Occlusion assessment of intracranial aneurysms treated with the WEB device

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The Bicêtre occlusion scale is well suited to assess the efficacy of the Contour embolization device

BACKGROUND

The Contour Embolization Device (CED) is typically assessed using coiling angiographic outcomes. However, these scales do not address device-specific problematics. We evaluated the usability of the Bicêtre occlusion scale (BOS) with the CED.

RESULTS

BOS scores can be analyzed as BOSS 0 = no residual flow, BOSS 1 = residual flow inside the CED but with complete neck-sealing, BOSS 2 = neck-remnant, BOSS 3 = aneurysm-remnant, BOSS 1 + 3 = contrast filling inside the device and aneurysmal sac without complete neck-sealing.

CONCLUSION

BOS usage should be encouraged as it provides a more comprehensive assessment of the mechanism of CED occlusion, especially considering the potential prognostic value of the neck sealing assessment.

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

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

Management of aneurysmal recurrence after Woven EndoBridge (WEB) treatment

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Neqstent coil-assisted flow diverter (NQS) for the treatment of bifurcation aneurysms: the coil-assisted flow diversion safety and performance study (CAFI)

BackgroundThe Neqstent coil-assisted flow diverter (NQS) is a neck bridging device to facilitate coil occlusion of intracranial aneurysms. CAFI is a prospective, single-arm, multicenter study on the safety and performance of the NQS adjunctive therapy device together with platinum coils for treatment of unruptured intracranial aneurysms.

METHODS

Thirty-eight patients were enrolled. Primary endpoints were occlusion at 6 months for efficacy, and any major stroke or non-accidental death up to 30 days or major disabling stroke within 6 months for safety. Secondary endpoints were re-treatment rate, procedure time, and procedure/device-related adverse events. Procedural and follow-up imaging was reviewed by an independent core laboratory. Adverse events were reviewed and adjudicated by a clinical events committee.

RESULTS

The NQS was successfully implanted in 36/38 aneurysms, 2/38 in the intention-to-treat group did not receive a NQS and were excluded from follow-up after 30 days. In the per protocol group (PP), 33/36 patients were available for angiographic follow-up. Device related adverse events were recorded in 4/38 (10.5%) patients, one hemorrhagic and three thromboembolic. In the PP group, immediate post-treatment adequate occlusion (RR1 and RR2) was seen in 9/36 (25%) and progressed to 28/36 (77.8%) at 6 months. Complete occlusion (RR1) was achieved in 29/36 (80.6%) at the last available angiogram (3/36 were post procedure). The mean procedure time was 129 min (50-300 min, median 120 min).

CONCLUSION

The NQS in conjunction with coils appears to be effective in the treatment of intracranial wide-neck bifurcation aneurysms, but its safety remains to be proved in larger series.

TRIAL REGISTRATION NUMBER

NCT04187573.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Persistent Opacification of the Woven EndoBridge Device: A Conebeam CT Analysis of the Bicêtre Occlusion Scale Score 1 Phenomenon

BACKGROUND AND PURPOSE

Some Woven EndoBridge devices present a persistent intradevice opacification at imaging follow-up, described as the Bicêtre Occlusion Scale Score 1 (BOSS 1) phenomenon. The clinical implications remain unknown. We aimed here to analyze the factors influencing this occurrence and to precisely describe the evolution of BOSS 1 with time using conebeam CT.

MATERIALS AND METHODS

We retrospectively analyzed a prospectively maintained Woven EndoBridge database at our tertiary center and included all patients with isolated BOSS 1 and BOSS 1 associated with small neck remnant (BOSS 1 + 2).

RESULTS

Two hundred sixty-seven aneurysms were treated with a Woven EndoBridge device between July 2012 and December 2021. Follow-up with DSA was available for 220 aneurysms (median, 5 months), among which BOSS 1 and 1 + 2 were found in 9.1% (20/220) (95% CI, 5.5%-12.7%). A second DSA follow-up (median, 17 months) was performed in 15 of these 20 aneurysms, which revealed that 40% had evolved to complete Woven EndoBridge occlusion, 33% showed a decreased persistent opacification, and 27% remained stable. BOSS 1 was significantly associated with postoperative antiplatelet medication, a lower aneurysm aspect ratio, and the use of the Woven EndoBridge 17 (P  < .05). The average Woven EndoBridge shape modification was less pronounced in the BOSS 1 population (P  < .02). None of the BOSS 1 or 1 + 2 aneurysms required retreatment or were associated with hemorrhage occurrence.

