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Updated: Oct 18, 2025
Experimental Investigation of Secondary Flow Structures Downstream of a Model Type IV Stent Failure in a 180° Curved Artery Test Section
Published on: July 19, 2016
Secondary flow in bifurcations - Important effects of curvature, bifurcation angle and stents
C Shen1, R Gharleghi1, D D Li1
1School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney NSW 2052, Australia.
Insights
Stents significantly alter coronary bifurcation blood flow, increasing adverse conditions more than vessel curvature or bifurcation angle. Understanding these hemodynamic changes is crucial for preventing atherosclerosis.
Area of Science:
- Cardiovascular fluid dynamics
- Biomechanical engineering
- Medical imaging and modeling
Background:
- Coronary bifurcations exhibit complex hemodynamics, influencing atherosclerosis development.
- Secondary flow and helical flow patterns are key factors in coronary artery disease.
- Understanding these flow dynamics is critical for effective treatment strategies.
Purpose of the Study:
- To investigate the impact of curvature, bifurcation angle, and stent presence on coronary left main bifurcation hemodynamics.
- To model blood flow patterns in idealized and patient-specific coronary bifurcation geometries.
- To analyze the resulting hemodynamic forces and their association with pathophysiological mechanisms.
Main Methods:
- Computational fluid dynamics (CFD) modeling of 128 coronary bifurcation geometries.
- Inclusion of varying degrees of vessel curvature and bifurcation angles.
- Simulation of blood flow in both stented and non-stented configurations.
Main Results:
- Increased vessel curvature significantly alters secondary flow, causing vortex asymmetry and reducing adverse low time-average wall shear stress (TAWSS).
- Asymmetric flow patterns correlate with regions of low TAWSS.
- Stents induce local recirculation zones near struts, creating adverse TAWSS, with a greater overall hemodynamic impact than curvature or bifurcation angle.
Conclusions:
- Stent implantation has a more pronounced effect on coronary bifurcation hemodynamics than vessel curvature or bifurcation angle.
- The presence of stents significantly impacts flow patterns, potentially influencing atherosclerosis progression.
- This study provides critical insights into the interplay of anatomical variations and stent design on coronary blood flow.
Abstract:
Coronary bifurcations have complex flow patterns including secondary flow zones and helical flow, which directly affect pathophysiological mechanisms such as the development of atherosclerosis. The objective of this study was to generate insights into the effects of curvature, bifurcation angle and the presence of stents on flow patterns and resulting haemodynamics in coronary left main bifurcations. The blood flow and associated metrics were modelled in both idealised and patient-specific bifurcations with varying curvature and bifurcation angles with and without stents, resulting in a total of 128 geometries considered. The results showed that larger curvature of bifurcating vessels has a significant influence on secondary flow, especially with distance to the bifurcation region, causing a skew, spin and asymmetry of Dean vortices, an increase in helical flow intensity with symmetry loss, and a decrease in adversely low time-average wall shear stress (TAWSS). Generally, asymmetric flow patterns coincided with adversely low TAWSS regions. In identical stented geometries, the presence of the stents induced local recirculation immediately adjacent to the stent struts, thus generating adversely low TAWSS in these areas, with some effect on the overall secondary flow. Overall, the effect of stents outweighed the effect of curvature and BA. This new knowledge contributes to a better understanding of the joint effects of curvature, bifurcation angle, and stents on flow patterns and haemodynamics in coronary bifurcations.
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