Safety and efficacy of aneurysm treatment with WEB: results of the WEBCAST study

Comparative analysis between stent-assisted coiling and Woven EndoBridge embolization for unruptured wide-necked bifurcation intracranial aneurysms: A propensity score matching study

BACKGROUND

Before the utilization of the Woven EndoBridge (WEB) for the treatment of wide-necked bifurcation intracranial aneurysms (WNBA), stent-assisted coiling (SAC) was the predominant endovascular treatment. Studies directly comparing the outcomes of these two methods are still limited. This study aimed to compare the safety and efficacy of SAC and WEB embolization for unruptured WNBAs through propensity score matching.

METHODS

This retrospective study included patients treated with SAC or WEB for unruptured WNBAs at a single institution between January 2014 and June 2023. Propensity score matching was conducted based on patient and aneurysm characteristics. The matched groups were compared for periprocedural events and 6-month clinical and radiological outcomes, assessed using the modified Rankin Scale and Raymond-Roy occlusion classification, respectively.

RESULTS

Among 286 patients, 74 were included in each group after propensity score matching. The WEB group exhibited significantly shorter fluoroscopy time than the SAC group (p < 0.001). Periprocedural complications primarily comprised intraoperative thromboembolic events, with nine cases (12.2 %) in the SAC group and five cases (6.8 %) in the WEB group (p = 0.388). Throughout the 6-month follow-up period, nuisance bleeding occurred significantly more frequently in patients with SAC (8 cases, 10.8 %). The 6-month complete occlusion rates were 85.9 % and 77.5 % for the SAC and WEB groups, respectively (p = 0.309), whereas adequate occlusion rates were 91.5 % and 90.1 % for the groups, respectively (p = 1.000).

CONCLUSIONS

The 6-month clinical and radiological outcomes of unruptured WNBAs treated with WEB and SAC were comparable. WEB has advantages over SAC, including reduced fluoroscopy time and avoidance of dual antiplatelet therapy.

ABSTRACT

Before the utilization of the Woven EndoBridge (WEB) for the treatment of wide-necked bifurcation intracranial aneurysms (WNBA), stent-assisted coiling (SAC) was the predominant endovascular treatment. Studies directly comparing the outcomes of these two methods are still limited. This study aimed to compare the safety and efficacy of SAC and WEB embolization for unruptured WNBAs through propensity score matching. This retrospective study included patients treated with SAC or WEB for unruptured WNBAs at a single institution between January 2014 and June 2023. Propensity score matching was conducted based on patient and aneurysm characteristics. The matched groups were compared for periprocedural events and 6-month clinical and radiological outcomes, assessed using the modified Rankin Scale and Raymond-Roy occlusion classification, respectively. Among 286 patients, 74 were included in each group after propensity score matching. The WEB group exhibited significantly shorter fluoroscopy time than the SAC group (p < 0.001). Periprocedural complications primarily comprised intraoperative thromboembolic events, with nine cases (12.2 %) in the SAC group and five cases (6.8 %) in the WEB group (p = 0.388). Throughout the 6-month follow-up period, nuisance bleeding occurred significantly more frequently in patients with SAC (8 cases, 10.8 %). The 6-month complete occlusion rates were 85.9 % and 77.5 % for the SAC and WEB groups, respectively (p = 0.309), whereas adequate occlusion rates were 91.5 % and 90.1 % for the groups, respectively (p = 1.000). The 6-month clinical and radiological outcomes of unruptured WNBAs treated with WEB and SAC were comparable. WEB has advantages over SAC, including reduced fluoroscopy time and avoidance of dual antiplatelet therapy.

Usefulness of non-contrast-enhanced ultrashort echo time magnetic resonance angiography for assessing cerebral aneurysms after woven endobridge device treatment

BACKGROUND AND OBJECTIVES

Digital subtraction angiography (DSA) is the gold standard follow-up modality for assessing aneurysm occlusion state after Woven EndoBridge (WEB; MicroVention/Terumo, Aliso Viejo, CA, USA) treatment. However, because of the invasiveness of DSA, time-of-flight (TOF) magnetic resonance angiography (MRA) is also used, although it has limited diagnostic accuracy: signal loss in MRA due to the WEB device hinders clear assessment of aneurysm remnants post-treatment. This study aimed to determine whether the non-contrast-enhanced (non-CE) ultrashort echo time (UTE)-MRA sequence, with its ability to reduce metal-induced susceptibility artifacts in MRA, is a reliable follow-up modality to assess aneurysm occlusion status after WEB device treatment.

MATERIALS AND METHODS

From June 2024 to February 2025 at our institution, 12 consecutive patients with 14 aneurysms underwent TOF-MRA, UTE-MRA, and DSA for occlusion assessment 6 months after WEB treatment. Angiographic assessments were independently performed by two observers using the WEB Occlusion Scale (WOS). Visibility of the parent vessel at the WEB placement site in TOF-MRA and UTE-MRA was also evaluated.

RESULTS

According to DSA, the rates of WOS grade A/B (complete occlusion), C, and D aneurysms were 64.3 %, 28.6 %, and 7.1 %, respectively. Regarding intermodality agreement between TOF-MRA and DSA, the κ coefficient was 0.19, indicative of poor agreement. Intermodality agreement between UTE-MRA and DSA was excellent (κ = 0.88). The parent vessel adjacent to the WEB device tended to be visible more often with UTE-MRA (85.7 %) than with TOF-MRA (50.0 %) (p = 0.10).

CONCLUSIONS

Non-CE UTE-MRA may be a reliable and less invasive imaging modality after WEB treatment.

Woven endobridge embolization versus microsurgical clipping for unruptured wide-neck cerebral aneurysms on middle cerebral artery bifurcation

Woven EndoBridge (WEB) is an endovascular treatment for wide-neck bifurcation aneurysms (WNBAs). This study aimed to clarify the efficacy and safety of the WEB comparing to clipping for treating the middle cerebral artery (MCA) WNBAs. For the matched analysis, we designed a retrospective, tertiary, single-center study including 288 MCA WNBAs treated with WEB (n = 37) or clipping (n = 251). Inverse probability of treatment weighting (IPTW) for the main analysis and 1:2 propensity score matching for the sensitivity analysis were used to adjust for aneurysm geometric parameters. Morbidity, major complications, and aneurysm occlusion grade were assessed at 1 year. In the IPTW analysis, no significant difference was observed in morbidity (2.1% vs. 1.6%, odds ratio [OR]: 1.34, p = 0.776) and major complications (3.3% vs. 3.1%, OR: 1.08, p = 0.926). Adequate aneurysm occlusion was achieved in 76.1% of the WEB group and 97.4% of the clipping group (OR: 0.09, p < 0.001). In line with the main analysis, the 1:2 propensity score matching analysis revealed no significant difference in the morbidity (OR: 2.00, 95% CI: 0.13-31.98, p = 0.624). This study supports that microsurgical clipping still requires to play a vital role, but WEB could be an alternative option for WNBAs in the MCA.

Long-Term Outcomes of Surgical Clipping of Woven EndoBridge-Eligible Middle Cerebral Artery Bifurcation Aneurysms

BACKGROUND AND OBJECTIVES

Endosaccular flow disruption with the Woven EndoBridge (WEB) embolization device emerged as an alternative treatment for wide-necked bifurcation aneurysms (WNBAs). Previous studies used pooled aneurysm locations to conclude the efficacy of the WEB device, failing to account for locational differences in outcomes, most notably at the middle cerebral artery (MCA). Thus, we analyzed characteristics and outcomes among a cohort of WEB-eligible MCA bifurcation aneurysms treated surgically.

METHODS

We retrospectively reviewed a prospectively maintained aneurysm database at UT Southwestern between 2002 and 2022. WEB-eligible aneurysms met the criteria of a dome-to-neck ratio ≥1, a neck diameter >4.0 mm or a dome-to-neck ratio of ≤2, and an aneurysm diameter of 3.0-11.0 mm. Both unruptured and ruptured aneurysms were included. The end points assessed were functional status changes (modified Rankin scale [mRS]), complication rates, aneurysm recurrence, residual, morbidity, and mortality.

RESULTS

One hundred two patients met radiographic inclusion criteria as WEB-eligible WNBA who underwent microsurgical clipping. Eighty-five (83.3%) aneurysms were unruptured. Patients with ruptured aneurysms presented with a worse mRS and experienced more significant improvements in functional status at the final follow-up. Regardless of rupture status, outcomes with open surgery were excellent, with a 99% treatment success rate, 4.9% morbidity rate, and 0% mortality rate. Among unruptured MCA WNBAs, functional outcomes showed a final mRS ≤2 in 94.1% of patients and an improved or stable functional status in 91.8%. Microsurgical treatment of unruptured MCA WNBA carried a 5.9% thromboembolic complication rate.

CONCLUSION

Outcomes of WEB-eligible MCA WNBAs are comparable with the high success rates in large, heterogeneous series of MCA aneurysms and superior to those in WEB cohorts. Functional outcomes remain excellent regardless of treatment strategy; however, surgical treatment may offer higher complete occlusion rates, lower retreatment rates, and lower complication rates than endovascular treatment with WEB.

Retreatment rate and strategies for recurrent and residual aneurysms after Woven EndoBridge (WEB) treatment: a comprehensive systematic review and meta-analysis

Woven Endo Bridge (WEB) is a flow diverter device used to treat wide-necked intracranial aneurysms. We conducted a systematic review and meta-analysis to determine the retreatment rate and strategies following aneurysmal recurrence after WEB treatment. A systematic literature search was conducted through four electronic databases. The Cochrane risk of bias tool for non-randomized trials (ROBINS-I) was used for risk of bias assessment. A meta-analysis and meta-regression were performed on relevant variables. A total of 29 studies with 2067 patients were included. Initially treated aneurysms had an adequate occlusion rate of 84.7% (20 studies, 980/1156, 95%CI: 79%-89%) at the last follow-up. The overall retreatment rate was 8.6% (24 studies, 251/2893, 95%CI: 6.5%-10.9%). Following retreatment, the immediate complete occlusion rate post retreatment and complete occlusion rate at last follow-up were 52% (six studies, 95%CI, 11%-91%) and 65% (six studies, 77/120, 95%CI: 56%-73%) respectively. Stent-assisted coiling achieved a 100% (95%CI: 57%-100%, P-value < 0.01) immediate adequate occlusion rate and 74% complete occlusion rate (95%CI: 16%-100%, P-value = 0.63) at last follow-up, which was higher than clipping, coiling, and flow diversion. On meta-regression, aneurysm height and neck width significantly associated with higher retreatment rate. The current meta-analysis showed a 9% retreatment rate after initial aneurysms treatment with WEB and overall adequate retreatment occlusion was high. Although stent-assisted coiling showed a higher adequate occlusion rate post-operatively, there was no significant difference between retreatment strategies in long-term radiological outcomes.

