Aneurysm growth occurs at region of low wall shear stress: Patient-specific correlation of hemodynamics and growth in a longitudinal study

Authors

Loic Boussel, University of California, San Francisco
Vitaliy Rayz, University of California, San Francisco
Charles McCulloch, University of California, San Francisco
Alastair Martin, University of California, San Francisco
Gabriel Acevedo-Bolton, University of California, San FranciscoFollow
Michael Lawton, University of California, San FranciscoFollow
Randall Higashida, University of California, San Francisco
Wade S. Smith, University of California, San Francisco
William L. Young, University of California, San Francisco
David Saloner, University of California, San Francisco

Document Type

Article

Abstract

BACKGROUND AND PURPOSE-Evolution of intracranial aneurysmal disease is known to be related to hemodynamic forces acting on the vessel wall. Low wall shear stress (WSS) has been reported to have a negative effect on endothelial cells normal physiology and may be an important contributor to local remodeling of the arterial wall and to aneurysm growth and rupture. METHODS-Seven patient-specific models of intracranial aneurysms were constructed using MR angiography data acquired at two different time points (mean 16.4 ±7.4 months between the two time points). Numeric simulations of the flow in the baseline geometries were performed to compute WSS distributions. The lumenal geometries constructed from the two time points were manually coregistered, and the radial displacement of the wall was calculated on a pixel-by-pixel basis. This displacement, corresponding to the local growth of the aneurysm, was compared to the time-averaged wall shear stress (WSSTA) through the cardiac cycle at that location. For statistical analysis, radial displacement was considered to be significant if it was larger than half of the MR pixel resolution (0.3 mm). RESULTS-Mean WSSTA values obtained for the areas with a displacement smaller and greater than 0.3 mm were 2.55±3.6 and 0.76±1.5 Pa, respectively (P<0.001). A linear correlation analysis demonstrated a significant relationship between WSSTA and surface displacement (P<0.001). CONCLUSIONS-These results indicate that aneurysm growth is likely to occur in regions where the endothelial layer lining the vessel wall is exposed to abnormally low wall shear stress. © 2008 American Heart Association, Inc.

Publication Date

11-1-2008

Publication Title

Stroke

ISSN

00392499

Volume

39

Issue

11

First Page

2997

Last Page

3002

PubMed ID

18688012

Digital Object Identifier (DOI)

10.1161/STROKEAHA.108.521617

Recommended Citation

Boussel, Loic; Rayz, Vitaliy; McCulloch, Charles; Martin, Alastair; Acevedo-Bolton, Gabriel; Lawton, Michael; Higashida, Randall; Smith, Wade S.; Young, William L.; and Saloner, David, "Aneurysm growth occurs at region of low wall shear stress: Patient-specific correlation of hemodynamics and growth in a longitudinal study" (2008). Neurosurgery. 968.
https://scholar.barrowneuro.org/neurosurgery/968