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Post-stenotic core flow behavior in pulsatile flow and its effects on wall shear stress
1Department of Mechanical and Aerospace Engineering, State University of New York, Buffalo 14260.
Journal of Biomechanics
|January 1, 1990
Summary
Arteries adapt to maintain a specific wall shear stress, but whether mean or pulsatile stress drives intimal thickening remains unclear. This study used models to investigate shear stress in post-stenotic flows, crucial for understanding atherogenesis.
Area of Science:
- Cardiovascular physiology
- Biomedical engineering
- Hemodynamics
Background:
- Arterial diameter adjusts to maintain mean wall shear stress (WSS) within a physiological range (10-20 dynes cm⁻²).
- Intimal thickening in human carotid bifurcations correlates inversely with WSS, suggesting protective effects at higher WSS (>10 dynes cm⁻²).
Purpose of the Study:
- To investigate the role of mean versus pulsatile shear stress in atherogenesis.
- To differentiate the effects of mean and pulsatile shear stress on arterial wall response.
- To analyze the hemodynamic environment in post-stenotic regions.
Main Methods:
- Utilized Plexiglas models of stenosed arteries (75% and 90% area reduction).
- Simulated pulsatile flow conditions mimicking cynomolgus monkey aortas.
- Employed laser velocimetry to study flow fields and wall shear stress.
Main Results:
- Identified regions with low mean WSS but significant pulsatile excursions in post-stenotic flow.
- Demonstrated complex flow dynamics and shear stress patterns downstream of arterial stenoses.
Conclusions:
- The study highlights the complexity of shear stress in post-stenotic arterial segments.
- Findings are critical for understanding mechanisms of atherogenesis influenced by hemodynamic forces.
- Further research is needed to fully elucidate the differential roles of mean and pulsatile WSS.