Safety/Efficacy of a Pusher, Thermal Detachment Coil for Ruptured Intracranial Aneurysms: A Multicenter Real-World Study

BACKGROUND AND PURPOSE

Optima coils are a new type of embolic coils with complex and WAVE shape properties and variable degrees of softness. In patients with ruptured intracranial aneurysms, we examined the safety (periprocedural complications) and efficacy (occlusion rate immediately postprocedure) of the Optima coil.

METHODS

We studied 103 consecutive patients with ruptured intracranial aneurysms who were treated exclusively with the Optima coil, without the use of accompanying implanted devices, at five centers in Spain. Endovascular techniques included stand-alone or balloon-assisted coiling. Postprocedural occlusion and periprocedural device-related adverse events were the endpoints. Aneurysm occlusion was graded according to the modified Raymond-Roy Occlusion scale.

RESULTS

Of the 103 enrolled patients (70 female; median age 59 years), 59 (57.3%) presented with an IV Fischer Scale grade, and 61 (59.2%) of the ruptured aneurysms were wide-necked. Thirty-eight (36.9%) aneurysms were located in the anterior communicating artery. Simple-coiling and balloon-assisted coiling were performed in 36 (34.9%) and 65 (63.1%) patients, respectively. Raymond-Roy Class I, II, and III were reached in 64 (60.3%), 29 (28.1%), and ten (9.7%) following the procedure. The periprocedural device-related serious adverse event rate was 12 (13.5%), of which eight (7.7%) were due to coil protrusion. Four (3.8%) patients had intraprocedural aneurysm rupture. No early rebleeding or death was reported.

CONCLUSION

This analysis suggests that the Optima coil is safe and effective for treating ruptured aneurysms, with satisfactory occlusion rates and low rates of periprocedural device-related serious adverse events.

Prediction of persistent incomplete occlusion of intracranial aneurysms treated with woven EndoBridge device

While the Woven EndoBridge (WEB) device has transformed the treatment of wide-neck intracranial aneurysms, incomplete occlusion remains a significant challenge requiring better understanding of contributing factors. A retrospective analysis was conducted on multicenter data from patients who underwent WEB device treatment for intracranial aneurysms between January 2011 and December 2022. Using machine learning models, Cox regression, and time-stratified analyses, we evaluated factors associated with persistent incomplete occlusion, defined as non-improving Raymond-Roy Occlusion Classification grade 2 or 3 at final follow-up. Among 813 patients (607 with < 24 months follow-up, 206 with ≥ 24 months), machine learning analysis identified aneurysm height, Acom location, neck diameter, and pretreatment mRS as predictors of persistent incomplete occlusion. On Cox regression. larger aneurysm neck diameter (HR 1.13, 95% CI 1.01-1.27, p = 0.027) and height (HR 1.14, 95% CI 1.02-1.26, p = 0.017), and radial access (HR 2.68, 95% CI 1.76-4.07, p < 0.001) increased, while posterior circulation location (HR 0.56, 95% CI 0.37-0.84, p = 0.005) decreased the risk of persistent incomplete occlusion. Time-stratified analysis revealed that in short-term follow-up (< 24 months), larger aneurysm neck diameter (OR 1.28, 95% CI 1.08-1.52, p = 0.004) increased the risk of incomplete occlusion. In long-term follow-up (≥ 24 months), smoking (OR 2.69, 95% CI 1.04-7.00, p = 0.04), higher pre-treatment mRS (OR 1.78, 95% CI 1.15-2.76, p = 0.009), and immediate flow stagnation (OR 0.33, 95% CI 0.11-0.96, p = 0.04) increased, while older age (OR 0.94, 95% CI 0.90-0.98, p = 0.002) and WEB-DL (OR 0.06, p < 0.001) and SLS devices (OR 0.02, p = 0.003) decreased the risk of persistent incomplete occlusion. Aneurysm characteristics and device type significantly influence long-term WEB treatment outcomes.

Contour Neurovascular System for endovascular embolization of cerebral aneurysms: a multicenter cohort study of 10 European neurovascular centers

BACKGROUND

Intrasaccular devices have become increasingly popular in the treatment of cerebral aneurysms, particularly at the bifurcation. Here we evaluate the Contour Neurovascular System, an intrasaccular device for the endovascular treatment of cerebral aneurysms, in a multicenter cohort study, the largest to the best of our knowledge.

METHODS

Consecutive patients with intracranial aneurysms treated with the Contour Neurovascular System between February 2017 and October 2022 at 10 European neurovascular centers were prospectively collected and retrospectively reviewed. Patient and aneurysm characteristics, procedural details, and angiographic and clinical outcomes were evaluated.

RESULTS

During the study period, 279 aneurysms (median age of patients 60 years, IQR 52-68) were treated with Contour. In 83.2% of patients the device was placed electively, whereas the remaining patients were treated in the setting of acute subarachnoid hemorrhage. The most common locations were the middle cerebral artery (26.5%) followed by the anterior communicating region (26.2%). Median aneurysm dome and neck size were 5.2 mm (IQR 4.2-7) and 3.9 mm (IQR 3-5). Contour size 7 (39%) and 9 (25%) were most used. Thromboembolic and hemorrhagic complications occurred in 6.8% and 0.4% of aneurysms, respectively. Raymond-Roy 1 and 2 occlusions at last follow-up were achieved in 63.2% and 28.3%, respectively, resulting in adequate occlusion of 91.5% of aneurysms.

CONCLUSION

This is the largest multicenter study reporting the outcome on the Contour Neurovascular System. At 1 year, the self-evaluated data on safety and efficacy are comparable to data of existing intrasaccular devices. Contour is a promising technology in the treatment of cerebral aneurysms.

Incidence and predictors of Woven EndoBridge (WEB) shape modification following treatment of intracranial aneurysms in a large multicenter study

The Woven EndoBridge (WEB) device is FDA-approved for the treatment of bifurcation aneurysms. Despite its wide popularity, it has been under scrutiny for its association with potential aneurysm recanalization and retreatment due to device shape modification. This study aims to analyze the shape modification rate of WEB devices and identify factors associated with this phenomenon, as well as its correlation with aneurysm retreatment. We conducted a retrospective review of the WorldWide WEB Consortium database, including adult patients treated for intracranial aneurysms with the WEB device. We assessed aneurysm occlusion using the WEB Occlusion Scale and defined WEB shape modification as a percentage reduction in the distance between two WEB markers. Logistic regression and Cox proportional hazards models were utilized to evaluate predictors of shape modification and retreatment. Kaplan-Meier curves were used to estimate the time-dependent probability of no or minor shape modification. A total of 405 patients were analyzed, with minor and major shape modification occurring in 31.4% and 10.1% of cases, respectively. Major shape modification was associated with lower rates of adequate occlusion (70.7%) compared to no or minor shape modification (86.6%) and a higher rate of retreatment (26.8% vs. 8.1%). Predictors of major shape modification included the presence of daughter sac, bifurcation aneurysms, absence of immediate flow stagnation, and a WEB width minus aneurysm width ratio ≤ 0.5. The probability of no or minor shape modification declined within the first 25 months and stabilized thereafter. WEB device shape modification is a significant predictor of aneurysm occlusion efficacy and retreatment. Recognizing the factors influencing shape modification can guide treatment decisions and follow-up protocols to improve patient outcomes.

Review of Endosaccular Flow Disrupters for Wide-Neck Aneurysm Treatment

Endosaccular flow disruption has emerged as a transformative approach for treating wide-neck intracranial aneurysms, which are characterized by neck diameters exceeding 4 millimeters or dome-to-neck ratios below 2. This review examines the technical specifications and clinical outcomes of major endosaccular devices, including the Woven EndoBridge (WEB) device, the Artisse embolization device, the Medina embolization device, the neck bridging device for bifurcation aneurysms, the polycarbonate urethane membrane-assisted device, the Galaxy saccular endovascular aneurysm lattice, and the Contour Neurovascular System. Analysis of pivotal trials reveals varying degrees of efficacy and safety across platforms. The WEB device demonstrated complete occlusion rates of 51.7% to 56.1% at 1 year, with adequate occlusion reaching 84.6% in the WEB Intrasaccular Therapy Study trial and sustained improvement in 76.8% of cases at 5 years. The Artisse system showed initial promise but concerning declines in adequate occlusion from 66.7% at 6 months to 57.1% at 36 months. More recent innovations such as the Galaxy SEAL device achieved complete occlusion in 76.9% of cases in preliminary studies in 1 year. Thromboembolic complications occurred in 12.9% to 17.7% of cases across devices though procedure-related mortality remained below 2%. While the WEB device has established a robust safety and efficacy profile through long-term follow-up data, newer technologies demonstrate promising early results but require extended surveillance. Current challenges focus on optimizing device sizing, improving delivery systems, and enhancing material properties to maximize occlusion rates while minimizing complications. The evolution of these technologies continues to expand treatment options for complex aneurysms previously challenging to address through conventional endovascular or surgical approaches.

Woven EndoBridge 17 device for intracranial aneurysms: A systematic review and meta-analysis

BACKGROUND

The Woven EndoBridge 17 (WEB-17) is the latest advancement in the WEB device family. Comprehensive data on its occlusion rates, procedural complications, and mortality is lacking. This meta-analysis aimed to evaluate the efficacy and safety of the WEB-17 device in intracranial aneurysms (IAs).

METHODS

A systematic literature search was conducted from inception to October 2023 across four databases for studies on IAs treated with WEB 17. Primary outcomes included adequate angiographic occlusion at last follow-up and a composite of intraprocedural and postprocedural complications. Comparative meta-analysis between WEB-17 and its predecessor versions (pvWEB) was performed. Subgroup analyses by IA rupture status were also conducted for the primary outcomes.

