How to WEB: a practical review of methodology for the use of the Woven EndoBridge

Non-invasive follow-up for intracranial aneurysms treated with contour neurovascular system-comparison of digital subtraction angiography (DSA) to magnetic resonance imaging (MRI) and spectral computed tomography angiography (CTA) in vitro

PURPOSE

The contour neurovascular system (CNS) is an intrasaccular flow-disrupting device designed for the treatment of intracranial wide-necked bifurcation aneurysms. Metal artifacts limit magnetic resonance imaging (MRI) accessibility after implantation. The purpose of this in vitro study was to evaluate non-invasive imaging alternatives to digital subtraction angiography (DSA).

MATERIAL AND METHODS

Three aneurysms of patients originally treated with CNS were three-dimensional (3D)-printed (one at the basilar tip and two at the middle cerebral artery bifurcation). CNS devices were implanted under fluoroscopic control into the 3D models. Post-implantation two-dimensional-DSA, flat panel computed tomography angiography (CTA), MRI, and spectral CTA were performed.

RESULTS

Time of flight angiography and T1 weighted sequences showed large susceptibility artifacts at the detachment zone of the devices. A thin-sliced T2 weighted sequence in cross-sectional orientation to the aneurysm allowed visualization of the aneurysm dome, but the aneurysm neck and parent vessel could not be assessed. Focused spectral CTA, especially a 40 keV reconstruction with a metal artifact reduction algorithm (orthopedic metal artifact reduction (OMAR)), showed only minor artifacts at the detachment zone. This approach achieved a very similar result to DSA and flat panel computed tomography, enabling the assessment of the device structure, aneurysm perfusion, and parent vessel perfusion.

DISCUSSION AND CONCLUSION

For non-invasive follow-up of CNS, focused 40 keV CTA with OMAR seems to be a valuable option. MRI can be valuable for larger aneurysms to assess the aneurysm dome, but was not suitable for evaluating the parent vessels and aneurysm neck after CNS implantation in this study.

The impact of delivery technique on Woven EndoBridge deployment and detachment in an in vitro aneurysm model

BACKGROUND

The Woven EndoBridge (WEB) device is increasingly used for treatment of wide-neck bifurcation aneurysms. With the newer 17 system, WEB deployment has been associated with a phenomenon known as incomplete or "sticky" detachment from the delivery wire, which may lead to imprecise placement. Optimal techniques for WEB manipulation and delivery to avoid this problem are poorly defined. This study aimed to evaluate standard WEB deployment techniques and determine the impact of delivery techniques and WEB stickiness on procedural success.

METHODS

An in vitro study using identical silicone middle cerebral artery aneurysm models (n = 32) assessed WEB (6 × 2 mm) deployment through a VIA 17 microcatheter via three techniques that involved: "loading," "neutral," and "tension" on the pusher wire. Microcatheter position was placed in varied positions from the WEB device. Woven EndoBridge stickiness was graded during detachment attempts. Primary outcomes were detachment stickiness and attempt number, compared between techniques using Fisher's exact test.

RESULTS

The tension technique resulted in significantly fewer sticky detachments and detachment attempts compared to forward load or neutral techniques (p < 0.001). Sticky detachment was lower with tension (0% sticky) versus forward load (42% sticky, 8% very sticky) (p < 0.001). Forward load had a 50% rate of stickiness versus 0% with tension and neutral (p < 0.001). Forward load required multiple attempts in 100%, compared to 57% with neutral and 8% with tension (p < 0.001). Higher stickiness grades increased the need for multiple attempts (p < 0.001).

CONCLUSION

The tension technique reduces incomplete WEB detachment and enables precise single-attempt detachment, optimizing delivery precision. In vivo confirmation is needed.

A comprehensive numerical approach to coil placement in cerebral aneurysms: mathematical modeling and in silico occlusion classification

Endovascular coil embolization is one of the primary treatment techniques for cerebral aneurysms. Although it is a well-established and minimally invasive method, it bears the risk of suboptimal coil placement which can lead to incomplete occlusion of the aneurysm possibly causing recurrence. One of the key features of coils is that they have an imprinted natural shape supporting the fixation within the aneurysm. For the spatial discretization, our mathematical coil model is based on the discrete elastic rod model which results in a dimension-reduced 1D system of differential equations. We include bending and twisting responses to account for the coils natural curvature and allow for the placement of several coils having different material parameters. Collisions between coil segments and the aneurysm wall are handled by an efficient contact algorithm that relies on an octree based collision detection. In time, we use a standard symplectic semi-implicit Euler time stepping method. Our model can be easily incorporated into blood flow simulations of embolized aneurysms. In order to differentiate optimal from suboptimal placements, we employ a suitable in silico Raymond-Roy-type occlusion classification and measure the local packing density in the aneurysm at its neck, wall region and core. We investigate the impact of uncertainties in the coil parameters and embolization procedure. To this end, we vary the position and the angle of insertion of the micro-catheter, and approximate the local packing density distributions by evaluating sample statistics.

Neck apposition is a key factor for aneurysm occlusion after Woven EndoBridge device embolization

BACKGROUND

Sealing of the aneurysm neck with a Woven EndoBridge (WEB) device is recommended for disrupting the blood flow inside the aneurysm. This study investigates the relationship between WEB neck apposition and aneurysm occlusion rates.

METHODS

Aneurysms treated with a WEB from March 2017 to May 2022 at a single center were included. WEB neck apposition (poor/good) and WEB protrusion (yes/no) were evaluated on post-detachment high resolution cone beam CT images. Angiographic occlusion was assessed with the Bicêtre Occlusion Scale score (BOSS). Univariate and multivariable analysis tested the association between neck apposition and occlusion rates.

