The Woven EndoBridge: a new aneurysm occlusion device

Trends in incidence and treatments of spontaneous subarachnoid hemorrhage- a 10 year hospital based study

BACKGROUND

Improved endovascular methods make it possible to treat complex ruptured aneurysms, but surgery is still needed in certain cases. We evaluated the effects on the clinical results of the changes in aneurysm treatment.

METHODS

The study cohort was 837 patients with spontaneous subarachnoid hemorrhage (SAH) and one or multiple aneurysms, admitted to Dept of Neurosurgery, Uppsala University Hospital from 2012 to 2021. Demography, location and treatment of aneurysms, neurologic condition at admission and discharge, mortality and last tier treatment of high intracranial pressure (ICP) was evaluated. Functional outcome was measured using the Extended Glasgow Outcome Scale (GOSE) Data concerning national incidences of stroke diseases was collected from open Swedish databases.

RESULTS

Endovascular methods were used in 666 cases (79.6%). In 111 (13.3%) with stents. Surgery was performed in 115 cases (13.7%) and 56 patients (6.7%) had no aneurysm treatment. The indications for surgery were a hematoma (51 cases, 44.3%), endovascular treatment not considered safe (47 cases, 40.9%), or had been attempted without success (13 cases, 11.3%). Treatment with stent devices increased, and with surgery decreased over time. There was a trend in decrease in hemicraniectomias over time. Both the patient group admitted awake (n = 681) and unconscious (n = 156) improved significantly in consciousness between admission and discharge. Favorable outcome (GOSE 5-8) was seen in 69% for patients admitted in Hunt & Hess I-II and 25% for Hunt & Hess III-V. Mortality at one year was 10.9% and 42.7% for those admitted awake and unconscious, respectively.The number of cases decreased during the study period, which was in line with Swedish national data.

CONCLUSIONS

The incidence of patients with SAH gradually decreased in our material, in line with national data. The treatment policy in our unit has been shifting to more use of endovascular methods. During the study period the use of hemicraniectomies decreased.

A large UK single-centre experience in the long-term safety and efficacy of Woven Endobridge in the treatment of wide-neck intracranial aneurysms and risk factors associated with re-bleeding and re-treatment

INTRODUCTION

Endovascular treatment of wide neck aneurysms remains complicated with a determined and continuous technological effort towards treatment options that can offer safer and efficacious outcomes. The Woven Endobridge device was introduced in 2010 and has become a mainstay endovascular treatment for wide neck and large intracranial aneurysms. A recent review of the Woven Endobridge Clinical Assessment of Intrasaccular Aneurysm Therapy (WEBCAST) and WEBCAST2 trials and the five-year follow-up of patients was published. Our aim is to demonstrate real-life experience of aneurysms and patients treated with Woven Endobridge from a large high-volume specialist centre.

METHODS

A retrospective review was performed of patients treated with Woven Endobridge from March 2013 to March 2018. Primary efficacy outcomes were defined as per Raymond-Roy Occlusion Criteria (RROC) resulting in long-term complete occlusion (RROC1) and adequate occlusion (RROC1 and RROC2). Primary Safety outcomes were defined as procedure-related morbidity, rate of re-bleeding and rate of re-treatment.

RESULTS

Seventy-nine aneurysms were treated during the five-year period. Adequate aneurysm occlusion (RROC1 and RROC2) achieved was 81%. Retreatment was required in 18% of patients (14/79). Greater retreatment rate was demonstrated in partially thrombosed aneurysms, aneurysms with larger neck and dome diameter and dome heights.

CONCLUSION

Woven Endobridge treatment of wide-neck intracranial aneurysms offers a safe and efficacious outcome. This large UK single-centre experience demonstrates congruity with recent five-year outcomes of WEBCAST and WEBCAST2 trials.

Stent-assisted Woven EndoBridge embolization for the treatment of pulsatile tinnitus caused by an ipsilateral high-riding jugular bulb

PURPOSE

Pulsatile tinnitus can be caused by a high-riding jugular bulb (HRJB), characterized by the superior position of the jugular bulb in the petrous temporal bone. The anatomical position and morphology of this entity make it challenging for endovascular treatment. We report our experience with two patients successfully treated with a stent-assisted Woven EndoBridge (WEB; Microvention, Tustin, CA, USA) device.

MATERIALS AND METHODS

We describe two cases of HRJB in patients presenting with disabling pulsatile tinnitus. Temporary balloon occlusion of the jugular bulb prior to the intervention reduced tinnitus intensity. Both patients were subsequently treated under general anesthesia with the WEB device deployed in the HRJB which was held by a stent deployed in the sigmoid sinus.

RESULTS

Both procedures were successful with good positioning of the WEB device and no procedural complications. Both patients had complete resolution of pulsatile tinnitus immediately after the procedure. Follow-up imaging showed successful occlusion of the venous cavity with a widely patent stent.

CONCLUSION

Among patients with pulsatile tinnitus caused by an ipsilateral HRJB, a stent-assisted WEB device seems to be a viable endovascular option with angiographic and clinical success.

Transradial access for the endovascular treatment of intracranial aneurysms using the Woven EndoBridge device: A systematic review and pooled analysis

BACKGROUND

The Woven EndoBridge (WEB) device is a minimally invasive endovascular treatment option for patients with cerebral aneurysms. Transradial access (TRA) is a technique that involves accessing the arterial system through the radial artery in the wrist rather than the femoral artery in the groin. Several studies have investigated the use of TRA for WEB device deployment in treating intracranial aneurysms.

METHODS

A systematic review was conducted to evaluate the TRA for WEB device deployment in treating intracranial aneurysms. The databases PubMed, Cochrane, Embase, Scopus, and Web of Science were searched. To reduce the risk of bias, this systematic review only included studies reporting on using TRA in WEB device deployment for intracranial aneurysm treatment with a minimum of four patients.

RESULTS

In this systematic review, 186 patients were included across five studies, with TRA used in 183 cases analyzed. The study population had a higher proportion of females (n = 118%-69%) than males, with a mean age of 62 years old. Among the aneurysms treated, 46 were ruptured, and 119 were located at bifurcation sites, with a mean maximum diameter/width of 6.6 mm and mean height of 5.9 mm. Adjunctive coiling was used in three cases, and adjunctive stenting was used in nine cases. In two cases, conversion to a femoral artery access was necessary.

CONCLUSION

The available results suggest TRA with the WEB device is a safe and effective alternative. However, using TRA versus TFA should be individualized based on patient factors and operator experience.

Dual Layer vs Single Layer Woven EndoBridge Device in the Treatment of Intracranial Aneurysms: A Propensity Score-Matched Analysis

BACKGROUND

The Woven EndoBridge (WEB) devices have been used for treating wide neck bifurcation aneurysms (WNBAs) with several generational enhancements to improve clinical outcomes. The original device dual-layer (WEB DL) was replaced by a single-layer (WEB SL) device in 2013. This study aimed to compare the effectiveness and safety of these devices in managing intracranial aneurysms.

