pediatric usage of pulmonary valves as a replacement, comparative studies on their full‐field collagenous architecture and macroscale geometries are limited. We applied laser micrometry and quantitative polarized light imaging (QPLI), a novel technique for assessing collagen fiber organization, to porcine aortic (n = 8) and pulmonary (n = 8) valve leaflets to non‐destructively compare thickness and anisotropy. We confirmed (1) light intensity and sample thickness are inversely related and (2) aortic valve leaflets are thicker with decreased fiber organization when unloaded. To demonstrate the ability of QPLI to capture dynamic collagen fiber alignment, we imaged leaflets during equibiaxial loading. There was an increase in the aortic leaflet's degree of alignment throughout loading, whereas the pulmonary valve leaflet exhibited relatively unchanged alignment. Ultimately, understanding the full‐field organization of a leaflet's heterogeneous ECM and how it is altered by pathology can inform therapy development.
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A model of fluid–structure and biochemical interactions for applications to subclinical leaflet thrombosis
Abstract Subclinical leaflet thrombosis (SLT) is a potentially serious complication of aortic valve replacement with a bioprosthetic valve in which blood clots form on the replacement valve. SLT is associated with increased risk of transient ischemic attacks and strokes and can progress to clinical leaflet thrombosis. SLT following aortic valve replacement also may be related to subsequent structural valve deterioration, which can impair the durability of the valve replacement. Because of the difficulty in clinical imaging of SLT, models are needed to determine the mechanisms of SLT and could eventually predict which patients will develop SLT. To this end, we develop methods to simulate leaflet thrombosis that combine fluid–structure interaction and a simplified thrombosis model that allows for deposition along the moving leaflets. Additionally, this model can be adapted to model deposition or absorption along other moving boundaries. We present convergence results and quantify the model's ability to realize changes in valve opening and pressures. These new approaches are an important advancement in our tools for modeling thrombosis because they incorporate both adhesion to the surface of the moving leaflets and feedback to the fluid–structure interaction.
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- PAR ID:
- 10495816
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- International Journal for Numerical Methods in Biomedical Engineering
- Volume:
- 39
- Issue:
- 5
- ISSN:
- 2040-7939
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1002/cnm.3700
