Page 12 - AN-2-3

Advanced Neurology Woven Endobridge embolization: Indications and innovation

Figure 2. Current classification for intracranial or cerebral aneurysm reoccurrence. Class III is divided to indicate progression to occlusion. Class IIIb
complete occlusion is less likely versus Class IIIa (85.11% vs. 16.67%, p < 0.001) [31,43] . This image was generated using Biorender.

the WEB II device was documented in a case study of a Over the past decade, a paradigm shift has occurred in
patient who presented with regrowth of an unruptured the treatment of wide-neck aneurysms. A new treatment
MCA aneurysm 9 months after implantation . During model emerged in 2011 when the FDA approved the first
[40]
the patient’s 6-month follow-up, the magnetic resonance flow-diverting device [12,14] . Conventionally, endovascular
imaging (MRI) showed continued progression of aneurysm treatment involves direct intrasaccular embolization,
neck filling, pushing the device distally. Balloon-assisted followed by immediate protection . On the contrary, flow-
[39]
coiling was used to treat the regrown aneurysm according to diverting devices delay aneurysm occlusion, an approach
standard neurointerventional approaches [41,42] . AltThough different from the traditional treatment model. The device
not desired, device failure can reveal deficiencies that lead diverts blood flow away from the aneurysm, allowing for
to improvement of subsequent device models. thrombosis to occur. Over time, endothelization of the

Pre-clinical studies continue to inform the modification device takes place in the aneurysm’s parent vessel wall [39,52] .
and development of these devices. Several changes have Several flow-diverting devices are under clinical trials,
been made to the device since its introduction in 2011 . and the FDA has approved various devices for treating
[12]
The current devices, the WEB SLS and WEB SL model, wide-neck aneurysms (Table 3) [11,53-57] . The WEB aneurysm
are spheroid and cylindrical shaped devices composed embolization system (MicroVention Terumo, Aliso Viejo,
of single layers of braided nitinol . Another change CA, USA) is a flow-diverting device that differs from
[24]
was incorporation of platinum into nitinol strands to traditional flow diverters [2,38,58] . Rather than occupying
enhance visualization in the WEB SLS EV and WEB SL the parent vessel’s lumen, the WEB device is intrasaccular
models . In the U.S., 27 cylindrical and eight spheroid and composed of nitinol-based braided wire . The
[43]
[38]
devices are available, differing in diameters and heights . device is not limited by the use of dual antiplatelet therapy
[43]
These improvements have expanded European treatment and can be used to treat both ruptured and unruptured
indications to treat distal and sidewall aneurysms and aneurysms [38,59] .
wide-neck bifurcation aneurysms [44,45] .
6. Discussion
5. Discuss novel innovations for wide-neck The WEB device is unique in its innovation and indications,
aneurysms yet further research and development is warranted in
Decades of research and development have been invested several areas. At present, the proposed grading scale, the
to make endovascular treatments the standard of care for RROC, with its modifications by Mascitelli et al., should
intrasaccular aneurysms. However, treating wide-neck be additionally classified based on the treatment used . It
[31]
aneurysms can be technically challenging as they have a would be advantageous to assess the rate of complications
higher risk of recanalization [46,47] . It has been demonstrated with WEB devices versus stents or clipping. Pre-clinical
that coil embolization can successfully treat aneurysm but studies are crucial to advancing the WEB device to its fullest
is limited by several factors, including neck size and the potential. Accurate WEB device size selection is imperative
dome-to-neck ratio [48-51] . In addition, the instability of coils to a safe and effective procedure; automated volumetric
can lead to herniation of the parent artery, and herniated software and digital subtraction angiography (DSA) are
coils may migrate or lead to thromboembolism and actively being studied to improve this aspect of the device .
[60]
incomplete occlusion . The need for guidelines for successful implantation could
[12]
Volume 2 Issue 3 (2023) 6 https://doi.org/10.36922/an.293