Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2014 Aug;35(8):1567-73.
doi: 10.3174/ajnr.A3913. Epub 2014 Apr 10.

Analysis of hemodynamics and aneurysm occlusion after flow-diverting treatment in rabbit models

J R Cebral  1 , F Mut  2 , M Raschi  2 , S Hodis  3 , Y-H Ding  3 , B J Erickson  3 , R Kadirvel  3 , D F Kallmes  4
Affiliations

Analysis of hemodynamics and aneurysm occlusion after flow-diverting treatment in rabbit models

J R Cebral et al. AJNR Am J Neuroradiol. 2014 Aug.

Abstract

Background and purpose: Predicting the outcome of flow diversion treatment of cerebral aneurysms remains challenging. Our aim was to investigate the relationship between hemodynamic conditions created immediately after flow diversion and subsequent occlusion of experimental aneurysms in rabbits.

Materials and methods: The hemodynamic environment before and after flow-diversion treatment of elastase-induced aneurysms in 20 rabbits was modeled by using image-based computational fluid dynamics. Local aneurysm occlusion was quantified by using a voxelization technique on 3D images acquired 8 weeks after treatment. Global and local voxel-by-voxel hemodynamic variables were used to statistically compare aneurysm regions that later thrombosed to regions that remained patent.

Results: Six aneurysms remained patent at 8 weeks, while 14 were completely or nearly completely occluded. Patent aneurysms had statistically larger neck sizes (P = .0015) and smaller mean transit times (P = .02). The velocity, vorticity, and shear rate were approximately 2.8 times (P < .0001) larger in patent regions-that is, they had larger "flow activity" than regions that progressed to occlusion. Statistical models based on local hemodynamic variables were capable of predicting local occlusion with good precision (84% accuracy), especially away from the neck (92%-94%). Predictions near the neck were poorer (73% accuracy).

Conclusions: These results suggests that the dominant healing mechanism of occlusion within the aneurysm dome is related to slow-flow-induced thrombosis, while near the neck, other processes could be at play simultaneously.

PubMed Disclaimer

Figures

Fig 1.
Fig 1.
Imaging, modeling, and data analysis.
Fig 2.
Fig 2.
Visualization of peak systole flow structures pre- and post-treatment in an incompletely occluded aneurysm (case 1, top) and in a completely occluded aneurysm (case 10, bottom). Each panel shows 20 cm/s velocity isosurfaces (top) and flow streamlines (bottom) before (left) and after (right) treatment.
Fig 3.
Fig 3.
Posttreatment hemodynamic variables averaged over open and occluded regions.
See this image and copyright information in PMC

References

    1. Lylyk P, Miranda C, Ceratto R, et al. Curative endovascular reconstruction of cerebral aneurysms with the Pipeline embolization device: the Buenos Aires experience. Neurosurgery 2009;64:632–642 - PubMed
    1. Nelson PK, Lylyk P, Szikora I, et al. . The Pipeline embolization device for the intracranial treatment of aneurysms trial. AJNR. AJNR Am J Neuroradiol 2011;32:34–40 - PMC - PubMed
    1. Seong J, Wakhloo AK, Lieber BB. In vitro evaluation of flow divertors in an elastase-induced saccular aneurysm model in rabbit. J Biomech Eng 2007;129:863–72 - PubMed
    1. Kulcsár Z, Houdart E, Bonafe A, et al. . Intra-aneurysmal thrombosis as a possible cause of delayed aneurysm rupture after flow-diversion treatment. AJNR Am J Neuroradiol 2011;32:20–25 - PMC - PubMed
    1. Kallmes D, Ding YH, Dai D, et al. . A new endoluminal, flow disrupting device for treatment of saccular aneurysms. Stroke 2007;38:2346–52 - PubMed

Publication types

LinkOut - more resources