RESULTS

Eleven studies with 880 patients and 933 IAs were included. Regarding efficacy, the rate of adequate occlusion at last follow-up was 91% (95% CI 86%-94%) and the complete occlusion rate was 69% (95% CI 65%-73%). Safety outcomes demonstrated a composite complication rate of 7% (95% CI 4%-11%), an intraprocedural complication rate of 7% (95% CI 5%-9%; I2 = 0%), and a postprocedural complication rate of 2% (95% CI 1%-5%; I2 = 0%). No differences were found between WEB-17 and pvWEB in terms of adequate occlusion (WEB-17: 87.7% vs pvWEB: 80.4%; OR = 1.35, 95% CI 0.71-2.55) and safety composite outcome (WEB-17: 8.7% vs pvWEB: 10%; OR = 1.05, 95% CI 0.51-2.16). Subgroup analysis did not evidence heterogeneity between subgroups.

CONCLUSIONS

The WEB-17 device demonstrates promising efficacy and safety profiles for the treatment of IAs. However, these results should be interpreted with caution due to the limited quality of evidence in the included studies. Further prospective, randomized studies are needed to validate these findings.

Safety and efficacy of the Contour Neurovascular System for treating intracranial aneurysms: a systematic review and meta-analysis

BACKGROUND

The Contour Neurovascular System (CNS, Stryker, Kalamazoo, MI) has a unique design that allows it to address various aneurysm morphologies, including wide-necked, irregular, and shallow-shaped lesions. However, evidence of its safety and efficacy remains limited. This systematic review and meta-analysis synthesizes the current data on CNS performance.

METHODS

A comprehensive search guided by the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) standards was performed across PubMed, Embase, and Web of Science, including studies with ≥5 patients reporting on CNS use. Efficacy outcomes included immediate and last follow-up adequate aneurysm occlusion and technical success. Safety outcomes included good functional outcome (modified Rankin Scale (mRS) score of 0-2 at last follow-up), procedure-related morbidity (permanent neurological deficits), procedure-related mortality, intraoperative and postoperative complications. Pooled analyses with 95% confidence intervals (CI) were conducted, with heterogeneity assessed using I² statistics, and a random-effects model was applied.

RESULTS

Nine studies, including 483 patients (58.8% female; mean age: 59.3±15.6 years) with 484 aneurysms, were analyzed. Of the 467 patients in whom rupture status was reported, 81.8% presented with unruptured aneurysms and 18.2% with ruptured aneurysms. Immediate adequate aneurysm occlusion rate was 53% (95% CI: 1% to 100%), with follow-up adequate occlusion at 93% (95% CI: 88% to 97%) and technical success at 98% (95% CI: 95% to 100%). Intraoperative and postoperative complication rates were 3% (95% CI: 0% to 7%) and 7% (95% CI: 3% to 12%), respectively. Procedure-related morbidity was 2% (95% CI: 0% to 3%), with no procedure-related mortality.

CONCLUSION

The CNS is a safe and effective novel intrasaccular device for treating intracranial aneurysms.

CLinical EValuation of WEB 17 device in intracranial aneuRysms (CLEVER): 1-year effectiveness results for ruptured and unruptured aneurysms

BACKGROUND

The Woven EndoBridge (WEB) device is designed to treat wide-necked bifurcation aneurysms. The WEB 17 is the latest iteration and can be delivered through a 0.017″ microcatheter. The CLEVER study demonstrated that WEB 17 is safe and effective for providing protection against bleeding or rebleeding at 1 month and 1 year.

OBJECTIVE

To evaluate angiographic stability at 1 year.

METHODS

The CLEVER study was a prospective multicenter study conducted in 17 European centers, involved 163 subjects, comprising 60 ruptured and 103 unruptured aneurysms. Independent assessment of 1-year follow-up imaging was incorporated into the study design.

RESULTS

Aneurysm diameters ranged from 2.0 to 9.2 mm, with 95.7% being broad-based (dome-to-neck ratio <2). Follow-up imaging at 1 year was completed for 146 out of 163 subjects (89.6%) and evaluated by an independent core laboratory. The primary efficacy endpoint of adequate occlusion without re-treatment at 1 year was achieved for 120 (82.2%) of all subjects. At 1 year, the adequate occlusion rate was 86.5% for ruptured aneurysms (73.1% complete occlusion) and 82.4% for unruptured aneurysms (57.1% complete occlusion). The overall re-treatment rate at 1 year was 2.6% (4/152), with 3.1% (3/97) for unruptured aneurysms and 1.8% (1/55) for ruptured aneurysms CONCLUSION: Delivery of the WEB 17 via 0.017 inch catheters represents a significant evolution of the WEB design. The results of CLEVER presented here demonstrate that it maintains the same efficacy as previous generations of WEB.

The impact of postoperative aspirin in patients undergoing Woven EndoBridge: a multicenter, institutional, propensity score-matched analysis

BACKGROUND

The Woven EndoBridge (WEB) device is frequently used for the treatment of intracranial aneurysms. Postoperative management, including the use of aspirin, varies among clinicians and institutions, but its impact on the outcomes of the WEB has not been thoroughly investigated.

METHODS

This was a retrospective, multicenter study involving 30 academic institutions in North America, South America, and Europe. Data from 1492 patients treated with the WEB device were included. Patients were categorized into two groups based on their postoperative use of aspirin (aspirin group: n=1124, non-aspirin group: n=368). Data points included patient demographics, aneurysm characteristics, procedural details, complications, and angiographic and functional outcomes. Propensity score matching (PSM) was applied to balance variables between the two groups.

RESULTS

Prior to PSM, the aspirin group exhibited significantly higher rates of modified Rankin scale (mRS) mRS 0-1 and mRS 0-2 (89.8% vs 73.4% and 94.1% vs 79.8%, p<0.001), lower rates of mortality (1.6% vs 8.6%, p<0.001), and higher major compaction rates (13.4% vs 7%, p<0.001). Post-PSM, the aspirin group showed significantly higher rates of retreatment (p=0.026) and major compaction (p=0.037) while maintaining its higher rates of good functional outcomes and lower mortality rates. In the multivariable regression, aspirin was associated with higher rates of mRS 0-1 (OR 2.166; 95% CI 1.16 to 4, p=0.016) and mRS 0-2 (OR 2.817; 95% CI 1.36 to 5.88, p=0.005) and lower rates of mortality (OR 0.228; 95% CI 0.06 to 0.83, p=0.025). However, it was associated with higher rates of retreatment (OR 2.471; 95% CI 1.11 to 5.51, p=0.027).

CONCLUSIONS

Aspirin use post-WEB treatment may lead to better functional outcomes and lower mortality but with higher retreatment rates. These insights are crucial for postoperative management after WEB procedures, but further studies are necessary for validation.

The Impact of Postprocedural Anticoagulant Use in Patients Undergoing Woven EndoBridge: A Multicenter Propensity Score-Matched Study

The Woven EndoBridge (WEB) device has become a prominent treatment for wide-neck bifurcation intracranial aneurysms since its FDA approval in 2018. However, the impact of anticoagulant therapy on its efficacy and patient outcomes remains underexplored. This study aims to evaluate the effects of postoperative anticoagulant use on aneurysm occlusion, retreatment rates, and functional outcomes following WEB device implantation. This retrospective multicenter study included 457 patients treated with the WEB device across 10 academic institutions in the United States between January 2012 and June 2024. Patients were categorized based on postoperative anticoagulant use: 91 patients (19.9%) received anticoagulants, while 366 patients (80.1%) did not. Propensity score matching (PSM) was employed to control for potential confounders, resulting in 316 matched patients (229 non-anticoagulant and 87 anticoagulant). After PSM, the anticoagulant group had lower rates of excellent functional outcomes (mRS 0-1: 73% vs. 85%, p = 0.026) and higher mortality rates (6.7% vs. 3.7%, p = 0.33), though the latter difference was not statistically significant. No significant differences in the last follow-up adequate occlusion were observed between the two groups (p = 0.7). However, patients in the anticoagulant group had lower major device compaction (> 50%) (4.9% vs. 12%, p = 0.12) and retreatment rates (4.6% vs. 12%, p = 0.045). Postoperative anticoagulant use is associated with poor functional outcomes and higher tendency for higher mortality rate. No significant differences in the last follow-up adequate occlusion rate were observed between the anticoagulant group and non-anticoagulant group. However, patients in the anticoagulant group had lower major compaction and retreatment rates. These findings suggest that the WEB mechanism of occlusion is more complex than what have been hypothesized and highlight the need for individualized management strategies to optimize outcomes in patients requiring anticoagulation post-WEB. Further studies are needed.

Woven endo bridge device for recurrent intracranial aneurysms: A systematic review and meta-analysis

BACKGROUND

Recurrent intracranial aneurysms present a significant clinical challenge, demanding innovative and effective treatment approaches. The Woven EndoBridge (WEB) device has emerged as a promising endovascular solution for managing these intricate cases. This study aims to assess the safety and efficacy of the WEB device in treating recurrent intracranial aneurysms.

METHODS

We conducted a comprehensive search across multiple databases, including PubMed, Scopus, Embase, and Web of Science, from inception to June 5, 2023. Eligible studies focused on evaluating WEB device performance and included a minimum of five patients with recurrent intracranial aneurysms. The complete and adequate occlusion rates, neck remnant rates, and periprocedural complication rates were pooled using SATA V.17.

RESULTS

Our analysis included five studies collectively enrolling 73 participants. Participant ages ranged from 52.9 to 65 years, with 64.4% being female. Aneurysms were wide-necked and predominantly located in the middle cerebral artery, basilar artery, and anterior cerebral artery. Previous treatments encompassed coiling, clipping, and the use of WEB devices. Our study found an overall adequate occlusion rate of 0.80 (95% CI 0.71-0.89), a complete occlusion rate of 0.39 (95% CI 0.28-0.50), and a neck remnant rate of 0.38 (95% CI 0.27-0.48). Periprocedural complications were reported at a rate of 0%, although heterogeneity was observed in this data. Notably, evidence of publication bias was identified in the reporting of periprocedural complication rates.

