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

Higher risk of recurrence in partially thrombosed cerebral aneurysms post-WEB (Woven EndoBridge) device treatment: insights from the WorldWideWEB Consortium registry

BACKGROUND

The Woven EndoBridge (WEB) device is a prevalent treatment for intracranial aneurysms. While many studies have assessed the obliteration rate post-WEB embolization, few have focused on long-term outcomes in partially thrombosed aneurysms.

OBJECTIVE

To assess whether partially thrombosed aneurysms are at higher risk of recurrence or retreatment following WEB embolization compared with non-thrombosed aneurysms.

METHODS

We evaluated data from 22 academic institutions, focusing on previously untreated cerebral aneurysms treated with the WEB device. Logistic regression was utilized to analyze factors predicting long-term aneurysm obliteration and retreatment necessity.

RESULTS

Among 1303 patients, 26 presented with a partially thrombosed aneurysm. In the partially thrombosed group, the mean aneurysm maximal diameter was 10.7±4 mm with a neck ratio of 1.99±1.19 mm, larger than in the control group where the mean aneurysm maximal diameter was 6.81±2.37 mm with a neck ratio of 1.64±0.51 mm (P<0.001 for both maximal diameter and neck ratio). At the final follow-up, partially thrombosed aneurysms treated by the WEB device had a 38.5% retreatment rate, compared with 7.0% for non-thrombosed aneurysms (P<0.001). Among partially thrombosed aneurysms, the Raymond-Roy type IIIa/b occlusion rate was higher (38.5% vs 9.9%, P<0.001). On multivariate analysis, partially thrombosed aneurysms compared with non-thrombosed aneurysms had an increased rate of retreatment (OR 3.64, 95% CI 1.28 to 10.1).

CONCLUSION

Partially thrombosed aneurysms are associated with a poorer occlusion rate and a higher rate of retreatment following WEB embolization. For partially thrombosed aneurysms, the WEB device appears suboptimal as a first-line treatment, and therefore alternative techniques should be prioritized.

Aneurysm clipping on WEB device: A feasibility study using a human ex-vivo aneurysm model

BACKGROUND AND OBJECTIVES

The Woven EndoBridge (WEB) device is a breakthrough in brain aneurysm treatment, widely used for intracranial wide neck and complex aneurysms, especially at bifurcations. Although effective, aneurysm recurrence can occur post-treatment and the impact of clipping angle on the WEB mesh remains unclear. In this study, using a human placenta-based ex-vivo aneurysm model, we simulated the application of aneurysm clipping on WEB-treated aneurysms to elucidate the technical aspects and nuances, particularly the influence of the angle of clip application on WEB collapse.

METHODS

Human placentas were used to create aneurysms by suture-closing of the placenta vessels. The WEB devices were positioned in the aneurysms under fluoroscopic guidance, and different clip positions/angles on the WEB device were tested. Imaging was used to monitor the effects of clipping on the WEB device and aneurysm.

RESULTS

All clipping positions achieved complete aneurysm occlusion, collapsing the WEB mesh with no flow observed into the aneurysm. Despite the WEB device's displacement within the sac, no significant morphological changes to the aneurysm were identified, and the presence of a neck remnant did not affect the adequacy of blade apposition.

CONCLUSION

Microsurgical clipping reliably collapses the WEB device, regardless of its placement or orientation. Our model suggests that clipping can effectively address in-vivo recurrences and persistent aneurysm filling of aneurysms treated with the WEB device. The model does not assess the influence of WEB healing within the aneurysm. Operators should be aware of possible WEB shape changes when clipping its mesh.

Addressing residual and recurrent aneurysms post-Woven EndoBridge device embolization: a systematic review and meta-analysis

BACKGROUND

Early literature on the Woven EndoBridge (WEB) device reported 80-90% adequate aneurysm occlusion but low complete occlusion (40-55%). It is uncertain whether residual or recurrent aneurysms require re-treatment to prevent future rupture.

