One-Year Angiographic Follow-Up after WEB-SL Endovascular Treatment of Wide-Neck Bifurcation Intracranial Aneurysms

Review of Endosaccular Flow Disrupters for Wide-Neck Aneurysm Treatment

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

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Intrasaccular flow disruption for brain aneurysms: a systematic review of long-term outcomes

OBJECTIVE

The long-term safety and efficacy of intrasaccular flow disruption (IFD) for the treatment of brain aneurysms remain unclear. With accumulating experience and increasing use of IFD devices, recent studies have provided additional data regarding their outcomes. This review summarizes the long-term outcomes of IFD-treated brain aneurysms.

METHODS

A systematic literature review was performed on May 23, 2021, in PubMed, Web of Science, and Ovid MEDLINE for aneurysm treatment outcomes with IFD devices. Procedural details, including use of adjunctive devices and complications, were collected. The quality of studies was assessed using the Downs and Black checklist. Angiographic outcomes were classified as complete occlusion, residual neck, and residual aneurysm. Other outcomes included need for retreatment, permanent neurological deficit, and mortality. Pooled analyses were performed.

RESULTS

The final analysis comprised 1217 patients with 1249 aneurysms from 22 studies. The mean aneurysm diameter and neck width were 6.9 and 4.5 mm, respectively, and 27.6% of aneurysms were ruptured. The complete occlusion rates at 12 months and final follow-up (pooled mean duration 15.7 months) were 50.1% and 58.2%, respectively. Adjunctive devices were used in 6.4% of cases. The rates of hemorrhage, symptomatic infarction, permanent neurological deficit, and mortality were 1.2%, 2.8%, 1.0%, and 2.6%, respectively.

CONCLUSIONS

IFD is a very safe treatment for appropriately selected brain aneurysms with low complication and neurological deterioration rates. However, complete occlusion is achieved in only half of IFD-treated aneurysms at 1 year with a modest increase beyond this time point. As the majority of the studies were single arm, the pooled data are subject to selection and reporting biases. Future device developments, increased operator experience, and direct comparisons with alternative endovascular strategies and surgical clipping may clarify the role of IFD in aneurysm management.

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

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

Retreatment of Residual and Recurrent Aneurysms After Embolization With the Woven EndoBridge Device: Multicenter Case Series

BACKGROUND

The Woven EndoBridge (WEB) device (Terumno Corp. [parent company of Microvention]) was approved by the U.S. Food and Drug Administration as the first intrasaccular device for intracranial aneurysm treatment in December 2018. Its use has become more common since then, but both trial results and postmarket experiences have raised questions about the efficacy in achieving complete aneurysm obliteration. Retreatment after WEB embolization has not been extensively discussed.

OBJECTIVE

To discuss the incidence and retreatment of aneurysms after initial WEB embolization.

METHODS

Retrospective review across 13 institutions identified all occurrences of WEB retreatment within neurovascular databases. Details regarding demographics, aneurysm characteristics, treatment considerations, clinical outcomes, and aneurysm occlusion were obtained and analyzed.

RESULTS

Thirty aneurysms were retreated in 30 patients in a cohort of 342 WEB-treated aneurysms. The retreatment rate was 8.8%. Endovascular methods were used for 23 cases, and 7 were treated surgically. Two aneurysms presented with rehemorrhage after initial WEB embolization. Endovascular treatments included stent-assisted coiling (12), flow diversion (7), coiling (2), PulseRider (Johnson & Johnson)-assisted coiling (1), and additional WEB placement (1). Surgical treatments included primary clipping (6) and Hunterian ligation (1). There were no major complications within the study group.

CONCLUSION

WEB retreatments were successfully performed by a variety of techniques, including stent-assisted coiling, clipping, and flow diversion as the most common. These procedures were performed safely with subsequent obliteration of most aneurysms. The potential need for retreatment of aneurysms should be considered during primary WEB treatments.

Endovascular Treatment of Small and Very Small Intracranial Aneurysms with the Woven EndoBridge Device

BACKGROUND AND PURPOSE

The Woven EndoBridge has proved to be a safe and effective treatment, especially for wide-neck intracranial aneurysms. The recent fifth-generation Woven EndoBridge came with smaller devices. The purpose of this study was to assess the safety and efficiency of Woven EndoBridge treatment of small and very small aneurysms.

MATERIALS AND METHODS

Between September 2017 and March 2020, all consecutive patients treated with a 3- or 3.5 mm-width Woven EndoBridge device were included in this retrospective intention-to-treat study. Clinical and radiologic findings were evaluated at immediate and last-available follow-up. Angiographic outcome was assessed by an external expert reader.

RESULTS

One hundred twenty-eight aneurysms were treated with a fifth-generation Woven EndoBridge device including 29 with a width of ≤3.5 mm. Ten aneurysms were ruptured (34%). In 3 cases (10%), Woven EndoBridge treatment could not be performed because the aneurysm was still too small for the smallest available Woven EndoBridge device and another endovascular strategy was chosen. The median follow-up time was 11.2 months. Complete and adequate occlusion was obtained in 71% and 90% of the treated aneurysms, respectively. Retreatment was needed in 2 cases (10%). Symptomatic ischemic complications leading to transient neurologic deficits occurred in 2 cases (7%) (1 procedure-related and 1 device-related) but with full spontaneous recovery at discharge.

