Risk Factors of Procedural Complications Related to Woven EndoBridge (WEB) Embolization of Intracranial Aneurysms

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.

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.

Aneurysmal recurrence and retreatment modalities after Woven EndoBridge (WEB) device implantation: A systematic review and meta-analysis

BACKGROUND

The Woven EndoBridge (WEB) device is used to treat wide-neck bifurcation aneurysms (WNBAs). We conducted a systematic review and meta-analysis to determine the retreatment rate strategies following aneurysmal recurrence of WEB device treated WNBAs.

METHODS

This study is reported following the PRISMA 2020 guidelines. We conducted a systematic review of the literature using PubMed, Scopus, Embase, and Web of Science. Data were pooled using a random-effects model. We calculated pooled prevalence and corresponding 95% confidence intervals (CI).

RESULTS

We included 11 studies. The overall retreatment rate was 171/1875 aneurysms (10.3%; 95% CI  =  8.3-12.9). Stent-assisted coiling was used to treat 59 aneurysms (36.7%; 95% CI  =  26.4-48.5), and flow diverters were used to treat 44 aneurysms (18.7%; 95% CI  =  9.9-32.5). Following retreatment, the complete occlusion rate was 57/91 aneurysms (62.8%; 95% CI  =  48.2-75.3) and the adequate occlusion rate was 24/91 aneurysms (26.4%; 18.4%-36.4%). The most common aneurysmal recurrence site was the anterior communicating artery (44/136 aneurysms, 32.4%; 95% CI  =  25.0-40.7).

CONCLUSIONS

Roughly 10% of WNBAs initially treated with the WEB device will undergo retreatment. Retreatment is an effective strategy for WEB-treated aneurysms, with high rates of adequate and complete occlusion. Future studies should work to identify risk factors for aneurysmal recurrence.

Identifying risk factors for perioperative thromboembolic complications in patients treated with the Woven EndoBridge device

INTRODUCTION

Woven EndoBridge (WEB) is a new endovascular treatment option for wide necked bifurcation aneurysms. Results from the WEB-IT trial showed a 0% risk of thromboembolic complications within 30 days post-op but the rate reported in the literature is as high as 10%. We are exploring potential risk factors associated with immediate thromboembolic complications in patients treated with the WEB device.

METHODS

Retrospective study of forty-two patients with intracranial aneurysms who were treated with WEB at a single center from 2019-2021. Data was collected on patient demographics, comorbidities, aneurysm characteristics, procedural details, and hospital course. Bivariate analyses were performed to compare patients who experienced a periprocedural ischemic stroke to those who did not. Multiple logistic regression modeling was performed to identify independent risk factors for thromboembolic complications.

RESULTS

Of the 42 patients that were treated with WEB, 6 suffered an ischemic stroke (AIS). These patients were more likely to have an underlying diagnosis of arrythmias (p value = 0.007). Furthermore, they had a median angle of 32.0° in the true neck view on diagnostic angiogram compared to 19.5° (p value = 0.046). Lastly, they had a longer procedure length of 228 min compared to 178 min (p value = 0.002). Patients with thromboembolic complications had a longer length of stay in the hospital and worse outcomes at three months follow up. On logistic regression modeling, these risk factors did not reach statistical significance.

CONCLUSION

Risk factors of thromboembolic complications after WEB placement include cardiac arrythmias, acute aneurysmal angle in the true neck view and a longer procedure length.

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.

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.

Successful WEBectomy during embolization of temporal arteriovenous malformation-associated flow-related basilar aneurysms

OBJECTIVE

Intra-procedural WEB device migration is a scarcely reported complication that necessitates prompt intervention.

CASE PRESENTATION

Endovascular treatment of two broad necked flow-related aneurysms was planned aided by WEB-SL (Woven EndoBridge-single layer) devices in a 71-year-old female with known left temporal arteriovenous malformation. Inadvertent distal migration occurred while performing a control angiogram with an automated iodine injector. Immediate retrieval was successfully performed using a Solitaire stent-retriever.