CONCLUSION

Our findings suggest that the WEB device is associated with favorable outcomes for treating recurrent wide-neck intracranial aneurysms.

Bailout Technique for Protrusion and Migration of Detached Woven EndoBridge Devices with Amplatz Goose Neck Microsnare

Objective

The Woven EndoBridge (WEB; MicroVention TERUMO, Tustin, CA, USA) is an intrasaccular flow disruptor developed for the treatment of wide-neck bifurcation aneurysms (WNBA). While its safety and satisfactory mid- to long-term treatment outcomes have been documented, there have also been reports of complications such as WEB protrusion and migration. We encountered 3 cases in which the WEB protruded or migrated to the parent vessel after deployment, necessitating retrieval. In this report, we address the technical tips for retrieval techniques and factors associated with these complications, including a literature review.

Case Presentation

Of the 120 cases of our experience with WEB treatment for cerebral aneurysms for the period since January 2021, 3 required WEB retrievals. In 2 cases, significant WEB migration toward the parent vessel occurred while maneuvering the delivery microcatheter because of sticky detachment. In the remaining case, after detachment of the WEB, tilting occurred, leading to a strong protrusion into one of the branches, which prevented guiding the microcatheter for bailout stenting. In all cases, the proximal marker of the WEB was captured using an Amplatz Goose Neck Microsnare (Medtronic, Minneapolis, MN, USA) pulled back into the VIA catheter (the delivery catheter for the WEB; MicroVention TERUMO), and further into an intermediate catheter positioned as close to the aneurysm as possible, enabling uneventful retrieval.

Conclusion

None of the cases damaged the aneurysm or proximal parent vessel wall, and additional aneurysm occlusion treatment was performed. However, WEB protrusions and migration are rare. When retrieval is required, it is crucial to act swiftly owing to the risk of distal thrombosis from the lumen inside of the WEB. Therefore, recognizing Goose Neck Microsnare as a retrieval technique is valuable.

Assessing Radiation Exposure and Contrast Agent Utilization: A Comparative Analysis of the Woven EndoBridge Device and Stent-Assisted Coil Embolization for Managing Unruptured Wide-Neck Bifurcation Aneurysms

PURPOSE

In this study, we determined whether there were significant differences in procedure time, radiation dose, fluoroscopy time, and total contrast media dose when unruptured wideneck bifurcation aneurysms (WNBAs) were treated with the Woven EndoBridge (WEB) device and stent-assisted coil (SAC) embolization.

MATERIALS AND METHODS

The WEB device and SAC embolization (14:17) were used to treat 31 cases of internal carotid artery bifurcation, anterior communicating artery, middle cerebral artery bifurcation, and basilar bifurcation aneurysms between August 2021 and December 2022. The procedure time, radiation dose, fluoroscopy time, and total contrast medium dose between the 2 treatment groups were compared and analyzed. In the WEB device group, the results between operators were compared, and the follow-up radiologic outcomes were investigated.

RESULTS

The procedure and fluoroscopy times were significantly shorter in the WEB device group. Radiation and total contrast media dose were also significantly smaller in the WEB device, but there was no significant difference in results between operators. The follow-up radiological outcome showed adequate occlusion in 83.3% (10/12) of cases.

CONCLUSION

The WEB device can be used as an alternative treatment method among the available endovascular treatment methods for WNBAs to reduce radiation exposure and the dose of contrast media when used adequately with appropriate indications.

Intrasaccular Treatment of Intracranial Aneurysms: A Comprehensive Review

Background: The endovascular treatment of complex intracranial aneurysms, such as wide-neck aneurysms (WNAs), remains a challenge. More established endovascular techniques, which include balloon-assisted coiling, stent-assisted coiling, and flow diversion, all have their drawbacks. Intrasaccular flow disruptor devices have emerged as a useful tool for the neurointerventionalist. Methods: Here, we discuss landmark studies and provide a comprehensive, narrative review of the Woven EndoBridge (WEB; Microvention, Alisa Viejo, CA, USA), Artisse (Medtronic, Irvine, CA, USA), Contour (Stryker, Kalamazoo, MI, USA), Saccular Endovascular Aneurysm Lattice Embolization System (SEAL; Galaxy Therapeutics Inc, Milpitas, CA, USA), Medina (Medtronic, Irvine, CA, USA), and Trenza (Stryker, Kalamazoo, MI, USA) devices. Results: Intrasaccular devices have proven to be effective in treating complex aneurysms like WNAs. Conclusions: Intrasaccular flow disruptors have emerged as a new class of effective endovascular therapy, and results of ongoing clinical studies for the newer devices (e.g., SEAL and Trenza) are much anticipated.

Lessons learned from 12 years using the Woven Endobridge for the treatment of cerebral aneurysms in a multi-center series

Intrasaccular flow disruption with the Woven Endobridge (WEB) has become a well-established endovascular technique for the treatment of intracranial aneurysms. This study presents our 12-year experience with the WEB and evaluates its evolving indications, procedures, and outcomes. A consecutive series of 324 aneurysms treated with WEB between 2011 and 2023 at three neurovascular centers was retrospectively analyzed and the study group was divided into four treatment periods. Uni- and multivariate analyses were performed to evaluate factors associated with technical success, thromboembolic complications, and angiographic outcome. The mean aneurysm size was 7.0 ± 3.6 mm and decreased during the study period, while the proportion of atypical sites for WEB implantation increased. WEB implantation was technically successful in 96.0%, and the ratio of WEB width to dome width increased during the study period, indicating oversizing. The neurological complication rate was 4.9% (1.5% major, 3.4% minor) and the mid-term complete occlusion rate was 60.6% (81.9% adequate occlusion), with no statistical differences in either outcome measure between the study periods. In multivariate analyses, the use of WEB 17 was associated with increased technical success (HR: 7.4, 95%CI: 2.4-23.6, p<0.01), whereas ruptured aneurysm status (HR: 2.5, 95%CI: 1.0-6.0, p=0.04) and the use of additional stents (HR: 4.8, 95%CI: 1.6-14.4, p<0.01) predicted thromboembolic complications. Appropriate oversizing of the WEB favored mid-term complete occlusion (HR: 10.5, 95%CI: 1.3-83.3, p=0.03). The results suggest an expansion of the indications for WEB implantation and highlight the importance of oversizing for treatment efficacy.

Comparative analysis of long term effectiveness of Neuroform Atlas stent versus low profile visualized intraluminal stent/Woven EndoBridge devices in treatment of wide necked intracranial aneurysms

BACKGROUND

We compared the outcomes of wide necked aneurysms (WNA) treated with the Neuroform Atlas with those treated with the low profile visualized intraluminal stent (LVIS) or the Woven EndoBridge (WEB).

METHODS

Objective, prospectively collected, core laboratory adjudicated data from published trials for the Neuroform Atlas, LVIS, and WEB devices were reviewed. ATLAS (Safety and Effectiveness of the Treatment of Wide Neck, Saccular Intracranial Aneurysms With the Neuroform Atlas Stent System) study patients were included if they met other studies' inclusion criteria. Outcomes included (1) primary effectiveness (complete aneurysmal occlusion without retreatment/>50% parent vessel stenosis), (2) primary safety, (3) complete aneurysmal occlusion, and (4) retreatment rates (outcomes evaluated at the 12 month follow-up). Matching adjusted indirect comparison analysis was used to compare outcomes.

RESULTS

Analytical samples included 141 ATLAS subjects meeting WEB-IT (Woven EndoBridge Intrasaccular Therapy Study) criteria (ATLAS/WEB-IT) and 241 meeting LVIS (Pivotal Study of the Low Profile Visualized Intraluminal Support) criteria (ATLAS/LVIS). ATLAS/WEB-IT exhibited significantly higher rates of primary effectiveness and complete occlusion versus WEB (86.6% vs 53.9 %, P<0.0001, and 90.3% vs 53.9%, P<0.0001, respectively). For LVIS, there was no significant differences in primary effectiveness rates between ATLAS and LVIS (84.2% vs 77.7%, respectively, P=0.12). However, ATLAS/LVIS had a significantly higher proportion of patients achieving complete occlusion than LVIS (88.1 vs 79.1, P=0.03). Retreatment rates and primary safety outcomes were not significantly different (P>0.05) for the Atlas versus other devices except for a lower retreatment rate for ATLAS/WEB-IT versus WEB-IT (2.4% vs 9.8%, P=0.01).

CONCLUSION

The Neuroform Atlas provided higher occlusion rates and similar retreatment rates in comparable datasets compared with LVIS and WEB devices when treating WNA.

Flow diversion for unruptured MCA bifurcation aneurysms: comparison of p64 classic, p64 MW HPC, and p48 MW HPC flow diverter stents

Background

MCA bifurcation aneurysms pose treatment challenges because of the complex hemodynamics at the bifurcation and the risk of rupture. FDS implantation has been controversial and there are only limited reports. Therefore, the aim of this study was to assess the efficacy and safety of this treatment strategy using p64 MW HPC and p48 MW HPC FDSs for MCA bifurcation aneurysms, compared with the p64 classic FDS.

Materials and methods

We retrospectively analyzed our institutional database and identified all patients with saccular, non-ruptured MCA bifurcation aneurysms treated with p64 MW HPC, p48 MW HPC, or p64 classic FDS implantation alone. Aneurysms with implantation of additional devices in the same session, previous treatments, and acutely ruptured and fusiform aneurysms were excluded.

Results

A total of 79 aneurysms met the inclusion criteria: 23 receiving a p64 MW HPC, 34 receiving a p48 MW HPC, and 22 receiving a p64 classic FDS. The occlusion rate was highest for the p48 MW HPC 2 mm FDS, at 88.9% at FU2, compared with 72.2% for the p64 MW HPC and 70.6% for the p64 classic. The time to aneurysm occlusion was shortest with the p64 MW HPC, at 178.31 days. The highest retreatment rate was observed with the p48 MW HPC 3 mm.

Conclusion

Treatment of MCA bifurcation aneurysms with a p48 MW HPC 2 mm or p64 MW HPC FDS is a safe and reliable strategy achieving high aneurysm occlusion rates - attributable to their lower porosity in relation to the parent vessel diameter as compared to the p48 MW HPC 3 mm FDS-, with reasonable morbidity and mortality.

