Parametric Characterization of the Hemodynamics Inside Cerebral Aneurysms Undergoing Flow Diverting Stent Therapy

ORAL

Abstract

Flow-diverting stents (FDS) are often used to endovascularly treat cerebral aneurysms(CAs). They are designed to reduce shear stresses and increase residence times of blood flow in the aneurysm sac, promoting the development of a stable thrombus. Successful treatment is highly dependent on the degree that CA hemodynamics are altered following treatment. Here, we study the flow-field inside idealized CA models via 3D particle image velocimetry. A pulsatile flow-loop allows for the regulation of the pulsatile waveform before and after FDS treatment. By varying the waveform frequency, mean flow-rate, and curvature of the model’s parent-vessel, we explore the CA flow field across the entire physiological range of Reynolds number(Re), Dean number(De) and Womersely number(Wom). Results show that stresses due to flow entering the aneurysm, both on the vessel walls (Eulerian) and on the flowing platelets (Lagrangian), are reduced following treatment, but the reduction is minimal at high values of De. The sense of rotation of the primary aneurysmal sac vortex is also highly dependent on De and Wom. This parametric characterization of the aneurysm flow-field will help establish a causal connection between the hemodynamics of FDS-treated CAs and clinical outcomes.

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Presenters

  • Michael C Barbour

    Department of Mechanical Engineering, University of Washington, Department of Mechanical Engineering, University of Washington, Seattle, WA, USA

Authors

  • Michael C Barbour

    Department of Mechanical Engineering, University of Washington, Department of Mechanical Engineering, University of Washington, Seattle, WA, USA

  • Fanette Chassagne

    Department of Mechanical Engineering, University of Washington, Department of Mechanical Engineering, University of Washington, Seattle, WA, USA, University of Washington, Department of Mechanical Engineering

  • Nathanael Machicoane

    University of Washington, Univ of Washington, Department of Mechanical Engineering, University of Washington

  • Venkat Keshav Chivukula

    Department of Mechanical Engineering, University of Washington, Department of Mechanical Engineering, University of Washington, Seattle, WA, USA, University of Washington, Department of Mechanical Engineering, University of Washington

  • Louis J. Kim

    Department of Neurological Surgery, University of Washington, Department of Neurological Surgery, University of Washington, Seattle, WA, USA, Department of Neurological Surgery, University of Washington, Seattle, WA, USA, Department of Radiology, University of Washington, Seattle, WA, USA

  • Michael R. Levitt

    Department of Neurological Surgery, University of Washington, Department of Mechanical Engineering, University of Washington, Department of Neurological Surgery, University of Washington, Seattle, WA, USA, Department of Mechanical Engineering, University of Washington, Seattle, WA, USA

  • Alberto Osuna Aliseda

    University of Washington, Department of Mechanical Engineering, University of Washington, Department of Mechanical Engineering, University of Washington, Seattle, WA, USA, Department of Neurological Surgery, University of Washington, Seattle, WA, USA, Mechanical Engineering Department, University of Washington, Department of Mechanical Engineering, University of Washington, Seattle, WA, USA, Mechanical Engineering, University of Washington, Seattle, USA