Woven EndoBridge (WEB)

The Woven EndoBridge (WEB) (Sequent Medical, Aliso Viejo, California), is an ellipsoid braided-wire embolization device designed to provide flow disruption along the aneurysm neck 1).

Placed in the aneurysm, the device will modify the blood flow at the level of the neck and induce aneurysmal thrombosis. The WEB shape was designed to treat wide necked aneurysm. The device has been developed progressively from a dual-layer version (WEB DL) to single-layer versions (WEB SL and WEB SLS [single-layer spherical]).

This device does not require long-term antiplatelet use.

The WEB device is made of a fine mesh composed of nitinol, a biocompatible metal alloy. It is designed to be delivered through a catheter and deployed within the aneurysm sac.

The Woven EndoBridge device is a treatment option for bifurcation wide-neck intracranial aneurysm. While this device has had good results, there remains a subset that fail this treatment.

For the treatment of both ruptured and unruptured aneurysms. The WEB has received the CE mark and to date has been used to treat a wide variety of more than 1,400 aneurysms in Europe, Latin America and New Zealand. The WEB is not available for sale or use in the United States.

The WEB is a self-expanding, oblate, braided nitinol mesh.

The device is composed of an inner and outer braid held together by proximal, middle, and distal radiopaque markers, creating 2 compartments: 1 distal and 1 proximal. Depending on the device diame- ter, the inner and outer braids are 108 wires or 144 wires. Therefore, blood flow into a WEB-embolized aneurysm initially encounters 2 layers of wires comprising 216 or 288 wires, with the largest interwire distance ranging from 106 to 181 􏰅m, respectively, depending on the device size. The WEB implant is deployed—or retrieved before de- tachment—in a manner similar to that in endovascular coil systems, through microcatheters with an internal diameter 􏰆0.027 inch. For devices with a diameter of 􏰇7 mm, microcatheters with an internal diameter of 0.027 inch are used; and for devices with a diameter 􏰁7 mm, microcatheters with an internal diameter 0.032 inch are used. The detachment system is electrothermal and instantaneous. 2).

In a study, there was no difference in the early clinical course between those treated with WEB embolization, coil embolization, or neurosurgical clipping. Since WEB embolization is a valuable treatment alternative to coiling, it seems not justified to exclude this procedure from upcoming clinical SAH trials, yet the clinical long-term outcome, aneurysm occlusion, and retreatment rates have to be analyzed in further studies 3).

WEB Intrasaccular Therapy Study (WEB-IT)

The WEB Clinical Assessment of Intrasaccular Aneurysm Therapy (WEBCAST) trial is a prospective European trial evaluating the safety and efficacy of WEB in wide necked aneurysm of the bifurcation.

The WEB Occlusion Scale (WOS) 4), a Raymond-inspired scale, is up to now the most frequently used for WEB angiographic evaluation, but it may not be optimal for this device. Indeed, the new concept of intrasaccular flow-disruption introduces new analytical issues, such as proximal recess appearance, residual filling of the WEB, and device compression 5).

see Bicêtre Occlusion Scale Score

Larger aneurysms are at risk for incomplete occlusion status post WEB treatment. Larger, ruptured aneurysms with minimal difference in aneurysm and WEB diameter that fail to occlude immediately post-treatment are more likely to present as residual aneurysms at short-term follow-up 6).

It does not immediately secure the aneurysm in most subarachnoid hemorrhage cases. Second, it may not be suitable for embolization of wide-neck aneurysms with an unfavorable aspect ratio. To overcome these limitations, Zanaty et al., used the WEB device in conjunction with stenting and/or coiling.

They presented a technical note with an illustrated case-series, and provide a detailed step-by-step description on how the WEB device can be used in adjunct to coiling and/or stenting to achieve successful angiographic results. Accurate sizing of the WEB device before deployment is critical. Larger case-series are required to further assess the safety and success of these combined techniques 7).

Zhang et al. searched the PubMed, Ovid MEDLINE, and EMBASE databases between December 1, 2012 and June 30, 2018.

Studies that included five or more patients undergoing WEB for Wide necked intracranial aneurysms, reported an angiographic or clinical outcome and risk factors, and were published after December 1, 2012 were eligible.