CONCLUSION

To our knowledge, we report for the first time the successful retrieval of a distally migrated WEB using a stent-retriever device.

Comparison of transradial and transfemoral access for the Woven EndoBridge embolization of intracranial aneurysms: A single-center experience

BACKGROUND

Transradial access has been adopted more commonly in the neuroendovascular field. However, the experience of using this access for the Woven EndoBridge embolization of intracranial aneurysms is still in the early stage.

OBJECTIVE

This study aimed to compare the outcomes between transradial access and transfemoral access for the Woven EndoBridge embolization of intracranial aneurysms.

METHODS

This is a retrospective analysis of consecutive intracranial aneurysms treated with Woven EndoBridge placement between May 2019 and August 2020 by the senior author at a high-volume center. The aneurysms of all sizes and locations treated with Woven EndoBridge placement with or without adjunctive stent or coiling were included. Patient demographics, aneurysm and treatment characteristics, procedural complications, and angiographic and functional outcomes were compared between two approaches.

RESULTS

This study included a total of 34 patients with intracranial aneurysms (median age 60 years, female-to-male ratio 2:1). Of these, the radial access was utilized in 20 (58.8%) patients, while the femoral access was used in 14 (41.2%) patients. A Woven EndoBridge device was successfully deployed in all cases, and none of the patients required a crossover to another access. There were no significant differences in baseline characteristics, procedure time and fluoroscopy time, outcomes, and complication rates between both groups.

CONCLUSION

Our report suggests the possible feasibility and safety of the transradial access for the Woven EndoBridge embolization of intracranial aneurysms. However, the results of this study are suggestive rather than conclusive, and there is still a need for future large prospective studies.

Study on the Effect of Hope Theory Combined with Psychological Intervention on the Improvement of Prognosis

In order to evaluate the effect of the hope theory combined with psychological intervention on patients with intracranial aneurysms after surgical treatment, a total of 98 patients with intracranial aneurysm surgery admitted to our hospital from March 2019 to January 2021 were analyzed. According to the random number table method, all patients are divided into two groups: the traditional group and the experimental group. After intracranial aneurysm surgery, the patients of the traditional group and of the joint group are treated with conventional nursing and hope theory combined with psychological intervention nursing mode, respectively. The results demonstrate that the hope theory combined with psychological intervention can improve the level of postoperative patients with intracranial aneurysm life hope, self-efficacy, and postoperative quality of life.

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.

Horizontal stent deployment via extracranial-intracranial bypass in coil embolization of basilar apex aneurysms: technical report

BACKGROUND

The endovascular treatment of large, wide-necked basilar apex aneurysms (BAAs) remains challenging. Although horizontal stent deployment across both P1 segments of the posterior cerebral arteries (PCAs) would be an optimal strategy in coil embolization of wide-necked BAAs, this is only feasible in cases with anatomically favorable access. In rare circumstances, large-diameter conduits of extracranial-intracranial (EC-IC) bypass can also provide a good access route for endovascular treatment of complex intracranial aneurysms.

METHODS

We describe the technique of accessing the PCA via EC-IC bypass grafts and deploying a stent horizontally across the neck of BAA and its coil embolization. We provide a detailed technical review and describe some pitfalls of the procedure.

RESULTS

Two patients underwent EC-IC bypass surgery prior to the treatment of a large, wide-necked BAA. The radial artery and saphenous vein were used as grafts, respectively. To facilitate coil embolization for a large BAA, a PCA-to-PCA horizontal stent was deployed via the bypass graft. Trans-cell and jailing techniques were used, respectively. Both aneurysms were completely occluded, and the patients were discharged without any neurological deficit.

CONCLUSION

Horizontal stent deployment via EC-IC bypass grafts can be performed safely, providing proper closure of the aneurysmal neck and apposition to both PCAs, facilitating complete coil embolization.

Woven Endobridge (WEB) augmented by Y-stent in a shallow basilar tip aneurysm

The Woven Endobridge (WEB) device can be an effective and simple treatment modality for wide-neck bifurcation intracranial aneurysms. We present a case of a shallow basilar tip aneurysm treated with the WEB device that required stabilization with Y-stent through radial access.

