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Introduction: The Woven EndoBridge (WEB) device is emerging as a novel therapy for intracranial aneurysms, but its use for off-label indications requires further study. Using machine learning, we aimed to develop predictive models for complete occlusion after off-label WEB treatment and to identify factors associated with occlusion outcomes., Methods: This multicenter, retrospective study included 162 patients who underwent off-label WEB treatment for intracranial aneurysms. Baseline, morphological, and procedural variables were utilized to develop machine-learning models predicting complete occlusion. Model interpretation was performed to determine significant predictors. Ordinal regression was also performed with occlusion status as an ordinal outcome from better (Raymond Roy Occlusion Classification [RROC] grade 1) to worse (RROC grade 3) status. Odds ratios (OR) with 95 % confidence intervals (CI) were reported., Results: The best performing model achieved an AUROC of 0.8 for predicting complete occlusion. Larger neck diameter and daughter sac were significant independent predictors of incomplete occlusion. On multivariable ordinal regression, higher RROC grades (OR 1.86, 95 % CI 1.25-2.82), larger neck diameter (OR 1.69, 95 % CI 1.09-2.65), and presence of daughter sacs (OR 2.26, 95 % CI 0.99-5.15) were associated with worse aneurysm occlusion after WEB treatment, independent of other factors., Conclusion: This study found that larger neck diameter and daughter sacs were associated with worse occlusion after WEB therapy for aneurysms. The machine learning approach identified anatomical factors related to occlusion outcomes that may help guide patient selection and monitoring with this technology. Further validation is needed., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The Woven EndoBridge (WEB) device is primarily used for treating wide-neck intracranial bifurcation aneurysms under 10 mm. Limited data exists on its efficacy for large aneurysms. We aim to assess angiographic and clinical outcomes of the WEB device in treating large versus small aneurysms. We conducted a retrospective review of the WorldWide WEB Consortium database, from 2011 to 2022, across 30 academic institutions globally. Propensity score matching (PSM) was employed to compare small and large aneurysms on baseline characteristics. A total of 898 patients were included. There was no significant difference observed in clinical presentations, smoking status, pretreatment mRS, presence of multiple aneurysms, bifurcation location, or prior treatment between the two groups. After PSM, 302 matched pairs showed significantly lower last follow-up adequate occlusion rates (81% vs 90%, p = 0.006) and higher retreatment rates (12% vs 3.6%, p < 0.001) in the large aneurysm group. These findings may inform treatment decisions and patient counseling. Future studies are needed to further explore this area., (© 2024. The Author(s).)

Background and Purpose: Despite the numerous studies evaluating the occlusion rates of aneurysms following WEB embolization, there are limited studies identifying predictors of occlusion. Our purpose was to identify predictors of aneurysm occlusion and the need for retreatment., Materials and Methods: This is a review of a prospectively maintained database across 30 academic institutions. We included patients with previously untreated cerebral aneurysms embolized using the WEB who had available intraprocedural data and long-term follow-up., Results: We studied 763 patients with a mean age of 59.9 (SD, 11.7) years. Complete aneurysm occlusion was observed in 212/726 (29.2%) cases, and contrast stasis was observed in 485/537 (90.3%) of nonoccluded aneurysms. At the final follow-up, complete occlusion was achieved in 497/763 (65.1%) patients, and retreatment was required for 56/763 (7.3%) patients. On multivariable analysis, history of smoking, maximal aneurysm diameter, and the presence of an aneurysm wall branch were negative predictors of complete occlusion (OR, 0.5, 0.8, and 0.4, respectively). Maximal aneurysm diameter, the presence of an aneurysm wall branch, posterior circulation location, and male sex increase the chances of retreatment (OR, 1.2, 3.8, 3.0, and 2.3 respectively). Intraprocedural occlusion resulted in a 3-fold increase in the long-term occlusion rate and a 5-fold decrease in the retreatment rate ( P < .001), offering a specificity of 87% and a positive predictive value of 85% for long-term occlusion., Conclusions: Intraprocedural occlusion can be used to predict the chance of long-term aneurysm occlusion and the need for retreatment after embolization with a WEB device. Smoking, aneurysm size, and the presence of an aneurysm wall branch are associated with decreased chances of successful treatment., (© 2024 by American Journal of Neuroradiology.)

Objective: This study was conducted to investigate the impact of antiplatelet administration in the periprocedural period on the occurrence of thromboembolic complications (TECs) in patients undergoing treatment using the Woven EndoBridge (WEB) device for intracranial wide-necked bifurcation aneurysms. The primary objective was to assess whether the use of antiplatelets in the pre- and postprocedural phases reduces the likelihood of developing TECs, considering various covariates., Methods: A retrospective multicenter observational study was conducted within the WorldWideWEB Consortium and comprised 38 academic centers with endovascular treatment capabilities. Univariable and multivariable logistic regression analyses were performed to determine the association between antiplatelet use and TECs, adjusting for covariates. Missing predictor data were addressed using multiple imputation., Results: The study comprised two cohorts: one addressing general thromboembolic events and consisting of 1412 patients, among whom 103 experienced TECs, and another focusing on symptomatic thromboembolic events and comprising 1395 patients, of whom 50 experienced symptomatic TECs. Preprocedural antiplatelet use was associated with a reduced likelihood of overall TECs (OR 0.32, 95% CI 0.19-0.53, p < 0.001) and symptomatic TECs (OR 0.49, 95% CI 0.25-0.95, p = 0.036), whereas postprocedural antiplatelet use showed no significant association with TECs. The study also revealed additional predictors of TECs, including stent use (overall: OR 4.96, 95% CI 2.38-10.3, p < 0.001; symptomatic: OR 3.24, 95% CI 1.26-8.36, p = 0.015), WEB single-layer sphere (SLS) type (overall: OR 0.18, 95% CI 0.04-0.74, p = 0.017), and posterior circulation aneurysm location (symptomatic: OR 18.43, 95% CI 1.48-230, p = 0.024)., Conclusions: The findings of this study suggest that the preprocedural administration of antiplatelets is associated with a reduced likelihood of TECs in patients undergoing treatment with the WEB device for wide-necked bifurcation aneurysms. However, postprocedural antiplatelet use did not show a significant impact on TEC occurrence.