OBJECTIVE

To systematically review the literature to meta-analyze occlusion and complication rates after re-treatment of these aneurysms.

METHODS

PubMed and EMBASE were queried for 're-treatment' of 'recurrent' or 'residual' aneurysms treated with the WEB device. Studies reporting strategies and outcomes were included. Patient and aneurysm characteristics, outcomes, and complications were extracted. Meta-analyses were conducted on variables reported by three or more studies.

RESULTS

We included 15 studies of 220 patients (220 aneurysms) with a mean age of 57.8 years (95% CI 55.1 to 60.7 years). At baseline, 42.8% (95% CI 35% to 51%) of aneurysms were ruptured, had a mean 8.6 mm dome (95% CI 7.3 to 10 mm) and a mean 5.2 mm neck (95% CI 4.7 to 5.7 mm), and 69.85% were at bifurcations (95% CI 47.63% to 85.51%). At mean 11.2 months' follow-up (95% CI 8 to 15.6 months), 75.9% (95% CI 66.1% to 83.5%) had residual dome filling, predominantly from incomplete occlusion in 84.7% of cases (95% CI 66.6% to 93.9%). Endovascular management was used in 82.5% (95% CI 72.6% to 89.3%) of recurrences, with stent-assisted or flow diverter-assisted coil embolization being used in 42.4% (95% CI 32.7% to 52.8%). Overall, complication rates were 8.9% (95% CI 4.9% to 15.6%) thromboembolic and 8% (95% CI 4.3% to 14.2%) device-related. Complete angiographic occlusion after re-treatment was achieved in 64.1% (95% CI 52.6% to 74.2%), of patients, with 15.2% (95% CI 8.8% to 24.9%) requiring additional re-treatment.

CONCLUSION

Our review reports excellent safety and modest occlusion outcomes with re-treatment of recurrent or residual aneurysms post-WEB embolization. Outcomes with observational management of residual or recurrent aneurysms are lacking, questioning the requirement for re-treatment. Endovascular strategies demonstrated excellent safety and additional re-treatment rates, highlighting their expanding role in post-WEB recurrences.

Predictors of Aneurysm Obliteration in Patients Treated with the WEB Device: Results of a Multicenter Retrospective Study

BACKGROUND AND PURPOSE

Despite the numerous studies evaluating the occlusion rates of aneurysms following WEB embolization, there are limited studies identifying predictors of occlusion. Our purpose was to identify predictors of aneurysm occlusion and the need for retreatment.

MATERIALS AND METHODS

This is a review of a prospectively maintained database across 30 academic institutions. We included patients with previously untreated cerebral aneurysms embolized using the WEB who had available intraprocedural data and long-term follow-up.

RESULTS

We studied 763 patients with a mean age of 59.9 (SD, 11.7) years. Complete aneurysm occlusion was observed in 212/726 (29.2%) cases, and contrast stasis was observed in 485/537 (90.3%) of nonoccluded aneurysms. At the final follow-up, complete occlusion was achieved in 497/763 (65.1%) patients, and retreatment was required for 56/763 (7.3%) patients. On multivariable analysis, history of smoking, maximal aneurysm diameter, and the presence of an aneurysm wall branch were negative predictors of complete occlusion (OR, 0.5, 0.8, and 0.4, respectively). Maximal aneurysm diameter, the presence of an aneurysm wall branch, posterior circulation location, and male sex increase the chances of retreatment (OR, 1.2, 3.8, 3.0, and 2.3 respectively). Intraprocedural occlusion resulted in a 3-fold increase in the long-term occlusion rate and a 5-fold decrease in the retreatment rate (P < .001), offering a specificity of 87% and a positive predictive value of 85% for long-term occlusion.