CONCLUSIONS

Isolated persistent flow inside the Woven EndoBridge device at follow-up is rare and notably associated with antiplatelet prescription. It seems to present a benign course in most cases.

Geometry of intracranial aneurysms and of intrasaccular devices may influence aneurysmal occlusion rates after endovascular treatment

INTRODUCTION

The Woven EndoBridge device (WEB) is used to treat wide-neck bifurcation aneurysms. These devices are deployed inside the sac. Therefore, the mesh structure provides apposition with the aneurysm wall and induces aneurysmal thrombosis. The objective of our study was to evaluate the anatomic and device-related parameters and indexes with Computational Fluid Dynamics (CFD) of the intracranial aneurysms before and after WEB simulation and find their relationship to complete occlusion.

MATERIALS AND METHODS

Using the heterogeneous model based on the marching cubes algorithm, we created 3D representations of 27 bifurcated intracranial aneurysms treated with the single-layer WEB device to evaluate anatomic and device-related parameters with CFD.

RESULTS

In our CFD analysis, we observed higher large volumes (Va) (0.25 ± 0.18 versus 0.39 ± 0.09, p-value= 0.025) and higher volume to neck surface ratio (Ra) (1.32 ± 0.17 versus 1.54 ± 0.14, p-value= 0.021) in cases with occlusion failure.

CONCLUSIONS

Large aneurysm volumes (Va) and higher volume to neck surface ratio (Ra) could be associated with occlusion failure in aneurysms treated with the WEB device.

Fast Transition from Open Surgery to Endovascular Treatment of Unruptured Anterior Communicating Artery Aneurysms-A Retrospective Analysis of 128 Patients

OBJECTIVE

Anterior communicating artery aneurysms (ACoAAs) are challenging to treat both surgically and endovascularly. In this study, we evaluate the treatment-related morbidity and clinical outcome of microsurgical clipping and endovascular treatment for a consecutive series of unruptured ACoAAs while the treatment paradigm was in transition from surgical to endovascular first.

METHODS

We retrospectively reviewed clinical and radiologic data of adult patients who underwent microsurgical clipping or endovascular treatment of an unruptured ACoAA at a high-volume academic neurovascular center (Helsinki University Hospital) during 2012-2019. During this period, a transition from microsurgical clipping to endovascular treatment took place. Regarding outcome, we focused on treatment-related complications, discharge-to-home rates, functional performance (modified Rankin Scale score), and obliteration rates.

RESULTS

Of 128 treated ACoAAs, 81 (64%) were treated surgically and 47 (36%) endovascularly. There was no difference in major complications, intracranial hemorrhagic complications or ischemic complications, discharge-to-home rates, or functional performance between the surgically and endovascularly treated patients. With time, a decrease in major complications was observed in the surgical cases (from 29% to 17%), whereas the major complication rate increased in the endovascularly patients (from 0% to 25%). Cerebral ischemia was the most frequent complication in both groups. The risk for permanent neurologic deficit remained low in both groups (9% for endovascular and 5% for surgery).

CONCLUSIONS

We did not find any major differences regarding complications and outcomes after the treatment paradigm shift from clipping to endovascular of unruptured ACoAAs. Prospective studies evaluating durability of treatments are needed to compare overall effectiveness.

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.

Determinants of cerebral aneurysm occlusion after embolization with the WEB device: a single-institution series of 215 cases with angiographic follow-up

Background

Woven EndoBridge (WEB) devices are becoming a reliable option for the treatment of wide-neck bifurcation aneurysms, but clear predictive factors are still missing to understand the one in five aneurysm remnant rate.

Objective

To evaluate occlusion outcomes after WEB treatment to identify potential determinants of aneurysm occlusion.

Methods

A single-center database with consecutive aneurysms treated with WEB between July 2012 and October 2021 was reviewed for potential determinants of aneurysm adequate occlusion (defined as a Bicêtre Occlusion Scale Score (BOSS) of 0, 0’, 1 or 2), through univariate and multivariable analysis. Patients without angiographic follow-up were excluded.

