Sensitivity of CFD based hemodynamic results in rabbit aneurysm models to idealizations in surrounding vasculature

Zijing Zeng, David F. Kallmes, Michael J. Durka, Yonghong Ding, Debra Lewis, Ramanathan Kadirvel, Anne M. Robertson

Research output: Contribution to journalArticle

20 Scopus citations

Abstract

Computational fluid dynamics (CFD) studies provide a valuable tool for evaluating the role of hemodynamics in vascular diseases such as cerebral aneurysms and atherosclerosis. However, such models necessarily only include isolated segments of the vasculature. In this work, we evaluate the influence of geometric approximations in vascular anatomy on hemodynamics in elastase induced saccular aneurysms in rabbits. One representative high aspect ratio (AR - height/neck width) aneurysm and one low AR aneurysm were created at the origin of the right common carotid artery in two New Zealand white rabbits. Three-dimensional (3D) reconstructions of the aneurysm and surrounding arteries were created using 3D rotational angiographic data. Five models with varying extents of neighboring vasculature were created for both the high and low AR cases. A reference model included the aneurysm sac, left common carotid artery (LCCA), aortic arch, and downstream trifurcation/quadrification. Three-dimensional, pulsatile CFD studies were performed and streamlines, wall shear stress (WSS), oscillatory shear index, and cross sectional velocity were compared between the models. The influence of the vascular domain on intra-aneurysmal hemodynamics varied between the low and high AR cases. For the high AR case, even a simple model including only the aneurysm, a small section of neighboring vasculature, and simple extensions captured the main features of the steamline and WSS distribution predicted by the reference model. However, the WSS distribution in the low AR case was more strongly influenced by the extent of vasculature. In particular, it was necessary to include the downstream quadrification and upstream LCCA to obtain good predictions of WSS. The findings in this work demonstrate the accuracy of CFD results can be compromised if insufficient neighboring vessels are included in studies of hemodynamics in elastase induced rabbit aneurysms. Consideration of aspect ratio, hemodynamic parameters of interest, and acceptable magnitude of error when selecting the vascular domain will increase reliability of the results while decreasing computational time.

Original languageEnglish (US)
Article number91009-1
JournalJournal of Biomechanical Engineering
Volume132
Issue number9
DOIs
StatePublished - Sep 2010

Keywords

  • Aneurysms
  • Animal models
  • CFD
  • Hemodynamics
  • Parent vasculature
  • Wall shear stress

ASJC Scopus subject areas

  • Biomedical Engineering
  • Physiology (medical)

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