CONCLUSIONS

Intraprocedural occlusion can be used to predict the chance of long-term aneurysm occlusion and the need for retreatment after embolization with a WEB device. Smoking, aneurysm size, and the presence of an aneurysm wall branch are associated with decreased chances of successful treatment.

Long-Term Follow-Up of Cerebral Aneurysms Completely Occluded at 6 Months After Intervention with the Woven EndoBridge (WEB) Device: a Retrospective Multicenter Observational Study

The Woven EndoBridge (WEB) device has been widely used to treat intracranial wide neck bifurcation aneurysms. Initial studies have demonstrated that approximately 90% of patients have same or improved long-term aneurysm occlusion after the initial 6-month follow up. The aim of this study is to assess the long-term follow-up in aneurysms that have achieved complete occlusion at 6 months. We also compared the predictive value of different imaging modalities used. This is an analysis of a prospectively maintained database across 13 academic institutions. We included patients with previously untreated cerebral aneurysms embolized using the WEB device who achieved complete occlusion at first follow-up and had available long-term follow-up. A total of 95 patients with a mean age of 61.6 ± 11.9 years were studied. The mean neck diameter and height were 3.9 ± 1.3 mm and 6.0 ± 1.8 mm, respectively. The mean time to first and last follow-up was 5.4 ± 1.8 and 14.1 ± 12.9 months, respectively. Out of all the aneurysms that were completely occluded at 6 months, 84 (90.3%) showed complete occlusion at the final follow-up, and 11(11.5%) patients did not achieve complete occlusion. The positive predictive value (PPV) of complete occlusion at first follow was 88.4%. Importantly, this did not differ between digital subtraction angiography (DSA), magnetic resonance angiography (MRA), or computed tomography angiography (CTA). This study underlines the importance of repeat imaging in patients treated with the WEB device even if complete occlusion is achieved short term. Follow-up can be performed using DSA, MRA or CTA with no difference in positive predictive value.

Trends in the Age of Patients Treated for Unruptured Intracranial Aneurysms from 1990 to 2020

BACKGROUND

The decision for treatment for unruptured intracranial aneurysms (UIAs) is often difficult. Innovation in endovascular devices have improved the benefit-to-risk profile especially for elderly patients; however, the treatment guidelines from the past decade often recommend conservative management. It is unknown how these changes have affected the overall age of the patients selected for treatment. Herein, we aimed to study potential changes in the average age of the patients that are being treated over time.

METHODS

A systematic search of the literature was performed to identify all studies describing the age of the UIAs that were treated by any modality. Scatter diagrams with trend lines were used to plot the age of the patients treated over time and assess the presence of a potential significant trend via statistical correlation tests.

RESULTS

A total of 280 studies including 83,437 UIAs treated between 1987 and 2021 met all eligibility criteria and were entered in the analysis. Mean age of the patients was 55.5 years, and 70.7% were female. There was a significant increasing trend in the age of the treated patients over time (Spearman r: 0.250; P < 0.001), with a 1-year increase in the average age of the treated patients every 5 years since 1987.

CONCLUSIONS

The present study indicates that based on the treated UIA patient data published in the literature, older UIAs are being treated over time. This trend is likely driven by safer treatments while suggesting that re-evaluation of certain UIA treatment decision scores may be of great interest.

Mid-to-long term safety and efficacy of Woven EndoBridge device for Treatment of intracranial wide neck aneurysms: A systematic review and meta-analysis

BACKGROUND

In recent 10 years, Woven EndoBridge(WEB) device has been used as endovascular instrumentation for treating wide neck Bifurcation aneurysms. Its safety and efficacy in the mid-term (6-24 months) and long-term (more than 24 months) follow-up period have yet to be systematically reviewed.

PURPOSE

To evaluate the WEB device safety and efficacy, relevant literature and publications were extensively reviewed, and a meta-analysis was conducted.

DATA RESOURCE

All relevant literature/publications were achieved from Pubmed, Cochrane, Embase, and Web of Science databases.