RESULTS

The study included 159 aneurysms in 141 patients (mean age 55.8±11.2 years; 64.2% women). Good neck apposition and protrusion were noted in 123 (77.4%) and 30 (18.9%) cases, respectively. Inter-rater agreements were good for neck apposition (κ=0.75) and protrusion (κ=0.78). Complete and adequate occlusion was achieved in 104 (65%) and 130 (82%) cases, respectively (median follow-up 18 months). Good neck apposition was a strong independent predictor for both adequate (adjusted OR (aOR)=5.9, 95% CI 2.4 to 14.9; P<0.001) and complete occlusion (aOR=7.1, 95% CI 3.0 to 18.1; P<0.001). Protrusion was more frequent in the adequate occlusion group versus the aneurysm recurrence group without reaching statistical significance (P=0.06), but was associated with more thromboembolic complications (9/30 (30%) vs 12/129 (9%); P<0.01). WEB shape modification was significantly greater in poor apposition cases (P=0.03).

CONCLUSIONS

Achieving good neck apposition of the WEB strongly predicts aneurysm occlusion during follow-up. WEB protrusion should be minimized due to the increase in thromboembolic risk with limited impact on aneurysm occlusion.

The Clinical and Radiological Outcomes of the Multimodal Use of the Woven EndoBridge Device: A Large Multicenter Study

BACKGROUND

The Woven EndoBridge (WEB) is a device used for intrasaccular flow diversion, designed for the elimination of wide-necked bifurcation aneurysms from the circulation. In this study, we aim to assess the safety and efficacy of the WEB and its uses in treating aneurysms of different morphologies and locations.

METHODS

In a retrospective analysis, we compiled a comprehensive dataset from patients treated with the WEB device across three major Australian neurovascular centers from May 2017 to September 2023. The case series encompassed a spectrum of aneurysm types, including wide-necked bifurcation, sidewall, and irregularly shaped aneurysms, as well as cases previously managed with alternative therapeutic strategies. This study additionally encompasses cases where aneurysms were managed using the WEB device in combination with supplementary endovascular devices.

RESULTS

The study included 169 aneurysms in 161 patients. The rate of satisfactory aneurysm occlusion was 85.6%, with 86.7% of patients maintaining good functional status at their most recent follow-up. The procedure exhibited a low mortality rate of 0.6% and a thromboembolic complication rate of 7.1% (n = 12/161). There were no instances of postoperative re-rupture and the procedure-related hemorrhage rate was low (1.2%, n = 2/169), aligning with the literature regarding the safety and efficacy of the WEB device.

CONCLUSIONS

Our multicenter trial reinforces the WEB device's role as an effective and safe modality for intracranial aneurysm management, supporting its expanded application beyond wide-necked bifurcation aneurysms. Further prospective studies are required to delineate its evolving role fully.

Treatment for middle cerebral artery bifurcation aneurysms: in silico comparison of the novel Contour device and conventional flow-diverters

Endovascular treatment has become the standard therapy for cerebral aneurysms, while the effective treatment for middle cerebral artery (MCA) bifurcation aneurysms remains a challenge. Current flow-diverting techniques with endovascular coils cover the aneurysm orifice as well as adjacent vessel branches, which may lead to branch occlusion. Novel endovascular flow disruptors, such as the Contour device (Cerus Endovascular), are of great potential to eliminate the risk of branch occlusion. However, there is a lack of valid comparison between novel flow disruptors and conventional (intraluminal) flow-diverters. In this study, two in silico MCA bifurcation aneurysm models were treated by specific Contour devices and flow-diverters using fast-deployment algorithms. Computational fluid dynamic simulations were used to examine the performance and efficiency of deployed devices. Hemodynamic parameters, including aneurysm inflow and wall shear stress, were compared among each Contour device, conventional flow-diverter, and untreated condition. Our results show that the placement of devices can effectively reduce the risk of aneurysm rupture, while the deployment of a Contour device causes more flow reduction than using flow-diverters (e.g. Silk Vista Baby). Besides, the Contour device presents the flow diversion capability of targeting the aneurysm neck without occluding the daughter vessel. In summary, the in silico aneurysm models presented in this study can serve as a powerful pre-planning tool for testing new treatment techniques, optimising device deployment, and predicting the performance in patient-specific aneurysm cases. Contour device is proved to be an effective treatment of MCA bifurcation aneurysms with less daughter vessel occlusion.

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.

Microsurgical Clip Ligation of a Large Anterior Communicating Artery Aneurysm Previously Treated With Woven Endobridge Device: 2-Dimensional Operative Video

The Woven Endobridge (WEB) intrasaccular flow diversion device (Microvention, Inc.) is commonly used to treat both unruptured and ruptured wide-necked bifurcation aneurysms.1 Despite its relative safety and comparable rates of aneurysm occlusion, the device may compress over time resulting in aneurysm recurrence.2 In this video, we demonstrate the microsurgical retreatment of a large anterior communicating artery (ACoA) aneurysm previously treated with WEB. A 53-year-old patient with hypertension and current tobacco use presented with a ruptured ACoA aneurysm measuring 8.4 mm × 8 mm × 7 mm. She was urgently treated with a 9 mm × 5 mm WEB SL and made a full recovery. At 6 months, cerebral angiography showed a significant recurrence secondary to WEB compression. We considered both endovascular and microsurgical approaches; however, the anatomy was unfavorable for endovascular treatment.3 Although previous reports have documented clipping as a retreatment strategy, a minority of these aneurysms were ACoA aneurysms.4-7 The patient consented to the surgical procedure. This operative video illustrates the in vivo appearance of the WEB device and the surgical technique used to treat this unusual situation. The WEB device was firm and not as compressible as previously reported, but clipping was still possible.4,6 We highlight the use of temporary clipping, fenestrated clips, and intraoperative angiography in treatment. The aneurysm was occluded, and the patient remained without deficits. In summary, clip ligation can be an excellent option for ACoA aneurysms in the setting of WEB recurrence. The patient consented to this report; Institutional Review Board/ethics committee approval was not required.

