Effect of exercise on patient specific abdominal aortic aneurysm flow topology and mixing

Amirhossein Arzani, Andrea S. Les, Ronald L. Dalman, Shawn C. Shadden

Research output: Contribution to journalArticlepeer-review

25 Scopus citations

Abstract

Computational fluid dynamics modeling was used to investigate changes in blood transport topology between rest and exercise conditions in five patient-specific abdominal aortic aneurysm models. MRI was used to provide the vascular anatomy and necessary boundary conditions for simulating blood velocity and pressure fields inside each model. Finite-time Lyapunov exponent fields and associated Lagrangian coherent structures were computed from blood velocity data and were used to compare features of the transport topology between rest and exercise both mechanistically and qualitatively. A mix-norm and mix-variance measure based on fresh blood distribution throughout the aneurysm over time were implemented to quantitatively compare mixing between rest and exercise. Exercise conditions resulted in higher and more uniform mixing and reduced the overall residence time in all aneurysms. Separated regions of recirculating flow were commonly observed in rest, and these regions were either reduced or removed by attached and unidirectional flow during exercise, or replaced with regional chaotic and transiently turbulent mixing, or persisted and even extended during exercise. The main factor that dictated the change in flow topology from rest to exercise was the behavior of the jet of blood penetrating into the aneurysm during systole.

Original languageEnglish (US)
Pages (from-to)280-295
Number of pages16
JournalInternational Journal for Numerical Methods in Biomedical Engineering
Volume30
Issue number2
DOIs
StatePublished - Feb 2014
Externally publishedYes

Keywords

  • Computational fluid dynamics
  • Hemodynamics
  • Lagrangian coherent structures
  • Transport

ASJC Scopus subject areas

  • Software
  • Biomedical Engineering
  • Modeling and Simulation
  • Molecular Biology
  • Computational Theory and Mathematics
  • Applied Mathematics

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