Creation of a predictive calculator to determine adequacy of occlusion of the woven endobridge (WEB) device in intracranial aneurysms-A retrospective analysis of the WorldWide WEB Consortium database

BACKGROUND

Endovascular treatment with the woven endobridge (WEB) device has been widely utilized for managing intracranial aneurysms. However, predicting the probability of achieving adequate occlusion (Raymond-Roy classification 1 or 2) remains challenging.

OBJECTIVE

Our study sought to develop and validate a predictive calculator for adequate occlusion using the WEB device via data from a large multi-institutional retrospective cohort.

METHODS

We used data from the WorldWide WEB Consortium, encompassing 356 patients from 30 centers across North America, South America, and Europe. Bivariate and multivariate regression analyses were performed on a variety of demographic and clinical factors, from which predictive factors were selected. Calibration and validation were conducted, with variance inflation factor (VIF) parameters checked for collinearity.

RESULTS

A total of 356 patients were included: 124 (34.8%) were male, 108 (30.3%) were elderly (≥65 years), and 118 (33.1%) were current smokers. Mean maximum aneurysm diameter was 7.09 mm (SD 2.71), with 112 (31.5%) having a daughter sac. In the multivariate regression, increasing aneurysm neck size (OR 0.706 [95% CI: 0.535-0.929], p = 0.13) and partial aneurysm thrombosis (OR 0.135 [95% CI: 0.024-0.681], p = 0.016) were found to be the only statistically significant variables associated with poorer likelihood of achieving occlusion. The predictive calculator shows a c-statistic of 0.744. Hosmer-Lemeshow goodness-of-fit test indicated a satisfactory model fit with a p-value of 0.431. The calculator is available at: https://neurodx.shinyapps.io/WEBDEVICE/.

CONCLUSION

The predictive calculator offers a substantial contribution to the clinical toolkit for estimating the likelihood of adequate intracranial aneurysm occlusion by WEB device embolization.

The safety and effectiveness of the Contour Neurovascular System for the treatment of wide-necked aneurysms: A systematic review and meta-analysis of early experience

BACKGROUND

The Contour is a new generation intrasaccular flow disruption tool that aims to cover the aneurysm neck and is sized according to the neck diameter. While several case series have been published, no literature review has been performed on this promising device.

OBJECTIVE

To assess the safety and effectiveness profile of the Contour Neurovascular System for wide-necked aneurysms.

METHODS

We followed the recommendations of the PRISMA checklist Four databases were searched with a supplemental manual search. All data were analyzed using R software version 4.2.1.

RESULTS

We finally included six studies with 131 treated aneurysms. The overall procedural time was 97.27 (95% CI = 70.07-124.47) minutes, ranging from 78.9 to 136.0 min. The pooled adequate occlusion rate was 84.21% (95% CI = 75.45-90.25), and the overall functional independence rate was 94.74% (87.97-97.79). The overall adverse event rate was 4.70 (95% CI = 3.24-6.76), varying among different events from 0.78 to 8.53%. Thromboembolic events were the most commonly encountered in 8.53% of the patients (95% CI = 4.78-14.74), followed by headache and minor stroke with incidence rates of 5.88 (95% CI = 2.83-11.83) and 4.35 (95% CI = 1.41-12.63), respectively. The overall procedural time in studies using the Contour system only was 86.17 (95% CI = 68.70-10.64) minutes, while it was 136 (95% CI = 90.96-181.04) in the Contour-assisted coiling procedures. However, both techniques were comparable regarding adequate occlusion rates and functional independence.

CONCLUSION

With the anticipation of future studies, the Contour Neurovascular System is a safe and effective treatment option for wide-necked intracranial aneurysms.

Flow Diversion for Endovascular Treatment of Intracranial Aneurysms: Past, Present, and Future Directions

Flow diversion for intracranial aneurysms emerged as an efficacious and durable treatment option over the last two decades. In a paradigm shift from intrasaccular aneurysm embolization to parent vessel remodeling as the mechanism of action, the proliferation of flow-diverting devices has enabled the treatment of many aneurysms previously considered untreatable. In this review, we review the history and development of flow diverters, highlight the pivotal clinical trials leading to their regulatory approval, review current devices including endoluminal and intrasaccular flow diverters, and discuss current and expanding indications for their use. Areas of clinical equipoise, including ruptured aneurysms and wide-neck bifurcation aneurysms, are summarized with a focus on flow diverters for these pathologies. Finally, we discuss future directions in flow diversion technology including bioresorbable flow diverters, transcriptomics and radiogenomics, and machine learning and artificial intelligence.

Modification of Woven Endo-Bridge After Intracranial Aneurysm Treatment: A Methodology for Three-Dimensional Analysis of Shape and Relative Position Changes

During follow-up of patients treated with WEB devices, shape changes have been observed. The quantitative three-dimensional measurement of the WEB shape modification (WSM) would offer useful information to be studied in association with the anatomical results and try to better understand mechanisms implicated in this modification phenomenon. We present a methodology to quantify the morphology and position of the WEB device in relation to the vascular anatomy. Three-dimensional rotational angiography (3DRA) images of seven aneurysms patients treated with WEBs were used, which also accompanied by a post-treatment 3DRA image and a follow-up 3DRA image. The device was manually segmented, obtaining the 3D models after treatment and at the follow-up. Volume, surface area, height, maximum diameter and WSM ratio of both surfaces were calculated. Position changes were evaluated measuring WEB axis and relative position between post-treatment and follow-up. Changes in WEB volume and surface area were observed with a mean modification of - 5.04 % ( ± 14.19 ) and - 1.68 % ( ± 8.29 ) , respectively. The positional variables also showed differences, mean change of device axis direction was 26.25 % ( ± 24.09 ) and mean change of distance l b was 5.87 % ( ± 10.59 ) . Inter-observer and intra-observer variability analyses did not show differences (ANOVA p > 0.05 ). This methodology allows quantifying the morphological and position changes suffered by the WEB device after treatment, offering new information to be studied in relation to the occurrence of WEB shape modification.

Kissing Aneurysms of the Anterior Communicating Artery Treated With Surgical Clipping: A Case Report and Literature Review

Intracranial "kissing" aneurysms are rare vascular conditions described as two anatomically adjacent aneurysms originating from either the same or different arteries, with their walls pressed together. Two-dimensional angiography was formerly considered the gold standard for diagnosis, with the three-dimensional rotational type now offering more insightful details about vascular discrepancies. The treatment of anterior communicating artery (AcoA) "kissing" aneurysms poses significant challenges, with surgical clipping proving difficult due to their deep midline location or the bilateral anterograde arterial supply. However, advancements in endovascular coil embolization, such as dual-volume reconstruction, can assist in diagnosis. This study presents the case of a 50-year-old patient who was diagnosed with "kissing" aneurysms of the AcoA. The patient underwent surgical clipping and showed no pathological follow-up findings. The surgical intervention often provides a more direct and effective approach. This case contributes to the body of knowledge surrounding the management of this complex disease.

Rescue Stenting for Inadvertent Branch Vessel Occlusion Following Cerebral Aneurysm Embolization With the Woven EndoBridge Device

Intrasaccular flow modification with devices like the Woven EndoBridge (WEB, MicroVention, Inc., Aliso Viejo, California, US) is an increasingly utilized endovascular treatment for bifurcation aneurysms. Among the potential complications of the procedure is branch vessel occlusion. There are no previous publications of rescue stenting for inadvertent branch vessel occlusion with the WEB device. We report two cases of rescue stenting following branch vessel occlusion after cerebral aneurysm embolization with the WEB device. In both cases, rescue stenting with a Neuroform Atlas stent Stryker, Fremont, CA, US) successfully revascularized the occluded vessel and led to good patient outcomes.

A large UK single-centre experience in the long-term safety and efficacy of Woven Endobridge in the treatment of wide-neck intracranial aneurysms and risk factors associated with re-bleeding and re-treatment

INTRODUCTION

Endovascular treatment of wide neck aneurysms remains complicated with a determined and continuous technological effort towards treatment options that can offer safer and efficacious outcomes. The Woven Endobridge device was introduced in 2010 and has become a mainstay endovascular treatment for wide neck and large intracranial aneurysms. A recent review of the Woven Endobridge Clinical Assessment of Intrasaccular Aneurysm Therapy (WEBCAST) and WEBCAST2 trials and the five-year follow-up of patients was published. Our aim is to demonstrate real-life experience of aneurysms and patients treated with Woven Endobridge from a large high-volume specialist centre.

METHODS

A retrospective review was performed of patients treated with Woven Endobridge from March 2013 to March 2018. Primary efficacy outcomes were defined as per Raymond-Roy Occlusion Criteria (RROC) resulting in long-term complete occlusion (RROC1) and adequate occlusion (RROC1 and RROC2). Primary Safety outcomes were defined as procedure-related morbidity, rate of re-bleeding and rate of re-treatment.

RESULTS

Seventy-nine aneurysms were treated during the five-year period. Adequate aneurysm occlusion (RROC1 and RROC2) achieved was 81%. Retreatment was required in 18% of patients (14/79). Greater retreatment rate was demonstrated in partially thrombosed aneurysms, aneurysms with larger neck and dome diameter and dome heights.

CONCLUSION

Woven Endobridge treatment of wide-neck intracranial aneurysms offers a safe and efficacious outcome. This large UK single-centre experience demonstrates congruity with recent five-year outcomes of WEBCAST and WEBCAST2 trials.

Endovascular treatment of intracranial internal carotid artery bifurcation region aneurysms

Intracranial internal carotid artery (ICA) bifurcation region aneurysms are uncommon. When treatment is necessary for ICA, endovascular treatment (EVT) can be a useful option. Due to the complexity of these aneurysms and the variability of EVT techniques, EVT for ICA bifurcation aneurysms is challenging. Currently, it is necessary to perform a review to explore this issue further. In this review, the following issues were discussed: the anatomy of the ICA bifurcation region; the classification, natural history and EVT status of ICA bifurcation region aneurysms; the technique used for identifying ICA bifurcation region aneurysms; and the prognosis and complications of EVT for ICA bifurcation region aneurysms. According to the review and our experience, traditional coiling is currently the preferred therapy for ICA bifurcation region aneurysms. In addition, in select cases, new devices, such as flow diverters and Woven EndoBridge devices, can also be used to treat ICA bifurcation region aneurysms. Generally, EVT is an alternative treatment option for ICA bifurcation region aneurysms.

