Treatment of Ruptured and Unruptured Intracranial Aneurysms with WEB 17 Versus WEB 21 Systems : Comparison of Indications and Early Angiographic Outcomes

Propensity Score-matched Comparison of WEB 17 and WEB 21 with 4-7 mm Device Sizes for the Treatment of Unruptured Intracranial Aneurysms

PURPOSE

The WEB 17 system represents the fifth generation of Woven Endobridge (WEB) flow disruptors and features a low profile with fewer wires than its predecessor, the WEB 21. The present study compares the safety and efficacy of the WEB 17 and WEB 21 for the treatment of unruptured cerebral aneurysms with 4-7 mm device sizes, which were available for both systems.

METHODS

Patient and aneurysm characteristics, complications, clinical outcome and angiographic results were retrospectively analysed. 1:1 propensity score matching was performed to adjust for minor baseline differences between the groups.

RESULTS

Sixty aneurysms treated with WEB 21 and 90 with WEB 17 were included. The overall failure rate (deployment failure and adjunctive stent) was significantly higher with WEB 21 (16.7%) than with WEB 17 (3.3%, p < 0.01). The rates of neurological events between WEB 21 (6.7%) and WEB 17 treatment (1.1%) were not significantly different (p = 0.08). Also, procedural morbidity was comparably low in both groups (WEB 21: 3.3%, WEB 17: 0%, p = 0.16). The rates of complete/adequate occlusion at follow up were 69.7%/86.4% for WEB 17 vs. 80.4%/91.3% for WEB 21 at short-term (p = 0.27), and 64.5%/83.9% vs. 75.9%/86.2% at mid-term (p = 0.41), respectively. Propensity score matching confirmed the results of the unmatched series.

CONCLUSION

WEB 17 and WEB 21 had a similar safety and efficacy profile, but WEB 17 was associated with an improved feasibility. Prospective studies with long-term follow-up will define the full potential of the WEB 17 system.

WEB embolization of very broad-based intracranial aneurysms with a dome-to-neck ratio ≤ 1.1

OBJECTIVE

The Woven EndoBridge (WEB) is a well-studied intrasaccular device for endovascular treatment of wide-necked bifurcation aneurysms. We evaluated the feasibility, safety and efficacy of the WEB for the treatment of very broad-based aneurysms with a dome-to-neck ratio ≤ 1.1.

METHODS

Thirty-four aneurysms treated at three neurovascular centers were retrospectively identified. The mean aneurysm size was 5.5 ± 1.6 mm with a mean neck width of 4.7 ± 1.5 and a mean dome-to-neck ratio of 1.0 ± 0.1. The primary outcome measures were immediate technical treatment success by WEB only, complete or near-complete occlusion at 6-month follow-up and ischemic stroke.

RESULTS

Aneurysm embolization by WEB only was technically feasible in 79.4%. Additional stenting was required in 14.7%. In two aneurysms (5.9%), WEB implantation failed, and the aneurysm was treated by stent- and balloon-assisted coiling, respectively. Thromboembolic events occurred during 5 interventions (14.7%), all of these performed in ruptured aneurysms. One patient (2.9%) remained asymptomatic (follow-up modified Rankin scale [mRS] score: 0), 2 patients (5.9%) had a transient deficit (mRS 0 and 1, respectively), and 2 (5.9%) had a disabling ischemic stroke (mRS 3, respectively). Mid-term angiographic follow-up of 29 patients (4.0 ± 2.6 months, range: 2-9 months) showed complete occlusion (WEB occlusion scale [WOS] A) in 41.4%, near-complete occlusion (WOS B) in 34.5%, a neck remnant (WOS C) in 10.3%, and aneurysm remnants (WOS D) in 13.8%.

CONCLUSIONS

WEB embolization of very broad-necked aneurysms was technically feasible and could be achieved by WEB only in the majority of cases. Considering the challenging anatomy of very broad-based aneurysms, the WEB procedure was reasonably safe and efficient.

Safety and efficacy of the Woven Endo-Bridge-17 device for intracranial aneurysm treatment: A systematic review and meta-analysis

BACKGROUND

The Woven Endo-Bridge (WEB) device revolutionized the treatment of wide-necked bifurcation aneurysms by intrasaccular flow diversion. The latest advancement is the WEB-17 system, offering greater flexibility with fewer wires, enabling treatment of smaller distal aneurysms using smaller microcatheters than the WEB-21 system.

