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Structure, stress, and tissue repair in aortic valve leaflets.
J D Deck1, M J Thubrikar, P J Schneider
1Department of Anatomy, University of Virginia School of Medicine, Charlottesville.
Cardiovascular Research
|January 1, 1988
Summary
Aortic valve leaflets experience significant stress, particularly at the attachment site during diastole. This mechanical stress may lead to tissue wear and valve failure without regular tissue replacement.
Area of Science:
- Biomedical Engineering
- Cardiovascular Research
- Tissue Mechanics
Background:
- Aortic valve leaflets undergo continuous mechanical stresses during normal function.
- Bending and pressure stresses are concentrated at the leaflet-aortic wall attachment zone.
- Shearing stresses in this region are complex due to the tissue's semi-fluid nature.
Purpose of the Study:
- To model and quantify stresses in the aortic valve leaflet attachment region.
- To correlate mechanical stress levels with tissue replacement patterns.
Main Methods:
- Utilized in vivo canine leaflet motion data and histological analysis.
- Developed a model of the attachment region to derive bending and membrane stresses.
- Employed radioautographic studies on rat valves to investigate tissue turnover.
Main Results:
- Diastolic stresses ranged from 76-95 g.mm-2 (circumferential) and 37-44 g.mm-2 (radial) at the attachment site.
- Systolic stresses were found to be negligible.
- Proteins and complex sugars in valve connective tissues showed replacement patterns linked to stress levels.
Conclusions:
- High diastolic stresses at the aortic valve attachment region may predispose to tissue wear and failure.
- Regular tissue replacement, influenced by stress, is crucial for valve integrity.
- Findings suggest potential for interventions to mitigate stress-induced valve degeneration.