Dual Layer vs Single Layer Woven EndoBridge Device in the Treatment of Intracranial Aneurysms: A Propensity Score-Matched Analysis

BACKGROUND

The Woven EndoBridge (WEB) devices have been used for treating wide neck bifurcation aneurysms (WNBAs) with several generational enhancements to improve clinical outcomes. The original device dual-layer (WEB DL) was replaced by a single-layer (WEB SL) device in 2013. This study aimed to compare the effectiveness and safety of these devices in managing intracranial aneurysms.

METHODS

A multicenter cohort study was conducted, and data from 1,289 patients with intracranial aneurysms treated with either the WEB SL or WEB DL devices were retrospectively analyzed. Propensity score matching was utilized to balance the baseline characteristics between the two groups. Outcomes assessed included immediate occlusion rate, complete occlusion at last follow-up, retreatment rate, device compaction, and aneurysmal rupture.

RESULTS

Before propensity score matching, patients treated with the WEB SL had a significantly higher rate of complete occlusion at the last follow-up and a lower rate of retreatment. After matching, there was no significant difference in immediate occlusion rate, retreatment rate, or device compaction between the WEB SL and DL groups. However, the SL group maintained a higher rate of complete occlusion at the final follow-up. Regression analysis showed that SL was associated with higher rates of complete occlusion (OR: 0.19; CI: 0.04 to 0.8, p = 0.029) and lower rates of retreatment (OR: 0.12; CI: 0 to 4.12, p = 0.23).

CONCLUSION

The WEB SL and DL devices demonstrated similar performances in immediate occlusion rates and retreatment requirements for intracranial aneurysms. The SL device showed a higher rate of complete occlusion at the final follow-up.

Woven Endo Bridge shape modification contributes to decrease in adequate occlusion rate after Woven Endo Bridge implantation for wide-neck bifurcation intracranial aneurysms

PURPOSE

Recently, a novel device, the Woven Endo Bridge (WEB), was developed for wide-neck bifurcation intracranial aneurysms (WNBAs). The aim of this study is to investigate factors that contribute to adequate occlusion (AO) after the operation using detailed radiological images.

METHODS

The subjects were 29 patients with 29 aneurysms who received WEB implantation for WNBAs between December 2020 and April 2022. We assessed the contributing factors to AO by retrospectively comparing the AO group and non-AO group.

RESULTS

The mean age was 64.6 ± 13.1 years, and 18 were female (62.1%). The mean aneurysm dome width, aneurysm height, and aneurysm neck diameter were 4.8 ± 0.6 mm, 5.1 ± 0.6 mm, and 3.7 ± 0.6 mm, respectively. After about 6 months, 22 of 29 patients (75.9%) had AO. Complications were observed in 2 patients (6.9%), renal artery injury in one, and minor cerebral infarction in another, but the modified Rankin scale scores of both patients remained unchanged. Multivariate analysis extracted only WEB shape modification (WSM) as a contributing factor to AO (odds ratio: 0.912, p = 0.0287).

CONCLUSION

WEB implantation for WNBAs was a treatment modality with acceptable efficacy and safety. WSM was the only significant factor contributing to non-AO after the treatment. We should clarify the mechanisms or causes of WSM to achieve AO after WEB implantation in future.

A new era in the treatment of wide necked bifurcation aneurysms: Intrasaccular flow disruption

Wide-necked bifurcation aneurysms (WNBAs) are challenging lesions to treat via both open surgical and endovascular techniques. Presently, there are 3 intrasaccular devices available to address many of the limitations of prior techniques, all of which are at different phases of approval for human use around the world. These devices include the Woven EndoBridge (WEB®) made by MicroVention, the Artisse™ Embolization Device made by Medtronic, and the Contour Neurovascular System™ made by Cerus Endovascular. Although heterogenous in design, these devices rely on the principle of using fine mesh overlying the aneurysm neck to slow blood inflow, promoting stagnation and thrombosis that ultimately leads to healing across the neck and exclusion from the circulation. While our understanding improves as long-term occlusion rates from these devices continue to be studied, the safety profiles and short-term success rates demonstrated in recent studies provide optimism for these innovative intrasaccular devices for the treatment of WNBAs. In this paper, we review these 3 intra-saccular flow disruption devices for use in WNBAs and summarize recent literature and studies of their effectiveness and safety.

Ultrasound robotics for precision therapy

In recent years, the application of microrobots in precision therapy has gained significant attention. The small size and maneuverability of these micromachines enable them to potentially access regions that are difficult to reach using traditional methods; thus, reducing off-target toxicities and maximizing treatment effectiveness. Specifically, acoustic actuation has emerged as a promising method to exert control. By harnessing the power of acoustic energy, these small machines potentially navigate the body, assemble at the desired sites, and deliver therapies with enhanced precision and effectiveness. Amidst the enthusiasm surrounding these miniature agents, their translation to clinical environments has proven difficult. The primary objectives of this review are threefold: firstly, to offer an overview of the fundamental acoustic principles employed in the field of microrobots; secondly, to assess their current applications in medical therapies, encompassing tissue targeting, drug delivery or even cell infiltration; and lastly, to delve into the continuous efforts aimed at integrating acoustic microrobots into in vivo applications.

Thromboembolic Events With the Woven Endobridge Device: Incidence, Predictive Factors, and Management

BACKGROUND AND OBJECTIVES

The Woven EndoBridge (WEB) device has been increasingly used to treat wide-neck aneurysms showing a safe and effective profile, but a relatively high number of thromboembolic events (TEEs) have been reported with such treatment. We aimed to evaluate the incidence and management of TEEs and possible predictive factors related to WEB embolization of ruptured and unruptured intracranial aneurysms.

METHODS

A single-center database with consecutive aneurysms treated with a WEB device between July 2012 and May 2022 was reviewed for intraoperative and delayed TEEs. Univariate and multivariable analyses were used to determine factors associated with TEEs.

RESULTS

A total of 266 independent aneurysms were treated with WEB devices in 245 patients (mean age 55.78 ± 11.64 years, 169 (63.5%) females, 80 (30%) ruptured). The overall rate of TEEs is 13% (35/266), including 8.7% intraoperative. Symptomatic TEEs with clinical sequelae at a 3-month follow-up are reported to be 2.6% (7/266) with no TEE-related mortality. Both the replacement of a WEB device during the procedure (adjusted odds ratio = 2.61, 95% CI 1.24-5.49; P = .01) and ruptured aneurysms (adjusted odds ratio = 2.74, 95% CI 1.31-5.7; P = .007) were independent predictors of TEEs. A case-by-case management of intraprocedural TEE is also presented; tirofiban was successfully used in most cases of this cohort.

CONCLUSION

In this study, we demonstrated that ruptured aneurysms and WEB device replacement during the procedure were independent predictive factors for TEEs. As a result, making the correct choice of WEB is crucial for improving treatment outcomes. Moreover, with proper medical management of TEEs, minimal morbidity and no mortality could be achieved, which reinforces the safety of the technique.

Influence of size ratio on retreatment after coil embolization for unruptured bifurcation aneurysms

Background

Aneurysm size is considered a risk factor for aneurysm rupture, and even small aneurysms may rupture, especially bifurcation aneurysms (BAs), which are occasionally detected. Therefore, we aimed to investigate the predictors of retreatment after coil embolization for unruptured BAs, with a particular focus on the absolute and relative size of the aneurysm (size ratio [SR]).

Methods

To evaluate the predictors of retreatment, patients were divided into two groups: those with and those without retreatment. Patient characteristics and radiographic assessments were compared between the groups. SR was defined as the ratio of the maximum aneurysm diameter and the average diameter of the parent artery.

Results

Overall, 181 unruptured BAs in 176 patients were investigated. The mean age of the patients was 63.8 ± 9.6 years. The mean aneurysm size and SR were 7.18 ± 2.94 mm and 2.49 ± 1.32, respectively. Further, 12 aneurysms with retreatment (6.6 %) and 169 aneurysms without retreatment were compared. In univariate analysis, SR was significantly higher in the group with retreatment (P = 0.02), but aneurysm size was not significantly different between the groups (P = 0.09). Multivariable analysis revealed that SR > 2.6 was a significant predictor of retreatment (P = 0.03; odds ratio: 10.41; 95 % confidence interval: 2.1-51.73).

Conclusions

This study showed that SR influences retreatment after coil embolization for unruptured BAs. Therefore, if the aneurysm size and parent artery diameter were small, as in cases with a large SR, meticulous follow-up after coil embolization is required to detect recurrence and recanalization.

Woven EndoBridge Device for Unruptured Wide-Neck Bifurcation Aneurysm: A Multicenter 5-Year Follow-up

BACKGROUND AND OBJECTIVES

This multicenter study aimed to assess the safety and efficacy of the Woven EndoBridge (WEB) device for treating unruptured wide-neck intracranial bifurcation aneurysms (WIBAs) with short-, mid-, and long-term follow-ups (FUPs).

METHODS

Consecutive patients with unruptured WIBAs treated with WEB between December 2014 and January 2018 were included. Patient, aneurysm, and device characteristics were collected and analyzed retrospectively. Morbidity and mortality rates were determined by collecting intraprocedural, periprocedural, and delayed complications. Aneurysm occlusion was assessed at 1, 3, and 5 years using a 3-grade scale: complete occlusion, neck remnant, and residual aneurysm. Complete occlusion and neck remnant were considered as adequate occlusion. Patients who received re-treatment were also evaluated.

RESULTS

The study included 104 consecutive patients (55.8% female, mean age 58.6 ± 11.8 years). Aneurysm maximum size, neck, and dome-to-neck mean were, respectively, 6.9 ± 2.1 mm, 4.5 ± 1.2 mm, and 1.4 ± 0.3 mm. One-year FUP was collected for 95 patients, and 3- and 5-year FUPs were collected for 83 patients. Adequate occlusion was observed at 1-year FUP in 90.5% (86/95), 91.6% (76/83) was observed at 3-year FUP, and 92.8% (77/83) at 5-year FUP. None of the aneurysms bled after treatment. During FUP, 6/83 patients (7.2%) were re-treated for residual aneurysm. Morbidity and mortality rates closely related to aneurysm occlusion were 0% (0/104).