RESULTS

767 patients that were studied in 13 literature were included. The focus of this review was placed on the clinical and anatomic outcomes. Complete occlusion was achieved in 67.3% (95% CI, 59.0-75.5%) and 69.3% (95% CI, 55.7-82.8%) of the cases at mid- and long-term follow-up. The rate of adequate occlusion was 86.6% (95% CI, 83.0-90.2%) and 90.1% (95% CI, 85.5-94.4%) for the mid and long-term, respectively. 51 patients (8.8%; 95% CI,5.6-11.9%) and 18 (8.1%; 95% CI,0.8-15.5%) received retreatments during mid- and long-term follow-up, respectively. 410 patients from 427 (94.3%; 95% CI, 89.7-98.9%) showed favorable clinical outcomes. The all-cause mortality rate was 3.5% (95% CI, 1.4-5.6%), where only a few cases were related to the WEB implantation. The WEB device deployment was associated with an overall clinical complication rate of 4.1% (95% CI, 2.7-6.6%), 3 hemorrhagic (1.2%; 95% CI, 0.2-2.6%), and 30 thromboembolic (4.0%; 95% CI, 4.0- 6.0%) complications.

CONCLUSIONS

The findings reveal the satisfactory safety and effectiveness of the WEB device for the Treatment of wide-neck aneurysms during mid-to-long-term follow-up, indicating the high potential of the WEB device for wide application.

The Woven EndoBridge for intracranial aneurysms: Radiological outcomes and factors influencing occlusions at 6 and 24 months

PURPOSE

To identify factors influencing short- and mid-term radiological outcomes of intracranial aneurysms (IAs) treated with the Woven EndoBridge (WEB).

METHODS

A total of 112 patients were treated for IAs with the WEB in at our institution between 2013 and 2020. Patients with 6- and/or 24-months follow-up data were included in the study. Aneurysm occlusion was evaluated using the Raymond-Roy occlusion classification (RR). RR 1 and RR 2 were considered as adequate outcomes, while RR 3 inadequate.

RESULTS

Data were available for 91 patients (56 females, 62%) at 6 months and 62 of those patients (39 females, 58%) at 24 months. The adequate occlusion (RR 1/RR 2) rate was 89% (n = 81/91) at the 6-months follow-up and 91% (n = 56/62) at the 24-months follow-up. The treatment-related morbidity rate was 4% (n = 4/91), and mortality rate was 1% (n = 1/91). The predictor for inadequate occlusion at the 6-months follow-up was the lobular shape of an aneurysm (p = .01). The aneurysm's height (p = .02), maximal diameter (p = .001), width (p = .002), aspect ratio (p = .03), dome-to-neck ratio (p = .04), and lobular shape (p= .03) were predictive factors for inadequate occlusion at 24 months. All the thrombosed aneurysms (n = 3) showed unfavorable radiological outcomes and required re-treatment within 24 months. None of the patient-related factors were significant.

CONCLUSIONS

The WEB provides favorable occlusion rates and low complications for both ruptured and unruptured wide-necked IAs. Unfavorable radiological outcomes after WEB treatment may be related to aneurysm morphology and size.

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.

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.

CLinical Assessment of WEB device in Ruptured aneurYSms (CLARYS): 12-month angiographic results of a multicenter study

BACKGROUND

The CLinical Assessment of WEB device in Ruptured aneurYSms (CLARYS) study has shown that the endovascular treatment of ruptured bifurcation aneurysms with the Woven EndoBridge (WEB) is safe and effective and provides protection against rebleeding at 1 month and 1 year. The 12-month angiographic follow-up is an important endpoint of the study.

METHODS

The CLARYS study is a prospective multicenter study conducted in 13 European centers. The study enrolled 60 patients with 60 ruptured aneurysms of the anterior and posterior circulation. The study was conducted with an independent assessment of safety outcomes and imaging.