CONCLUSIONS

The fifth-generation Woven EndoBridge device seems to be a safe and technically feasible treatment for both ruptured and unruptured small and very small intracranial aneurysms, with satisfactory occlusion rates on midterm follow-up. However, further study is needed to evaluate longer-term efficiency.

WEB Device Shape Changes in Elastase-Induced Aneurysms in Rabbits

BACKGROUND AND PURPOSE

While WEB devices have been shown to be safe and effective for aneurysm treatment, WEB-shape modification compression has been associated with incomplete aneurysm occlusion. We explored the relationship between occlusion rates and WEB-shape modification in different WEB device types in an experimental aneurysm model.

MATERIALS AND METHODS

Elastase-induced aneurysms were created in rabbits and treated with dual-layer (n = 12), single-layer (n = 12), or single-layer sphere (n = 12) WEB devices. Aneurysms were followed up either at 3 or 12 months. Angiographic occlusion was graded using the WEB Occlusion Scale: grade I, complete; grade II, complete but recess filling; grade III, residual neck; or grade IV, residual aneurysm. WEB-shape modification and histologic features were also analyzed.

RESULTS

Grade I or II occlusion was seen in 16 (44%) aneurysms, and grade I, II, or III ("adequate") occlusion was observed in 22 (61.1%) aneurysms at follow-up. WEB-shape modification was observed in 22 (61.1%) aneurysms. WEB-shape modification was higher in single-layer (9/12) and dual-layer (10/12) devices compared with single-layer sphere devices (3/12). Aneurysms with WEB-shape modification had a higher level of thrombus organization in the dome compared with those without WEB-shape modification (68% [15/22] versus 50% [7/14]). WEB-shape modification was not correlated with angiographic or histologic outcomes but was significantly correlated with levels of fibrosis and smooth muscle cells in the aneurysm.

CONCLUSIONS

WEB-shape modification is not associated with incomplete aneurysm occlusion of WEB devices in the rabbit model but may be related to connective tissue formation and the healing response to WEB device implantation.

Shape Modification is Common in Woven EndoBridge-Treated Intracranial Aneurysms: A Longitudinal Quantitative Analysis Study

BACKGROUND AND PURPOSE

After endovascular treatment of intracranial aneurysms with the Woven EndoBridge (WEB) device, worsening of aneurysm occlusion or re-opening was reported to be possibly associated with WEB shape modification. This study analyzed quantitatively the WEB shape modification with time in association with anatomic results.

MATERIALS AND METHODS

Thirty patients with 32 WEB-treated intracranial aneurysms fulfilled the inclusion criteria of cranial CT at baseline (day of intervention) and a follow-up CT at least >1 months' later (median follow-up time, 11.4 months; interquartile range, 6.5-21.5 months). Adequate occlusion was observed in 84.4%, and aneurysm remnant, in 15.6%. WEB shape modification was quantified by a semiautomated approach on CT scans. Time courses were evaluated graphically and analytically; association analyses were performed by linear mixed-effects regression models.

RESULTS

In 29/32 WEB devices (90.6%), the reduction in height was found to be at least 5%. The decrease in height with time was significantly associated with the time interval in days since the intervention (P < .0001): A stronger decrease in WEB height was associated with a longer time since the intervention (median reduction in 1 year, 19.2%; range, 8.6%-52.3%). No significant association was found with the quality of aneurysm occlusion, device size, rupture status of the aneurysm, aneurysm location, and reintervention rate.

CONCLUSIONS

Shape modification was common in WEB-treated intracranial aneurysms with a median height reduction of 19.2% in 1 year. The quality of aneurysm occlusion was not associated with WEB modification.

Long-Term Outcomes of the WEB Device for Treatment of Wide-Neck Bifurcation Aneurysms

BACKGROUND AND PURPOSE

Treatment of wide-neck bifurcation aneurysms using endovascular therapy is still challenging even with the development of treatment devices. The purpose of this investigation was to assess the safety and efficacy of treatment with a Woven EndoBridge (WEB) device for wide-neck bifurcation aneurysms.

MATERIALS AND METHODS

All patients treated with a WEB device at our institution between May 2009 and November 2016 were retrospectively evaluated. Clinical and imaging evaluation, aneurysm occlusion status, and modified Rankin scale score were analyzed 1 day after treatment and in the short- (<6 months), mid- (<24 months), and long-term (>24 months) follow-up periods.

RESULTS

Forty-one cases of wide-neck aneurysms were analyzed in this study. Overall, 78.8% of the aneurysms had complete occlusion in the last follow-up, and 19.5% required retreatment with additional endovascular devices. A good clinical outcome (modified Rankin scale: 0-2) was obtained in 95.1% of the patients, and the overall treatment-related morbidity and mortality rates were 2.4% and 0.0%, respectively. The mean follow-up time was 15.3 ± 13.5 months.

CONCLUSIONS

The results obtained in this study suggest that treatment of wide-neck bifurcation aneurysms with a WEB device is feasible with an acceptable safety and efficacy rate.

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.

Endosaccular flow disruption: where are we now?

Endosaccular flow disruption is an innovative method of treating wide-necked complex aneurysms. Currently four types of devices have obtained the CE mark for use within Europe. These are the Woven EndoBridge device (WEB), the Luna Aneurysm Embolization System, the Medina Embolic Device (Medtronic), and the Contour Neurovascular System. The aim of this article is to provide an overview of these devices and to summarize the evidence in the literature pertaining to the treatment of intracranial aneurysms with them.

WEB embolization versus stent-assisted coiling: comparison of complication rates and angiographic outcomes

Background

Intrasaccular flow disruption represents a new paradigm in endovascular treatment of wide-necked bifurcation aneurysms.