Results

215 of 247 individual aneurysms were included in the final analysis, of which 59 (27%) were ruptured. Mean age of patients was 56 years (range 23–90 years) and 65% were female. Mean angiographic follow-up was at 18 months (range 3–97 months). Adequate and complete occlusion were achieved in 171/215 (79.5%) and 135/215 (62.8%) of cases, respectively. Aneurysm irregular shape (aOR=0.42, 95% CI 0.20 to 0.88; p=0.02), aneurysm height (aOR=0.79, 95% CI 0.66 to 0.94; p<0.01), and WEB shape modification (aOR=0.98, 95% CI 0.97 to 1.00; p=0.02) were all independent predictors of aneurysm recurrence, whereas the WEB oversizing ratio (WEB width/aneurysm mean width) (aOR=16.4, 95% CI 1.4 to 266.7; p=0.04) was an independent predictor of adequate occlusion.

Conclusion

In this study we demonstrated that a width oversizing strategy of the WEB device was an independent predictor of aneurysm angiographic occlusion. Conversely, aneurysm height, irregular aneurysm, and WEB shape modification were all independent determinants of angiographic aneurysm remnant. These results may help to select aneurysms suitable for the WEB device and WEB sizing.

Delayed rebleeding of an Acom aneurysm treated with a web device: Endovascular management

We report a case of cerebral aneurysm rerupture 24 months after initial bleeding and complete occlusion using a WEB device. A middle-aged patient was transferred at our institution because of a recurrent aneurysmal bleeding. The patient was graded WFNS2 and unenhanced CT showed a modified Fisher grade 3 SAH. DSA showed an increased compaction and an evolutive "proximal recess" of the WEB device associated with a small unprotected part of the aneurysm wall and a bleb pointing towards the haemorrhage. Balloon- and stent-assisted coiling was performed, allowing to completely occlude the recurrence. The patient suffered no neurological deficit neither delayed complication and was discharged at day 16.

Predictors of aneurysm occlusion following treatment with the WEB device: systematic review and case series

The Woven EndoBridge (WEB) device is becoming increasingly popular for treatment of wide-neck aneurysms. As experience with this device grows, it is important to identify factors associated with occlusion following WEB treatment to guide decision making and screen patients at high risk for recurrence. The aim of this study was to identify factors associated with adequate aneurysm occlusion following WEB device treatment in the neurosurgical literature and in our case series. A systematic review of the present literature was conducted to identify studies related to the prediction of WEB device occlusion. In addition, a retrospective review of our institutional data for patients treated with the WEB device was performed. Demographics, aneurysm characteristics, procedural variables, and 6-month follow-up angiographic outcomes were recorded. Seven articles totaling 450 patients with 456 aneurysms fit our criteria. Factors in the literature associated with inadequate occlusion included larger size, increased neck width, partial intrasaccular thrombosis, irregular shape, and tobacco use. Our retrospective review identified 43 patients with 45 aneurysms. A total of 91.1% of our patients achieved adequate occlusion at a mean follow-up time of 7.32 months. Increasing degree of contrast stasis after WEB placement on the post-deployment angiogram was significantly associated with adequate occlusion on follow-up angiogram (p = 0.005) and with Raymond-Roy classification (p = 0.048), but not with retreatment (p = 0.617). In our systematic review and case series totaling 450 patients with 456 aneurysms, contrast stasis on post-deployment angiogram was identified as a predictor of adequate aneurysm occlusion, while morphological characteristics such as larger size and wide neck negatively impact occlusion.

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.

Woven EndoBridge (WEB) Width at the Aneurysm Neck Level Affects Early Angiographic Aneurysm Occlusion

Purpose

Endovascular therapy with the Woven EndoBridge (WEB) device is a safe treatment approach, whereby neoendothelialization at the neck area is a crucial element for aneurysm occlusion. We hypothesized that WEB sizing at the aneurysmal neck level has an impact on early aneurysm occlusion.

Methods

Patients with short-term follow-up digital subtraction angiography following WEB treatment of unruptured aneurysms were included. Aneurysms were categorized according to the Bicêtre Occlusion Scale Score (BOSS) as adequately (BOSS 0, 0′, 1) or partially occluded (BOSS 2, 3, 1 + 3). The WEB device dimensions, including the average aneurysm diameter (AADi) and the average neck diameter (ANDi) as well as baseline patient characteristics were documented.