RESULTS

Sixty patients with 60 ruptured bifurcation aneurysms to be treated with the WEB were included. Fifty-three aneurysms (88.3%) had a broad base with a dome to neck ratio <2 (mean 1.6). Of these, 46 patients were evaluated by an independent core laboratory with follow-up imaging performed at 12 months or before eventual retreatment. At 1 year, 19/46 aneurysms (41.3%) were completely occluded (Raymond-Roy grade I), 21/46 (45.7%) had a residual neck and 6/46 (13.0%) had residual aneurysm filling. Adequate occlusion was reported in 40/46 (87%) aneurysms. Six patients underwent target aneurysm retreatment.

CONCLUSIONS

The CLARYS study has previously shown that the use of the WEB in the endovascular treatment of ruptured bifurcation aneurysms provides effective protection against rebleeding with a good safety profile. The angiographic occlusion rates at 1 year reported here are comparable to those already seen in previous multicenter studies which primarily included unruptured aneurysms.

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%.

Simulation of intra-saccular devices for pre-operative device size selection: Method and validation for sizing and porosity simulation

Intra-saccular devices (ID) are novel braided devices used for complex intracranial aneurysms treatment. Treatment success is associated with correct device size selection. A technique that predicts the ID size within the aneurysm before intervention will provide a powerful computational tool to aid the interventionist during device selection. We present a method to calculate the device's final height, radial expansion and porosity within the patient's anatomy, which allows assessing different device sizes before treatment takes place. The proposed sizing technique was tested in-vitro and in real patient's geometries obtained from 3DRA angiographic images of 8 unruptured aneurysms previously treated with IDs. The obtained simulated height was compared to the real height, with a mean error of less than 0.28 mm (±0.44). The porosity calculation method was tested in-vitro with an error of 0.02 (±0.022). The results of both sizing and porosity experiments resemble well measures from real patients. This methodology could be used before treatment to provide the interventionist with additional information that allows selecting the device that best fits the patient's aneurysm to be treated.

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

BACKGROUND

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

TECHNICAL REPORT

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

CLINICAL TRIAL REGISTRATION NUMBER

N/A.

The Woven EndoBridge for unruptured intracranial aneurysms: Results in 95 aneurysms from a single center

BACKGROUND AND PURPOSE

The Woven EndoBridge (WEB) is an intrasaccular flowdisruptor that is increasingly used for the treatment of (wide-necked) aneurysms. We present our experience with the WEB for unruptured aneurysms.

MATERIALS AND METHODS

Between April 2014 and August 2019, 93 patients with 95 unruptured aneurysms were primarily treated with the WEB. There were 69 women and 24 men, mean age 61 years (median 58, range 37-80).

RESULTS

Of 95 aneurysms, 86 had been discovered incidentally, 3 were symptomatic and 6 were additional to another ruptured aneurysm. Location was anterior communicating artery 33, middle cerebral artery 29, basilar tip 19, carotid tip 8, posterior communicating artery 4, posterior inferior cerebellar artery 1, superior cerebellar artery 1. Mean aneurysm size was 6 mm (median 6, range 3-13 mm).In one aneurysm additional coils were used and in another, a stent was placed. There was one procedural rupture without clinical sequelae. There were two thrombo-embolic complications leading to permanent deficit in one patient (mRS 2). Morbidity rate was 1.0% (1 of 93, 95%CI 0.01-6.5%) and mortality was 0% (0 of 93, 95%CI 0.0-4.8%). Angiographic follow-up at six months was available in 85 patients with 87 aneurysms (91%). Of 87 aneurysms, 68 (78%) were completely occluded, 14 (16%) had a neck remnant and 5 were incompletely occluded. Four aneurysms were retreated. Retreatment rate was 4.5% (4 of 87, 95%CI 1.7-13.6%).

CONCLUSION

WEB treatment of unruptured aneurysms is safe and effective. Additional devices are needed only rarely and retreatment at follow-up is infrequent.