Objective

To perform a matched case–control study comparing complications and angiographic outcome using the Woven Endobridge (WEB) device and stent-assisted coiling (SAC).

Methods

Sixty-six patients treated with the WEB at three German tertiary care centers were included and matched with 66 patients treated with SAC based on aneurysm location and unruptured/ruptured aneurysm status. Parameters were retrospectively analysed and compared between the treatment groups using inverse probability of treatment weighting (IPTW) with propensity scores.

Results

Procedural complication rates were 12.1% in the WEB group and 21.2% in the SAC group, which was statistically significant after IPTW adjustment (OR=2.2, 95% CI 1.08 to 4.4, p=0.03). Favourable outcome (modified Rankin scale score ≤2) was achieved by 57/66 (86.4%) in the WEB group and 57/66 (86.4%) in the SAC group (p=1.0). At mid-term follow-up, a similar number of aneurysms achieved adequate occlusion (complete occlusion or neck remnant) in the WEB group (93.9%) and in the SAC group (93.9%, p=1.0). Re-treatment was performed in 10.6% after WEB embolization and 12.1% after SAC (p=1.0).

Conclusions

The WEB provides similar mid-term aneurysm occlusion rates to those of SAC, with no additional morbidity and potentially lower complication rates. Long-term outcome analysis will provide a definite conclusion on the use of WEB for intracranial aneurysms.

Factors that determine aneurysm occlusion after embolization with the Woven EndoBridge (WEB)

Background

The Woven EndoBridge (WEB) device is a novel endovascular tool for the treatment of wide-necked intracranial aneurysms.

Objective

To evaluate factors influencing aneurysm occlusion and aneurysm recurrence after WEB embolization.

Methods

A total of 113 patients (mean age 58.9±11.9 years) with 114 aneurysms (mean size 8.6±4.6 mm) were successfully treated with the WEB device at three German tertiary care centers between May 2011 and February 2018. Aneurysm occlusion was evaluated using the Raymond-Roy occlusion classification. We retrospectively collected patient characteristics, anatomical details, and procedural aspects and evaluated their impact on aneurysm occlusion and recurrence.

Results

Of 98 patients available for a 6-month angiographic follow-up, complete occlusion was achieved in 62.2%, neck remnants in 21.4%, and aneurysm remnants in 16.3%. Aneurysm recurrence occurred in 15.3%. Initial partial aneurysm thrombosis, recurrent aneurysms, aneurysm size, and simultaneous treatment by WEB and coil were associated with aneurysm remnants (p<0.05). Initial partial aneurysm thrombosis, increasing aneurysm size, and treatment by WEB and coil also predicted aneurysm recurrence (p<0.05).

In the subgroup analysis of 71 aneurysms treated with WEB only, initial incomplete occlusion and male sex were associated with aneurysm remnants (p<0.05), while aneurysm height correlated with aneurysm recurrence (p=0.008).

Conclusions

The WEB provides a high rate of adequate occlusion even in a subset of complex wide-necked intracranial aneurysms. Anatomic results tend to be less favourable in large and partially thrombosed aneurysms and after treatment with WEB and coil.

Treatment strategies for recurrent and residual aneurysms after Woven Endobridge implantation

Background

Woven Endobridge (WEB) embolization is a safe and efficient technique for endovascular treatment of intracranial aneurysms. However, the management of aneurysm recurrence after WEB placement has not been well described to date. We present our multicenter experience of endovascular retreatment of aneurysm recurrence after WEB implantation.

Methods

This is a multicenter study of patients who underwent endovascular retreatment after WEB implantation in three German tertiary care centers. Treatment strategies, complications, and angiographic outcome were retrospectively assessed.

Results

Among 122 aneurysms treated with the WEB device, 15 were retreated. Of these, six were initially treated with the WEB only, two were pretreated by coiling, and seven large aneurysms were treated in a multimodality approach. Ten were true aneurysm remnants and five were neck remnants. The reasons for retreatment were WEB migration (n=6), initial incomplete occlusion (n=5), and WEB compression (n=4). Retreatment strategies included coiling (n=4), stent-assisted coiling (n=7), flow diversion (n=3), and placement of an additional WEB (n=1). All procedures were technically successful and there were no procedure-related complications. Among 11 patients available for follow-up after retreatment, three were retreated again. At last angiographic follow-up, available in 11/15 cases at a median of 23 months, complete occlusion was obtained in eight cases and neck remnants in three.

Conclusions

This pilot study shows that endovascular retreatment of recurrent or residual aneurysms after WEB implantation can be done safely and can achieve adequate occlusion rates.

The Woven EndoBridge (WEB) as primary treatment for unruptured intracranial aneurysms

Purpose The intrasaccular flow disruptor Woven EndoBridge (WEB) device is developed for the treatment of wide-necked aneurysms without supportive devices. We used the WEB as primary treatment for unruptured aneurysms suitable for the device, regardless of neck size. Methods Between February 2015 and June 2017, 59 aneurysms in 51 patients were selectively treated with the WEB. There were 15 men and 36 women with a mean age of 59 years. Mean aneurysm size was 7.0 mm (range 3-22 mm). Of 59 aneurysms, 45 (76%) had a wide neck defined as ≥4 mm or dome-neck ratio ≤1.5. No stents or supporting balloons were used. Results Initial WEB position was judged good in all 59 unruptured aneurysms. One patient with a basilar tip aneurysm had a late thrombotic posterior cerebral artery occlusion by protrusion of the WEB over the artery. There were no procedural ruptures. Overall complication rate was 2.0% (1 of 51, 95% CI 0.01-11.3%). Imaging follow-up was available in 55 of 59 aneurysms (93%). At 3 months, 41 of 57 aneurysms (72%) were completely occluded, 12 (21%) had a neck remnant and 4 (7%) were incompletely occluded. Conclusion WEB treatment is safe and effective in selected unruptured aneurysms suitable for the device, regardless of neck size or location. There was no need for supportive devices. Three-quarters of all unruptured small aneurysms could be treated with the WEB. In our opinion, the WEB is a valuable alternative to coils, especially in wide-necked aneurysms.

