The Woven EndoBridge: a new aneurysm occlusion device

Abstract

Background and purpose: The WEB device is an intrasaccular ellipsoid braided-wire embolization device designed to provide flow disruption along the aneurysm neck. The purpose of this study was to evaluate, in an in vivo aneurysm model, the acute and chronic performance of the WEB device regarding immediacy, degree, and durability of aneurysm occlusion.

Materials and methods: The WEB device was implanted in 24 elastase-induced aneurysms in New Zealand white rabbits and followed for 1, 3, 6, and 12 months (n = 6 at all time points). Degree of intra-aneurysmal flow disruption was graded on a 4-point scale based on DSA within 10 minutes following device implantation. Chronic aneurysm occlusion was rated by using a 3-point scale. All aneurysms were harvested for histologic analysis.

Results: Immediate postimplant grade 1 (complete flow cessation) was noted in 7 (29%) of 24 cases. Grade 2 (near-complete flow cessation) was noted in 13 (54%) of 24 cases. At follow-up, complete occlusion was noted in 8 (33%) of 24 cases. Near-complete aneurysm occlusion was noted in 14 (58%) of 24 cases, while incomplete occlusion was noted in 2 (8%) cases. Stable aneurysm occlusion was present in 7 (29%) of 24 cases; progressive occlusion, in 14 (58%); and recanalization, in 3 (13%) cases. Histologic findings included aneurysm cavities filled with organized thrombus with connective tissue across the aneurysm neck.

Conclusions: The WEB device in experimental aneurysms demonstrated promising rates of immediate and long-term aneurysm occlusion.

Fig 1.

Photograph of the WEB device. The proximal and distal ends of the device have radiopaque markers attached.

Fig 2.

A, Anteroposterior DSA before treatment. B, DSA after device deployment shows complete immediate cessation of flow. Note radiopaque distal (block arrow) and proximal markers (black arrow) denoting the ends of the device. C, DSA at 3 months shows complete aneurysm occlusion. D, Photomicrograph (HE, original magnification ×100) shows organized connective tissue within the aneurysm lumen and attenuated connective tissue across the aneurysm neck (block arrow).

Fig 3.

A, Anteroposterior DSA before treatment. B, DSA after device deployment shows near-complete cessation of flow. C, DSA at 6 months shows aneurysm recanalization. D, Photomicrograph (HE, original magnification ×100) shows concave connective tissue across the aneurysm neck (block arrow).