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SNIS 8th annual meeting oral abstracts
O-025 The WEB aneurysm embolization device: design, evolution and CFD evaluation
  1. C Strother1,
  2. J Jiang2,
  3. K Pulfer1,
  4. D Consigny1
  1. 1Department of Radiology, CSC E1/320, University of Wisconsin, Madison, Wisconsin, USA
  2. 2Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA

Abstract

Experience with a variety of intra-luminal “flow diverters” has demonstrated the ability of these high-density, metallic mesh devices to disrupt flow into intracranial aneurysms to a degree where thrombosis will occur. Thus far, limitations in their use includes the inability to treat aneurysms of some geometries, for example, bifurcation, as well as the need for the use of dual antiplatelet therapy during, immediately after and for some months following treatment. Over the last 3 years Sequent Medical has designed and developed a novel intra-saccular flow diverter aimed at expanding the utility and ease of use of these devices in aneurysm treatment. In this presentation I will illustrate some of the steps in the development, testing and evolution of the WEB as well as describe and illustrate a computational comparison of the flow diversion achieved by use of a Sequent WEB device or a generic intra-luminal flow diverter in two human aneurysms. Since 2007 we have evaluated a variety of WEB designs using the canine bifurcation aneurysm model. Our aim in these studies was to identify a design which allowed: (1) controlled and reproducible device delivery, retrieval and detachment; (2) aneurysm isolation from the circulation within minutes of deployment; (3) stable aneurysm occlusion at follow-up. A final device design consisting of a high density, two-layer nitinol mesh with variable porosity was selected for clinical use. Using examples from our canine studies, I will discuss and illustrate how changes in pore distribution (density), pore size and the addition of an internal compartment impacted the WEBs performance. To assess the differences between the extent of flow diversion achieved by the WEB as compared to a generic intra-luminal flow diverter, we performed computational studies comparing the two devices imbedded in two human aneurysms from our in-house data base (one a ICA sidewall aneurysm and the other a basilar apex aneurysm). To reduce computational requirements a porous media approach was used for these simulations. In these two aneurysms a comparison of the TA-WSS, flow entering the aneurysms and, changes in a surrogate of kinetic energy before and after virtual “treatment” all indicated potential advantages of the WEB over the generic intra-luminal device. Over the course of our studies, the Sequent WEB evolved into a device that was effective in the treatment of the canine bifurcation aneurysm. Computational studies in two human aneuyrms illustrate the potential advantages of this intra-saccular flow diverter over a generic intra-luminal flow diverter.

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Footnotes

  • Disclosures C Strother: Sequent Medical. J Jiang: Sequent Medical. K Pulfer: None. D Consigny: None.