The New Low-Profile WEB 17 System for Treatment of Intracranial Aneurysms: First Clinical Experiences

BACKGROUND AND PURPOSE

The Woven EndoBridge (WEB) is an intrasaccular flow diverter intended to treat wide-neck aneurysms. The latest generation WEBs needed a 0.021-inch microcatheter in the small sizes. Recently, a lower profile range of WEBs compliant with a 0.017-inch microcatheter (WEB 17) has been introduced. We present the first clinical results of treatment of both ruptured and unruptured aneurysms with the WEB 17.

MATERIALS AND METHODS

Between December 2016 and September 2017, forty-six aneurysms in 40 patients were treated with the WEB 17. No supporting stents or balloons were used. Twenty-five aneurysms were ruptured (54%). There were 6 men and 34 women (mean age, 62 years; median, 63 years; range, 46-87 years). The mean aneurysm size was 4.9 mm (median, 5 mm; range, 2-7 mm).

RESULTS

There were 2 thromboembolic procedural complications without clinical sequelae and no ruptures. The overall permanent procedural complication rate was 0% (0 of 40; 97.5% CI, 0%-10.4%). Imaging follow-up at 3 months was available in 33 patients with 39 aneurysms (97.5% of 40 eligible aneurysms). In 1 aneurysm, the detached WEB was undersized and the remnant was additionally treated with coils after 1 week. This same aneurysm reopened at 3 months and was again treated with a second WEB. One other aneurysm showed persistent WEB filling at 3 months. Complete occlusion was achieved in 28 of 39 aneurysms (72%), and 9 aneurysms (23%) showed a neck remnant.

CONCLUSIONS

The WEB 17 is safe and effective for both ruptured and unruptured aneurysms. The WEB 17 is a valuable addition to the existing WEB size range, especially for very small aneurysms.

The LUNA aneurysm embolization system for intracranial aneurysm treatment: short-term, mid-term and long-term clinical and angiographic results

BACKGROUND AND PURPOSE

Intrasaccular aneurysm flow disruption represents an emerging endovascular approach to treat intracranial aneurysms. The purpose of this study was to determine the clinical and angiographic outcomes of using the LUNA aneurysm embolization system (AES) for treatment of intracranial aneurysms.

MATERIALS AND METHODS

The LUNA AES Post-Market Clinical Follow-Up study is a prospective, multicenter, single-arm study that was designed to evaluate device safety and efficacy. Bifurcation and sidewall aneurysms were included. Aneurysm occlusion was assessed using the Raymond-Roy classification scale. Disability was assessed using the Modified Rankin Scale (mRS). Morbidity was defined as mRS >2 if baseline mRS ≤2, increase in mRS of 1 or more if baseline mRS >2, or mRS >2 if aneurysm was ruptured at baseline. Clinical and angiographic follow-up was conducted at 6, 12 and 36 months.

RESULTS

Sixty-three subjects with 64 aneurysms were enrolled. Most aneurysms were unruptured (60/63 (95.2%)); 49 were bifurcation or terminal (49/64 (76.6%)). Mean aneurysm size was 5.6±1.8 mm (range, 3.6-14.9 mm), and mean neck size was 3.8±1.0 mm (range, 1.9-8.7 mm). Though immediate postoperative adequate occlusion was low (11/63, 18%), adequate occlusion was achieved in 78.0% (46/59) and 79.2% (42/53) of the aneurysms at 12 months and 36 months, respectively. Four patients were retreated by the 12-month follow-up (4/63 (6.3%)) and three patients were retreated by the 36-month follow-up (3/63 (4.8%)). There were two major strokes (2/63 (3.2%)), one minor stroke (1/63 (1.6%)) and three incidents of intracranial hemorrhage in two subjects (2/63 (3.2%)) prior to the 12-month follow-up. There was one instance of mortality (1/63, 1.6%). Morbidity was 0% (0/63) and 1.8% (1/63) at the 12-month and 36-month follow-ups, respectively.

CONCLUSIONS

LUNA AES is safe and effective for the treatment of bifurcation and sidewall aneurysms.

CLINICAL TRIAL REGISTRATION

ISRCTN72343080; Results.

The Barrel vascular reconstruction device for endovascular coiling of wide-necked intracranial aneurysms: a multicenter, prospective, post-marketing study

Background and purpose

The Barrel vascular reconstruction device (Barrel VRD) is a novel stent with design features that allow endovascular coiling of wide-necked bifurcation aneurysms while preserving adjacent branches, without necessitating dual stent implantation. This study aimed to assess the safety and effectiveness of the Barrel VRD at 12-month follow-up.