Large Single-Center Experience with Short-Term Follow-up of Neqstent-Assisted Coiling

BACKGROUND AND PURPOSE

Endovascular treatment of wide-neck bifurcation aneurysms has historically proved difficult with variable outcomes. Different endovascular techniques such as balloon-assisted coiling, stent-assisted coiling, or intrasaccular devices provide a varied range of efficacy and safety. Neqstent-assisted coiling is a new device and technique that aim to provide a maximum of both. We analyzed the early clinical and radiologic outcomes after the use of this new technique and device in our practice.

MATERIALS AND METHODS

This study was a retrospective analysis of ruptured and unruptured intracranial aneurysms treated with the Neqstent. The primary radiologic outcomes were quantified on DSA, CTA, or MRA using the modified Raymond-Roy criteria. The outcomes were defined as immediate complete occlusion (modified Raymond-Roy criteria 1) and complete (modified Raymond-Roy criteria 1) and adequate occlusion (modified Raymond-Roy criteria 1 and modified Raymond-Roy criteria 2) at 6 months posttreatment. The primary safety outcome was the rate of device-related adverse events. Secondary safety outcomes included time to discharge and change in the mRS score at 6-month follow-up.

RESULTS

Twenty patients were treated with the Neqstent from November 2020 to January 2023. Nine had unruptured aneurysms, and 11 were patients with subarachnoid haemorrhage due to ruptured aneurysms. Eighteen of 20 aneurysms (90%) treated demonstrated complete occlusion (modified Raymond-Roy criteria 1) on immediate postembolization angiograms. Sixteen of 17 aneurysms treated (94.1%) remained adequately occluded on 6-month follow-up (modified Raymond-Roy criteria 1 and modified Raymond-Roy criteria 2). Immediate postoperative complications occurred in 2 patients; only 1 patient had residual neurologic deficits at 6 months (mRS = 2).

CONCLUSIONS

Management of large, wide-neck aneurysms remains difficult, with high rates of recurrence and complications. The use of the Neqstent shows promising short-term results for the treatment of complex wide-neck aneurysms. Initial complication rates for our cohort were relatively high. However, this result is likely related to the initial learning experience of device deployment and the use of antiplatelets.

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.

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.

Initial Experiences with the Trenza Embolization Device for the Treatment of Wide-Neck Intracranial Aneurysms: A 12-Patient Case Series

The Trenza embolization device is a frame coil implant with flow-disruption properties and is a new alternative to treat challenging mid-to-large-sized broad-neck bifurcation or sidewall aneurysms. We conducted an observational single-center retrospective study of 12 consecutive patients treated for 10 unruptured and 2 ruptured 6- to 12-mm broad-neck bifurcation or sidewall aneurysms with the Trenza device during 2022-2023. The median patient age was 64 years (interquartile range, 59-70 years), 58% were women, the median largest aneurysm diameter was 9.6 mm (interquartile range, 7.5-11.9 mm), the median dome-to-neck ratio was 1.8 (interquartile range, 1.6-1.9), the most common aneurysm locations were the anterior communicating artery (33%) and basilar artery tip (33%). After a median follow-up of 6.5 months, adequate aneurysm occlusion was achieved in 83%. There were 3 major ischemic complications (25%), leading to 2 permanent neurologic deficits (17%) and 1 transient neurologic deficit (8%). There was 1 fatal rupture of a treated aneurysm 1.6 months after the index treatment. Two patients were retreated (17%). Ischemic complications occurred in patients after a too-dense coil packing at the base of the aneurysm. No technical issues related to the device were encountered. In summary, an adequate aneurysm occlusion rate was achieved using the Trenza-assisted coiling technique for otherwise challenging mid-to-large-sized broad-neck aneurysms. Ischemic complications seemed to occur following overdense coiling at the base of the aneurysm.

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.

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.

Evaluating Efficacy and Complications of Contour Intrasaccular Device in Cerebral Aneurysm Management: A Multicenter Analysis

BACKGROUND

Intrasaccular devices provide a method for treating complex aneurysms without leaving metallic materials in the parent artery. Compared to other well-studied devices in neurointervention, the Contour device is relatively new as an intrasaccular flow diverter. This study examines its use in cases of incidental aneurysms and its application in the acute treatment of ruptured aneurysms. Additionally, it covers potential complications that may arise and methods for prevention.

METHODS

We conducted a retrospective analysis of 25 patients who underwent treatment with the Contour device at 3 hospital centers. We collected data related to age, gender, baseline modified Rankin Scale, personal habits, medical history, procedure details, and angiographic results according to the Woven endobridge occlusion scale.

RESULTS

A total of 15 patients (65.5%) achieved a satisfactory angiographic result (grade 0-0') 1 year after embolization. Contrast stagnation was observed in 14 patients (58.3%). Intraprocedural complications, such as device displacement, were documented in 3 patients (12%), while 2 patients (8%) had aggregates attached to the device. Regarding late complications, 5 patients (20%) experienced device displacement and 1 patient had a minor stroke (4%). Retreatment was necessary for 3 patients (12%), involving a flow diverter, stenting, and coiling.

CONCLUSIONS

In summary, the Contour device offers a viable option for treating complex aneurysms. While initial results are promising, it is crucial to acknowledge a learning curve to minimize complications and achieve satisfactory angiographic results without the need for additional treatments.