Results

In this study 75 patients with 76 aneurysms were included and 65 aneurysms showed adequate occlusion at short-term follow-up (86%). In univariable logistic regression analysis, smaller differences in WEB size to ANDi (D-ANDi) were significantly associated with adequate aneurysm occlusion (odds ratio, OR = 0.41, 95% confidence interval, CI 0.23–0.71, p = 0.002). Receiver operating characteristic (ROC) curve analyses displayed higher discriminative power for the D‑ANDi (AUC = 0.77, 95% CI 0.66–0.86, cut-off ≤2.9 mm) compared to the difference in WEB size to the average aneurysm diameter (D-AADi, AUC = 0.65, 95% CI 0.53–0.75, cut-off ≤1.0 mm).

Conclusion

Smaller differences between the WEB width and ANDi were associated with adequate early aneurysm occlusion and might thus have a higher impact on the results than the traditional device sizing considering the mean aneurysm diameter. D‑ANDi ≤2.9 mm served as an optimal cut-off to classify occlusion after WEB treatment at the short-term follow-up. Further external validation is warranted.

Supplementary Information

The online version of this article (10.1007/s00062-021-01034-0) contains supplementary material, which is available to authorized users.

The Woven EndoBridge device for ruptured intracranial aneurysms: international multicenter experience and updated meta-analysis

PURPOSE

The Woven EndoBridge (WEB) can be used to treat wide-necked aneurysms without antiplatelet medications, suggesting it may have advantages in the setting of aneurysmal subarachnoid hemorrhage (aSAH). The goal was assessment of safety and efficacy of WEB in aSAH given the delayed nature of aneurysmal thrombosis.

METHODS

An international retrospective analysis of patients with aSAH treated with WEB was conducted at 7 tertiary centers from 2016 to 2020. Outcomes included rates of rebleeding, retreatment, complications, and complete occlusion. Furthermore, a systematic review and meta-analysis was conducted from 2011 to 2020 assessing the same outcomes. All pooled event rates were calculated using a random effect model.

RESULTS

Consecutive patients with aSAH harbored 25 aneurysms that were treated with 29 WEB devices. The mean age was 53 years, and 65% were female. Zero experienced rebleeding, 2 were retreated, 2 experienced complications, 16 were completely occluded at 3 months, and 21 were completed occluded at 9-12 months. Meta-analysis of 309 WEB treatments for aSAH from 7 case series revealed 2.5% (95% CI 1-5%) had rebleeding, 9% (95% CI 4-17%) were retreated, 17% (95% CI 10-30%) had complications, and 61% (95% CI 51-71%) were completely occluded at 3-6 months.

CONCLUSION

WEB embolization in the setting of aSAH provides similar protection against rebleeding with comparable retreatment rates to traditional approaches. However, there is a higher rate of incomplete radiographic occlusion and operative complications compared to WEB embolization of unruptured aneurysms. Long-term prospective studies are needed to fully delineate the role of WEB embolization in aSAH.

WEB device for treatment of posterior communicating artery aneurysms

BACKGROUND

Woven EndoBridge (WEB) device treatment of wide-neck bifurcation aneurysms has proved to be safe and effective, but the use of these devices in sidewall aneurysms has been reported only in a small number of case series.

OBJECTIVE

To report our results in a cohort of consecutive patients in whom a WEB device was used as first-line treatment for posterior communicating artery (PComA) aneurysms.

METHODS

We conducted a retrospective analysis of a prospectively maintained database of PComA aneurysms treated with a WEB device in our institution from June 1, 2012 to November 15, 2020. Clinical and radiological findings were evaluated at immediate and last follow-up.

RESULTS

A total of 219 aneurysms were treated with a WEB device, including 15 PComA aneurysms in 15 patients, 10 of which were ruptured. Aneurysms were wide necked, with a mean aspect ratio of 1.6 (range 0.7-3.0) and a mean neck size of 4.2 mm (range 2.6-7.4 mm). No intraoperative rupture occurred and only one thromboembolic event was noted. Among the group with at least a 3-month digital subtraction angiography (DSA) follow-up, complete and adequate occlusion were obtained in 54% and 72%, respectively (average follow-up 13 months). Re-treatment was needed for two initially ruptured aneurysms. No procedure-related morbidity or mortality was reported.