METHODS

We conducted a systematic review following preferred reporting items for systematic reviews and meta-analyses guidelines, analyzing data from seven retrospective cohort studies involving 483 aneurysms treated with the WEB-17 device. Statistical analysis computed pooled prevalence rates and 95% confidence intervals using appropriate models for each outcome and R software version 4.3.1 (R Foundation for Statistical Computing, Vienna, Austria).

RESULTS

Technical success was achieved in 475 out of 483 aneurysms treated with the WEB-17 device, with a success rate of 98.34% (95% confidence interval (CI) = 96.72-99.17). Among the successful cases, 4.97% (95% CI = 1.60-14.39) required adjunctive devices. Adequate occlusion, defined as complete occlusion or neck remnants, was observed in 94.41% (95% CI = 88.17-97.46) of cases. Periprocedural complications were infrequent, with thromboembolic complications occurring in 4.93% (95% CI = 3.29-7.30) of cases, hemorrhagic complications in 1.28% (95% CI = 0.58-2.83), and postprocedural neurologic complications in 0.99% (95% CI = 0.31-3.14). Procedure-related morbidity was observed in 1.71% (95% CI = 0.86-3.39) of cases, and there was one procedure-related mortality reported at 0.21% (95% CI = .03-1.50). Mortality unrelated to the procedure occurred in 1% (95% CI = 0.23-4.15).

CONCLUSION

Our findings suggest that the WEB-17 device is associated with a high rate of technical success, favorable angiographic outcomes, and a low rate of periprocedural complications. Further research, including prospective trials, is needed to confirm these findings and establish its safety and efficacy definitively.

CLinical EValuation of WEB 17 device in intracranial aneuRysms (CLEVER): procedural, 30-day and 1-year safety results for ruptured and unruptured aneurysms

BACKGROUND

Intrasaccular flow disruption is an endovascular approach for the treatment of wide-neck aneurysms and, more specifically, wide-neck bifurcation aneurysms, which are challenging to treat with previously developed technologies. The Woven EndoBridge (WEB) device has demonstrated its efficacy and safety, for both unruptured and ruptured aneurysms.

METHODS

The CLEVER study was an observational, multicenter, prospective study conducted in 17 European investigational sites using the WEB 17 device, for the treatment of ruptured and unruptured aneurysms. The study objective was to provide safety and efficacy data on the WEB 17 device in the treatment of wide-neck bifurcation aneurysms. Imaging results were assessed independently by a Corelab and adverse events adjudicated by a Clinical Event Adjudicator. This analysis reports procedural results and safety at 30 days and 12 months.

RESULTS

A total of 163 patients (mean age 58.1 years; 68.1% women) with 103 unruptured aneurysms and 60 ruptured aneurysms were enrolled. Most aneurysms were located on the anterior communicating artery (ACom) (37.4%) or the middle cerebral artery (MCA) bifurcation (30.1%). Aneurysm widths ranged from 2.0-9.2 mm, and the mean sac width was 5.0 mm. The WEB procedure was successfully completed in 163 patients (100%). At the 12-month follow-up, major stroke events occurred in 3 of 163 patients (1.8%), and no device-related mortality was observed.

CONCLUSION

Endovascular treatment of ruptured and unruptured wide-neck bifurcation aneurysms using WEB 17 is safe, with a low complication rate and no device-related mortality. In particular, none of the ruptured aneurysms bled again up to 1 year of follow-up.

TRIAL REGISTRATION NUMBER

NCT03844334.

Aneurysm Treatment with Woven EndoBridge-17: Angiographic and Clinical Results at 12 Months from a Retrospective, 2-Center Series

BACKGROUND AND PURPOSE

This retrospective, 2-center study investigated the feasibility, safety, and efficacy at 12-month follow-up of the treatment of ruptured, unruptured, and recurrent intracranial aneurysms using the latest generation of the Woven EndoBridge (WEB) device, the WEB-17 system.