The Woven EndoBridge Device for the Treatment of Intracranial Aneurysms: Initial Clinical Experience within an Australian Population

Purpose

Advances in endovascular technology have expanded the treatment options for intracranial aneurysms. Intrasaccular flow diversion is a relatively new technique that aims to disrupt blood inflow at the neck of the aneurysm, hence promoting intrasaccular thrombosis. The Woven EndoBridge device (WEB; MicroVention, Aliso Viejo, CA, USA) is an US Food and Drug Administration approved intrasaccular flow diverter for wide-necked aneurysms. We report the early interim clinical and radiological outcomes of patients with both ruptured and unruptured intracranial aneurysms (IAs) treated using the WEB device in an Australian population.

Materials and Methods

A retrospective analysis was done of patients with ruptured or unruptured IAs who received treatment with WEB across 5 Australian neuroendovascular referral centers between May 2017 and November 2020. Angiographic occlusion was assessed with time-of-flight magnetic resonance angiography. Complications were recorded and clinical outcomes were assessed using the modified Rankin scale at follow-up.

Results

In total, 66 aneurysms were treated in 63 patients, with successful deployment of the WEB device in 98.5% (n=65). Eighteen (26.9%) ruptured aneurysms were included. Failure of deployment occurred in a single case. Adjunct coiling and/or stenting was performed in 20.9% (n=14) cases. Sixty-two patients with 65 aneurysms using a WEB device were followed up (mean=9.1 months), and 89.4% of these had complete aneurysm occlusion while 1.5% remained patent. Functional independence was achieved in 93.5% of cases.

Conclusion

Early results following the use of WEB devices in Australia demonstrate safety and adequate aneurysm occlusion comparable to international literature.

Stent-assisted WEB embolization: aneurysm characteristics, outcome and case report of a WEB delivered through a stent

PURPOSE

Woven Endobridge (WEB) embolization has become a well-established endovascular treatment option for wide-necked bifurcation aneurysms. The objective was to analyse cases that required additional stent-implantation.

METHODS

Images of 178 aneurysms ≤ 11 mm treated by WEB only or by WEB plus stent were retrospectively reviewed, evaluating aneurysm characteristics, procedural specifics, adverse events and angiographic results. Moreover, we report a case of a WEB delivered through a previously implanted stent.

RESULTS

Additional stent implantation was performed in 15 patients (8.4%). Baseline patient and aneurysm characteristics were comparable between both groups. A single stent was used in 12 cases and 2 stents in Y-configuration in 3. Thromboembolic complications occurred more often with stent assistance (33.3% vs. 8.0%, p = 0.002), while ischemic stroke rates were comparable between both groups (0% vs. 1.8%, p = 1.0). Six-month angiographic follow-up showed complete occlusion, neck remnants and aneurysm remnants in 73.4%, 19.4% and 7.3% after WEB only, respectively, and in 66.7%, 20.0% and 16.7% after WEB plus stent, respectively (p = 0.538). A case report shows that WEB deployment through the struts of a previously implanted standard microstent is feasible, even if a VIA 33 microcatheter is needed.

CONCLUSION

In the present study, stent-assisted WEB embolization had a comparable safety and efficacy profile compared to treatment by WEB only. However, stent-assisted WEB embolization requires long-term anti-platelet medication, which annihilates the advantages of the WEB as a purely intrasaccular device.

CLINICAL TRIAL REGISTRATION NUMBER

N/A.

Influence of operator experience on the technical and clinical results of Woven EndoBridge endovascular treatment for intracranial aneurysms

BACKGROUND & PURPOSE

The safety and efficacy of the Woven EndoBridge (WEB) device has been proven in recent multicenter trials. This study investigated whether operator experience influences WEB treatment-related outcomes.