METHODS

A multicenter cohort study was conducted, and data from 1,289 patients with intracranial aneurysms treated with either the WEB SL or WEB DL devices were retrospectively analyzed. Propensity score matching was utilized to balance the baseline characteristics between the two groups. Outcomes assessed included immediate occlusion rate, complete occlusion at last follow-up, retreatment rate, device compaction, and aneurysmal rupture.

RESULTS

Before propensity score matching, patients treated with the WEB SL had a significantly higher rate of complete occlusion at the last follow-up and a lower rate of retreatment. After matching, there was no significant difference in immediate occlusion rate, retreatment rate, or device compaction between the WEB SL and DL groups. However, the SL group maintained a higher rate of complete occlusion at the final follow-up. Regression analysis showed that SL was associated with higher rates of complete occlusion (OR: 0.19; CI: 0.04 to 0.8, p = 0.029) and lower rates of retreatment (OR: 0.12; CI: 0 to 4.12, p = 0.23).

CONCLUSION

The WEB SL and DL devices demonstrated similar performances in immediate occlusion rates and retreatment requirements for intracranial aneurysms. The SL device showed a higher rate of complete occlusion at the final follow-up.

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.

Endovascular Treatments for Aneurysms Involving a Major Branch

Remarkable advances have been made in the endovascular treatment of intracranial cerebral aneurysms. These advances include various adjunctive techniques, increased indications for endovascular treatment, and improved treatment results. Furthermore, the number of cerebral aneurysm treatments using flow diverters (FDs) is expected to increase. However, the reported long-term rate of branch artery occlusion after FD treatment has been reported is 15.8%. Moreover, the complete aneurysm obliteration rate is low if normal branches arise from an aneurysm neck or dome. Flow diverter placement for ophthalmic artery, posterior communicating artery, and anterior choroidal artery aneurysms is often difficult because these normal branches often arise from the aneurysm neck or dome. Therefore, in many cases, coil embolization, which can occlude the aneurysm while preserving branch vessels, should be selected. Although not yet established, various adjunctive techniques and other endovascular treatments that can be performed safely have been reported. Treatment must be planned after understanding the advantages and disadvantages of each treatment method.

WEB shape modifications: angiography-histopathology correlations in rabbits

BACKGROUND

WEB Shape Modification (WSM) over time is frequent after aneurysm treatment. In this study, we explored the relationship between histopathological changes and angiographic evolution over time in experimental aneurysms in rabbits treated with the Woven EndoBridge (WEB) procedure.

METHODS

Quantitative WSM was assessed using flat-panel computed tomography (FPCT) during follow-up by calculating height and width ratio (HR, WR), defined as the ratio between either measurement at an index time point and the measurement immediately after WEB implantation. The index time point varied from 1 day to 6 months. HR and WR were evaluated with angiographic and histopathological assessments of aneurysm healing.

RESULTS

Final HR of devices varied from 0.30 to 1.02 and final WR varied from 0.62 to 1.59. Altogether, at least 5% of HR and WR variations were observed in 37/40 (92.5%) and 28/40 (70%) WEB devices, respectively, at the time of final assessment. There was no significant correlation between complete or incomplete occlusion groups and HR or WR (p=0.15 and p=0.43). Histopathological analysis revealed a significant association between WR and aneurysm healing and fibrosis 1 month following aneurysm treatment (both p<0.05).

CONCLUSION

Using longitudinal FPCT assessment, we observed that WSM affects both the height and width of the WEB device. No significant association was found between WSM and aneurysm occlusion status. Although presumably a multifactorial phenomenon, the histopathological analysis highlighted a significant association between width variations, aneurysm healing and fibrosis in the first month following aneurysm treatment.

Woven EndoBridge versus stent-assisted coil embolization for the treatment of ruptured wide-necked aneurysms: A multicentric experience

BACKGROUND

The potentially higher risk of hemorrhagic complications is of concern in stent-assisted coiling (SAC) of ruptured wide-necked intracranial aneurysms (IAs). The Woven EndoBridge (WEB) is considered an appealing alternative since antiplatelet therapy is not required. Herein, we aimed to compare the safety and effectiveness of WEB vs. SAC for the treatment of ruptured wide-necked IAs.

METHODS

This was an international cross-sectional study of consecutive patients treated for ruptured wide-neck IAs with WEB or SAC at four high-volume neurovascular centers between 2019 and 2022. Primary and secondary efficacy outcomes were radiographic aneurysm occlusion at follow-up and functional status at last follow-up. Safety outcomes included periprocedural hemorrhagic/ischemia-related complications.

RESULTS

One hundred five patients treated with WEB and 112 patients treated with SAC were included. The median procedure duration of endovascular treatment was shorter for WEB than for SAC (69 vs. 76 min; p = 0.04). There were no significant differences in complete aneurysm occlusion rates (SAC: 64.5% vs. WEB: 60.9%; adjusted OR [aOR] = 0.70; 95%CI 0.34-1.43; p = 0.328). SAC had a significantly higher risk of complications (23.2% vs. 9.5%, p = 0.009), ischemic events (17% vs. 6.7%, p = 0.024), and EVD hemorrhage (16% vs. 0%, p = 0.008). The probability of procedure-related complications across procedure time was significantly lower with WEB compared with SAC (aOR = 0.40; 95%CI 0.20-1.13; p = 0.03).

CONCLUSION

WEB and SAC demonstrated similar obliteration rates at follow-up when used for embolization of ruptured wide-necked IAs. However, SAC showed higher rates of procedure-related complications primarily driven by ischemic events and higher rates of EVD hemorrhage. The overall treatment duration was shorter for WEB than for SAC.

Thromboembolic Events With the Woven Endobridge Device: Incidence, Predictive Factors, and Management

BACKGROUND AND OBJECTIVES

The Woven EndoBridge (WEB) device has been increasingly used to treat wide-neck aneurysms showing a safe and effective profile, but a relatively high number of thromboembolic events (TEEs) have been reported with such treatment. We aimed to evaluate the incidence and management of TEEs and possible predictive factors related to WEB embolization of ruptured and unruptured intracranial aneurysms.

METHODS

A single-center database with consecutive aneurysms treated with a WEB device between July 2012 and May 2022 was reviewed for intraoperative and delayed TEEs. Univariate and multivariable analyses were used to determine factors associated with TEEs.