Materials and methods

The Barrel VRD trial is a prospective, multicenter, observational post-marketing registry evaluating the use of the Barrel VRD for treatment of wide-necked bifurcation aneurysms. The primary effectiveness endpoint was successful aneurysm treatment measured by digital subtraction angiography with a Raymond–Roy occlusion grade of 1 or 2 in the absence of retreatment, parent artery stenosis (>50%), or target aneurysm rupture at 12 months. The primary safety endpoint was the absence of neurological death or major stroke at 12 months.

Results

Twenty patients were enrolled from December 2013 to December 2014. The device was implanted in 19 patients with 19 aneurysms (8 middle cerebral artery, 4 anterior communicating artery, 1 internal carotid artery terminus, 4 basilar artery aneurysms; mean dome height 5.7±1.91 mm; mean neck length 4.8±1.35 mm, mean dome-to-neck ratio 1.6±2.0). Coiling was performed in all cases. The primary effectiveness endpoint was achieved in 78.9% of subjects (15/19; 12 complete occlusions, 3 neck remnants), and the primary safety endpoint was 5.3% (1/19).

Conclusions

This prospective study demonstrates that the Barrel VRD device resulted in ~80% occlusion rates and ~5% rates of neurological complications at 1 year after endovascular treatment of wide-necked bifurcation intracranial aneurysms.

Registered clinical trial

NCT02125097;Results.

WEB Treatment of Ruptured Intracranial Aneurysms: A Single-Center Cohort of 100 Patients

BACKGROUND AND PURPOSE

The Woven EndoBridge device was recently introduced for the intrasaccular treatment of wide-neck aneurysms without the need for adjunctive devices. We present our results of the primary treatment of ruptured aneurysms with the Woven EndoBridge regardless of location or neck size.

MATERIALS AND METHODS

Between February 2015 and April 2017, 100 ruptured aneurysms were selectively treated with the Woven EndoBridge. No supporting stents or balloons were used. There were 71 women treated (mean patient age, 59 years; median age, 60 years; range, 23-82 years).

RESULTS

The mean aneurysm size was 5.6 mm (range, 3-13 mm), and 42 aneurysms were ≤4 mm. Sixty-six aneurysms (66%) had a wide neck, defined as ≥4 mm or a dome-neck ratio ≤1.5. There was 1 procedural rupture without sequelae. In 9 patients (9%), thromboembolic complications occurred. One poor grade patient died; neurologic deficits remained in 3. Overall treatment-related morbidity-mortality was 4% (4 of 100; 95% CI, 1.2%-10.2%).Two of 100 aneurysms were initially incompletely occluded and were additionally treated early after initial intervention. Of 80 eligible patients, 74 (93%) had 3-month angiographic follow-up. Fifty-four aneurysms (73%) were completely occluded, 17 (23%) had a small neck remnant, and 3 (4%) were incompletely occluded. One patient was additionally treated with a second Woven EndoBridge, and in 2 patients, additional treatment is scheduled. The overall reopening/retreatment rate was 6.8% (5 of 74; 95% CI, 2.6%-15.2%). There were no rebleeds during follow-up.

CONCLUSIONS

Treatment of small ruptured aneurysms with the Woven EndoBridge was safe and effective. The Woven EndoBridge proved to be a valuable alternative to coils without the need for stents or balloons.

The Medina Embolic Device: Karolinska experience

Background The aim of this study was to report our single centre experience with the Medina Embolic Device (MED). Methods We performed a retrospective analysis of prospectively collected data to identify all patients treated with the MED. A total of 14 aneurysms (non-consecutive), in 13 patients, were treated including one ruptured and one partially thrombosed aneurysm. Fundus diameter was ≥5 mm in all cases. We evaluated the angiographic appearances, the clinical status, complications, and the need for adjunctive devices or repeat treatments. Results Aneurysm location was cavernous internal carotid artery (ICA; n = 1), supraclinoid ICA ( n = 1), terminal ICA ( n = 2), anterior communicating artery (AComA; n = 4), A2-3 ( n = 1), M1-2 junction ( n = 1), posterior communicating artery (PComA; n = 1), superior cerebellar artery (SCA; n = 1), and basilar tip ( n = 2). The average aneurysm fundus size was 8.6 mm (range 7-10 mm) and average neck size 3.75 mm (range 1.9-6.9 mm). Immediate angiographic results were modified Raymond-Roy occlusion classification (mRRC) I n = 2, mRRC II n = 1, mRRC IIIa n = 2, mRRC IIIb n = 2, the remaining 7 aneurysms showed complete opacification. At follow-up angiography (mean 5 months) mRRC I n = 5, mRRC II n = 5, mRRC IIIa n = 3, and persistent filling was seen in 1 aneurysm. Overall, four patients had repeat treatment and one is pending further treatment. Of the aneurysms treated with more than one MED, 75% showed complete occlusion at 6-month follow up whereas only one aneurysm treated with a single device showed complete occlusion. Overall, three patients had temporary complications and there were no deaths. Conclusions The MED is an intra-saccular flow-diverting device with satisfactory angiographic results and an acceptable safety profile. Use of a single MED cannot be recommended and further longer term studies are needed prior to widespread clinical use.

Medina® Embolization Device for the Treatment of Intracranial Aneurysms: Safety and Angiographic Effectiveness at 6 Months

BACKGROUND

The Medina Embolization Device (MED) is a new concept device that combines the design of a detachable coil and the one of an intrasaccular flow disruption device.

OBJECTIVE

To evaluate the feasibility, safety, and 6- to 9-mo effectiveness of this new device for the treatment of intracranial wide-necked aneurysms.