MATERIAL AND METHODS

This was a retrospective analysis of a prospectively collected multicenter database. The data of all patients who underwent WEB treatment for an intracranial aneurysm from March 2014 to June 2020 in two high-volume centers were pooled. Operator experience was indexed by the number of WEB treatments performed previously. The primary endpoint was the overall complication rate. Secondary endpoints were long-term adequate (Raymond-Roy classification of 1-2.) angiographic occlusion, WEB-related complications, number of WEB not deployed, procedure duration, and radiation exposure (air kerma).

RESULTS

Among 237 patients (mean age 59.4 +/- 11.5 years) treated with WEB (median aneurysm diameter, 5.8 mm; interquartile range 4.5-7 mm), WEB-related complications occurred in 28 patients (11.8%) and adequate long-term occlusion was achieved for 154 aneurysms (86%). The median number of WEB treatment performed previously per operator was 20 (IQR, 9-41). The overall complication rate, WEB-related complication rate and aneurysm occlusion rate were not significantly correlated with WEB operator experience. There were also no significant correlations between the WEB operator experience and the number of WEB not deployed, procedure duration or radiation exposure.

CONCLUSION

There was no significant association between the number of WEB treatments previously performed per operator and any technical or clinical results after intracranial aneurysm treatment with WEB. These results imply a relatively short learning curve for this device in high-volume neurovascular centers.

Silk Vista Baby Is a Safe and Technically Feasible Flow Diverting Stent for Distal Aneurysm Treatment

Background and Purpose: Flow diverting stents are designed to divert blood flow from the aneurysm sac, allowing for eventual occlusion following endovascular therapy. This case series reports clinical experience using the Silk Vista Baby (SVB, Balt Extrusion, Montmorency, France), a flow diverter (FD) designed to treat intracranial aneurysms in small, distal vessels.

Methods: All patients who underwent treatment with SVB at the University Hospital “Santa Maria della Misericordia” of Udine between July 2018 and September 2020 were retrospectively identified. Baseline patient and aneurysm characteristics, intraprocedural technical outcomes, periprocedural complications, modified Rankin Scale (mRS) at discharge, magnetic resonance imaging (MRI) results at 3-month follow-up, and angiographic results at 6-month follow-up were collected.

Results: A total of 18 patients (55.6% [10/18] male; mean age 62.6 years, range: 42–77 years) were retrospectively identified, receiving treatment for 22 aneurysms. Most patients were symptomatic (14/18, 77.8%) and approximately half had subarachnoid hemorrhage (10/18, 55.6%). Sufficient aneurysm coverage was achieved in 88.9% (16/18) of patients with a single device. Mortality did not occur (0/18, 0%); adverse device-related events included side branch occlusion (1/18, 5.6%) and in-stent thrombosis (1/18, 5.6%). At discharge, 77.8% (14/18) had an mRS of 0. In most cases, patients showed complete occlusion (10/15, 66.7%) or a small aneurysmal remnant (3/15, 20.0%) upon MRI; upon angiography, most showed complete occlusion (10/13, 76.9%) or only a small aneurysmal remnant (2/13, 15.4%).

Conclusion: This case series showed that the SVB FD is safe and feasible to use in patients with aneurysms in small, distal vessels. Additional randomized, prospective studies with larger cohorts are needed for the SVB.

Microsurgical Clipping versus Advanced Endovascular Treatment of Unruptured Middle Cerebral Artery Bifurcation Aneurysms After a "Coil-First" Policy

OBJECTIVE

Although intracranial aneurysms are increasingly treated endovascularly, microsurgical clipping has been the standard approach for middle cerebral artery (MCA) aneurysms. We compared microsurgical clipping and state-of-the-art endovascular treatment of unruptured MCA bifurcation aneurysms treated at a neurovascular center following a "coil-first" policy.

METHODS

This single-center study included 148 patients treated for 160 unruptured MCA bifurcation aneurysms. Technical success, complications, clinical outcome, and angiographic results were retrospectively compared.