RESULTS

A total of 266 independent aneurysms were treated with WEB devices in 245 patients (mean age 55.78 ± 11.64 years, 169 (63.5%) females, 80 (30%) ruptured). The overall rate of TEEs is 13% (35/266), including 8.7% intraoperative. Symptomatic TEEs with clinical sequelae at a 3-month follow-up are reported to be 2.6% (7/266) with no TEE-related mortality. Both the replacement of a WEB device during the procedure (adjusted odds ratio = 2.61, 95% CI 1.24-5.49; P = .01) and ruptured aneurysms (adjusted odds ratio = 2.74, 95% CI 1.31-5.7; P = .007) were independent predictors of TEEs. A case-by-case management of intraprocedural TEE is also presented; tirofiban was successfully used in most cases of this cohort.

CONCLUSION

In this study, we demonstrated that ruptured aneurysms and WEB device replacement during the procedure were independent predictive factors for TEEs. As a result, making the correct choice of WEB is crucial for improving treatment outcomes. Moreover, with proper medical management of TEEs, minimal morbidity and no mortality could be achieved, which reinforces the safety of the technique.

Woven EndoBridge Device for Unruptured Wide-Neck Bifurcation Aneurysm: A Multicenter 5-Year Follow-up

BACKGROUND AND OBJECTIVES

This multicenter study aimed to assess the safety and efficacy of the Woven EndoBridge (WEB) device for treating unruptured wide-neck intracranial bifurcation aneurysms (WIBAs) with short-, mid-, and long-term follow-ups (FUPs).

METHODS

Consecutive patients with unruptured WIBAs treated with WEB between December 2014 and January 2018 were included. Patient, aneurysm, and device characteristics were collected and analyzed retrospectively. Morbidity and mortality rates were determined by collecting intraprocedural, periprocedural, and delayed complications. Aneurysm occlusion was assessed at 1, 3, and 5 years using a 3-grade scale: complete occlusion, neck remnant, and residual aneurysm. Complete occlusion and neck remnant were considered as adequate occlusion. Patients who received re-treatment were also evaluated.

RESULTS

The study included 104 consecutive patients (55.8% female, mean age 58.6 ± 11.8 years). Aneurysm maximum size, neck, and dome-to-neck mean were, respectively, 6.9 ± 2.1 mm, 4.5 ± 1.2 mm, and 1.4 ± 0.3 mm. One-year FUP was collected for 95 patients, and 3- and 5-year FUPs were collected for 83 patients. Adequate occlusion was observed at 1-year FUP in 90.5% (86/95), 91.6% (76/83) was observed at 3-year FUP, and 92.8% (77/83) at 5-year FUP. None of the aneurysms bled after treatment. During FUP, 6/83 patients (7.2%) were re-treated for residual aneurysm. Morbidity and mortality rates closely related to aneurysm occlusion were 0% (0/104).

CONCLUSION

The WEB device was safe and effective for treating unruptured WIBAs, both in short-term and long-term FUPs.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Intrasaccular flow disruption for ruptured aneurysms: an international multicenter study

BACKGROUND

The Woven EndoBridge (WEB) device is a novel intrasaccular flow disruptor tailored for bifurcation aneurysms. We aim to describe the degree of aneurysm occlusion at the latest follow-up, and the rate of complications of aneurysms treated with the WEB device stratified according to rupture status.

METHODS

Our data were taken from the WorldWideWeb Consortium, an international multicenter cohort including patients treated with the WEB device. Aneurysms were classified into two groups: ruptured and unruptured. We compared clinical and radiologic outcomes of both groups. Propensity score matching (PSM) was done to match according to age, gender, bifurcation, location, prior treatment, neck, height, dome width, daughter sac, incorporated branch, pretreatment antiplatelets, and last imaging follow-up.

RESULTS

The study included 676 patients with 691 intracranial aneurysms (529 unruptured and 162 ruptured) treated with the WEB device. The PSM analysis had 55 pairs. In both the unmatched (85.8% vs 84.3%, p=0.692) and matched (94.4% vs 83.3%, p=0.066) cohorts there was no significant difference in the adequate occlusion rate at the last follow-up. Likewise, there were no significant differences in both ischemic and hemorrhagic complications between the two groups. There was no documented aneurysm rebleeding after WEB device implantation.

CONCLUSION

There was no significant difference in both the radiologic outcomes and complications between unruptured and ruptured aneurysms. Our findings support the feasibility of treatment of ruptured aneurysms with the WEB device.

A novel intrasaccular aneurysm device with high complete occlusion rate: initial results in a rabbit model

BACKGROUND

Intrasaccular flow-disrupting devices are a safe and effective treatment strategy for intracranial aneurysms. We utilized high-frequency optical coherence tomography (HF-OCT) and digital subtraction angiography (DSA) to evaluate SEAL Arc, a new intrasaccular device, and compare the findings with the well-established Woven EndoBridge (WEB) device in an animal model of saccular aneurysms.

METHODS

In a rabbit model, elastase-induced aneurysms were treated with SEAL Arc (n=11) devices. HF-OCT and DSA were performed after implant and repeated after 12 weeks. Device protrusion and malapposition were assessed at implant time and scored on a binary system. Aneurysm occlusion was assessed at 12 weeks with the WEB Occlusion Scale and dichotomized to complete (A and B) or incomplete (C and D) occlusion. The percentage of neointimal coverage after 12 weeks was quantified using HF-OCT. We compared these data to previously published historical controls treated with the gold-standard WEB device (n=24) in the same model.

RESULTS

Aneurysm size and device placement were not significantly different between the two groups. Complete occlusion was demonstrated in 80% of the SEAL Arc devices, which compared favorably to the 21% of the aneurysms treated with WEB devices (P=0.002). Neointimal coverage across SEAL Arc devices was 86±15% compared with 49±27% for WEB (P=0.001). Protruding devices had significantly less neointimal coverage (P<0.001) as did incompletely occluded aneurysms (P<0.001). Histologically, all aneurysms treated with SEAL Arc devices were completely healed.

CONCLUSION

Complete early aneurysm occlusion was frequently observed in the SEAL Arc treated aneurysms, with significant neointimal coverage after 12 weeks.

A review and journey in intrasaccular treatment of intracranial aneurysms

The invested effort and collaboration of clinicians and medical device companies to improve occlusion rates and clinical outcomes for patients with intracranial aneurysms treated via less invasive endovascular means led to the development of the concept of intrasaccular devices. Intrasaccular devices were introduced to offer simple treatment options, offering easier navigation through difficult anatomy, simpler and quicker deployment into large and wide-neck aneurysms. Additionally, they offer easier sizing, whilst offering a wide range of options suitable for aneurysms of different sizes. The concept of most intrasaccular devices is to occupy the aneurysm neck, however offering better stability than simple coiling, therefore increasing the chance of long-term aneurysm occlusion. This is achieved without a sizable metal content within the parent vessel, contrary to flow diverters, theoretically reducing the risk of thromboembolic events. This review aims to discuss the history and latest developments of intrasaccular intracranial devices, which offer an exciting and potentially successful option for treatment of complex intracranial aneurysms.