METHODS

Twelve patients (10 females, mean age = 56 yr) with 13 wide-necked intracranial aneurysms (3 ruptured; 10 unruptured) were treated by means of the MED from January 2015 to October 2015. In 15% of the cases, MEDs were used in a standalone fashion; in 85% of the cases, additional regular coils were used. Adjunctive compliant balloon was used in 4 of 13 cases (31%). Procedure-related complications were systematically recorded; discharge and 6- to 9-mo follow-up modified Rankin Scale was assessed. Angiographic follow-up was performed with a mean delay of 5.5 ± 1.7 mo. Occlusion rate was evaluated in postprocedure and at midterm follow-up using the Roy–Raymond scale.

RESULTS

The deployment of the MED was feasible in all cases. No perforation was recorded. One case of thromboembolic complication was observed in a ruptured anterior communicating artery aneurysm, without any clinical consequence at follow-up. Grade A occlusion rate was 61.5% in postprocedure and 83% at 6-mo follow-up. Two cases (17%) of recanalization were documented angiographically.

CONCLUSION

The MED is a new generation device combining the design of a detachable coil and an intrasaccular flow disruption device. According to our early experience, this device is safe and provides a satisfactory occlusion rate at angiographic follow-up of 6 mo.

One-year Angiographic Results After pCONus Stent-Assisted Coiling of 40 Wide-Neck Middle Cerebral Artery Aneurysms

BACKGROUND: Bifurcation middle cerebral artery (MCA) aneurysms with wide neck are amenable to endovascular coiling with pCONus stent, a recent device dedicated to wide-neck bifurcation intracranial aneurysms.

OBJECTIVE: To evaluate the 1-year angiographic follow-up of wide-neck MCA aneurysms treated with pCONus.

METHODS: Forty MCA aneurysms (mean dome size, 7.7 mm; mean neck size, 5.6 mm) coiled with pCONus were retrospectively evaluated. “Recanalization” was defined as worsening, and “progressive thrombosis” was defined as improvement on the Raymond scale.

RESULTS: Angiographic midterm (mean, 11.9 months; range, 3-20) follow-up was obtained in all aneurysms. Retreatment was performed in 9 aneurysms (22.5%) without clinical complications, and postoperative angiographic outcome included 2 complete occlusions and 7 neck remnants. Six aneurysms were followed after retreatment (mean, 8.8 months), and presented complete occlusion in 1 case, neck remnant in 4 cases, and aneurysm remnant in 1 case. Among the 31 aneurysms, follow-up showed complete occlusion in 67.7% (21/31), neck remnants in 29% (9/31), and aneurysm remnants in 3.3% (1/31). Adequate aneurysm occlusion (total occlusion and neck remnant) was obtained in 96.7% (30/31). Among these 31 aneurysms, improvement of the rate of occlusion was observed in 15 aneurysms (48.4%), and recurrence in 2 aneurysms (6.5%). There was no 1-year angiographic recurrence of 3- or 6-month totally occluded aneurysms.

CONCLUSION: pCONus stent allows a safe coiling of wide-neck MCA aneurysms usually considered as surgical with a low recanalization rate for those adequately occluded at 3 to 6 months. Angiographic results improve over time due to progressive aneurysm thrombosis in around 50% of cases.

Endovascular treatment of intracranial aneurysms with the Woven EndoBridge device: mid term and long term results

Purpose

To evaluate the clinical and anatomical results of treatment of intracranial aneurysms (IA) with the Woven EndoBridge (WEB) device, with emphasis on mid term and long term follow-up.

Methods

Between November 2010 and November 2015, we retrospectively identified, in our prospectively maintained database, all patients treated by WEB device placement for an IA at three institutions. Clinical charts, procedural data, and angiographic results were reviewed.

Results

48 patients with 49 IAs were identified. There were 35 women and 13 men with a mean age of 57 years (range 35–76 years). All IA were wide necked. Mean aneurysm size was 8.6 mm. There were 44 unruptured IA and 5 ruptured IA. During endovascular treatment (EVT), adjunctive devices were used in 22.4% of procedures. A good clinical outcome (modified Rankin Scale score ≤2) was achieved in 44/48 patients (92%). There was no mortality. Mean follow-up was 25 months (range 3–72 months; median 24 months). Between mid term and long term follow-up, occlusion was stable in 19/23 IA (82.6%), improved in 2/23 IA (8.7%), and worsened in 2/23 IA (8.7%). Retreatment was performed in 8/49 IA (16.3%). At the latest available follow-up, there were 34/47 (72.3%) complete occlusions and 13/47 (27.7%) neck remnants.

Conclusions

Our study suggests that EVT of IA with the WEB device provides adequate and stable long term occlusion.

PulseRider for Treatment of Wide-Neck Bifurcation Intracranial Aneurysms: 6-Month Results

BACKGROUND/OBJECTIVE

PulseRider is a new endovascular stent dedicated to treat bifurcation intracranial aneurysms with a wide neck. Our purpose was to evaluate 6-month clinical and anatomic results of the device when used to facilitate endovascular coiling of wide-neck bifurcation aneurysms.

METHODS

Unruptured intracranial aneurysms coiled with PulseRider, in 6 European centers and 1 U.S. center, were retrospectively reviewed from June 2014 to October 2015. Immediate and 6-month results were evaluated independently by using the Raymond classification scale. Recanalization was defined as worsening, and progressive thrombosis was defined as improvement on the Raymond scale.