CONCLUSION

This series suggests the high safety profile of WEB devices even when used in off-label indications. Treatment with these devices seems to be a valuable strategy for ruptured wide-neck PComA aneurysms, avoiding the need for antiplatelet medication. However, occlusion rates should be investigated in further larger studies.

Imaging for Treated Aneurysms (Including Clipping, Coiling, Stents, Flow Diverters)

Intracranial aneurysms are common in the adult population and carry a risk of rupture leading to catastrophic subarachnoid hemorrhage. Treatment of aneurysms has evolved significantly, with the introduction of new techniques and devices for minimally invasive and endovascular approaches. Follow-up imaging after aneurysm treatment is standard of care to monitor for recurrence or other complications, and the preferred imaging modality and schedule for follow-up are areas of active research. The modality and follow-up schedule should be tailored to treatment technique, aneurysm characteristics, and patient factors.

Semi-automated cerebral aneurysm segmentation and geometric analysis for WEB sizing utilizing a cloud-based computational platform

BACKGROUND

Accurate aneurysm measurements are important for selecting the WEB device. The objective was to validate a cloud-based platform, SurgicalPreview (SP) against manual measurements for aneurysm analysis.

METHODS

Two sets of measurements each for SP and manual methods were obtained for 40 aneurysms. Reliability and agreement were assessed with intra-class correlation coefficient (ICC) and Bland-Altman plots respectively. Kappa coefficient was used to assess agreement for predicting WEB size.

RESULTS

There was good reliability for repeat SP measurements: aneurysm diameter (ICC-1, 95%CI 0.98-1), height (ICC-1, 95%CI 0.99-1) and neck diameter (ICC-0.96, 95%CI 0.93-0.98). There was good reliability for the two manual diameter (ICC-0.97, 95%CI 0.9-0.97) and height (ICC-0.93, 95%CI 0.87-0.96) measurements and moderate for neck diameter (ICC-0.76, 95%CI 0.54-0.87). There was greater agreement for SP versus manual repeat measurements on Bland-Altman plots. Reliability between the SP and manual methods was good for aneurysm diameter (ICC-0.98, 95%CI 0.95-1) and height (ICC-0.96, 95%CI-0.93-0.98) and moderate for neck. (ICC-0.6, 95%CI -0.22-0.87). The Bland-Altman plots confirmed better agreement between the two methods for the aneurysm diameter and height than the neck. There was strong agreement between the methods for predicting the WEB diameter (Kappa-0.84, 95%CI 0.71-0.97) and moderate for predicting WEB height (Kappa-0.66, 95%CI 0.43-0.89). There was moderate agreement for predicted versus deployed WEB diameter: SP (Kappa-0.56, 95%CI 0.38-0.74), Manual (Kappa-0.53, 95%CI 0.34-0.71).

CONCLUSION

The SurgicalPreview® had greater agreement for repeat measurements. There was good reliability between the two methods for predicting WEB diameter and height and moderate agreement between predicted versus deployed WEB diameter.

Woven EndoBridge device shape modification can be mitigated with an appropriate oversizing strategy: a VasoCT based study

BACKGROUND

The Woven EndoBridge (WEB) shape modification (WShM) during follow-up may be a potential cause of poor angiographic outcomes. WShM predisposing factors have not yet been determined. Our systematic use of rotational cone beam computed tomography (VasoCT) imaging during follow-up allowed us to perform the first quantitative analysis of the shape of WEBs over time. Our goal was to identify possible strategies to reduce the occurrence of this phenomenon.

METHODS

All patients treated in our hospital with a WEB device between October 2015 and January 2019 were included. Using VasoCT acquisitions, systematically performed after implantation and during follow-up, we analyzed WEB morphology. WShM was defined as the percentage reduction in the distance between the two WEB markers.

RESULTS

Sixty-three aneurysms treated with a WEB device were finally included in this analysis. At the last follow-up (mean 15.5 months), mean WShM was 48%±24. The mean WShM was significantly higher in the aneurysm recurrence group than in the adequate occlusion group (51±6.5% vs 36±3.4%, difference 15% points (95% CI 0.7 to 30); p<0.05). Conversely, the extent of WShM did not directly correlate with occlusion rates. Indeed, 32% of completely occluded aneurysms presented severe WShM (≥50%). Importantly, the absence of WShM guaranteed complete occlusion in our study (n=12). We demonstrated that oversizing the width of the WEB significantly correlated with WShM reduction during follow-up (r=-0.38, p=0.002).