The effect of the size of the new contour neurovascular device for altering intraaneurysmal flow

BACKGROUND

Recently, a novel intrasaccular device (contour neurovascular system, contour) was introduced to treat intracranial aneurysms. Contour is placed at thе aneurysm neck and reduces the intraaneurysmal blood inflow. Contour comes in a range of sizes to target different aneurysms. The efficiency of altering flow with contour and the effect of device size have not yet been investigated. Therefore, we studied the effect of the device size with patient-based aneurysm models using 2D digital subtraction angiography (DSA).

METHODS

Three patient-based aneurysm models with necks ranging from 2.7 to 9.7 mm were produced, providing standardized testing conditions. Contours with diameters of 5, 11, and 14 mm were implanted into the models, four of each size. 2D DSA images were acquired before and after implanting contour (15 frames/s, manual contrast injection). After injecting angiographic contrast agent, the DSA signal was recorded over time to calculate the contrast washout time (WOT), which is a measure of flow diversion efficiency.

RESULTS

All contour devices caused contrast agent stasis and increased WOT in aneurysm sac (p-value = 0.0005). The median relative WOT was largest for 5-mm contour (6.6 ± 3.2) and similar for 11-mm contour (3.4 ± 2.6) and 14-mm contour (3.2 ± 3.8). The implantation procedure might affect WOT values even for contours of the same size; the overall relative WOT ranged between 1.5 and 10.89.

CONCLUSION

The 5-mm contour showed the longest WOT value in our study, while no apparent difference between 11-mm contour and 14-mm contour was found.

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

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

Treatment of Wide-Necked Cerebral Aneurysms Using the WEB Device Including Flow Alteration Assessment With Color-Coded Imaging: A Single Center Experience

Objective

The Woven EndoBridge (WEB) device (MicroVention, Tustin, CA) has extended the treatment of cerebral aneurysms. Despite the fact that the WEB device has shown promising clinical results, little is known about the caused intra-aneurysmal flow alterations. Here we present our clinical experience with the WEB, including examining various syngo iFlow (Siemens AG, Erlangen, Germany) parameters to predict aneurysm occlusion.

Methods

We reviewed the data from patients with unruptured cerebral aneurysms treated with a WEB device between 2016 and 2020. Aneurysm occlusion and complications were assessed. Furthermore, different quantitative criteria were evaluated using syngo iFlow after digital subtraction angiography.

Results

A total of 26 patients hosting 26 cerebral aneurysms met the inclusion criteria. Follow-up was available for 21 patients, with a mean of 7.3 ± 6.3 months. A total of 71.4% (n = 15) of the aneurysms included were located in the anterior and 28.6% (n = 6) in the posterior circulation. Adequate aneurysm occlusion was achieved in 85.7% (n = 18). The iFlow parameters for reduced aneurysm outflow (ID-R) differed significantly from the parameters for reduced inflow (PI-R and PI-D) (P < 0.001). The parameters did not differ significantly between adequately and insufficiently occluded aneurysms. Only a trend towards a lower ID-R of insufficiently occluded aneurysms was observed (P = 0.063), indicating a potential predictive value for insufficient aneurysmal outflow. There was no treatment-related morbidity or mortality.

Conclusions

The applied syngo iFlow parameters confirmed that flow changes induced by the WEB device significantly affect outflow compared to inflow and have potential predictive value for adequate aneurysm occlusion.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Lumen-oriented versus wall-oriented treatment strategies for intracranial aneurysms - A systematic review of suggested therapeutic concepts

The development of new treatment strategies for intracranial aneurysms (IAs) has been and continues to be a major interest in neurovascular research. Initial treatment concepts were mainly based on a physical-mechanistic disease understanding for IA occlusion (lumen-oriented therapies). However, a growing body of literature indicates the important role of aneurysm wall biology (wall-oriented therapies) for complete IA obliteration. This systematic literature review identified studies that explored endovascular treatment strategies for aneurysm treatment in a preclinical setting. Of 5278 publications screened, 641 studies were included, categorized, and screened for eventual translation in a clinical trial. Lumen-oriented strategies included (1) enhanced intraluminal thrombus organization, (2) enhanced intraluminal packing, (3) bridging of the intraluminal space, and (4) other, alternative concepts. Wall-oriented strategies included (1) stimulation of proliferative response, (2) prevention of aneurysm wall cell injury, (3) inhibition of inflammation and oxidative stress, and (4) inhibition of extracellular matrix degradation. Overall, lumen-oriented strategies numerically still dominate over wall-oriented strategies. Among the plethora of suggested preclinical treatment strategies, only a small minority were translated into clinically applicable concepts (36 of 400 lumen-oriented and 6 of 241 wall-oriented). This systematic review provides a comprehensive overview that may provide a starting point for the development of new treatment strategies.

Comparison of angiographic outcomes and complication rates of WEB embolization and coiling for treatment of unruptured basilar tip aneurysms

Endovascular coiling represents the standard treatment for basilar tip aneurysms. Some of these aneurysms are not amenable to conventional coiling due to a complex aneurysm geometry, hence, novel devices such as the Woven Endobridge (WEB) have been developed. We retrospectively compared WEB embolization and coiling for the treatment of unruptured basilar tip aneurysms. Patients treated with WEB or coiling at four centers were reviewed. Procedure-related complications, clinical outcome and angiographic results were retrospectively evaluated and compared. Forty patients treated with the WEB and 35 patients treated by coiling were included. Stent-assistance was more often necessary for coiling than for WEB embolization (71% vs 2.5%, p < 0.001). The technical success rates were 100% for both methods. The overall complication rates were not significantly different between groups (WEB: 5%, coil: 11%, p = 0.409). Procedural morbidity rates were 9% in the coiling group and 2.5% in the WEB group (p = 0.334). There was no mortality. Treatment duration was shorter for WEB implantation than for coiling (p = 0.048). At mid-term follow-up, complete occlusion, neck remnants and aneurysm remnants were observed in 89%, 4% and 7% for the WEB, respectively, and in 100%, 0% and 0% for coiling. While complication rates and mid-term angiographic outcome was comparable between the groups, the WEB was associated with a shorter treatment duration and required stent-assistance less frequently. The choice of the treatment modality should be made based on the specific aneurysm characteristics, the individual experience of the neurointerventionalist and patient preference.

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.

