Intracranial broad-based aneurysms located at bifurcations remain a challenge for endovascular treatment. The WEB device (Sequent Medical, Aliso Viejo, California) was initially designed to address this kind of aneurysm. It allows placing within the sac of the aneurysm an intrasaccular device that will divert the flow towards the parent vessel.

From the very beginning, we have decided to carefully and prospectively assess the safety of the WEB device and its efficacy. For that purpose, we set up a registry named “the French Observatory”, which is a prospective observational study of consecutive cases with independent monitoring across 10 centers in France. Patients were enrolled from November 2012 to January 2014.

During the time-window of the registry, the WEB device has evolved from a dual-layer version (WEB-DL; CE-marked 2010) to a single-layer version (WEB-SL; CE-marked 2013). The latter was designed to offer smaller-sized devices with a lower profile in order to optimize navigability and delivery, which may in turn broaden its range of use.

Thus, we were naturally pushed to assess the potential advantage of the new WEB-SL compared with the WEB-DL in terms of safety and efficacy, and this is the topic that was addressed in this paper.

In our reported series, among 63 patients treated with the WEB, 31 were treated with WEB-DL and 32 with WEB-SL. We found that morbidity was similar in both groups (WEB-DL, 3.3%; WEB-SL, 3.1%), and mortality was 0.0% in both groups. However, the percentage of anterior communicating artery aneurysms treated with WEB-SL was significantly higher (37.5%) compared with WEB-DL (12.9%) (P = .04). The WEB-SL was more frequently used in aneurysms smaller than 10 mm compared with the WEB-DL (respectively, 96.9% and 67.7%; P = .002).

The present analysis shows a change in the way the WEB device is used. The lower device profile offered by the WEB-SL is the most important factor making it more suitable for small aneurysms and/or aneurysms with difficult access.

Indeed, entering a A1 segment of the anterior cerebral artery with a 0.027  to 0.033-inch microcatheter is not always simple, and the anatomy of the anterior communicating artery complex is transiently modified when the microcatheter is in the A1 segment and when the device is pushed into the microcatheter, making correct positioning of the device sometimes more difficult. The improvement of the WEB-SL device profile consequently makes the procedure easier and increases the feasibility of treating more wide-neck anterior communication artery aneurysms.

To conclude, our findings have changed the choice of the WEB device to be used to treat intracranial aneurysms. Nowadays in our daily practice, when we have an aneurysm with indication to be treated with the WEB device, we do use the SL version as the first and preferred option. This choice is applied to any kind and to any location of aneurysm, but especially when the aneurysm is small and/or difficult to access with the delivery microcatheter and/or ruptured.

 

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