Endovascular Treatment of Bifurcation Aneurysms with the Woven EndoBridge: Product Features and Selected Results of Off-Label Use

Treatment for wide-neck bifurcation cerebral aneurysms (WNBAs) is widely performed by endovascular treatment as well as open surgical clipping. However, due to factors such as the shape and size of the aneurysms, as well as the anatomical features of surrounding branch vessels, there are some cases in which simple coiling or conventional adjunctive techniques, such as balloon-assisted or neck bridge stent-assisted coiling, are not sufficient to achieve a satisfactory cure. Against this backdrop, the device known as the Woven EndoBridge (WEB) (MicroVention, Aliso Viejo, CA, USA) was developed and can be deployed directly into the aneurysm for treatment. Over a decade has passed since its development, and it is now used in many countries worldwide. This review provides insights into the evolution of the WEB device from its development to the date of this writing, highlighting the unique features of the device and its treatment indications. Additionally, it discusses the posttreatment course, perspectives on recurrence and retreatment, imaging assessments, and potential off-label use based on numerous studies primarily conducted in Europe and the USA.

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.

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.

Oversizing of the Woven EndoBridge for Treatment of Intracranial Aneurysms Improves Angiographic Results (WEBINAR)

OBJECTIVE

Several studies have demonstrated a high safety and efficacy profile of the Woven EndoBridge (WEB) for endovascular aneurysm treatment. However, contemporary large-scale studies of the WEB are rare. This multicenter study attempts to set a benchmark for state-of-the-art WEB treatment with consistent application of the WEB oversizing technique.

METHODS

This is a retrospective, multicenter study of aneurysms (dome width 2-10 mm) treated with the WEB between 2015 and 2023. Patient and aneurysm characteristics, complications, and clinical and angiographic outcomes were analyzed.

RESULTS

The study consisted of 247 patients treated for 251 aneurysms (25.5% ruptured, 5.6% recurrent). WEB implantation was feasible in 98.8%, achieving a mean WEB/dome ratio of 1.2 ± 0.1. The thromboembolic complication rate was 7.2%, which was higher in ruptured versus unruptured aneurysms (hazard ratio: 2.8, 95%CI: 1.0-7.6, P = 0.04), but lower in cases where WEB 17 was used (hazard ratio: 4.0, 95%CI: 1.4-11.2, P = 0.01). Neurological complications occurred in 8 procedures (3.2%), including 3 (1.2%) major, and 5 (2.0%) minor events. Procedural morbidity and mortality were 0.8% and 0%, respectively. Mid-term complete and adequate occlusion rates were 66.3% and 88.4%, respectively. The retreatment rate was 5.2%. Feasibility, complication, and occlusion rates were comparable between typical and atypical aneurysm locations.

CONCLUSIONS

Oversizing the WEB and using currently available WEB types in this series resulted in slightly better treatment outcomes compared to early WEB studies, confirming the high safety, feasibility, and efficacy of this technique.

Cost-effectiveness of WEB Embolization, Coiling and Stent-assisted Coiling for the Treatment of Unruptured Intracranial Aneurysms

PURPOSE

Information about the cost-effectiveness of a certain treatment is relevant for decision-making and healthcare providers. This study compares the cost-effectiveness of the novel Woven Endobridge (WEB) for intracranial aneurysm treatment with conventional coiling and stent-assisted coiling (SAC) from the perspective of the German Statutory Health Insurance.

METHODS

A patient-level simulation was constructed to simulate 55-year-old patients with an unruptured middle cerebral artery aneurysm (size: 3-11 mm) considering WEB treatment, coiling or SAC in terms of morbidity, angiographic outcome, retreatment, procedural and rehabilitation costs and rupture rates. Incremental cost-effectiveness ratios (ICERs) were calculated as costs per quality-adjusted life years (QALYs) and costs per year with neurologic morbidity avoided. Uncertainty was explored with deterministic and probabilistic sensitivity analyses. The majority of data were obtained from prospective multi-center studies and meta-analyses of non-randomized studies.

RESULTS

In the base case, lifetime QALYs were 13.24 for the WEB, 12.92 for SAC and 12.68 for coiling. Lifetime costs were 20,440 € for the WEB, 23,167 € for SAC, and 8200 € for coiling. Compared to coiling, the ICER for the WEB was 21,826 €/QALY, while SAC was absolutely dominated by WEB. Probabilistic sensitivity analysis revealed that at a willingness-to-pay of ≥ 30,000 €/QALY, WEB was the preferred treatment. Deterministic sampling showed that the discount rate, material costs and retreatment rates had the largest impact on the ICERs.

CONCLUSION

The novel WEB showed at least comparable cost-effectiveness to SAC for treatment of broad-based unruptured aneurysms. Considering all three modalities, coiling had the least costs; however this modality is often not appropriate for the treatment of wide-necked aneurysms.

The Safety and Efficacy of eCLIPs for Treatment of Wide-Necked Bifurcation Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND

Wide-necked bifurcation aneurysms (WNBAs) are challenging intracranial aneurysms. Several device and treatment approaches have been proposed for the treatment of WNBAs. The endovascular clip system (eCLIPs) is a newly developed endovascular device with flow diverter and flow disruptor features. This study aims to investigate the safety and efficacy of the eCLIPs for treatment of patients with WNBAs.

METHODS

This is a systematic review and meta-analysis study conducted in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines. The electronic databases of PubMed, Embase, Scopus, and Web of Science were systematically reviewed from inception to June 19, 2023. The rate of complete and near-complete occlusion, successful device implantation, and serious adverse events were pooled using STATA, version 17.

RESULTS

A total of 5 studies with 110 patients with WNBAs were systematically investigated. Our findings show that the immediate successful implantation rate of eCLIPs was 0.93 (95% confidence interval [CI], 0.88-0.97). Moreover, the immediate postoperative complete occlusion rate was 0.34 (95% CI, 0.10-0.58), and the immediate postoperative near-complete occlusion rate was 0.35 (95% CI, 0.24-0.45). Also, the near-complete occlusion rate at the latest follow-up was 0.3 (95% CI, 0.16-0.44). The serious adverse event rate was 0.14 (95% CI, 0.05-0.22). Stroke was also reported in 2 studies, with 1 study reporting 1 patient who experienced stroke within the first 24 hours and 1 study reporting no patients with stroke.