Woven EndoBridge in Wide-Neck Bifurcation Aneurysms: Digital Subtraction Angiography at 3-Year Follow-Up

Introduction: The Woven EndoBridge (WEB) device is a self-expanding intrasaccular braided-wire device for the treatment of wide-neck bifurcation aneurysms (WNBAs). Even though this device has an excellent safety profile and a low risk of rebleeding, little is known about its long-term effects. Material and Methods: All patients treated with WEB due to ruptured WNBAs were subjected to follow-up digital subtraction angiography (DSA) at 2 and 3 years after device deployment. The degree of residual neck was assessed through BOSS, Lubicz, and WEBCAST scales. Data on modified Rankin scale (mRS), bleeding events, and ischemic events occurring during this time period were collected as well. Lastly, overall and procedure-related mortality rates were calculated. Results: A total of 21 patients were treated between 1 January 2016, and 31 December 2018. DSA demonstrated a patency grade of 57.1% and 61.1% at 2 and 3 years, respectively. The overall 2-year mortality rate due to causes unrelated to the aneurysm was 14.3%. None of the patients were retreated between the 2- and the 3-year follow-up. No rebleeding or stroke events occurred during the follow-up. Conclusions: WEB-treated ruptured aneurysms showed an excellent degree of stability over time. The overall mortality rate—unrelated to the procedure–observed in our sample was higher than what reported in the literature, a possible bias associated with the COVID-19 pandemic.

Horizontal stenting via retrograde route for recurrent ruptured posterior communicating artery aneurysm after clipping: A case report and literature review

Treatment of recurrent ruptured aneurysms incorporating a branch vessel arising from the dome is challenging. Here, we attempted horizontal stent-assisted coil embolization via a retrograde route from the contralateral internal carotid artery to treat a small ruptured posterior communicating artery aneurysm incorporating a fetal variant posterior cerebral artery after clipping.

Rabbit Elastase Aneurysm Model Mimics the Recurrence Rate of Human Intracranial Aneurysms following Platinum Coil Embolization

BACKGROUND AND PURPOSE

Intracranial aneurysms treated with coils have been associated with incomplete occlusion, particularly in large or wide-neck aneurysms. This study aimed to validate the accuracy of the rabbit elastase model in predicting aneurysm recurrence in humans treated with platinum coils.

MATERIALS AND METHODS

Elastase-induced saccular aneurysms were induced in rabbits and embolized with conventional platinum coils. The recurrence rates of aneurysms were retrospectively analyzed. Morphologic characteristics of aneurysms, angiographic outcomes, and histologic healing were evaluated.

RESULTS

A total of 28 (15.3%) of 183 aneurysms recurred. The aneurysm recurrence rate observed in this study (15.3%) is similar to those reported in multiple analyses of aneurysm recurrence rates in humans (7%-27%). The rate of recurrence was higher in aneurysms treated without balloon assistance (19/66, 28.8%) compared with those treated with balloon assistance (9/117, 7.7%). Aneurysms treated with balloon-assisted coiling had a lower recurrence rate (OR = 0.17; 95% CI, 0.05-0.47; P = .001) and higher occlusion rate (OR = 6.88; 95% CI, 2.58-20.37; P < .001) compared with those treated without balloon-assisted coiling. In this rabbit elastase-induced aneurysm model, packing density and aneurysm volume were weak predictors of aneurysm recurrence; however, the packing density was a good predictor of the occlusion rate (OR = 1.05; 95% CI, 1.02-1.10; P = .008).

CONCLUSIONS

The rabbit elastase aneurysm model may mimic aneurysm recurrence rates observed in humans after platinum coil embolization. Moreover, balloon assistance and high packing densities were significant predictors of aneurysm recurrence and occlusion.

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.

Targeted and Staged Treatment for Ruptured Wide-neck Intracranial Aneurysms: Bleb Coiling Strategy as a New Approach

RATIONALE AND OBJECTIVE

This study aimed to investigate the feasibility, safety, and efficiency rates of the bleb coiling technique for the treatment of acute ruptured wide-neck bifurcation aneurysm (WBNAs) by comparing it with device-assisted coiling.

MATERIALS AND METHODS

Patients with ruptured WNBAs who underwent endovascular treatment (EVT) were reviewed. The study sample was divided into five groups according to treatment type: bleb coiling, single catheter coiling, balloon-assisted coiling (BAC), neck remodeling mesh-assisted coiling, and stent-assisted coiling (SAC). The feasibility, safety, efficiency and complication rates of the bleb coiling technique were compared with each group.

RESULTS

This study included 109 patients with ruptured WNBAs. Bleb coiling was performed in 24 blebs of 20 WNBAs. The mean time interval between initial and complementary treatment in the bleb coiling group was 12.53± 5 .27 weeks (min-max: 4-23 weeks). No rebleeding occurred during this interval time, and no mortality or new permanent neurologic deficit caused by the bleb coiling technique was noted. The bleb coiling technique had a lower complication rate than other techniques (p <0.05).

CONCLUSION

The bleb coiling strategy led to favourable clinical outcomes with low complication rates and it can be considered as an alternative treatment option at acute phase of SAH in the endovascular treatment of ruptured WBNAs with coilable-bleb.

Retreatment Strategies in Aneurysm Woven Endobridge Recurrences: A Case Series

BACKGROUND

The treatment of wide-necked and bifurcation aneurysms has become a common indication for the Woven Endobridge (WEB) device. In many instances, WEB embolization fails and retreatment strategies for the recanalized aneurysms have not been established and may be challenging.

OBJECTIVE

To report an experience with retreatment strategies after WEB failure in 7 cases involving various aneurysm shapes, sizes, and location using multiple strategies including endovascular modalities and microsurgical clip ligation.

METHODS

Data were retrospectively collected from 1 high-volume cerebrovascular center for 7 patients treated with a WEB device for an aneurysm who subsequently required retreatment for that same aneurysm from 2015 through January 2021.

RESULTS

We identified 7 patients with WEB recurrences over a period of 6 years. Four patients initially presented with incidental findings, whereas 3 patients presented with subarachnoid hemorrhage. One patient was lost to follow-up and presented with a rerupture, whereas the 6 other patients were diagnosed with routine follow-up. Two patients received clip ligation, 2 had simple coil embolization, 1 had stent-assisted coil embolization, 1 had a flow-diverting stent, and 1 patient required 2 retreatments; he received stent-assisted coil embolization for the first retreatment and a simple coil embolization for the second retreatment. All patients had excellent angiographic outcomes and no complications.

CONCLUSION

The authors conclude that aneurysm recurrence after WEB is very diverse, and no single modality can properly address all recurrences. Rather, an individualized approach based on aneurysm features, neurointerventionalist expertise, and patient preference should be implemented.