MATERIALS AND METHODS

Aneurysms treated with WEB-17 were extracted from the databases of 2 neurovascular centers. Patients, aneurysm characteristics, complications, and clinical and anatomic results were analyzed.

RESULTS

From February 2017 to May 2021, two hundred twelve patients with 233 aneurysms (181/233, 77.7%, unruptured-recurrent, and 52/233, 22.3%, ruptured) were included. High treatment feasibility (95.3%) was reported and was similar in ruptured aneurysms (94.2%) and unruptured-recurrent aneurysms (95.6%) (P = .71) and in typical (95.4%) and atypical (94.7%) locations (P = .70), but it was lower in aneurysms with an angle between the parent artery and main aneurysm axis of ≥45° (90.2%) compared with those with an angle of <45° (97.1%) (P = .03). Global mortality and morbidity were 1.9% and 3.8% at 1 month, respectively, and 4.4% and 1.9% at 12 months, respectively. One-month morbidity (P = .02) and mortality (P = .003) were higher in the ruptured group (10.0% and 8.0%, respectively) compared with unruptured-recurrent group (1.9% and 0.0%, respectively). Overall adequate occlusion (complete occlusion and neck remnant) was 86.3%. The percentage of adequate occlusion was higher (P = .05) in the unruptured-recurrent group (88.5%) compared with the ruptured group (77.5%).

CONCLUSIONS

The WEB-17 system showed high feasibility for ruptured and unruptured aneurysms, typical and atypical locations, and some aneurysms with an angle of ≥45°. As the most recent generation device, the WEB-17 also demonstrates high safety and good efficacy.

Trends of Expanding Indications of Woven EndoBridge Devices for the Treatment of Intracranial Aneurysms: A Systematic Review and Meta-analysis

PURPOSE

Woven EndoBridge (WEB) was introduced for the endovascular therapy of wide-neck intracranial aneurysms. The safety and efficacy have been evaluated through several meta-analyses. However, these reviews did not cover the expanding indications in detail. Therefore, we aimed to show the changing trends for intracranial aneurysm treatment using the WEB device.

METHODS

A systematic review and meta-analysis was conducted with PubMed, Embase, and Cochrane databases. We searched for studies that reported baseline characteristics of aneurysms and the WEB devices, which had treated more than 20 aneurysms consecutively. The pooled proportions of aneurysm indications and used WEB device types were obtained. To evaluate the changing indications for the treated aneurysm size, including the neck diameter, a trend line and linear regression model was measured.

RESULTS

A total of 27 cohorts were included encompassing 1831 aneurysms treated with the WEB. A total of 86% were used in the four major locations as on-label indications (middle cerebral artery bifurcation; 34%, anterior communicating artery; 26%, basilar tip; 18%, internal carotid artery terminus; 7%). Among off-label indications, the most common location was the posterior communicating artery (8%), followed by the anterior cerebral artery including the pericallosal artery (6%). The median aneurysm size and neck diameter was 7 mm and 4.6 mm, respectively. The WEB device has been used for the treatment of smaller aneurysms than the initial indication. Also, the proportion for ruptured aneurysm treatment was increased up to 15%.

CONCLUSION

The mechanical and technical development of the WEB resulted in expanding the indications for the treatment of intracranial aneurysms. The off-label indications accounted for 14% in total and an increasing number of small aneurysms are treated with WEB devices. Moreover, the proportion for ruptured aneurysm treatment was currently increased up to 14% more than in the beginning.

Long-term clinical and angiographic outcome of the Woven EndoBridge (WEB) for endovascular treatment of intracranial aneurysms

