Hemodynamic variations due to spiral blood flow through four patient-specific bifurcated stent graft configurations for the treatment of abdominal aortic aneurysms

Abdominal aortic aneurysms (AAA) are characterized by disturbed flow patterns, low and oscillatory wall shear stress with high gradients, increased particle residence time, and mild turbulence. Diameter is the most common metric for rupture prediction, although this metric can be unreliable. We hypothesize that understanding the flow topology and mixing inside AAA could provide useful insight into mechanisms of aneurysm growth. AAA morphology has high variability, as with AAA hemodynamics, and therefore we consider patient-specific analyses over several small to medium sized AAAs. Vortical patterns dominate AAA hemodynamics and traditional analyses based on the Eulerian fields (e.g. velocity) fail to convey the complex flow structures. The computation of finite-time Lyapunov exponent (FTLE) fields and underlying Lagrangian coherent structures (LCS) help reveal a Lagrangian template for quantifying the flow [1].

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A computational assessment of the hemodynamic effects of crossed and non-crossed bifurcated stent-graft devices for the treatment of abdominal aortic aneurysms

Medical Engineering & Physics ◽

10.1016/j.medengphy.2016.09.011 ◽

2016 ◽

Vol 38 (12) ◽

pp. 1458-1473 ◽

Cited By ~ 8

Author(s):

Florian Stefanov ◽

Tim McGloughlin ◽

Liam Morris

Keyword(s):

Stent Graft ◽

Abdominal Aortic Aneurysms ◽

Aortic Aneurysms ◽

Hemodynamic Effects ◽

Abdominal Aortic

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Method for Incorporating Three-Dimensional Residual Stresses Into Patient-Specific Simulations of Arteries

Volume 1B: Extremity; Fluid Mechanics; Gait; Growth, Remodeling, and Repair; Heart Valves; Injury Biomechanics; Mechanotransduction and Sub-Cellular Biophysics; MultiScale Biotransport; Muscle, Tendon and Ligament; Musculoskeletal Devices; Multiscale Mechanics; Thermal Medicine; Ocular Biomechanics; Pediatric Hemodynamics; Pericellular Phenomena; Tissue Mechanics; Biotransport Design and Devices; Spine; Stent Device Hemodynamics; Vascular Solid Mechanics; Student Paper and Design Competitions ◽

10.1115/sbc2013-14232 ◽

2013 ◽

Author(s):

David M. Pierce ◽

Thomas E. Fastl ◽

Hannah Weisbecker ◽

Gerhard A. Holzapfel ◽

Borja Rodriguez-Vila ◽

...

Keyword(s):

Medical Imaging ◽

Three Dimensional ◽

Constitutive Models ◽

Abdominal Aortic Aneurysms ◽

Aortic Aneurysms ◽

Patient Specific ◽

Abdominal Aortic ◽

Model Geometry ◽

Reconstructed Model

Through progress in medical imaging, image analysis and finite element (FE) meshing tools it is now possible to extract patient-specific geometries from medical images of, e.g., abdominal aortic aneurysms (AAAs), and thus to study clinically relevant problems via FE simulations. Medical imaging is most often performed in vivo, and hence the reconstructed model geometry in the problem of interest will represent the in vivo state, e.g., the AAA at physiological blood pressure. However, classical continuum mechanics and FE methods assume that constitutive models and the corresponding simulations start from an unloaded, stress-free reference condition.

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