RESULTS

Nineteen patients (10 women, 9 men; mean age, 63 years) harboring 19 bifurcation aneurysms (mean dome size, 8.8 mm; mean neck size, 5.8 mm) were included. Immediate angiographic outcome showed 11 complete aneurysm occlusions, 6 neck remnants, and 2 residual aneurysms. Follow-up at 6 months, obtained in all patients, included 12 complete aneurysm occlusions (63.1%), 6 neck remnants (31.6%), and 1 residual aneurysm (5.3%). Adequate occlusion (defined as complete occlusion and neck remnant combined) was observed in 94.7%. Progressive thrombosis was observed in 2 cases (10.6%) and recanalization in 1 case (5.3%). There was no in-stent stenosis or jailed branch occlusion. No bleeding was observed during the follow-up period. Permanent morbidity rate was 5.3% (1/19), and the mortality rate was 0% at 6 months.

CONCLUSIONS

The PulseRider allows endovascular treatment of wide-neck bifurcation intracranial aneurysms. Larger series are needed to confirm our preliminary results.

The Medina Embolic Device: early clinical experience from a single center

Objective

To report our initial experience with the Medina Embolic Device (MED) in unruptured intracranial aneurysms either as sole treatment or in conjunction with additional devices.

Methods

15 consecutive patients (6 women, 9 men) with unruptured aneurysms were treated between September 2015 and April 2016. The aneurysm fundus measured at least 5 mm. We evaluated the angiographic appearances of treated aneurysms at the end of the procedure and at follow-up, the clinical status, complications, and requirement for adjunctive devices.

Results

The MED was successfully deployed in all but one case and adjunctive devices were required in 10 cases. Aneurysm locations were middle cerebral artery bifurcation (n=3), internal carotid artery (ICA) bifurcation (n=1), supraclinoid ICA (n=5), posterior communicating artery (n=1), anterior communicating artery (n=2), cavernous ICA (n=2), distal basilar sidewall (n=1), basilar tip (n=1). Three patients had complications although none could be attributed to the MED. Immediate angiographic results were modified Raymond-Roy classification (mRRC) I=1, mRRC II=5, mRRC IIIa=3, mRRC IIIb=5, and one patient showed contrast stasis within the fundus of the aneurysm. Follow-up angiography was available in 11 patients, with four showing complete aneurysm exclusion, six with stable remnants and one patient with an enlarging neck remnant.

Conclusions

The MED represents a major step forward in the treatment of intracranial aneurysms. It can result in rapid exclusion of an aneurysm from the circulation and has a good safety profile. We believe that the true value of the MED will be in combining its use with adjunctive devices such as endoluminal flow diverters that will result in rapid aneurysmal exclusion.

Stent deployment protocol for optimized real-time visualization during endovascular neurosurgery

Successful application of endovascular neurosurgery depends on high-quality imaging to define the pathology and the devices as they are being deployed. This is especially challenging in the treatment of complex cases, particularly in proximity to the skull base or in patients who have undergone prior endovascular treatment. The authors sought to optimize real-time image guidance using a simple algorithm that can be applied to any existing fluoroscopy system. Exposure management (exposure level, pulse management) and image post-processing parameters (edge enhancement) were modified from traditional fluoroscopy to improve visualization of device position and material density during deployment. Examples include the deployment of coils in small aneurysms, coils in giant aneurysms, the Pipeline embolization device (PED), the Woven EndoBridge (WEB) device, and carotid artery stents. The authors report on the development of the protocol and their experience using representative cases. The stent deployment protocol is an image capture and post-processing algorithm that can be applied to existing fluoroscopy systems to improve real-time visualization of device deployment without hardware modifications. Improved image guidance facilitates aneurysm coil packing and proper positioning and deployment of carotid artery stents, flow diverters, and the WEB device, especially in the context of complex anatomy and an obscured field of view.

Contrast-Enhanced and Time-of-Flight MRA at 3T Compared with DSA for the Follow-Up of Intracranial Aneurysms Treated with the WEB Device

BACKGROUND AND PURPOSE

Imaging follow-up at 3T of intracranial aneurysms treated with the WEB Device has not been evaluated yet. Our aim was to assess the diagnostic accuracy of 3D-time-of-flight MRA and contrast-enhanced MRA at 3T against DSA, as the criterion standard, for the follow-up of aneurysms treated with the Woven EndoBridge (WEB) system.

MATERIALS AND METHODS

From June 2011 to December 2014, patients treated with the WEB in our institution, then followed for ≥6 months after treatment by MRA at 3T (3D-TOF-MRA and contrast-enhanced MRA) and DSA within 48 hours were included. Aneurysm occlusion was assessed with a simplified 2-grade scale (adequate occlusion [total occlusion + neck remnant] versus aneurysm remnant). Interobserver and intermodality agreement was evaluated by calculating the linear weighted κ. MRA test characteristics and predictive values were calculated from a 2 × 2 contingency table, by using DSA data as the standard of reference.

RESULTS

Twenty-six patients with 26 WEB-treated aneurysms were included. The interobserver reproducibility was good with DSA (κ = 0.71) and contrast-enhanced-MRA (κ = 0.65) compared with moderate with 3D-TOF-MRA (κ = 0.47). Intermodality agreement with DSA was fair with both contrast-enhanced MRA (κ = 0.36) and 3D-TOF-MRA (κ = 0.36) for the evaluation of total occlusion. For aneurysm remnant detection, the prevalence was low (15%), on the basis of DSA, and both MRA techniques showed low sensitivity (25%), high specificity (100%), very good positive predictive value (100%), and very good negative predictive value (88%).

