Neurointervention.  2011 Feb;6(1):13-16. 10.5469/neuroint.2011.6.1.13.

Computational Flow Dynamics of the Severe M1 Stenosis Before and After Stenting

• Suh DC
• Ko YB
• Park ST
• Yoon K
• Lim OK
• Oh JS
• Jeong YG
• Kim JS

• KMID: 1783976
• DOI: http://doi.org/10.5469/neuroint.2011.6.1.13

Abstract

PURPOSE
Computational flow dynamic (CFD) study has not been widely applied in intracranial artery stenosis due to requirement of high resolution in identifying the small intracranial artery. We described a process in CFD study applied to symptomatic severe intracranial (M1) stenosis before and after stenting.
MATERIALS AND METHODS
Reconstructed 3D angiography in STL format was transferred to Magics (Materialise NV, Leuven, Belgium) for smoothing of vessel surface and trimming of branch vessels and to HyperMesh (Altair Engineering Inc., Auckland, New Zealand) for generating tetra volume mesh from triangular surface-meshed 3D angiogram. Computational analysis of blood flow in the blood vessels was performed using the commercial finite element software ADINA Ver 8.5 (ADINA R & D, Inc., Lebanon, MA). The distribution of wall shear stress (WSS), peak velocity and pressure in a patient was analyzed before and after intracranial stenting.
RESULTS
Computer simulation of wall shear stress, flow velocity and wall pressure before and after stenting could be demonstrated three dimensionally by video mode according to flow vs. time dimension. Such flow model was well correlated with angiographic finding related to maximum degree of stenosis. Change of WSS, peak velocity and pressure at the severe stenosis was demonstrated before and after stenting. There was no WSS after stenting in case without residual stenosis.
CONCLUSION
Our study revealed that CFD analysis before and after intracranial stenting was feasible despite of limited vessel wall dimension and could reveal change of WSS as well as flow velocity and wall pressure.

Keyword

Cerebral artery; Atherosclerosis; Magnetic resonance imaging (MRI); Plaque rupture; Fluid structure interaction

MeSH Terms

Angiography
Arteries
Atherosclerosis
Blood Vessels
Cerebral Arteries
Characidae
Computer Simulation
Constriction, Pathologic
Glycosaminoglycans
Humans
Lebanon
Magic
Stents
Glycosaminoglycans

Figure

• 

  Fig. 1 Cerebral angiogram and Computational flow dynamics (CFD) study in the severe M1 stenosis. Angiograms before (A) and after (B) stenting show relieved severe stenosis of the right M1 and normalization of decreased size and filling of the right MCA branches after stenting (arrows in A & B). Note upward shift of borderzone area to the upward normal postion after stenting (asterisk in B compared to A).C, D. Contour plot of the wall shear stress (WSS) map before stenting shows an increased WSS corresponding to the stenosis site during systole (C) and end-diastole (D) (arrows).E, F. Contour plot of the WSS map after stenting shows disappearance of high WSS area at normalized contour of the right M1suggesting hemodynamically successful stenting during systole (E) and end-diastole (F) (arrows).

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