CONCLUSION

The WEB device was safe and effective for treating unruptured WIBAs, both in short-term and long-term FUPs.

Safety and effectiveness of the Woven EndoBridge (WEB) system for the treatment of wide necked bifurcation aneurysms: final 5 year results of the pivotal WEB Intra-saccular Therapy study (WEB-IT)

INTRODUCTION

The US Woven EndoBridge Intra-saccular Therapy (WEB-IT) study is a pivotal, prospective, single arm, investigational device exemption study to evaluate the safety and effectiveness of the WEB device for the treatment of wide neck bifurcation aneurysms (WNBAs). We present complete 5 year data for the cohort of 150 patients.

METHODS

150 patients with WNBAs were enrolled at 21 US and six international centers. Imaging from the index procedure, 6 month, 1 year, 3 year, and 5 year follow-up were reviewed by a core laboratory. Adverse events were reviewed and adjudicated by a clinical events adjudicator.

RESULTS

83 patients had 5 year follow-up imaging and 123 had clinical follow-up. No ruptured (0/9) or unruptured aneurysm (0/141) rebled or bled during follow-up. No new device or procedure related adverse events or serious adverse events were reported after 1 year. At 5 years, using the LOCF method, complete occlusion was observed in 58.1% and adequate occlusion in 87.2% of patients. For patients with both 1 year and 5 year occlusion statuses available, 76.8% (63/82) of aneurysms remained stable or improved with no retreatment. After 1 year, 18 aneurysms were retreated, 11 of which were adequately occluded at 1 year, and 15 of which were retreated in the absence of any deterioration in occlusion grade.

CONCLUSIONS

Five year follow-up data from the WEB-IT study demonstrated that the WEB device was safe and effective when used in the treatment of WNBAs. Aneurysm occlusion rates achieved at 1 year follow-up were durable, with rates of progressive thrombosis far exceeding rates of recurrence over time.

Endovascular treatment of middle cerebral artery aneurysms: current status and future prospects

Middle cerebral artery (MCA) aneurysms are complex and widely distributed throughout the course of the MCA. Various types of aneurysms can occur in the MCA. Ruptured as well as unruptured MCA aneurysms may require treatment to avoid bleeding or rebleeding. Currently, clipping is regarded as the first-line choice for the treatment of MCA aneurysms. However, endovascular treatment (EVT) is emerging as an alternative treatment in selected cases. EVT techniques vary. Therefore, it is necessary to review EVT for MCA aneurysms. In this review, the following issues were discussed: MCA anatomy and anomalies, classifications of MCA aneurysms, the natural history of MCA aneurysms, EVT status and principle, deployments of traditional coiling techniques and flow diverters (FDs), and deployments and prospects of intrasaccular flow disruptors and stent-like devices. According to the review and our experience, traditional coiling EVT is still the preferred therapy for most MCA aneurysms. FD deployment can be used in selective MCA aneurysms. Parent artery occlusion (PAO) can be used to treat distal MCA aneurysms. In addition, new devices can be used to treat MCA aneurysms, such as intrasaccular flow disruptors and stent-like devices. In general, EVT is gaining popularity as an alternative treatment option; however, there is still a lack of evidence regarding EVT, and longer-term data are not currently available for most EVT devices.

Endosaccular flow disruption with the Contour Neurovascular System: angiographic and clinical results in a single-center study of 60 unruptured intracranial aneurysms

BACKGROUND

The Contour Neurovascular System is a novel device designed to treat intracranial aneurysms by intrasaccular flow disruption. We report our experience and mid-term follow-up in a series of patients treated with the Contour.

METHODS

The patients were divided into an intention to treat and a per protocol population, the latter defined by the successful implantation of the Contour device. The intention to treat population included 53 patients (30 women, mean age 56 years) with 60 unruptured intracranial aneurysms (53 in the anterior circulation and seven in the posterior circulation). There was clinical and angiographic follow-up immediate postoperatively and at 24 hours, 3 months and 1 year using the Raymond-Roy classification and the O'Kelly-Marotta grading scale.

RESULTS

The Contour was successfully implanted in 54/60 (90%) aneurysms. With regard to the angiographic follow-up, there was adequate occlusion (defined as complete occlusion or presence of a neck remnant) in 31.5% of 54 aneurysms immediately postoperatively, 62.3% (in 53/54 aneurysms) at 24 hours, 81.4% (in 43/54 aneurysms) at 3 months, and 89.3% (in 28/54 aneurysms) at 1 year. Technical complications in 60 aneurysms of the intention to treat population included two (3.3%) inadvertent detachments of the device. Thromboembolic events were observed in four of the 60 aneurysms (6.7%), with no clinical symptoms in three patients and transient morbidity in one (1.7%). No aneurysm bleeding was observed and no patient was retreated during the 1-year follow-up period. There was no permanent morbidity or mortality.

CONCLUSIONS

The Contour device is effective and safe in the treatment of intracranial aneurysms. However, more experience and long-term follow-up are needed.

Lateral Compression is the Strongest Independent Predictor of Aneurysm Occlusion After Endovascular Treatment of Intracranial Aneurysms With the Woven EndoBridge Device

BACKGROUND AND OBJECTIVES

The effect of lateral compression (LC) of the Woven EndoBridge (WEB) device on intracranial aneurysm (IA) occlusion and retreatment has not been studied in depth. This study aims to determine the effect of LC on aneurysm occlusion and retreatment after endovascular treatment with WEB.

METHODS

We retrospectively reviewed IAs treated with WEB at our institution between February 5th, 2019, and March 31st, 2022. LC was determined in the immediate postdetachment angiogram by measuring the mean implanted WEB width at the equator in two orthogonal projections and subtracting it from the nominal WEB width. LC was then converted to the percentage of nominal WEB width (percent LC [%LC]). Independent predictors of complete and adequate aneurysm occlusion at follow-up and retreatment were determined using multivariate logistic regression analysis. Optimal %LC thresholds were determined using receiver operating characteristic analysis.

RESULTS

One hundred and fifty-five IAs were included, with a mean size of 6.4 mm, a mean neck of 3.6 mm, and a mean time to last follow-up of 15.5 months. At last follow-up, complete and adequate aneurysm occlusion was present in 98 (63.2%) and 139 (89.7%) IAs, respectively. Twelve IAs were retreated (7.7%). %LC was the strongest independent predictor of complete and adequate aneurysm occlusion at first and last follow-up and an independent predictor of aneurysm retreatment. Optimal %LC thresholds for complete and adequate aneurysm occlusion at first follow-up were >17.1% and >15.7%, respectively. Compared with IAs in which these thresholds were not attained, IAs in which these thresholds were attained had significantly higher rates of complete (31% vs 68%, P-value <.0001) and adequate occlusion (81% vs 96%, P-value .004) at first follow-up. The optimal %LC threshold for aneurysm retreatment was ≤15.6%. IAs with ≤15.6% LC had a significantly higher rate of retreatment (15%) than IAs with >15.6% LC (4%, P-value .025).

CONCLUSION

LC is the strongest independent predictor of aneurysm occlusion in IAs treated with WEB.

The Woven EndoBridge (WEB) Device for the Treatment of Intracranial Aneurysms: Ten Years of Lessons Learned and Adjustments in Practice from the WorldWideWEB Consortium

Several studies have shown promising outcomes of the Woven EndoBridge (WEB) device for the treatment of wide-necked intracranial bifurcation aneurysms. This is a multicenter study attempts to explore the changes in trends and treatment outcomes over time for WEB embolization of intracranial aneurysms. The WorldWideWEB consortium is a retrospective multicenter collaboration of data from international centers spanning from January 2011 and June 2021, with no limitations on aneurysm location or rupture status. Both bifurcation and sidewall aneurysms were included. These patients were stratified based on treatment year into five treatment intervals: 2011-2015 (N = 66), 2016-2017 (N = 77), 2018 (N = 66), 2019 (N = 300), and 2020-2021 (N = 173). Patient characteristics and angiographic and clinical outcomes were compared between these time intervals. This study comprised 671 patients (median age 61.4 years; 71.2% female) with 682 intracranial aneurysms. Over time, we observed an increasing tendency to treat patients presenting with ruptured aneurysms and aneurysms with smaller neck, diameter, and dome widths. Furthermore, we observed a trend towards more off-label use of the WEB for sidewall aneurysms and increased adoption of transradial access for WEB deployment. Moreover, the proportion of patients with adequate WEB occlusion immediately and at last follow-up was significantly higher in more recent year cohorts, as well as lower rates of compaction and retreatment. Mortality and complications did not differ over time. This learning curve study suggests improved experience using the WEB for the treatment of intracranial aneurysms and has yielded higher rates of adequate occlusion over time.

A single centre retrospective analysis of short- and medium-term outcomes using the Woven EndoBridge (WEB) device and identification of the device-to-aneurysm volume ratio as a potential predictor of aneurysm occlusion status

BACKGROUND

The Woven EndoBridge (WEB) is a potential treatment option in patients with wide-necked bifurcation aneurysms (WNBAs). We analysed our WEB device outcomes (occlusion rates and complications) and studied factors that may predict aneurysm occlusion status at short- and medium-term follow-up.

METHODS

74 patients with ruptured and unruptured aneurysms underwent treatment with the WEB device over a 5-year period. Simple hypothesis tests assessed differences between treated ruptured and unruptured aneurysms. Univariable binary logistic regression was used to assess the effect of age, gender, and aneurysm location on the likelihood of adequate occlusion at six months. Aneurysm dimentions including device-to-aneurysm volume (DAV) ratios were compared between adequately and inadequately occluded aneurysms.

RESULTS

The mean age at the time of the procedure was 58.2 years (SD 12.2; range 34-88) and the male to female ratio was 1:2.7. Middle cerebral artery (MCA) was the most commonly treated aneurysm. There was no significant difference in occlusion rates between ruptured and unruptured aneurysms. The six- and 18-month angiographic follow-up data was available for 61 and 32 patients respectively with adequate occlusion rates of 78.7% (48/61) and 78.1% (25/32). Procedure-related complications occurred in 6 patients (8.1%). Baseline DAV ratio was found to be significantly higher in aneurysms that were adequately occluded at both short- (p-value 0.015) and medium-term (p-value 0.047) follow-up.