RESULTS

Microsurgical clipping was performed for 120 MCA aneurysms (75%) and endovascular treatment for 40 (25%; conventional coiling: 8, stent-assisted coiling: 16, balloon-assisted coiling: 3, and flow-disruption: 13). Technical treatment success was higher in the clipping group (100%) than in the endovascular group (92.5%, P = 0.015). Overall, complications occurred in 16.7% for clipping and in 20.0% for endovascular treatment (P = 0.631). Major ischemic stroke rates were 4.2% in the clipping group and 7.5% in the endovascular group (P = 0.414). At 6 months, a favorable outcome was obtained by 99.2% after clipping and 95.0% after endovascular treatment (P = 0.154). The 6-month complete aneurysm occlusion rates were by trend higher in the clipping group (89.2%) than in the endovascular group (75.9%, P = 0.078).

CONCLUSIONS

Microsurgical clipping was associated with a higher technical success rate and tendentially higher complete occlusion than endovascular treatment, with no additional morbidity and similar clinical outcome. On the basis of these results, clipping proves to be the standard treatment option for MCA bifurcation aneurysms. However, endovascular treatment represents a safe and efficient alternative treatment option for patients.

Volume-based sizing of the Woven EndoBridge (WEB) device: A preliminary assessment of a novel method for device size selection

INTRODUCTION

Accurate sizing of the Woven EndoBridge (WEB) device is of critical importance as it determines procedural safety and successful occlusion of wide neck bifurcation aneurysms. The aim of this study was to assess the ability of aneurysm volume to assist in accurate WEB size selection.

METHODS

All patients with an intracranial aneurysm treated with the WEB SL or WEB SLS device between March 2019 and October 2019 were identified for this retrospective study. Aneurysm volumes were calculated with auto-segmentation using a three-dimensional volume rendering program on an independent Syngo workstation (Siemens Healthineers AG). Pearson correlation coefficients were calculated for aneurysm auto-segmented volumes and WEB volumes, as well as for aneurysm height × width and WEB height × width. Follow-up angiographic outcomes were collected at 6-9 months post-procedure.

RESULTS

Twenty-nine aneurysms were evaluated by 3D rotational angiography. The correlation coefficient with WEB size was larger for auto-segmented aneurysm volumes (r = 0.979) compared to height × width measurements (r = 0.867). Using Fisher r-to-z transformations, we found the difference between the two correlations to be statistically significant (p = 0.0007). Follow-up angiography available in 13 subjects demonstrated an 85% complete aneurysm occlusion rate.

CONCLUSION

Aneurysm volumes are highly correlated with WEB volumes, with auto-segmentation volumes displaying statistically significant difference against conventional height by width measurements. These results suggest that volumetric measurements of aneurysm size provide a useful adjuvant measure to assist in appropriate size selection of the WEB device.

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

BACKGROUND

The concept of intrasaccular flow diversion using the Woven EndoBridge (WEB) device changed the traditional endovascular concept for wide-necked bifurcation aneurysms. The latest technical advancement resulted in the WEB 17 system, a softer device composed of fewer wires which enables treatment of smaller more distally located aneurysms by using smaller microcatheters as compared to the WEB 21 system.

OBJECTIVE

This retrospective observational study aimed to evaluate and compare the angiographic and clinical results achieved with WEB 21 and WEB 17 in aneurysm morphologies eligible for both systems (maximum width 3-6 mm).

METHODS

Between August 2014 and August 2019 a total of 63 and 130 aneurysms with a maximum width of 3-6 mm were treated with either WEB 21 and WEB 17, respectively, at 2 neurovascular centers. Cases were analyzed based on a comparison regarding aneurysm size, location and rupture status.

RESULTS

The technical success, the periprocedural complication rate and the rate of additional devices used showed no relevant differences between the two groups. Aneurysms treated with the WEB 17 system were smaller and more frequently distally located. The overall complete occlusion rate at 3 months was higher in the WEB 17 group (65.5% versus 55.1%). The superiority of complete aneurysm occlusion achieved with WEB 17 was statistically significant in the subgroup of unruptured middle cerebral artery aneurysms.