The next step in balloon assisted endovascular neurosurgical procedures: A case series of initial experience with the Scepter Mini balloon microcatheter

BACKGROUND

The use of compliant dual lumen balloon microcatheters (CDLB) for the endovascular treatment of vascular malformations, wide neck aneurysms, and intracranial angioplasty (for vasospasm) is well documented. Navigation of 4 mm or larger CDLB within tortuous and small distal intracranial vessels can be challenging. Recently, the lower profile Scepter Mini balloon microcatheter (SMB) has been approved for use, with potential for improved intracranial navigation.

OBJECTIVE

Discuss operative experience of Scepter Mini (Microvention, Aliso Viejo, CA).

METHODS

We describe our initial experience with the SMB in a series of nine patients.

RESULTS

The balloon microcatheter was used for delivery of liquid embolic in six patients (Case 1, 2, 6-9), adjunct support for delivery or positioning of the Woven Endobridge (WEB) device in two (Case 3,4), and gentle post-deployment repositioning of a WEB device in the last one (Case 5). We were able to successfully navigate the SMB over a 0.008 "micro wire to the target lesion in all the patients. We experienced initial difficulty with injecting liquid embolic in Case 2. We postulate that the SMB was in a tortuous segment of a dural vessel in this patient, and that it kinked on inflation with occlusion of the liquid embolic delivery lumen; this was overcome with slightly proximal repositioning and reinflation of the SMB.

CONCLUSION

Our initial experience shows that the SMB has potential to be useful in endovascular neurosurgical procedures requiring balloon assistance within smaller diameter blood vessels.

The Woven EndoBridge embolization device for the treatment of intracranial wide-necked bifurcation aneurysms

Wide-necked bifurcation aneurysms are common when evaluating both ruptured and unruptured intracranial aneurysms and can pose unique challenges. The Woven EndoBridge device (recently approved in the US) is specifically designed for the treatment of these aneurysms. This article serves to introduce the device to a wider audience with a thorough review of the literature, device design, indications, pre-operative evaluation, procedural usage and potential pitfalls.

Endosaccular Flow Disruption: A New Frontier in Endovascular Aneurysm Management

Flow modification has caused a paradigm shift in the management of intracranial aneurysms. Since the FDA approval of the Pipeline Embolization Device (Medtronic, Dublin, Ireland) in 2011, it has grown to become the modality of choice for a range of carefully selected lesions, previously not amenable to conventional endovascular techniques. While the vast majority of flow-diverting stents operate from within the parent artery (ie, endoluminal stents), providing a scaffold for endothelial cells growth at the aneurysmal neck while inducing intra-aneurysmal thrombosis, a smaller subset of endosaccular flow disruptors act from within the lesions themselves. To date, these devices have been used mostly in Europe, while only utilized on a trial basis in North America. To the best of our knowledge, there has been no dedicated review of these devices. We therefore sought to present a comprehensive review of currently available endosaccular flow disruptors along with high-resolution schematics, presented with up-to-date available literature discussing their technical indications, procedural safety, and reported outcomes.

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.

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

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

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

BACKGROUND

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

METHODS

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

CONCLUSION

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

WEB-only treatment of ruptured and unruptured intracranial aneurysms: a retrospective analysis of 47 aneurysms

BACKGROUND

WEB (Woven EndoBridge) device is an intrasaccular flow diverter designed for endovascular treatment of intracranial aneurysms. Recent clinical trials showed good feasibility, safety, and efficacy profiles. In most of the published studies however, aneurysms treated with adjunctive devices other than WEB such as coils or stents were included which might make it difficult to reflect the real potential of this device. The purpose of this single-center study was to present the results of ruptured and unruptured aneurysms treated only with WEB device.