CONCLUSIONS

Our findings document that the eCLIPs is a safe and effective device for treating patients with WNBAs and associated with favorable outcomes.

Vertebro-Vertebral Fistula Occlusion Using a Woven EndoBridgeTM-Device

Vertebro-vertebral fistulas (VVFs) are vascular lesions that may develop after trauma or spontaneously in association with connective tissue disorders. We present a rare case of a post-traumatic VVF in a young patient presenting with a painless swelling and a bruit in her left upper neck. Digital subtraction angiography showed an arteriovenous fistula between the left vertebral artery (VA) and the vertebral venous plexus with significant steal phenomenon. Endovascular therapy was performed using a Woven EndoBridgeTM (WEB)-device combined with coils that allowed preservation of the VA. The patient fully recovered from her symptoms and follow-up imaging showed stable occlusion. In conclusion, VVFs can be effectively treated using intrasaccular flow diverters such as the WEB-device, allowing for complete and stable occlusion while preserving the parent artery.

Quantitative radial force measurements of Woven EndoBridge devices

BACKGROUND

Lateral/radial forces and the mechanical properties of Woven EndoBridge (WEB) devices have significant importance for therapeutic success. In other words, adequate apposition of the lateral wall of a cerebral aneurysm is critical for preventing recurrence or re-rupture risk.

OBJECTIVE

This study aimed to investigate the pressure values applied by different WEB devices to the lateral walls of aneurysms and the relationships between these pressure measurements and the diameters of WEB devices.

METHODS

By placing four WEB devices of different sizes and types between two rigid metal plates, the lateral forces applied by these WEB devices to plates of different apertures were measured quantitatively. We tested a single device of each size over multiple periods. The total number of examined WEB devices is four.

RESULTS

There was a significant negative relationship between plate distances and pressure values (correlation coefficient:-0.956, p = 0.000). The lateral wall apposition pressure of a 4- or 5-mm aperture size was higher than a 6-mm aperture size for SL-type WEB devices with a 7-mm diameter. Similarly, the lateral wall apposition pressure detected for a 3- or 3.5-mm aperture size was higher than a 4-mm aperture size for W5-4.5-3 and W5-5-3.6. It was observed that maximum lateral wall pressure was detected in plate measurements of SLS-type devices compared to SL-type devices. The diameter and height values of 3 of the 4 unconstrained WEB devices analyzed differed from the catalog values.

CONCLUSION

It seems that SLS-type devices apply more pressure on the aneurysm's lateral borders than SL-type devices.

Use of a Woven Endobridge device (WEB) for the treatment of an aneurysmal diverticulum of the transverse sinus causing pulsatile tinnitus

Pulsatile tinnitus is a symptom with a potentially significant impact on the quality of life of patients.1 In some cases the pulsatile tinnitus is secondary to an arterial, arteriovenous, or a venous condition that can be treated endovascularly.2-5 One of the newly recognized entities that can cause pulsatile tinnitus is the presence of an ipsilateral aneurysmal diverticulum of the transverse sinus. The Woven EndoBridge (WEB) is an intra-aneurysmal flow disruptor for the treatment of broad-based arterial aneurysms with a high safety and effectiveness profile.3 The initial version of the WEB with a dual-layer structure evolved into a single-layer structure in two different versions (WEB SL, a barrel shape, and WEB SLS, a spherical shape).4 The WEB system does not require concomitant antiplatelet therapy, unlike other intraluminal devices such as flow diverters or intracranial stents. We describe a case of pulsatile tinnitus secondary to an aneurysmal diverticulum of the transverse sinus successfully treated with a WEB SL device instead of stent-assisted coiling, therefore alleviating the need for antiplatelets (video 1). The patient had an immediate clinical response with complete and persisting disappearance of her pulsatile tinnitus.neurintsurg;jnis-2023-020981v1/V1F1V1Video 1.

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.

Management of aneurysmal recurrence after Woven EndoBridge (WEB) treatment

BACKGROUND

Around 10% of Woven EndoBridge device (WEB)-treated intracranial aneurysms will need retreatment, and it is generally believed to be more challenging than retreatment after an initial coiling. We aim to report retreatment strategies and outcomes after initial WEB embolizations.

METHODS

Databases from four treatment centers, containing consecutive aneurysms treated with a WEB between 2013 and 2022, were reviewed. Demographics, aneurysm characteristics, retreatment strategies and outcomes were collected and analyzed.

RESULTS

From a 756 WEB database, 57 aneurysms were included. The global retreatment rate was 7.5% (95% CI 5.6% to 9.4%). The retreatment rate was significantly higher in the ruptured compared with the unruptured population (13% vs 3.9%, respectively, P<0.0001). Aneurysms were retreated on average 21.2 months after the initial WEB treatment (range 4.8-70 months). Surgery was performed in 11% and endovascular treatment in 89% of cases, consisting of flow diversion (48%), stent-assisted coiling (30%), coiling (12%), and second WEB placement (10%). Imaging follow-up was available in 88% of all WEB retreatments (50/57) (average 17 months, 49% digital subtraction angiography), demonstrating complete occlusion in 56% and 'adequate' occlusion in 88%. Morbidity was 5.3% (95% CI 0% to 12.0%) and mortality 0%. No patient experienced rebleeding during the follow-up period.

CONCLUSION

The retreatment rate after an initial WEB treatment seems to compare favorably with that of coiling. Endovascular treatment of recurrence following WEB implantation is feasible in most situations; it generally requires the use of a stent and leads to a high rate of satisfactory occlusion.

How a decade of aneurysms embolization with the Woven EndoBridge has changed our understanding and practices?