The Woven EndoBridge (WEB) is a well-established device for endovascular treatment of wide-necked bifurcation aneurysms. The objective was to evaluate the long-term angiographic outcome of the WEB and to identify factors that influence aneurysm occlusion. Patient, aneurysm and procedural characteristics of 213 consecutive patients treated with the WEB at three German tertiary care centers between 2011 and 2020 were retrospectively reviewed. Aneurysm occlusion was determined immediately after the procedure, at mid-term (≤ 12 months) and at long-term (> 12 months) follow-up. Among 182 included aneurysms (mean diameter: 7.0 ± 2.4, mean neck width: 4.3 ± 1.6 mm), 29.7% were ruptured. The novel WEB 17 was used in 41.8%, and 11.0% were treated in combination with coiling and/or stenting. Complete and adequate occlusions were observed in 101/155 (65.2%) and 133/155 (85.8%) at mid-term, respectively, and in 59/94 (62.8%) and 87/94 (92.6%) at long-term follow-up (median: 19 months), respectively. Among 92 patients available for both mid- and long-term follow-up, occlusion was stable in 72.8%, improved in 16.3% and worsened in 10.9%. There were no major recurrences leading to aneurysm remnants between mid- and long-term follow-up. Retreatment was performed in 10/155 (6.5%) during mid-term and in 1/94 (1.0%) during long-term follow-up. The WEB provides durable aneurysm occlusion at the long-term. Nevertheless, follow-up imaging is necessary to identify late recurrences that may occur in around 10%.

Delayed rupture of an anterior communicating artery aneurysm after elective Woven EndoBridge embolization, re-treated with microsurgical clipping: operative technique and systematic review

BACKGROUND

The Woven EndoBridge (WEB) device is designed for intrasaccular flow disruption for embolization of intracranial aneurysms. In limited experience so far, the rate of rupture after adequate occlusion by embolization is low.

TECHNICAL REPORT

A 58-year-old man initially had an incidental, unruptured 10.4 mm anterior communicating artery (ACoA) aneurysm treated with WEB embolization. Although his 6-month follow-up angiogram showed adequate occlusion of the aneurysm, he presented to our facility with aneurysmal recurrence due to WEB compaction and rupture. This was treated with surgical clipping of the aneurysm.

METHODS

The literature was systematically reviewed for cases of delayed rupture after WEB embolization. Statistical analyses included studies with at least 20 patients and follow-up of 3 months.

RESULTS

We identified 36 studies, which were primarily retrospective observational studies. The rate of complete occlusion ranged from 33% to 89%, and the rate of re-treatment ranged from 1.5% to 27%. Across four studies, the rate of recanalization ranged from 8.7% to 13%. Two cases of delayed rupture were reported; an additional four cases were found in case reports and case series. In only one previous case, the aneurysm was reported as previously untreated.

CONCLUSION

Early retrospective data has begun to define the history of WEB-treated aneurysms. Rupture of a previously unruptured, WEB-treated aneurysm with adequate initial occlusion is rare. We describe such a case with techniques for management, demonstrating that aneurysm recurrence and delayed rupture is possible despite good interim angiographic result. This report raises questions about follow-up for WEB-treated aneurysms.

Indirect Flow Diversion for Off-Centered Bifurcation Aneurysms and Distant Small-Vessel Aneurysms, a Retrospective Proof of Concept Study From Five Neurovascular Centers

Background: Treatment of cerebral aneurysms using hemodynamic implants such as endosaccular flow disruptors and endoluminal flow diverters has gained significant momentum during recent years. The intended target zone of those devices is the immediate interface between aneurysm and parent vessel. The therapeutic success is based on the reduction of aneurysmal perfusion and the subsequent formation of a neointima along the surface of the implant. However, a subset of aneurysms-off-centered bifurcation aneurysms involving the origin of efferent branches and aneurysms arising from peripheral segments of small cerebral vessels-oftentimes cannot be treated via coiling or implanting a hemodynamic implant at the neck level for technical reasons. In those cases, indirect flow diversion-a flow diverter deployed in the main artery proximal to the parent vessel of the aneurysm-can be a viable treatment strategy, but clinical evidence is lacking in this regard. Materials and Methods: Five neurovascular centers contributed to this retrospective analysis of patients who were treated with indirect flow diversion. Clinical data, aneurysm characteristics, anti-platelet medication, and follow-up results, including procedural and post-procedural complications, were recorded. Results: Seventeen patients (mean age: 60.5 years, range: 35-77 years) with 17 target aneurysms (vertebrobasilar: n = 9) were treated with indirect flow diversion. The average distance between the flow-diverting stent and the aneurysm was 1.65 mm (range: 0.4-2.4 mm). In 15/17 patients (88.2%), perfusion of the aneurysm was reduced immediately after implantation. Follow-ups were available for 12 cases. Delayed opacification (OKM A3: 11.8%), reduction in size (OKM B1-3: 29.4%) and occlusion (D1: 47.1%) were observable at the latest investigation. Clinically relevant procedural complications and adverse events in the early phase and in the late subacute phase were not observed in any case. Conclusion: Our preliminary data suggest that indirect flow diversion is a safe, feasible, and effective approach to off-centered bifurcation aneurysms and distant small-vessel aneurysms. However, validation with larger studies, including long-term outcomes and optimized imaging, is warranted.