METHOD

Between April 2013 and July 2018, 47 (ruptured, 12; 25.5%) intracranial aneurysms treated only with WEB and a follow-up of at least 3 months were included in the study. Angiographic outcome at follow-up, peri-procedural complication rate, and rate of retreatment were recorded.

RESULTS

Of the 47 aneurysms, 12 (25.5%) were ruptured. The mean size of the aneurysms was 6.3 mm (ruptured, 5.4 mm; unruptured, 6.6 mm). Median follow-up period was 9 months. Complete occlusion was observed in 26/47 aneurysms (55.3%; ruptured, 66.6%; unruptured, 51.4%). Thirteen aneurysms (27.6%; ruptured, 16.6%; unruptured, 31.4%) showed a neck remnant. In 4/47 aneurysms (8.5%; ruptured, 8%; unruptured, 8.5%), persistent contrast enhancement inside the WEB was recorded. In 4/47 patients (8.5%; ruptured, 8%; unruptured, 8.5%), an aneurysm remnant was noted. Adequate occlusion (complete occlusion and neck remnant) was observed in 43/47 aneurysms (91.4%; ruptured, 91.6%; unruptured, 91.4%). Retreatment rate was 6.3% (ruptured, 8%; unruptured, 5.7%). Six (12.7%; ruptured, 25%; unruptured, 8.5%) thromboembolic events were recorded. Hemorrhagic complications occurred in two patients (4.2%; ruptured, 16.6%; unruptured, 0%).

CONCLUSIONS

WEB enables adequate occlusion of ruptured and unruptured intracranial aneurysms mostly without requirement of long-term antiplatelet therapy. The benefit is seen especially by the wide-necked aneurysms, but indications should be extended to include narrow-necked, smaller, and side-wall aneurysms.

Clipping of recanalized intracerebral aneurysms initially treated by the Woven EndoBridge device

Background and purpose

Intrasaccular flow disruption using the Woven EndoBridge (WEB) is a safe and effective method to treat intracranial aneurysms, particularly wide neck bifurcation aneurysms. However mid term and long term follow-up imaging can show aneurysm remnant or recanalization, and retreatment is therefore sometimes necessary. In most cases, retreatment is performed using an endovascular approach. The present series reports and analyzes aneurysm clipping of recanalized or incompletely occluded aneurysms following WEB treatment.

Methods

All patients treated with the WEB device since the beginning of our experience in June 2011 were prospectively collected in a local database. Among them, patients who were retreated by clipping for aneurysm remnants were included in the present series.

Results

In the cumulative population of 130 patients with aneurysms treated by the WEB device from June 2011 to February 2019, 4 patients (3.1%) were retreated with surgical clipping due to incomplete occlusion (2 patients) and aneurysm recanalization (2 patients). Three of the four aneurysms retreated (75%) were located in the middle cerebral artery and one in the anterior communicating artery (25.0%). The aneurysm was ruptured in 1 of 4 patients (25%). Clipping was performed 10–54 months after initial treatment with the WEB. Surgical exposure showed that the WEB device was inside the aneurysm sac in all cases. Clipping was easily performed in all but 1 case. Control DSA showed complete occlusion in two aneurysms and a neck remnant in two.

Conclusion

Clipping is a feasible option for treating aneurysm remnants following initial treatment with intrasaccular flow disruption using the WEB.

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.

Development of New Endovascular Devices for Aneurysm Treatment

Since the first use of the Guglielmi detachable coil system for cerebral aneurysm embolization in 1990, various endovascular methods have been developed to treat large numbers of aneurysms. The main strategic and technical modifications introduced to date include balloon-assisted coil embolization, stent-assisted coil embolization, flow diverters, and flow disrupters. The development and introduction of such devices have been so persistent and rapid that new devices are being approved worldwide even before the earlier ones become available in some countries. However, even if some patient populations may possibly benefit from earlier introduction of new devices, the approval authorities should balance the available evidence of the safety and effectiveness of novel devices. This review aims to provide an overview of the recent innovations in endovascular treatment of cerebral aneurysms and a brief review of market access policies and regulations for importing high-risk medical devices, such as those used for endovascular aneurysm management, which correspond to class III devices, as defined by the U.S. Food and Drug Administration. We focus on the current situation in Korea and compare it with that in other Asian countries, such as China and Japan.