Indirect Flow Diversion for Off-Centered Bifurcation Aneurysms and Distant Small-Vessel Aneurysms, a Retrospective Proof of Concept Study From Five Neurovascular Centers

Background: Treatment of cerebral aneurysms using hemodynamic implants such as endosaccular flow disruptors and endoluminal flow diverters has gained significant momentum during recent years. The intended target zone of those devices is the immediate interface between aneurysm and parent vessel. The therapeutic success is based on the reduction of aneurysmal perfusion and the subsequent formation of a neointima along the surface of the implant. However, a subset of aneurysms-off-centered bifurcation aneurysms involving the origin of efferent branches and aneurysms arising from peripheral segments of small cerebral vessels-oftentimes cannot be treated via coiling or implanting a hemodynamic implant at the neck level for technical reasons. In those cases, indirect flow diversion-a flow diverter deployed in the main artery proximal to the parent vessel of the aneurysm-can be a viable treatment strategy, but clinical evidence is lacking in this regard. Materials and Methods: Five neurovascular centers contributed to this retrospective analysis of patients who were treated with indirect flow diversion. Clinical data, aneurysm characteristics, anti-platelet medication, and follow-up results, including procedural and post-procedural complications, were recorded. Results: Seventeen patients (mean age: 60.5 years, range: 35-77 years) with 17 target aneurysms (vertebrobasilar: n = 9) were treated with indirect flow diversion. The average distance between the flow-diverting stent and the aneurysm was 1.65 mm (range: 0.4-2.4 mm). In 15/17 patients (88.2%), perfusion of the aneurysm was reduced immediately after implantation. Follow-ups were available for 12 cases. Delayed opacification (OKM A3: 11.8%), reduction in size (OKM B1-3: 29.4%) and occlusion (D1: 47.1%) were observable at the latest investigation. Clinically relevant procedural complications and adverse events in the early phase and in the late subacute phase were not observed in any case. Conclusion: Our preliminary data suggest that indirect flow diversion is a safe, feasible, and effective approach to off-centered bifurcation aneurysms and distant small-vessel aneurysms. However, validation with larger studies, including long-term outcomes and optimized imaging, is warranted.

The Evolution of Endovascular Therapy for Intracranial Aneurysms: Historical Perspective and Next Frontiers

The history of cerebral aneurysm treatment has a rich and storied past with multiple notable luminaries contributing insights. The modern era has transitioned from primarily clip ligation to increasing use of endovascular therapy. Even more recently, the use of intrasaccular flow diverters has been introduced for the treatment of wide necked aneurysms. The field is continuing to transform, and bioactive coils and stents have resurfaced as promising adjuvants to promote aneurysm healing. Advanced imaging modalities are being developed that could further advance the endovascular arsenal and allow for porous memory polymer devices to enter the field. This focused review highlights notable historic contributions and advances to the point of futuristic technology that is actively being developed.

Virtual Flow-T Stenting for Two Patient-Specific Bifurcation Aneurysms

The effective treatment of wide necked cerebral aneurysms located at vessel bifurcations (WNBAs) remains a significant challenge. Such aneurysm geometries have typically been approached with Y or T stenting configurations of stents and/or flow diverters, often with the addition of endovascular coils. In this study, two WNBAs were virtually treated by a novel T-stenting technique (Flow-T) with a number of braided stents and flow-diverter devices. Multiple possible device deployment configurations with varying device compression levels were tested, using fast-deployment algorithms, before a steady state computational hemodynamic simulation was conducted to examine the efficacy and performance of each scenario. The virtual fast deployment algorithm based on a linear and torsional spring analogy is used to accurately deploy nine stents in two WNBAs geometries. The devices expand from the distal to proximal side of the devices with respect to aneurysm sac. In the WNBAs modelled, all configurations of Flow-T device placement were shown to reduce factors linked with increased aneurysm rupture risk including aneurysm inflow jets and high aneurysm velocity, along with areas of flow impingement and elevated wall shear stress (WSS). The relative position of the flow-diverting device in the secondary daughter vessel in the Flow-T approach was found to have a negligible effect on overall effectiveness of the procedure in the two geometries considered. The level of interventionalist-applied compression in the braised stent that forms the other arm of the Flow-T approach was shown to impact the aneurysm inflow reduction and aneurysm flow pattern more substantially. In the Flow-T approach the relative position of the secondary daughter vessel flow-diverter device (the SVB) was found to have a negligible effect on inflow reduction, aneurysm flow pattern, or WSS distribution in both aneurysm geometries. This suggests that the device placement in this vessel may be of secondary importance. By contrast, substantially more variation in inflow reduction and aneurysm flow pattern was seen due to variations in braided stent (LVIS EVO or Baby Leo) compression at the aneurysm neck. As such we conclude that the success of a Flow-T procedure is primarily dictated by the level of compression that the interventionalist applies to the braided stent. Similar computationally predicted outcomes for both aneurysm geometries studied suggest that adjunct coiling approach taken in the clinical intervention of the second geometry may have been unnecessary for successful aneurysm isolation. Finally, the computational modelling framework proposed offers an effective planning platform for complex endovascular techniques, such as Flow-T, where the scope of device choice and combination is large and selecting the best strategy and device combination from several candidates is vital.

Ten Years of Clinical Evaluation of the Woven EndoBridge: A Safe and Effective Treatment for Wide-Neck Bifurcation Aneurysms

Intrasaccular flow disruption is an innovative approach for the endovascular treatment of intracranial aneurysms. As of now, only one device is currently available worldwide: the Woven EndoBridge (WEB) device (MicroVention, Aliso Viejo, CA, USA). After 10 years of clinical use and careful clinical evaluation of the WEB device by multiple prospective, multicenter studies, this article is summarizing the current knowledge regarding this endovascular technique; indications, modalities, safety and efficacy of the WEB procedure are described.

The ARTISSE intrasaccular device for intracranial aneurysm treatment: short-term, mid-term and long-term clinical and angiographic results

BACKGROUND

The concept of intra-aneurysmal flow disruption has emerged as a new paradigm for the treatment of primarily bifurcation aneurysms. The purpose of this study was to determine the clinical and angiographic outcomes of patients treated with the new ARTISSE intrasaccular device (ISD).

METHODS

Selected patients with bifurcation aneurysms that matched the indications of the ARTISSE ISD defined by the manufacturer were treated in a single center. Clinical and angiographic follow-up was conducted at 6 and 36 months. Aneurysm occlusion was assessed using the Raymond-Roy classification scale.

RESULTS

Nine subjects with nine unruptured bifurcation aneurysms were enrolled. Mean aneurysm size was 7.2±1.2 mm (range 5.5-9.7 mm). An adequate aneurysm occlusion (defined as a complete occlusion or a neck remnant) was achieved in 6/9 patients (66.7%) at 6 months and 4/7 patients (57.1%) at 36 months follow-up. Two of the nine subjects experienced a major stroke (22.2%), including one on postoperative day 1 due to a procedure-related parent vessel occlusion and subsequent ischemic stroke. The other major stroke occurred within the 36-month follow-up period during treatment of a separate aneurysm with coils, leading to perforation with hemorrhagic stroke causing a permanent neurological deficit.

CONCLUSION

The ARTISSE ISD was successfully deployed in all nine cases. There were, however, several procedure-related complications and results in terms of angiographic aneurysm occlusion were modest.