CONCLUSION

The use of WEB 17 expands the treatment indications for intrasaccular flow-diversion towards smaller and more distally located aneurysms with a safety profile comparable with that of the WEB 21.

Residual Flow Inside the Woven EndoBridge Device at Follow-Up: Potential Predictors of the Bicêtre Occlusion Scale Score 1 Phenomenon

BACKGROUND AND PURPOSE

The Woven EndoBridge (WEB) device is an established technique for the treatment of intracranial aneurysms. Occasionally, persistent opacification inside the WEB lumen can be observed at follow-up (previously described as Bicêtre Occlusion Scale Score 1). We evaluated potential risk factors of this phenomenon, hypothesizing that initial deviation of the WEB device from the aneurysm axis, size of the aneurysmal neck surface, or inappropriate WEB sizing correlates with Bicêtre Occlusion Scale Score 1 findings.

MATERIALS AND METHODS

We systematically reviewed all patients treated with the WEB device between February 2014 and December 2018 in our neurointerventional center. Patients with midterm follow-up DSA available were considered for aneurysm evaluation applying the Bicêtre Occlusion Scale Score. WEB angle deviation from the aneurysm axis, neck widths, and WEB sizes were collected.

RESULTS

We included 65 patients with 67 intracranial aneurysms. Eleven of 67 (16.4%) intracranial aneurysms showed the Bicêtre Occlusion Scale Score 1 phenomenon at follow-up. Anterior-posterior projections of WEB axis deviation (angles measured in degrees) were significantly different between the Bicêtre Occlusion Scale Score 1 cohort (median ± interquartile range, 17 ± 17) and all other Bicêtre Occlusion Scale Scores (median ± interquartile range, 7 ± 11; P = .023), whereas in lateral projections, no significant difference was observed (median ± interquartile range, 10 ± 10 versus 8 ± 9; P = .169). Neck or aneurysm recurrence, but not the Bicêtre Occlusion Scale Score 1 phenomenon, occurred significantly more often in patients with inappropriate WEB sizing compared with appropriate WEB sizing (median ± interquartile range, 1 ± 1.3 versus 0 ± 0; P < .001/P = .664).

CONCLUSIONS

The Bicêtre Occlusion Scale Score 1 phenomenon is associated with an initial deviation of the WEB device from the aneurysm axis but does not correlate with aneurysmal neck surface measurements or WEB sizing.

Advances in endovascular aneurysm management: flow modulation techniques with braided mesh devices

Flow diverters and flow disruption technology, alongside nuanced endovascular techniques, have ushered in a new era of treating cerebral aneurysms. Here, we provide an overview of the latest flow modulation devices and highlight their clinical applications and outcomes.

Low-Profile Laser-Cut Stents for Endovascular Treatment of Intracranial Aneurysms : Incidence, Clinical Presentation and Risk Factors of Thromboembolic Events

PURPOSE

Low-profile intracranial stents are characterized by a miniaturized design that enables deployment via a 0.0165″ or 0.017″ internal diameter microcatheter, which is typically intended for coil delivery. This study analyzed the incidence, clinical relevance and risk factors of thromboembolic events (TEE) occurring during low-profile stent-assisted coiling of intracranial aneurysms.

METHODS

This was a retrospective, multicenter analysis of consecutive patients who underwent stent-assisted aneurysm coiling (SAC) with the laser-cut Acandis Acclino and Neuroform Atlas stents. The study evaluated the incidence of symptomatic and asymptomatic TEEs and the impact on functional outcome. Risk factors for TEEs were determined by univariate and bivariate logistic regression analyses.

RESULTS

Among 131 procedures (mean patient age 56.5 ± 12.8 years, mean aneurysm size: 6.7 ± 3.9 mm) TEEs occurred in 14 cases (10.7%) of which 2 patients (1.5%) developed ischemic stroke, while the remaining TEEs remained asymptomatic. Multivariate analysis revealed Y‑stenting as potential risk factor for TEEs (odds ratio: 3.9, 95% confidence interval: 1.0-16.5; p = 0.08).