Two-Center Experience in the Endovascular Treatment of Ruptured and Unruptured Intracranial Aneurysms Using the WEB Device: A Retrospective Analysis

BACKGROUND AND PURPOSE

The safety and efficacy of the Woven EndoBridge (WEB) device for the treatment of cerebral aneurysms has been investigated in several studies. Our objective was to report the experience of 2 neurovascular centers with the WEB device in the treatment of broad-based intracranial aneurysms, including the technical feasibility and safety as well as short- and midterm angiographic and clinical follow-up-results.

MATERIALS AND METHODS

We performed a retrospective analysis of all ruptured and unruptured aneurysms treated with a WEB device (WEB Single-Layer and Single-Layer Sphere) between August 2014 and February 2017. Primary outcome measures included the feasibility of implantation and the angiographic outcome. Secondary outcome measures included the clinical outcome at discharge and procedural complications.

RESULTS

One hundred two aneurysms in 101 patients, including 37 (36.3%) ruptured aneurysms, were treated with the WEB device. Implantation was successful in 98 (96.1%) aneurysms. Additional devices (stents/coils) were necessary in 15.3% (15/98) of aneurysms. Procedural complications occurred in 4.9% (5/102). Of these, 4 were thromboembolic events and 1 was an intraprocedural rupture. Angiographic follow-up at 3 and 12 months was available for 79.6% (78/98) and 50.0% (49/98) of all aneurysms to date, respectively, showing a sufficient aneurysm occlusion in 80.7% (63/78) at 3 months and 77.6% (38/49) at 12 months. Delayed aneurysm ruptures have not been observed during the follow-up period to date.

CONCLUSIONS

The WEB device offers a safe and effective treatment option for broad-based intracranial aneurysms without the need for dual antiplatelet therapy.

Endovascular Treatment of Unruptured Intracranial Aneurysms by the Woven EndoBridge Device (WEB): Are There Any Aspects Influencing Aneurysm Occlusion?

BACKGROUND

The experience with Woven EndoBridge (WEB) device is still limited. The aim of this study is to discuss the efficacy of this new device, focusing on any anatomical and procedural factors influencing aneurysm occlusion.

METHODS

Between October 2011 and November 2016, 24 patients (10 female, 14 male) harboring 24 cerebral aneurysms treated with WEB in a single center were retrospectively reviewed. Patients underwent 6-month and 12- to 24-month (median 18 months) clinical and neuroradiologic follow-up. We evaluated whether any procedural or anatomical aspect influenced the occlusion rate.

RESULTS

Adequate occlusion (AO) was achieved in 68% of cases at 6 months' and in 87% at 18 months' follow-up respectively. Technical difficulties occurred in 3 procedures (12.5%). No postprocedural morbidity was reported. One patient (4%) died after 1 month for reasons unrelated to the procedure. Neck size and dome-to-neck ratio were significantly associated with aneurysm occlusion (P < 0.05). AO was not associated with postoperative dual antiplatelet therapy (P > 0.99) or device compression at both first and second follow-up (P > 0.99). Immediate contrast agent stagnation was more common in aneurysms that were occluded at first (P = 0.37) and second follow-up (P = 0.24), but statistical significance was not reached.

CONCLUSIONS

Endovascular treatment with WEB is a safe treatment for unruptured cerebral aneurysms, also resulting in a good AO rate in aneurysms that would otherwise require complex assisted coiling techniques. However, results are less favorable in cases of very large aneurysmal neck. Nevertheless, further series with larger patient populations and longer follow-up will define the role of WEB in the treatment of aneurysms.