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

BACKGROUND & PURPOSE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSION

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

Safety, Efficacy, and Durability of Stent Plus Balloon-Assisted Coiling for the Treatment of Wide-Necked Intracranial Bifurcation Aneurysms

BACKGROUND

Wide-necked bifurcation aneurysms remain a challenge for endovascular surgeons. Dual-stent-assisted coiling techniques have been defined to treat bifurcation aneurysms with a complex neck morphology. However, there are still concerns about the safety of dual-stenting procedures. Stent plus balloon-assisted coiling is a recently described endovascular technique that enables the coiling of wide-necked complex bifurcation aneurysms by implanting only a single stent.

OBJECTIVE

To investigate the feasibility, efficacy, safety, and durability of this technique for the treatment of wide-necked bifurcation aneurysms.

METHODS

A retrospective review was performed of patients with wide-necked intracranial bifurcation aneurysms treated with stent plus balloon-assisted coiling. The initial and follow-up clinical and angiographic outcomes were assessed. Preprocedural and follow-up clinical statuses were assessed using modified Rankin scale.

RESULTS

A total of 61 patients (mean age: 54.6 ± 10.4 yr) were included in the study. The immediate postprocedural digital subtraction angiography revealed complete aneurysm occlusion in 86.9% of the cases. A periprocedural complication developed in 11.5% of the cases. We observed a delayed ischemic complication in 4.9%. There was no mortality in this study. The permanent morbidity rate was 3.3%. The follow-up angiography was performed in 55 of 61 patients (90.1%) (the mean follow-up period was 25.5 ± 27.3 mo). The rate of complete aneurysm occlusion at the final angiographic follow-up was 89.1%. The retreatment rate was 1.8%.

CONCLUSION

The results of this study showed that stent plus balloon-assisted coiling is a feasible, effective, and relatively safe endovascular technique for the treatment of wide-necked bifurcation aneurysms located in the posterior and anterior circulation.

High-resolution image-guided WEB aneurysm embolization by high-frequency optical coherence tomography

BACKGROUND

High-frequency optical coherence tomography (HF-OCT) is an intra-vascular imaging technique capable of assessing device-vessel interactions at spatial resolution approaching 10 µm. We tested the hypothesis that adequately deployed Woven EndoBridge (WEB) devices as visualized by HF-OCT lead to higher aneurysm occlusion rates.

METHODS

In a leporine model, elastase-induced aneurysms (n=24) were treated with the WEB device. HF-OCT and digital subtraction angiography (DSA) were performed following WEB deployment and repeated at 4, 8, and 12 weeks. Protrusion (0-present, 1-absent) and malapposition (0-malapposed, 1-neck apposition >50%) were binary coded. A device was considered 'adequately deployed' by HF-OCT and DSA if apposed and non-protruding. Aneurysm healing on DSA was reported using the 4-point WEB occlusion score: A or B grades were considered positive outcome. Neointimal coverage was quantified on HF-OCT images at 12 weeks and compared with scanning electron microscopy (SEM).

RESULTS

Adequate deployment on HF-OCT correlated with positive outcome (P=0.007), but no statistically significant relationship was found between good outcome and adequate deployment on DSA (P=0.289). Absence of protrusion on HF-OCT correlated with a positive outcome (P=0.006); however, malapposition alone had no significant relationship (P=0.19). HF-OCT showed a strong correlation with SEM for the assessment of areas of neointimal tissue (R²=0.96; P<0.001). More neointimal coverage of 78%±32% was found on 'adequate deployment' cases versus 31%±24% for the 'inadequate deployment' cases (P=0.001).

CONCLUSION

HF-OCT visualizes features that can determine adequate device deployment to prognosticate early aneurysm occlusion following WEB implantation and can be used to longitudinally monitor aneurysm healing progression.

Intra-saccular device modeling for treatment planning of intracranial aneurysms: from morphology to hemodynamics

MOTIVATION

Intra-saccular devices (ID), developed for the treatment of bifurcation aneurysms, offer new alternatives for treating complex terminal and bifurcation aneurysms. In this work, a complete workflow going from medical images to post-treatment CFD analysis is described and used in the assessment of a concrete clinical problem.

MATERIALS AND METHODS

Two different intra-saccular device sizes were virtually implanted in 3D models of the patient vasculature using the ID-Fit method. After deployment, the local porosity at the closed end of the device in contact with the blood flow was computed. This porosity was then used to produce a CFD porous medium model of the device. Velocities and wall shear stress were assessed for each model.

RESULTS

Six patients treated with intra-saccular devices were included in this work. For each case, 2 different device sizes were virtually implanted and 3 CFD simulations were performed: after deployment simulation with each size and before deployment simulation (untreated). A visible reduction in velocities was observed after device implantation. Velocity and WSS reduction was statistically significant (K-S statistics, [Formula: see text]).

CONCLUSIONS

Placement of different device size can lead to a partial filling of the aneurysm, either at the dome or at the neck, depending on the particular positioning by the interventionist. The methodology used in this work can have a strong clinical impact, since it provides additional information in the process of device selection using preoperative data.

Woven EndoBridge device for the treatment of ruptured intracranial aneurysms: A systematic review of clinical and angiographic results

BACKGROUND AND OBJECTIVE

The clinical outcome and angiographic outcome data of Woven EndoBridge (WEB) device for the treatment of ruptured intracranial aneurysms (IAs) are limited. We conducted a meta-analysis of the latest literature on the WEB device in the treatment of ruptured IAs.

METHODS

A comprehensive literature search of 4 databases (PubMed, Web of Science, Cochrane library, and Embase) was conducted for studies published from January 1, 2010 to December 31, 2020. Two reviewers independently extracted variables (aneurysm and patient characteristics) using a prespecified data-collection sheet. Outcomes studied included initial and latest follow-up angiographic outcomes, technical success rate, perioperative mortality, retreated rate, perioperative re-bleeding, complication, intraoperative rupture, favorable neurologic outcome at discharge. We used random-effects model to pool the data.

RESULTS

We finally presented the results of 7 articles including 276 patients with 283 aneurysms. Initial complete and adequate occlusion rate were 38% (95% CI, 25%-50%) and 98% (95% CI, 95%-100%), respectively. Latest follow-up complete and adequate occlusion rate were 61% (95% CI, 46%-75%) and 91% (95% CI, 84%-98%), respectively.Technical success rate was 99% (95% CI, 98%-100%). Perioperative mortality rates and perioperative re-bleeding rate were 9% (95% CI, 3%-15%) and 1% (95% CI, 0%-2%), respectively. Retreated rate was 6% (95% CI, 3%-10%). Overall and WEB treatment-related thromboembolic complication was 10% (95% CI, 6%-13%) and 7% (95% CI, 2%-12%), respectively. Intraoperative rupture rate was 3% (95% CI, 0%-6%).

CONCLUSION

Endovascular treatment of ruptured IAs with the WEB device has a good safety profile and an acceptable aneurysm occlusion rate.

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.

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.