CONCLUSION

WShM can be partly overcome by use of an appropriate width oversizing strategy that could lead to improved angiographic results.

Widening the Indications for Intrasaccular Flow Disruption: WEB 17 in the Treatment of Aneurysm Locations Different from Those in the Good Clinical Practice Trials

BACKGROUND AND PURPOSE

The safety and efficacy of the Woven EndoBridge (WEB) device has been shown in multiple good clinical practice trials, whereas aneurysm locations in these trials were restricted to bifurcation aneurysms located at the circle of Willis (MCA bifurcation, ICA bifurcation, anterior communicating artery, basilar artery tip). Our aim was to evaluate angiographic and clinical results with the WEB 17 in aneurysm locations that were excluded from the good clinical practice trials, assuming that the angiographic and clinical results are similar to those of the good clinical practice trials for aneurysms in traditional locations.

MATERIALS AND METHODS

We performed retrospective analysis of immediate and follow-up results of aneurysms in locations outside the good clinical practice trials in which the WEB 17 was used on an intention-to-treat approach.

RESULTS

Between June 2017 and May 2020, forty-seven aneurysms in 44 patients met the inclusion criteria. Aneurysm locations were the ICA posterior communicating artery in 19 (40.3%), the ICA paraophthalmic or choroidal locations in 4 (8.6%), anterior cerebral artery A2 segment in 13 (27.7%), MCA M1 segment in 2 (4.3%), posterior cerebral artery P2 segment in 2 (4.3%), PICA in 3 (6.4%), and the superior cerebellar artery in 4 (8.4%) cases. The procedure-related morbidity and mortality rates in the entire series were 0.0%. The early and late (<12 and >12 months) complete occlusion rates were 63.9% (23/36) and 77.8% (14/18), respectively.

CONCLUSIONS

The WEB 17 is safe and effective in aneurysm locations different from the traditional bifurcation aneurysms included in the good clinical practice trials. Further studies will help to define the entire spectrum of aneurysm morphologies and locations suitable for the WEB 17.

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

BACKGROUND AND PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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.

Clipping as re-treatment strategy after treatment of a cerebral aneurysm with the Woven EndoBridge embolization device: case report

Recently, treatment of cerebral aneurysms with the Woven EndoBridge (WEB) device has become an established endovascular strategy. However, over time, neurosurgeons and neuroradiologists will be confronted with the challenge of how to treat aneurysm recanalization. The authors report the case of a 49-year-old woman who underwent re-treatment with clipping after the recanalization of a 4 × 3-mm anterior communicating artery aneurysm that had previously been treated using a 4 × 3 WEB device. In contrast to the authors' prior experiences with clipping of previously coiled aneurysms, the WEB device was found to have a responsive softness during clip placement, and the aneurysm was more maneuverable. Moreover, evaluation with indocyanine green angiography was easy to perform because of the transparent mesh of the WEB device. No profound scarring or WEB protrusion was noted during surgery, making the procedure easier and less dangerous with regard to additional complications. The authors suggest that re-treatment via clipping should be considered in select cases of aneurysm recurrence after treatment with an intraaneurysmal flow diverter.

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.

Treatment of recurrent aneurysms using the Woven EndoBridge (WEB): anatomical and clinical results

Background

The safety and efficacy of the Woven EndoBridge (WEB) for the treatment of naïve intracranial aneurysms has been confirmed.

Purpose

To analyze the safety and efficacy of the WEB in the treatment of recurrent aneurysms.

Methods

Anatomical and clinical results in consecutive patients with a recurrent aneurysm, who were treated using the WEB device in two French neurointerventional centers, were evaluated.

Results

Seventeen patients with 17 aneurysms were included. Treatment was feasible in 16 patients. In seven patients (41.2%), ancillary devices were used. Permanent morbidity due to a thromboembolic complication occurred in one patient (5.9%). There was no mortality. Follow-up angiographic studies were available for 15 patients after a mean of 12.1±6.1 months. Rates of complete occlusion, neck remnant, and aneurysm remnant were 33.3%, 40.0%, and 26.7%, respectively.

Conclusions

Treatment of recurrent aneurysms using the WEB device may be reasonably safe and effective.

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.