BACKGROUND

Safety and efficacy of the WEB (Woven EndoBridge) device have been extensively evaluated in several good clinical practice studies. Nonetheless, the WEB had several structural evolutions overtime up to the fifth generation WEB device (WEB17). Here, we tried to understand how this may have modified our practices and enlarged our indications for its use.

METHODS

We retrospectively analyzed data from all patients with aneurysms treated (or intended to be treated) with a WEB at our institution between July 2012 and February 2022. The time frame was split in two periods: before and after the arrival of the WEB17 in our center (February 2017).

RESULTS

252 patients with 276 wide-necked aneurysms were included; 78 aneurysms (28.2%) were ruptured. Successful embolization with a WEB device was achieved in 263/276 aneurysms (95.3%). With the availability of WEB17, treated aneurysms were significantly smaller (8.2 mm versus 5.9 mm, p<0.001) and off-label location significantly increased (4.4% versus 17.3%, p = 0.02) with an increase of sidewall aneurysm (4.4% versus 11.6%, p = 0.06). Also, WEB were more significantly oversized (1.05 versus 1.11, p<0.01). Adequate and complete occlusion rates increased constantly during the two periods (54.8% versus 67.5%, p = 0.08 and 74.2% versus 83.7%, p = 0.10, respectively). The proportion of ruptured aneurysms slightly increased between the two periods (24.6% versus 29.5%, p = 0.44).

CONCLUSIONS

Over the first decade of its availability, the WEB device usage shifted towards smaller aneurysms and broader indications, including ruptured aneurysms. The oversizing strategy also became the standard of practice for WEB deployment in our institution.

Usefulness of Y-shaped PulseRider-assisted coil embolization for basilar artery tip aneurysm with a misaligned axis: A case report

Background

Endovascular treatment of wide-necked bifurcation aneurysms remains challenging. Although the advent of PulseRider and Web has expanded treatment options, aneurysms with a large deviation from the parent artery axis remains difficult to treat. We present the case of a wide-necked bifurcation aneurysm that was misaligned with the angle between the long axis of the parent artery and the aneurysm and was successfully treated with Y-shaped PulseRider-assisted coil embolization.

Case Description

A 64-year-old woman presented with an unruptured basilar tip aneurysm. Cerebral angiography showed a wide-necked aneurysm measuring 8.1 mm × 6.1 mm, neck 5.7 mm. The aneurysm was strongly tilted to the right and posterior relative to the basilar artery, and the bilateral posterior cerebral artery (PCA) and superior cerebellar artery (SCA) diverged from the aneurysm body. PulseRider-assisted coil embolization was performed. A Y-shaped PulseRider was selected to be placed in a hybrid fashion with the right arch in the aneurysm and the left arch in the branch. Adequate coil embolization with preservation of the bilateral PCA and SCA was possible, and cerebral angiography immediately after the treatment showed slight dome filling. Cerebral angiography 6 months after the procedure showed that the embolic status had improved to complete occlusion.

Conclusion

For wide-neck bifurcation aneurysms with a misaligned axis, a Y-shaped PulseRider used in a hybrid fashion, in which the leaflet on the side with the tilted axis is placed in the aneurysm, allows the PulseRider to be deployed more closely to the aneurysm, thereby enabling good coil embolization.

Trends in Dual Antiplatelet Therapy Use for Neurointerventional Procedures for the Management of Intracranial Aneurysms

The use of periprocedural dual antiplatelet therapy (DAPT) has significantly evolved along with innovations in the endovascular management of intracranial aneurysms. Historically, aspirin and clopidogrel have been the most commonly employed regimen due to its safety and efficacy. However, recent studies highlight the importance of tailoring DAPT regimens to individual patient characteristics which may affect clopidogrel metabolism, such as genetic polymorphisms. In the present report, a systematic review of the literature was performed to determine optimal antiplatelet use with flow diverting stents, intracranial stents, intrasaccular devices, and stent-assisted coiling. Studies were analyzed for the number of aneurysms treated, DAPT regimen, and any thromboembolic complications. Based on inclusion criteria, 368 studies were selected, which revealed the increasing popularity of alternative DAPT regimens with the aforementioned devices. Thromboembolic or hemorrhagic complications associated with antiplatelet medications were similar across all medications. DAPT with ticagrelor, tirofiban, or prasugrel are effective and safe alternatives to clopidogrel and do not require enzymatic activation. Further clinical trials are needed to evaluate different antiplatelet regimens with various devices to establish highest-level evidence-based guidelines and recommendations.

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.

Woven EndoBridge Device Migration and Microsnare Retrieval Strategy: Single Institutional Case Reports with Technical Video Demonstration

The Woven EndoBridge (WEB) (MicroVention/Terumo) device is a treatment option for wideneck bifurcation aneurysms. An uncommon adverse effect is WEB device migration. While certain bailout strategies for WEB recovery have been described, there is still a paucity of information on optimal strategies to maximize both short and long-term post-operative outcomes. We add 2 cases at our institution to the existing literature of WEBectomy in the setting of complicated intracranial aneurysm treatment. We discuss the long-term imaging outcomes with additional fluoroscopy video demonstrating our technique. Our findings reflect a clear benefit for the use of the Amplatz GooseneckTM microsnare (Medtronic) device as a means of WEB recovery, coupled with potential stent-assisted WEB embolization to remove the aneurysm from the parent circulation, while minimizing recurrence and thromboembolic complications.

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.

Decision-making tree for optimal Woven EndoBridge device sizing with ideal Woven EndoBridge-aneurysm volume (iWAVe) ratio

PURPOSE

Optimal size selection is important for successful Woven EndoBridge (WEB) treatment. Conventional recommendations for WEB sizing based on aneurysm width and height sometimes require device exchange. We aimed to design a novel volume-based parameter, the ideal WEB-aneurysm volume (iWAVe) ratio, for optimal WEB sizing.

