Physiological remodeling of bifurcation aneurysms: preclinical results of the eCLIPs device

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Intracranial bifurcation aneurysms are complex lesions for which current therapy, including simple coiling, balloon- or stent-assisted coiling, coil retention, or intrasaccular devices, is inadequate. Thromboembolic complications due to a large burden of intraluminal metal, impedance of access to side branches, and a high recurrence rate, due largely to the unmitigated high-pressure flow into the aneurysm (water hammer effect), are among the limitations imposed by current therapy. The authors describe herein a novel device, eCLIPs, and its use in a preclinical laboratory study that suggests the device's design and functional features may overcome many of these limitations.


A preclinical model of wide-necked bifurcation aneurysms in rabbits was used to assess functional features and efficacy of aneurysm occlusion by the eCLIPs device.


The eCLIPs device, in bridging the aneurysm neck, allows coil retention, disrupts flow away from the aneurysm, leaves the main vessel and side branches unencumbered by intraluminal metal, and serves as a platform for endothelial growth across the neck, excluding the aneurysm from the circulation.


The eCLIPs device permits physiological remodeling of the bifurcation.

ABBREVIATIONS eBRS = eCLIPs Bifurcation Remodelling System.

Article Information

Correspondence Thomas R. Marotta, Diagnostic and Therapeutic Neuroradiology, St. Michael's Hospital, 30 Bond St., Toronto, ON M5B 1W8, Canada. email:

INCLUDE WHEN CITING Published online March 17, 2017; DOI: 10.3171/2016.10.JNS162024.

Drs. Marotta, Riina, and Ricci and Mr. McDougall contributed equally to this work.

Disclosures The preclinical trial was supported entirely by Evasc Medical Systems Corp., Vancouver, BC, Canada. The authors also report the following. Dr. Marotta: financial stakeholder in Evasc Neurovascular, and medical consultant and proctor for eCLIPs, part of Evasc. Dr. Riina: financial stakeholder in Evasc Neurovascular. Mr. McDougall: employee of Evasc Medical Systems Corp. Dr. Ricci: financial stakeholder in Evasc Neurovascular.

© AANS, except where prohibited by US copyright law.



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    eCLIPs device: 3D view (A), side view (B), plan view (C).

  • View in gallery

    A: Illustrated eCLIPs deployment sequence. B and C: Radiographic images of a clinical implant. Frontal view of implanted eCLIPs, with overlapped markers, showing appropriate orientation of the leaf segment across the neck, delimited by the middle and rightmost set of markers (arrows, B). Lateral view showing 3 pairs of markers immediately beneath the neck (C).

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    A: Serial angiograms obtained preimplantation to 30 days postimplantation, showing a bifurcation aneurysm in a rabbit treated with eCLIPs. B–D: Histological images showing a cross-section of the parent lumen in the area of the aneurysm sac (B) 30 days after eCLIPs implantation and loose coiling. The lumen is widely patent, and the eCLIPs device ribs are completely incorporated with organized smooth muscle neointimal growth over the aneurysm neck. Black circles within the aneurysm represent coils. Close-up view of the parent vessel wall with neointimal overgrowth incorporating a device rib (arrow, C). Close-up view of the aneurysm sac (D), showing embolic coils incorporated by the fibrous matrix of the aneurysm sac. Toluidine blue/basic fuchsin stain. Courtesy Renu Virmani, CVPath Institute, Inc., Gaithersburg, MD.

  • View in gallery

    A: Serial angiograms obtained preimplantation to 90 days postimplantation, showing a bifurcation aneurysm in a rabbit treated with eCLIPs. B and C: Gross pathology (B) and scanning electron microscopy (C, original magnification ×15) of eCLIPs and aneurysm explanted from the animal at 90 days. Courtesy Renu Virmani, CVPath Institute, Inc., Gaithersburg, MD.

  • View in gallery

    A: Serial angiograms, from preimplantation to 30 days postimplantation, of a bifurcation aneurysm in rabbit treated with eCLIPs. B: Scanning electron microscopy of the eCLIPs device and aneurysm explanted from the animal model at 30 days (original magnification ×15) shows endothelialization of the device and exclusion of the aneurysm (left arrow). The ribs are covered by endothelium, but they are not yet fully incorporated in the wall (right arrow). Courtesy Renu Virmani, CVPath Institute, Inc., Gaithersburg, MD.



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