CONCLUSION

The use of SAC with low-profile intracranial stents is associated with a favorable safety profile; however, Y‑stenting may carry an increased risk of TEEs, which needs to be considered during treatment planning.

The RISE trial: A Randomized Trial on Intra-Saccular Endobridge devices

BACKGROUND

Wide-necked bifurcation aneurysms (WNBA) are a difficult subset of aneurysms to successfully repair endovascularly, and a number of treatment adjuncts have been designed to improve on the results of coiling, including stenting and flow diversion of the parent vessel. Surgical clipping is commonly performed for certain WNBAs, such as middle cerebral aneurysms, in some centres. Intra-saccular flow diversion (ISFD) using the Woven Endo-Bridge (WEB) or similar devices, has been developed as a new endovascular alternative to coiling for WNBAs. Meta-analyses of case series suggest satisfactory results, both in terms of safety and efficacy, but in the absence of randomized evidence, whether ISFD leads to better outcomes for patients with WNBA remains unknown. There is a need to offer ISFD within the context of a randomized care trial.

METHODS

The proposed trial is a multicentre, randomized controlled care trial comparing ISFD and best conventional management option (surgical or endovascular), as determined by the treating physician prior to randomized allocation. At least 250 patients will be recruited in at least 10 centres over a four-year period, and followed for one year, to show that ISFD can increase the incidence of successful therapy from 75 to 90% of patients, defined as complete or near-complete occlusion of the aneurysm AND a good clinical outcome (mRS ≤ 2) at one year. The trial will be followed by an independent data safety monitoring committee to assure the safety of participants.

CONCLUSION

Introduction of intra-saccular flow diversion can be accomplished within a care trial context.

Low-Profile Intra-Aneurysmal Flow Disruptor WEB 17 versus WEB Predecessor Systems for Treatment of Small Intracranial Aneurysms: Comparative Analysis of Procedural Safety and Feasibility

BACKGROUND AND PURPOSE

The Woven EndoBridge 17 has recently been introduced to the market for facilitated endovascular treatment of small bifurcation aneurysms (≤7 mm) with low-profile microcatheters. We compared the Woven EndoBridge 17 with its predecessor versions in terms of procedural safety and feasibility.

MATERIALS AND METHODS

This was a multicenter review of aneurysms ranging from 3 to 7 mm treated with the Woven EndoBridge between 2011 and 2019. Aneurysm characteristics, procedural parameters, and complications were retrospectively compared between treatment with the Woven EndoBridge 17 and a control group that was treated with its predecessor versions, using inverse probability of treatment weighting.

RESULTS

Thirty-eight aneurysms treated with a Woven EndoBridge 17 (mean size, 4.9 ± 1.5 mm) and 70 treated with a predecessor version of the Woven EndoBridge 17 (mean size, 5.6 ± 1.4 mm) were included. The predecessor version of the Woven EndoBridge 17 had a higher failure rate (10.3%) than the Woven EndoBridge 17 (0%, P = .05). Additional stent placement was performed more often with the predecessor version of the Woven EndoBridge 17 (10.0%) than with the Woven EndoBridge 17 (2.6%, adjusted P = .005). The predecessor version of the Woven EndoBridge 17 was associated with a higher thromboembolic event rate (14.3%) than the Woven EndoBridge 17 (5.3%, adjusted P = .002). Neurologic complications (Woven EndoBridge 17: 2.6%; predecessor version of the Woven EndoBridge 17: 2.9%, adjusted P = 1.0) and immediate complete aneurysm occlusion rates (Woven EndoBridge 17: 57.9%; predecessor version of the Woven EndoBridge 17: 54.3%, adjusted P = .21) did not differ significantly between groups.

CONCLUSIONS

In the current study, the Woven EndoBridge 17 was associated with a potentially lower thromboembolic event rate than the predecessor version of the Woven EndoBridge 17, without compromising the immediate aneurysm occlusion rate. Long-term clinical and angiographic outcome analysis will be necessary to draw a definite conclusion.