METHODS

Consecutive patients who underwent WEB treatment for wide-neck bifurcation aneurysms between January 2021 and May 2022 were retrospectively reviewed. Aneurysm volume was automatically calculated using software. We measured the aneurysm volume based on the expected position of the device within the aneurysm. The WAVe ratio was defined as the ratio of the aneurysm volume to WEB volume. We dichotomized aneurysms treated with a successful sizing or unsuccessful sizing for WEB (successful group and unsuccessful group, respectively).

RESULTS

Thirty-five patients were eligible for study enrollment. Ten patients (28.6%) needed to exchange the WEB on the first attempt and required another WEB on the second attempt resulting in deployment success. Hence, 35 aneurysms were in the successful group and 10 were in the unsuccessful group. The median WAVe ratio was 1.0 (range 0.76-1.31) in the successful group and 1.27 (0.58-1.89) in the unsuccessful group. Using logistic regression, iWAVe ratio was from 0.90-1.16 to secure a >80% probability of success by the 95% lower confidence limit. The sensitivity and specificity of the iWAVe ratio for optimal size selection on the first attempt were 0.60 and 1.00, respectively.

CONCLUSION

Decision-making based on aneurysm width and the iWAVe ratio could promote optimal WEB sizing.

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.

Endovascular and Medical Management of Unruptured Intracranial Aneurysms

Unruptured intracranial aneurysms are often discovered incidentally on noninvasive imaging. As use of noninvasive imaging has increased, our understanding of the presumed prevalence of intracranial aneurysms in adults has increased. Incidentally found aneurysms are often asymptomatic; however, they can rarely rupture and cause life-threatening illness. Elective treatment of intracranial aneurysms carries risks which need to be considered along with patient-specific factors (e.g., anatomy, medical comorbidities, personal preferences). In this article, we review the natural history, risk factors for cerebral aneurysm formation and rupture, evidence for medical management, and the safety profile and efficacy of available endovascular treatment options.

Need for Y-stenting in stent-assisted coiling of wide-neck bifurcation aneurysms

BACKGROUND AND PURPOSE

Stent-assisted coiling of wide neck bifurcation aneurysms in the anterior communicating segment and basilar tip region can be performed with varying stent configurations, including single stenting or Y-stenting. Y-stenting requires two stents and thus incurs greater cost and procedural complexity than single-stent constructs. The influence of first stent type on the need for Y-stenting remains unknown.

MATERIALS AND METHODS

Clinical and angiographic data were retrospectively obtained for patients that underwent stent-assisted coiling for basilar tip or anterior communicating aneurysms at a high-volume center. Patients were included in this study if stent-assisted coiling was performed using Neuroform Atlas or LVIS Jr stents. A multivariate binary logistic regression was performed to measure the influence of first stent type on the need for Y-stenting.

RESULTS

Stent-assisted coiling was used to treat 82 aneurysms in 81 patients during the study period, and Y-stenting was performed in 18.3% (15/82) of cases. In multivariate logistic regression analysis, use of LVIS Jr. as the first stent did not significantly influence the need for subsequent Y-stenting after controlling for aneurysm morphology (OR 0.65, 95% CI 0.18-2.43).

CONCLUSION

Controlling for aneurysm morphology and location, the use of Y-stenting for stent-assisted coiling was not independently influenced by the choice of LVIS Jr or Neuroform Atlas as the first stent. A larger cohort may reveal differences between these two stents, particularly for aneurysms with large neck sizes.

Management of Unruptured Intracranial Aneurysms and Brain Arteriovenous Malformations

OBJECTIVE

Managing a patient with an unruptured brain aneurysm or brain arteriovenous malformation (AVM) can lead to uncertainty about preventive treatment. While the bleeding risks are low, the morbidity or mortality associated with a hemorrhagic event is not insignificant. The objective of this article is to review the natural history of these vascular entities, the risk factors for hemorrhage, preventive treatment options, and the risks of treatment.

LATEST DEVELOPMENTS

Randomized trials to inform preventive treatment strategies for unruptured intracranial aneurysms and brain AVMs are ongoing. Higher angiographic obliteration rates of unruptured intracranial aneurysms have been reported with the flow-diversion technique compared with alternative standard techniques. One randomized trial for unruptured brain AVMs showed a higher rate of morbidity and mortality in patients who underwent interventional treatment compared with observation.

ESSENTIAL POINTS

The decision to treat a patient with a brain aneurysm should consider patient factors, the patient's life expectancy, aneurysm anatomical factors, and treatment risks. Patients with unruptured brain AVMs should be observed in light of recent clinical trial data or enrolled in an ongoing clinical trial.

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

BACKGROUND AND PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

The Rationale Behind Transcirculation Neuroendovascular Interventions: Literature Review Through a Case-Series Approach

BACKGROUND

With the development of advanced endovascular techniques and materials, neurointerventionalists can perform challenging and complex cases that were previously difficult to perform. Transcirculation approaches could be a useful tool used in complicated cases, providing access to the target vessel, through the contralateral or opposite circulation, when anterograde access is difficult or nonachievable.

OBJECTIVE

To retrospectively review cerebrovascular interventions performed through a transcirculation approach performed by staff at our Institution.

METHODS

English-language studies, published until August 2022, reporting transcirculation interventions in the cerebrovascular circulation were retrospectively collected. Type of intervention, number of cases, rationale, and complications were analyzed. Furthermore, similar cases performed by staff currently at our institution were also reviewed and described.

RESULTS

Including our cases, a total of 273 transcirculation treatment approaches have been reported. Intracranial aneurysm embolization, stroke thrombectomies, intra-arterial ophthalmic chemotherapy, arteriovenous malformationss, arteriovenous fistulas embolizations, and intracranial angioplasty and stenting are common indications. Reason for using a retrograde approach were stent/balloon-assisted coiling of wide neck aneurysm in 116 cases, difficult angulation of branch in 91 cases, occlusion of parent vessel in 55 cases, and bailout/other in 11 cases.