The Geometry of Y-Stent Configurations Used for Wide-Necked Aneurysm Treatment: Analyzing Double-Barrel Stents In Vitro Using Flat-Panel Computed Tomography

BACKGROUND

Stent-assisted coil embolization of wide-necked bifurcation aneurysms often employs a Y configuration stent. A similar stent configuration, termed kissing/double-barrel (KDB), is used often at the aortoiliac bifurcation. Studies of KDB stents in aortoiliac disease show that rates of thromboembolic complications vary with the cross-sectional geometry of the stent pair, a function of the radial crush resistive force of each stent. We assessed cross-sectional geometry of intracranial stent pairs in an in vitro model of the basilar artery using flat-panel computed tomography.

METHODS

In a silicone model of a wide-necked basilar tip aneurysm, 6 simulated KDB stent deployment trials were performed using combinations of 5 stents (Enterprise 1, Enterprise 2, Neuroform Atlas, LVIS, LVIS Jr.). Flat-panel computed tomography reconstructions were used to assess cross-sectional stent geometry. Relative conformability, defined by ovalization and D-ratio, radial crush resistive force (predicted vs. actual), and radial mismatch fraction were compared by stent type (braided vs. laser-cut).

RESULTS

Several distinct forms of cross-sectional stent geometry were observed. Braided stents had lower ovalization and D-ratio (P = 0.015) than laser-cut stents. The Neuroform Atlas/LVIS combination yielded the lowest radial mismatch fraction (19.7% vs. mean 44.3% ± 0.7%). Braided stents tended to have a deployed stent radius closer to the expected (nominal) diameter (i.e., higher relative crush resistive force) than laser-cut stents (measured vs. nominal diameter discrepancy +38.6% ± 21.1% vs. -10.7% ±16.1%, P = 0.14).

CONCLUSIONS

In constant anatomy, cross-sectional geometry of the KDB stent configuration will vary depending on the design and structure of the stents employed.

Recurrent and Residual Aneurysms After Woven EndoBridge (WEB) Therapy: What's Next?

The prevalence of recurrent and residual aneurysms following Woven EndoBridge (WEB) treatment is not insignificant. The goal of this systematic review was to evaluate retreatment methods for such aneurysms and their outcomes. PubMed, Embase, and Scopus databases were systematically searched, and results were reported according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Original studies reporting on aneurysms that were retreated after WEB were included. Sixteen studies (n = 901 aneurysms), of which three were prospective, reported on retreated aneurysms following initial WEB treatment. Of those 901 aneurysms, on average 18.7 ± 11.5% were recurrent or residual at the last follow-up and 10.7 ± 11% required some form of retreatment. When compared to WEB-IT (WEB Intra-saccular Therapy) data, retreated aneurysms were more likely to be large in size (p < 0.0001) and more likely to have been initially treated with the WEB dual-layer configuration. The mean age of those with retreated aneurysms was 58 ± 5.7 years old, and the mean size of aneurysm dome was 11.1 ± 5.5 millimeters. Majority (34.1%) of the aneurysms were located at the basilar apex. Retreatment modalities included coiling (20%), stent-assisted coiling (38.7%), additional WEB device (13.3%), flow diversion (16%), and clipping (12%). Majority of retreated cases had favorable outcomes, with 96.4 ± 13.4% of the cases demonstrating technical success and 90.5 ± 18.2% having adequate occlusion at the last follow-up. Our systematic review suggests that retreatment of recurrent and residual aneurysms after initial WEB treatment is feasible. Future prospective studies would be helpful in validating these results.

Case Report: Persistent Primitive Hypoglossal Artery Accompanied by a Basilar Bifurcation Aneurysm Treated by Y-Stent-Assisted Coil Embolization

Successful embolization of a basilar bifurcation aneurysm associated with a persistent primitive hypoglossal artery (PPHA) using Y-stent-assisted coiling.

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.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

WEB Device Shape Changes in Elastase-Induced Aneurysms in Rabbits

BACKGROUND AND PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

The Woven EndoBridge (WEB) Versus Conventional Coiling for Treatment of Patients with Aneurysmal Subarachnoid Hemorrhage: Propensity Score-Matched Analysis of Clinical and Angiographic Outcome Data

OBJECTIVE

Conventional coiling is standard for treatment of ruptured intracranial aneurysms. We compared clinical and angiographic outcomes between intrasaccular flow disruption with the Woven EndoBridge (WEB) and conventional coiling in patients with aneurysmal subarachnoid hemorrhage (aSAH) using a propensity score-matched analysis.

METHODS

This is a retrospective study of consecutive patients with aSAH treated with the WEB or conventional coiling between 2010 and 2019. Baseline characteristics, procedural complications, angiographic results, and functional outcome were compared between both groups.

RESULTS

Fifty-two patients treated with the WEB and 236 patients treated by coiling were included. The WEB group was characterized by a higher patient age (P = 0.024), a wider aneurysm neck (P < 0.001), and more frequent location at the posterior circulation (P = 0.004). Procedural complications were comparable between WEB (19.2%) and coiling (22.7%, P = 0.447). In-hospital mortality rates were higher in the coiling group (WEB: 5.8%, coiling: 17.8%; P = 0.0034). Favorable outcome (modified Rankin scale ≤2) was obtained in 51.3% after WEB embolization and in 55.0% after coiling (P = 0.653). Retreatment was performed in 26.4% of patients after WEB and in 25.8% after coiling (P = 0.935). Propensity score analysis confirmed these results and revealed higher adequate occlusion rates at midterm follow-up for WEB-treated aneurysms (WEB: 93.9%, coiling: 76.2%, P = 0.058).

CONCLUSIONS

Compared with conventional coiling, aSAH patients treated with the WEB have a similar clinical and potentially improved angiographic outcome at midterm follow-up. The WEB might be considered as an alternative to conventional coiling for the treatment of RIAs, in particular for those with wide-necked and thus challenging anatomy.

[Woven-EndoBridge (WEB) as an intrasaccular method of aneurysm occlusion]

CLINICAL PROBLEM

The treatment of intracranial wide-necked bifurcation aneurysms-which account for approximately 26-36% of all brain aneurysms-can be challenging both endovascularly and surgically, as a complete cut-off of the blood flow into the aneurysm should be achieved without disruption of the flow into the bifurcation vessels. Intrasacular flow disruption with the Woven-EndoBridge (WEB) is an innovative technique for the treatment of such aneurysms. This review article discusses various aspects of the treatment of intracranial aneurysms with the WEB device, including indications, aneurysm/device selecting strategies, antiplatelet therapy requirements, procedural technique and potential complications.

PRACTICAL RECOMMENDATIONS

Intrasacular flow disruption with the WEB device is a safe and effective treatment method for intracranial wide-necked bifurcation aneurysms, especially for patients with ruptured aneurysms, in patients with contraindications for antiplatelet therapy, and for patients in whom clipping is associated with high risks.