Intracranial aneurysm treatment with intrasaccular flow disruption: comparison of WEB-21 and WEB-17 systems

BACKGROUND

New generations of Woven EndoBridge (WEB) devices (WEB-21 and WEB-17) are available to treat aneurysms with a width <6.5 mm. Limited comparisons between both systems exist in the literature, but mid-term efficacy has not been compared. Our study aimed to compare the indications, feasibility, and safety of both systems and to evaluate their efficacy at mid-term follow-up (12 months).

METHODS

Aneurysms treated with WEB-21 and WEB-17 were extracted from a prospective database. Patient and aneurysm characteristics, complications, and anatomical results were analyzed by an interventional neuroradiologist, independent of the procedures.

RESULTS

From June 2015 to November 2019, 87 patients with 92 aneurysms were treated with WEB-21 (38/92, 41.3%) and WEB-17 (54/92, 58.7%). WEB-21 and WEB-17 had high treatment feasibility (97.4% and 94.4%, respectively). A higher percentage of ruptured aneurysms were treated with WEB-17 (9.3%) than with WEB-21 (2.6%; p=0.03). Morbidity and mortality at 1 month were similar in both groups (no morbidity in either group, and mortality 2.7% in the WEB-21 group and 2.0% in the WEB-17 group). The rate of complete and adequate aneurysm occlusion was not significantly higher with the WEB-17 system (59.2% and 95.9%, respectively) compared with the WEB-21 (52.9% and 85.3%, respectively).

CONCLUSIONS

This study showed the high feasibility of aneurysm treatment with both the WEB-21 and WEB-17 systems. Indications were relatively similar with both devices except for ruptured aneurysms, which were more frequently treated with the WEB-17 device. Efficacy at 12 months (complete and adequate occlusions) was slightly, but not significantly, better with the WEB-17 device.

Widening the Indications for Intrasaccular Flow Disruption: WEB 17 in the Treatment of Aneurysm Locations Different from Those in the Good Clinical Practice Trials

BACKGROUND AND PURPOSE

The safety and efficacy of the Woven EndoBridge (WEB) device has been shown in multiple good clinical practice trials, whereas aneurysm locations in these trials were restricted to bifurcation aneurysms located at the circle of Willis (MCA bifurcation, ICA bifurcation, anterior communicating artery, basilar artery tip). Our aim was to evaluate angiographic and clinical results with the WEB 17 in aneurysm locations that were excluded from the good clinical practice trials, assuming that the angiographic and clinical results are similar to those of the good clinical practice trials for aneurysms in traditional locations.

MATERIALS AND METHODS

We performed retrospective analysis of immediate and follow-up results of aneurysms in locations outside the good clinical practice trials in which the WEB 17 was used on an intention-to-treat approach.

RESULTS

Between June 2017 and May 2020, forty-seven aneurysms in 44 patients met the inclusion criteria. Aneurysm locations were the ICA posterior communicating artery in 19 (40.3%), the ICA paraophthalmic or choroidal locations in 4 (8.6%), anterior cerebral artery A2 segment in 13 (27.7%), MCA M1 segment in 2 (4.3%), posterior cerebral artery P2 segment in 2 (4.3%), PICA in 3 (6.4%), and the superior cerebellar artery in 4 (8.4%) cases. The procedure-related morbidity and mortality rates in the entire series were 0.0%. The early and late (<12 and >12 months) complete occlusion rates were 63.9% (23/36) and 77.8% (14/18), respectively.

CONCLUSIONS

The WEB 17 is safe and effective in aneurysm locations different from the traditional bifurcation aneurysms included in the good clinical practice trials. Further studies will help to define the entire spectrum of aneurysm morphologies and locations suitable for the WEB 17.