Major outcomes included initial or short-term complete and adequate occlusion. Secondary outcomes included treatment failure, recanalization, mortality, morbidity, and complication (e.g., thromboembolism or intraoperative rupture) rates. A random-effect model was used to pool the data. To assess risk factors for short-term angiographic outcomes and the most common complications, they conducted subgroup analyses and obtained odds ratios with 95% confidence intervals.

They included 36 studies (1759 patients with 1749 aneurysms). The initial complete and adequate occlusion rates were 35% and 77%, respectively. After a mean follow-up of 9.34 months, the short-term complete and adequate occlusion rates were 53% and 80%, respectively. Thromboembolism and recanalization were the most common complications (both 9%), followed by mortality (7%), morbidity (6%), failure (5%) and intraoperative rupture (3%). The following factors were related to higher short-term obliteration rates: unruptured status, in the anterior circulation, a medium neck (4-9.9 mm), newer-generation WEB and treatment without additional devices. Ruptured status, anterior circulation, preoperative antiplatelet therapy and newer-generation WEB were not significantly related to withto thromboembolism.

WEB has a satisfactory safety profile and shows promising efficacy in treating wide-neck intracranial aneurysms. They preliminarily identified several risk factors for short-term angiographic outcomes 8).

A 68-year-old male patient with known hypertension, coronary artery disease, and Benign Prostatic Hyperplasia was admitted after a ruptured aneurysm of 4.5 mm in the right middle cerebral artery M1 segment and subarachnoid hemorrhage were detected in the emergency room imaging after syncope at home. WEB device was placed into the aneurysm in the patient who was planned for endovascular treatment. After 3 days of the procedure, neurologic examination showed regression. In the brain computed tomography imaging, it was observed that there was an intraparenchymal hematoma of 4,5 cm in the right temporoparietal region, and the aneurysm, which had been treated with endovascular WEB, was ruptured. The aneurysm was clipped in the patient for whom emergency surgical treatment was planned.

As a conclusion, re-bleeding can be seen after aneurysm treatment with the Web device. If it is planned to re-close the aneurysm treated with the web device with a surgical clip, the pressure created by the device against the vessel can be reduced with the additional clip 9).

A case of a shallow basilar tip aneurysm treated with the WEB device that required stabilization with Y-stent through radial access 10).

What is the primary purpose of the Woven EndoBridge (WEB) device? a) To enhance blood flow in aneurysms b) To treat ruptured intracranial aneurysms c) To induce aneurysmal thrombosis by disrupting blood flow at the neck d) To replace the use of antiplatelet medications

What material is the WEB device primarily composed of? a) Stainless steel b) Biocompatible metal alloy c) Nitinol d) Braided wires

In which regions has the WEB device been used to treat aneurysms? a) United States b) Europe, Latin America, and New Zealand c) Asia and Australia d) Africa and the Middle East

How does the WEB device create flow disruption in an aneurysm? a) By constricting the aneurysm sac b) By inducing blood clot formation c) By expanding its inner braid d) By pushing against the aneurysm walls

What is the primary limitation associated with the WEB device in the treatment of larger aneurysms? a) It requires long-term antiplatelet use b) It may not secure the aneurysm immediately in most subarachnoid hemorrhage cases c) It cannot be deployed through microcatheters d) It cannot treat wide-neck aneurysms

What is the role of the WEB Occlusion Scale (WOS)? a) To assess patient outcomes after WEB treatment b) To evaluate the device's composition c) To measure the size of the aneurysm sac d) To provide a scale for angiographic evaluation of WEB-treated aneurysms

Which trial assessed the safety and efficacy of the WEB device in treating wide-necked aneurysms? a) WEB Occlusion Scale (WOS) trial b) WEB Intrasaccular Therapy Study (WEB-IT) c) Woven EndoBridge Shape Modification trial d) WEB Clinical Assessment of Intrasaccular Aneurysm Therapy (WEBCAST) trial

What is the most common complication associated with the use of the WEB device, as mentioned in the systematic review and meta-analysis? a) Device rupture b) Hemorrhage c) Thromboembolism d) Aneurysm expansion

In what situation might re-bleeding occur after aneurysm treatment with the WEB device? a) If the patient has a known history of hypertension b) If the aneurysm is in the anterior circulation c) If the aneurysm is clipped during the procedure d) If the device does not create sufficient pressure against the vessel

