Alteration of intraaneurysmal hemodynamics by placement of a self-expandable stent: Laboratory investigation

Satoshi Tateshima, Kazuo Tanishita, Yasuhiro Hakata, Shin Ya Tanoue, Fernando Viñuela

Research output: Contribution to journalArticle

63 Citations (Scopus)

Abstract

Object. Development of a flexible self-expanding stent system and stent-assisted coiling technique facilitates endovascular treatment of wide-necked brain aneurysms. The hemodynamic effect of self-expandable stent placement across the neck of a brain aneurysm has not been well documented in patient-specific aneurysm models. Methods. Three patient-specific silicone aneurysm models based on clinical images were used in this study. Model 1 was constructed from a wide-necked internal carotid artery - ophthalmic artery aneurysm, and Models 2 and 3 were constructed from small wide-necked middle cerebral artery aneurysms. Neuroform stents were placed in the in vitro aneurysm models, and flow structures were compared before and after the stent placements. Flow velocity fields were acquired with particle imaging velocimetry. Results. In Model 1, a clockwise, single-vortex flow pattern was observed in the aneurysm dome before stenting was performed. There were multiple vortices, and a very small fast flow stream was newly formed in the aneurysm dome after stenting. The mean intraaneurysmal flow velocity was reduced by ∼ 23-40%. In Model 2, there was a clockwise vortex flow in the aneurysm dome and another small counterclockwise vortex in the tip of the aneurysm dome before stenting. The small vortex area disappeared after stenting, and the mean flow velocity in the aneurysm dome was reduced by 43-64%. In Model 3, a large, counterclockwise, single vortex was seen in the aneurysm dome before stenting. Multiple small vortices appeared in the aneurysm dome after stenting, and the mean flow velocity became slower by 22-51%. Conclusions. The flexible self-expandable stents significantly altered flow velocity and also flow structure in these aneurysms. Overall flow alterations by the stent appeared favorable for the long-term durability of aneurysm embolization. The possibility that the placement of a low-profile self-expandable stent might induce unfavorable flow patterns such as a fast flow stream in the aneurysm dome cannot be excluded.

Original languageEnglish
Pages (from-to)22-27
Number of pages6
JournalJournal of Neurosurgery
Volume111
Issue number1
DOIs
Publication statusPublished - 2009 Jul
Externally publishedYes

Fingerprint

Stents
Aneurysm
Hemodynamics
Intracranial Aneurysm
Ophthalmic Artery
Endovascular Procedures
Rheology
Internal Carotid Artery
Silicones

Keywords

  • Aneurysm model
  • Coil embolization
  • Hemodynamics
  • Intracranial aneurysm
  • Intracranial stent
  • Neuroform stent

ASJC Scopus subject areas

  • Clinical Neurology
  • Surgery

Cite this

Alteration of intraaneurysmal hemodynamics by placement of a self-expandable stent : Laboratory investigation. / Tateshima, Satoshi; Tanishita, Kazuo; Hakata, Yasuhiro; Tanoue, Shin Ya; Viñuela, Fernando.

In: Journal of Neurosurgery, Vol. 111, No. 1, 07.2009, p. 22-27.

Research output: Contribution to journalArticle

Tateshima, Satoshi ; Tanishita, Kazuo ; Hakata, Yasuhiro ; Tanoue, Shin Ya ; Viñuela, Fernando. / Alteration of intraaneurysmal hemodynamics by placement of a self-expandable stent : Laboratory investigation. In: Journal of Neurosurgery. 2009 ; Vol. 111, No. 1. pp. 22-27.
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title = "Alteration of intraaneurysmal hemodynamics by placement of a self-expandable stent: Laboratory investigation",
abstract = "Object. Development of a flexible self-expanding stent system and stent-assisted coiling technique facilitates endovascular treatment of wide-necked brain aneurysms. The hemodynamic effect of self-expandable stent placement across the neck of a brain aneurysm has not been well documented in patient-specific aneurysm models. Methods. Three patient-specific silicone aneurysm models based on clinical images were used in this study. Model 1 was constructed from a wide-necked internal carotid artery - ophthalmic artery aneurysm, and Models 2 and 3 were constructed from small wide-necked middle cerebral artery aneurysms. Neuroform stents were placed in the in vitro aneurysm models, and flow structures were compared before and after the stent placements. Flow velocity fields were acquired with particle imaging velocimetry. Results. In Model 1, a clockwise, single-vortex flow pattern was observed in the aneurysm dome before stenting was performed. There were multiple vortices, and a very small fast flow stream was newly formed in the aneurysm dome after stenting. The mean intraaneurysmal flow velocity was reduced by ∼ 23-40{\%}. In Model 2, there was a clockwise vortex flow in the aneurysm dome and another small counterclockwise vortex in the tip of the aneurysm dome before stenting. The small vortex area disappeared after stenting, and the mean flow velocity in the aneurysm dome was reduced by 43-64{\%}. In Model 3, a large, counterclockwise, single vortex was seen in the aneurysm dome before stenting. Multiple small vortices appeared in the aneurysm dome after stenting, and the mean flow velocity became slower by 22-51{\%}. Conclusions. The flexible self-expandable stents significantly altered flow velocity and also flow structure in these aneurysms. Overall flow alterations by the stent appeared favorable for the long-term durability of aneurysm embolization. The possibility that the placement of a low-profile self-expandable stent might induce unfavorable flow patterns such as a fast flow stream in the aneurysm dome cannot be excluded.",
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KW - Coil embolization

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KW - Neuroform stent

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