CONCLUSIONS

Despite acceptable interobserver reproducibility and predictive values, the low sensitivity of contrast-enhanced MRA and 3D-TOF-MRA for aneurysm remnant detection suggests that MRA is a useful screening procedure for WEB-treated aneurysms, but similar to stents and flow diverters, DSA remains the criterion standard for follow-up.

WEB Treatment of Ruptured Intracranial Aneurysms

BACKGROUND AND PURPOSE

The Woven EndoBridge (WEB) device was recently introduced for intrasaccular treatment of wide-neck aneurysms without the need for adjunctive support. We present our first experience in using the WEB for small ruptured aneurysms.

MATERIALS AND METHODS

During 11 months, 32 of 71 (45%) endovascularly treated acutely ruptured aneurysms were treated with the WEB. The patients were 12 men and 20 women, with a mean age of 61 years (range, 34-84 years). The mean aneurysm size was 4.9 mm, and 14 were ≤4 mm. Of 32 aneurysms, 24 (75%) had a wide neck.

RESULTS

All 32 aneurysms were adequately occluded after WEB placement. There were no procedural ruptures and no complications related to the WEB device. No adjunctive stents or balloons were needed. In 3 patients, thromboembolic complications occurred. One patient developed an infarction, and 2 patients were asymptomatic. The procedural complication rate was 3%. Seven patients admitted in poor clinical grade conditions died during hospital admission due to the sequelae of SAH. In 18 patients with angiographic follow-up at 3 months, 16 aneurysms remained adequately occluded. Two aneurysms showed slight compression of the WEB without reopening. Clinical follow-up in the 25 patients who survived the hospital admission period revealed mRS 1-2 in 24 and mRS 4 in 1. There were no rebleeds from the ruptured aneurysms during follow-up.

CONCLUSIONS

WEB treatment of small ruptured aneurysms was safe and effective without the need for anticoagulation, adjunctive stents, or balloons. Our preliminary experience indicates that the WEB may be a valuable alternative to coils in the treatment of acutely ruptured aneurysms.

Experimental testing of the dual-layer Woven EndoBridge device using an elastase-induced aneurysm model in rabbits

The dual-layer Woven EndoBridge (WEB) device (WEB II) is designed to improve the performance of the first-generation WEB device. This study was performed to evaluate the acute and chronic performance of WEB II for aneurysm occlusion in an elastase-induced aneurysm model in rabbits. We implanted WEB II devices in 36 elastase-induced aneurysms and followed up for one, three, six, and 12 months. Degree of aneurysm occlusion at follow-up was graded on the Web Occlusion Scale (WOS): Grade A, complete aneurysm occlusion; Grade B, complete occlusion with recess filling; Grade C, residual neck filling; and Grade D, residual aneurysm filling. Hematoxylin and eosin staining was performed for histological assessment of aneurysm healing. Grades A, B, C, and D aneurysm occlusion at one-month follow-up were noted in three (17%), three (17%), eight (44%), and four (22%) of 18 cases, respectively. At the three-month time point Grades A, B, C, and D were shown in two (33%), two (33%), one (17%), and one (17%) aneurysms. Six months after treatment, one (17%), two (33%), two (33%), and one (17%) cases demonstrated Grades A, B, C, and D occlusion. At the 12-month time point, Grades B, C, and D were shown in three (50%), two (33%), and one (17%) aneurysms. Histologic evaluation showed progressive thrombus organization within aneurysm lumen from one to 12 months. These results indicated that the WEB II device can achieve high rates of aneurysm occlusion over time in experimental aneurysms.

Endovascular Treatment of Intracranial Aneurysms with the WEB Device: A Systematic Review of Clinical Outcomes

BACKGROUND AND PURPOSE

Despite the improvement in technology, endovascular treatment of bifurcation intracranial wide-neck aneurysms remains challenging, mainly due to the difficulty of maintaining coils within the aneurysm sac without compromising the patency of bifurcation arteries. The Woven EndoBridge (WEB) device is a recent intrasaccular braided device specifically dedicated to treating such aneurysms with a wide neck by disrupting the flow in the aneurysmal neck and promoting progressive aneurysmal thrombosis.

MATERIALS AND METHODS

Using several health data bases, we conducted a systematic review of all published studies of WEB endovascular treatment in intracranial aneurysms from 2010 onward to evaluate its efficacy and safety profile.

RESULTS

The literature search identified 6 relevant studies (7 articles) including wide-neck bifurcation aneurysms in ≥80% of cases. Clinical data supporting the efficacy and safety of the WEB are limited to noncomparative cohort studies with large heterogeneity from a methodologic standpoint. The WEB deployment was feasible with a success rate of 93%-100%. Permanent morbidity (mRS of >1 at last follow-up) and mortality were measured at 2.2%-6.7% and 0%-17%, respectively. The adequate occlusion rate (total occlusion or neck remnant) varied between 65% and 85.4% at midterm follow-up (range, 3.3-27.4 months).

CONCLUSIONS

Endovascular treatment of bifurcation wide-neck aneurysms with the WEB device is feasible and allows an acceptably adequate aneurysm occlusion rate; however, the rate of neck remnants is not negligible. The WEB device needs further clinical and anatomic evaluation with long-term prospective studies, especially of the risk of WEB compression. Prospective controlled studies should be encouraged.