What additional intervention was required in the case of a shallow basilar tip aneurysm treated with the WEB device in 2022? a) Surgical clipping b) Coiling c) Stent placement d) Medication adjustment


c) To induce aneurysmal thrombosis by disrupting blood flow at the neck c) Nitinol b) Europe, Latin America, and New Zealand c) By expanding its inner braid b) It may not secure the aneurysm immediately in most subarachnoid hemorrhage cases d) To provide a scale for angiographic evaluation of WEB-treated aneurysms b) WEB Intrasaccular Therapy Study (WEB-IT) c) Thromboembolism d) If the device does not create sufficient pressure against the vessel c) Stent placement

Ding YH, Lewis DA, Kadirvel R, Dai D, Kallmes DF. The Woven EndoBridge: a new aneurysm occlusion device. AJNR Am J Neuroradiol. 2011 Mar;32(3):607-11. doi: 10.3174/ajnr.A2399. Epub 2011 Feb 17. PubMed PMID: 21330397.
Pierot L, Liebig T, Sychra V, Kadziolka K, Dorn F, Strasilla C, Kabbasch C, Klisch J. Intrasaccular flow-disruption treatment of intracranial aneurysms: preliminary results of a multicenter clinical study. AJNR Am J Neuroradiol. 2012 Aug;33(7):1232-8. doi: 10.3174/ajnr.A3191. Epub 2012 Jun 7. PubMed PMID: 22678844.
Sauvigny T, Nawka MT, Schweingruber N, Mader MM, Regelsberger J, Schmidt NO, Westphal M, Czorlich P. Early clinical course after aneurysmal subarachnoid hemorrhage: comparison of patients treated with Woven EndoBridge, microsurgical clipping, or endovascular coiling. Acta Neurochir (Wien). 2019 Jul 6. doi: 10.1007/s00701-019-03992-4. [Epub ahead of print] PubMed PMID: 31280480.
Fiorella D, Arthur A, Byrne J, Pierot L, Molyneux A, Duckwiler G, Mccarthy T, Strother C (2014) Interobserver variability in the assessment of aneurysm occlusion with the WEB aneurysm embolization system. J Neurointerv Surg:1-6. doi:10.1136/neurintsurg2014-011251
Cognard C, Januel AC (2015) Remnants and recurrences after the use of the WEB intrasaccular device in large-neck bifurcation aneurysms. Neurosurgery 76(5):522–530. doi:10.1227 /NEU.0000000000000669
Fortunel A, Javed K, Holland R, Ahmad S, Haranhalli N, Altschul D. Impact of aneurysm diameter, angulation, and device sizing on complete occlusion rates using the woven endobridge (WEB) device: Single center United States experience. Interv Neuroradiol. 2022 Mar 7:15910199221084804. doi: 10.1177/15910199221084804. Epub ahead of print. PMID: 35253525.
Zanaty M, Roa JA, Dandapat S, Samaniego EA, Jabbour P, Hasan D. Diverse Use of the WEB Device: A Technical Note on WEB Stenting and WEB Coiling of Complex Aneurysms. World Neurosurg. 2019 Jul 10. pii: S1878-8750(19)31933-3. doi: 10.1016/j.wneu.2019.07.027. [Epub ahead of print] PubMed PMID: 31301439.
Zhang SM, Liu LX, Ren PW, Xie XD, Miao J. Effectiveness, safety and risk factors of Woven EndoBridge device in the treatment of wide-neck intracranial aneurysms : systematic review and meta-analysis. World Neurosurg. 2019 Aug 13. pii: S1878-8750(19)32175-8. doi: 10.1016/j.wneu.2019.08.023. [Epub ahead of print] PubMed PMID: 31419591.
Sahin MC, Oncu F, Karaaslan B. Clipping of a Rebleeding Ruptured Aneurysm After Woven EndoBridge Treatment. Turk Neurosurg. 2023;33(5):916-918. doi: 10.5137/1019-5149.JTN.41381-22.2. PMID: 37715605.
Nordmann NJ, Weber MW, Dayoub H. Woven Endobridge (WEB) augmented by Y-stent in a shallow basilar tip aneurysm. J Cerebrovasc Endovasc Neurosurg. 2022 Feb 17. doi: 10.7461/jcen.2022.E2021.08.006. Epub ahead of print. PMID: 35172073.
  • woven_endobridge.txt
  • Last modified: 2023/09/16 20:45
  • by administrador