CONCLUSION

Transcirculation approaches can be considered for cases where conventional anterograde treatment options are not feasible or as a bailout strategy in failed or complicated treatment attempts. They represent a strategy to consider when facing challenging cases, and if performed by experienced and dedicated neurointerventionalists, they can represent a safe alternative.

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.

Heterogeneous model to evaluate CFD in intracranial bifurcation aneurysms treated with the WEB device to predict angiographic outcome

INTRODUCTION

The Woven EndoBridge device (WEB) was developed as an alternative to treat Wide-Necked bifurcation aneurysms. It has proven to be effective and safe, however, cases of recanalization have been reported. The purpose of this study was to evaluate and quantify hemodynamic parameters and indexes with CFD of the intracranial aneurysms before and after WEB simulation and to establish their relationship to complete occlusion.

MATERIALS AND METHODS

Using the heterogeneous model based on the marching cubes algorithm, we created 3D representations of 27 bifurcated intracranial aneurysms treated with the single-layer WEB device to evaluate hemodynamics parameters with CFD, calculated with and without the WEB.

RESULTS

We observed a lower treatment entry concentration indices (ICI) (2.12 ± 1.31 versus 3.14 ± 0.93, p-value: 0.029) previous to placement of WEB and higher pre-treatment FN (7.56 ± 5.92 versus 3.35 ± 1.51, p-value: 0.018) and post-treatment FN (5.34 ± 5.89 versus 1.99 ± 0.83, p-value: 0.021) for cases with successful occlusions. Lower post-treatment SRa (197.81 ± 221.29 versus 80.02 ± 45.25, p-value: 0.044) and higher pre (0.11 ± 0.07 versus 0.25 ± 0.19, p-value: 0.011) and post-treatment MATT (0.69 ± 1.23 versus 1.02 ± 0.46, p-value: 0.006) were observed in non-occluded cases.

CONCLUSIONS

In our CFD analysis of the hemodynamic parameters of IA, we found lower ICI before the placement of the WEB device and higher FN pre- and post-treatment for cases with successful occlusions. Non-occluded cases had lower post-treatment SRa and higher pre-treatment and post-treatment MATT.

Transcirculation Approach for Matricidal Carotid Cavernous Aneurysm: Not a Good Choice - A Case Report of Unsuccessful Endovascular Treatment of Matricidal Carotid Cavernous Aneurysm

Matricidal carotid cavernous aneurysm (CCA) is a rare and dangerous condition. The treatment failure of the endovascular approach like flow diversion, coiling, or stent-coiling is relatively high with considerable morbidity and mortality. The transcirculation approach is an alternative treatment option, but in case of matricidal CCAs, the results are not well documented in the literature. The authors present a complicated case of an unsuccessful transcirculation approach for matricidal CCA finally treated with sacrifice of the parent artery and high-flow bypass.

A review of technological innovations leading to modern endovascular brain aneurysm treatment

Tools and techniques utilized in endovascular brain aneurysm treatment have undergone rapid evolution in recent decades. These technique and device-level innovations have allowed for treatment of highly complex intracranial aneurysms and improved patient outcomes. We review the major innovations within neurointervention that have led to the current state of brain aneurysm treatment.

Innovation in Neurosurgery: Lessons Learned, Obstacles, and Potential Funding Sources

Innovation is central to neurosurgery and has dramatically increased over the last twenty years. Although the specialty innovates as a whole, only 3-4.7% of practicing neurosurgeons hold patents. Various roadblocks to innovation impede this process such as lack of understanding, increasing regulatory complexity, and lack of funding. Newly emerging technologies allow us to understand how to innovate and how to learn from other medical specialties. By further understanding the process of innovation, and the funding that supports it, Neurosurgery can continue to hold innovation as one of its's central tenets.

Long-term efficacy and safety of WovenEndoBridge (WEB)-assisted cerebral aneurysm embolization

PURPOSE

Long-term compaction, compression, migration, and recurrence rates of the WovenEndoBridge devices remain unknown. The purpose of this study was to detect these rates and safety profiles of the WovenEndoBridge within 7 years period.

MATERIALS AND METHODS

Eighty-three aneurysms of 79 patients treated with the WovenEndoBridge device were retrospectively evaluated using an occlusion scale (e.g. complete occlusion, neck remnant, and aneurysm remnant) on angiography images.

RESULTS

The residual aneurysm was observed in 11 (13%) aneurysms. The mean and median diameters of the recurrent aneurysms were 6 and 7 mm. Most of the recurrent aneurysms were complex type and/or ruptured. Mean diameters and the neck-to-body ratios of all residual aneurysms in the preoperative imaging exams were above 4 mm and 0.6, respectively. The median values of preoperative height and neck measurements were higher in the recurrent aneurysms than in the adequate occlusion group (p = 0.006, p = 0.019, respectively). There was a statistically significant positive relationship between preoperative height/neck measurements and the mean diameters of residual aneurysms (rs = 0.32 and p = 0.003; rs = 0.28 and p = 0.011, respectively). The WovenEndoBridge compaction/compression and migration were observed in 5 (45%) and 2 (18%) of the recurrent aneurysms. In 7 (64%) of the residual aneurysms, thrombosed areas were found within the aneurysm. In the follow-up period, four aneurysms (4.8%) were retreated due to widened residual aneurysm. Other aneurysms were improved or stable within 7 years.

DISCUSSION

Our adequate occlusion rate was 87%. Occlusion rates are less favorable than aneurysms with a long height, wide neck, or high neck-to-body ratio. Our study confirms the high safety and efficiency of the WovenEndoBridge. Compaction, compression, and/or migration of the WovenEndoBridge and the presence of intra-aneurysmal thrombosis are the main reasons for the recurrences.