CONCLUSIONS

WEB devices are a safe and effective endovascular treatment option for WNBAs. WEB device selection incorporating the peri-procedural DAV ratio may help improve the accuracy of device sizing thereby improving the successful occlusion rate.

Questionnaire Survey of Neurointerventional Simulation Training in the Japanese Society for Neuroendovascular Therapy

Objective

Simulation training has focused on education and practical training. However, the adoption rate of neurointerventional simulation training in Japan is unknown. Therefore, we sent a questionnaire survey form to consulting specialists from the Japanese Society for Neuroendovascular Therapy (JSNET) to clarify the actual simulation training situation and compare the differences between university hospitals and general hospitals in Japan.

Methods

The questionnaire survey was conducted in 243 neurosurgical training facilities that had JSNET consulting specialists between May 31, 2021 and July 31, 2021. The questionnaire survey forms were distributed by Google Forms.

Results

A total of 162 facilities responded to the survey (response rate: 66.7%; 35.2% from university hospitals and 64.8% from general hospitals). The adoption rate for simulation training was 53.7%, and it was significantly higher in the university hospitals than in the general hospitals (64.9% vs. 47.6%, p = 0.035). On the simulation effectiveness survey, more than 80% of respondents answered that the simulation training was a useful tool for upskill training. The open-ended question on interventional simulation training showed that there are limiting factors such as financial constraints. Additionally, respondents expressed a desire for a standard neurointerventional simulation training and education program.

Conclusion

The adoption rate for simulation training was 53.7% in the training facilities of JSNET, and it was higher in the university hospitals than in the general hospitals. Most of the respondents answered that simulation training is an effective tool to improve neurointerventional skills. They also requested the establishment of simulation training programs and simulation tools.

A review and journey in intrasaccular treatment of intracranial aneurysms

The invested effort and collaboration of clinicians and medical device companies to improve occlusion rates and clinical outcomes for patients with intracranial aneurysms treated via less invasive endovascular means led to the development of the concept of intrasaccular devices. Intrasaccular devices were introduced to offer simple treatment options, offering easier navigation through difficult anatomy, simpler and quicker deployment into large and wide-neck aneurysms. Additionally, they offer easier sizing, whilst offering a wide range of options suitable for aneurysms of different sizes. The concept of most intrasaccular devices is to occupy the aneurysm neck, however offering better stability than simple coiling, therefore increasing the chance of long-term aneurysm occlusion. This is achieved without a sizable metal content within the parent vessel, contrary to flow diverters, theoretically reducing the risk of thromboembolic events. This review aims to discuss the history and latest developments of intrasaccular intracranial devices, which offer an exciting and potentially successful option for treatment of complex intracranial aneurysms.

Persistent contrast-filling in the woven endobridge device three months after its implantation for cerebral aneurysm: Incidence, predictive factors, and outcome

OBJECTIVE

The Woven EndoBridge (WEB) was developed to treat wide-neck bifurcation intracranial aneurysms. Occasionally, persistent contrast-filling has been observed in the WEB after treatment. The purpose of our study was to investigate its incidence, predictive factors, and clinical impact.

METHODS

All patients treated with the WEB between January 2021 and September 2021 at our institute were reviewed. Age, gender, antiplatelet therapy, and angioarchitecture were compared between the persistent-filling group and the no-filling group at the three-month follow-up angiography.

RESULTS

We included 20 patients with 20 unruptured aneurysms. Ten of the 20 intracranial aneurysms (50 %) showed contrast-filling in the WEB after three months. Two of the 10 had contrast not only inside, but around the device. Statistically significant differences were observed between the persistent-filling group and the no-filling group in neck size (median: 4.5 mm vs. 3.8 mm), deviation of the aneurysm axis from the inlet flow line where the orifice of the bifurcated arteries overlaps (mean: 15.1° vs. 33.0°), and postoperative dual antiplatelet therapy (DAPT) for at least a month (90 % vs. 20 %). One case had additional coil embolization six months after the WEB implantation. Including this case, one year after the treatment or the re-treatment, the filling in the device had disappeared in nine of 10 cases. No bleeding was observed during the mean follow-up period of 24 months.

CONCLUSION

Persistent contrast-filling was associated with postoperative DAPT for at least a month, a wide neck, and less deviation of the aneurysm axis from the inlet flow line. If the contrast-filling is only within the WEB and not between the aneurysmal wall and the WEB, we are not concerned. To further assess the clinical impact of this phenomenon, long-term follow-up will be needed.

A systematic review of the Woven EndoBridge device-do findings in pre-clinical animal models compare to clinical results?

BACKGROUND

The Woven Endobridge (WEB) is designed to treat intracranial wide-neck bifurcation aneurysms, preventing subarachnoid hemorrhage. The translational value of animal models used for WEB device testing is unknown. With this systematic review, we aim to identify the existing animal models used in testing the WEB device and compare the efficacy and safety outcomes to those of prospective clinical studies.

METHODS

This study was funded by ZonMw: project number 114024133. A comprehensive search was performed in PubMed and in EMBASE via the Ovid interface. The following exclusion criteria were used: 1) not an original full-length research paper, 2) not an in vivo animal study or a human study, 3) no WEB implantation, 4) if in humans: not a prospective study. The SYRCLE risk of bias tool (animal studies) and the Newcastle-Ottawa quality assessment scale for cohort studies (clinical studies) were used to assess risks of bias. A narrative synthesis was performed.

RESULTS

Six animal studies and 17 clinical studies met the inclusion criteria. The rabbit elastase aneurysm model was the only animal model used to assess WEB device performance. Safety outcomes were never reported in animal studies. Efficacy outcomes were more heterogeneous in animal studies than in clinical studies, which could be due to limited external validity of the animal models in terms of aneurysm induction and dimensions. Both animal and clinical studies were predominantly single-arm studies, and were at unclear risk of several types of bias.

CONCLUSIONS

The rabbit elastase aneurysm model was the only pre-clinical animal model used to assess WEB device performance. Safety outcomes were not evaluated in animal studies and could therefore not be compared to clinical outcomes. Efficacy outcomes were more heterogeneous in animal studies than in clinical studies. Future research should focus on improving methodology and reporting in order to draw accurate conclusions on the performance of the WEB device.

Impact of aneurysm diameter, angulation, and device sizing on complete occlusion rates using the woven endobridge (WEB) device: Single center United States experience

BACKGROUND

The Woven EndoBridge device is a novel treatment option for wide-necked bifurcation intracranial aneurysms (WNBA). While this device has had good results, there remains a subset of WNBA that fail this treatment. The main objective of this study is to identify risk factors that are associated with incomplete occlusion of WEB treated aneurysms at short-term follow up.

METHODS

This was a retrospective study of 31 patients with intracranial aneurysms who were treated with WEB at a single institution in the USA in 2019-2021. Data was collected via chart review on patient demographics, aneurysm characteristics, procedural details, and occlusion status at six months follow up. Bivariate analyses were performed comparing completely occluded aneurysms with neck remnants and residual aneurysms.

RESULTS

16 (52%) had completely occluded aneurysms while 11 (35%) patients had a neck remnant, and 4 (13%) patients had a residual aneurysm at follow up. Patients with neck remnants and residual aneurysms had aneurysms with a larger diameter. A large aneurysm diameter is an independent risk factor for incomplete occlusion (OR 4.23 95% CI 1.08-16.53 P value = 0.038). Patients with residual aneurysms had an average difference between the aneurysm width and WEB diameter of -0.08mm compared to 1.2 mm in patients with occluded aneurysms. 75% of patients with a residual aneurysm presented with a ruptured aneurysm. Lastly, more patients with a residual aneurysm had an immediate angiographic outcome of incomplete occlusion.

CONCLUSION

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.

Comparative effectiveness of stent-assisted coiling and Woven EndoBridge embolization for the treatment of unruptured wide-neck bifurcation intracranial aneurysms

OBJECTIVE

Woven EndoBridge (WEB) intrasaccular flow disruptors and stent-assisted coiling (SAC) are viable endovascular treatment options for wide-neck bifurcation intracranial aneurysms (WNBAs). Data directly comparing these two treatment options are limited. The authors aimed to compare radiographic occlusion rates and complication profiles between patients who received WEB and those who received SAC for WNBAs.

METHODS

Retrospective review of a prospectively maintained cerebrovascular procedural database was performed at a single academic medical center between 2017 and 2021. Patients were included if they underwent WEB embolization or SAC of an unruptured WNBA. SAC patients were propensity matched to WEB-embolized patients on the basis of aneurysm morphology. Complete and adequate (complete occlusion or residual neck remnant) occlusion rates at last angiographic follow-up, as well as periprocedural complications, were compared between the two groups. A cost comparison was performed for a typical 5-mm WNBA treated with WEB versus SAC by using manufacturer-suggested retail prices.

RESULTS

Thirty-five WEB and 70 SAC patients were included. Aneurysm width, neck size, and dome-to-neck ratio were comparable between groups. Follow-up duration was significantly longer in the SAC group (median [interquartile range] 545 [202-834] days vs 228 [177-494] days, p < 0.001, Mann-Whitney U-test). Complete (66% of WEB patients vs 69% of SAC patients) and adequate (94% WEB vs 91% SAC) occlusion rates were similar between groups at the last available angiographic follow-up (p = 0.744, chi-square test). Complete occlusion rates were comparable on Cox regression analysis after correction for follow-up duration (hazard ratio 1.5, 95% CI 0.8-3.1). Average time to residual aneurysm or neck formation was not statistically different between treatment groups (613 days for SAC patients vs 347 days for WEB patients, p = 0.225, log-rank test). Periprocedural complications trended higher in the SAC group (0% WEB vs 9% SAC, p = 0.175, Fisher exact test), although this finding was not significant. The equipment costs for a typical SAC case were estimated at $18,950, whereas the costs for a typical WEB device case were estimated at $18,630.

CONCLUSIONS

Midterm complete and adequate occlusion rates were similar between patients treated with WEB and those treated with SAC. Given these comparable outcomes, there may be equipoise in treatment options for WNBAs.