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., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: The Woven EndoBridge (WEB) device is an intrasaccular flow disruptor designed for wide-necked bifurcation aneurysms. These aneurysms may require the use of a concomitant stent. The objective of this study was to determine the clinical and radiological outcomes of patients undergoing stent-assisted WEB treatment. In addition, the authors also sought to determine the predictors of a concomitant stent in aneurysms treated with the WEB device., Methods: The data for this study were taken from the WorldWideWEB Consortium, an international multicenter cohort including patients treated with the WEB device. Aneurysms were classified into two groups based on treatment: stent-assisted WEB and WEB device alone. The authors compared clinical and radiological outcomes of both groups. Univariable and multivariable binary logistic regression analyses were performed to determine factors that predispose to stent use., Results: The study included 691 intracranial aneurysms (31 with stents and 660 without stents) treated with the WEB device. The adequate occlusion status did not differ between the two groups at the latest follow-up (83.3% vs 85.6%, p = 0.915). Patients who underwent stenting had more thromboembolic (32.3% vs 6.5%, p < 0.001) and procedural (16.1% vs 3.0%, p < 0.001) complications. Aneurysms treated with a concomitant stent had wider necks, greater heights, and lower dome-to-neck ratios. Increasing neck size was the only significant predictor for stent use., Conclusions: This study demonstrates that there is no difference in the degree of aneurysm occlusion between the two groups; however, complications were more frequent in the stent group. In addition, a wider aneurysm neck predisposes to stent assistance in WEB-treated aneurysms.

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., Competing Interests: Competing interests: JDBD: Honoraria from Medtronic. Travel grant from Microvention. MD: No relevant relationships NA: No relevant relationships RWR: Grants from National Institutes of Health, Heitman foundation, Society of vascular and interventional neurology; Advisory board participation for Rapid medical; Site PI for Microvention and Penumbra JEV: No relevant relationships AG : No relevant relationships SVL: No relevant relationships LR: No relevant relationships AAB: No relevant relationships ES: No relevant relationships KP: No relevant relationships KEL: No relevant relationships GS : No relevant relationships MAM: No relevant relationships IL: No relevant relationships PMR: No relevant relationships JAV: Fees from MicroVention for proctoring cases for new physician users of the Woven EndoBridge device; Medtronic travel expense VŽ: Participation on the data safety monitoring board or advisory board for KBC Sestre Milosrdnice, Zagreb / OB Nova Gradiška MUH: No relevant relationships CR: No relevant relationships HR: No relevant relationships VMT: No relevant relationships SM: No relevant relationships SG: No relevant relationships PH: No relevant relationships NA: No relevant relationships JDR: No relevant relationships YR: No relevant relationships CMS: No relevant relationships OG: No relevant relationships MP: No relevant relationships ALK: No relevant relationships CM: No relevant relationships SE: No relevant relationships RMS: Supported by the NREF, Joe Niekro Foundation, Brain Aneurysm Foundation, Bee Foundation, and the National Institutes of Health (R01NS111119-01A1, UL1TR002736, and KL2TR002737) through the Miami Clinical and Translational Science Institute, from the National Center for Advancing Translational Sciences and the National Institute on Minority Health and Health Disparities. AH: Consulting or speaker fees from Medtronic, MicroVention, Stryker, Penumbra, Cerenovus, Genentech, GE Healthcare, Scientia, Balt, Viz.ai, Insera Therapeutics, Proximie, NeuroVasc, NovaSignal, Vesalio, and Galaxy Therapeutics. AS: No relevant relationships AN: No relevant relationships JJ: Consulting and speaker fees from Cerenovus MP: No relevant relationships JS: No relevant relationships CPF: No relevant relationships MBB: No relevant relationships MM: Grants from Balt, Medtronic, MicroVention, and Stryker. MMS: No relevant relationships JB: No relevant relationships BTJ: No relevant relationships RAD: No relevant relationships TH: No relevant relationships RT: Medtronic Stocks CU: No relevant relationships BL : No relevant relationships PP: No relevant relationships ASP: Grants from NIH, Microvention, Cerenovus, Medtronic and Stryker; Consulting fees from Neurovascular, Stryker NeurovascularBalt, Q’Apel Medical, Cerenovus, Microvention, Imperative Care, Agile, Merit, CereVasc and Arsenal Medical; stock options from InNeuroCo, Agile, Perfuze, Galaxy and NTI GP: No relevant relationships CJG: Grants to institution from Medtronic and Penumbra; consulting fees from Stryker and MicroVention. HA: Proctoring fees from MicroVention. Grants to institution from the National Institutes of Health; consulting fees from Amnis Therapeutics, Apellis Pharmaceuticals, Boston Scientific, Canon Medical Systems, Cardinal Health 200, Cerebrotech Medical Systems, Cerenovus, Cerevatech Medical, Cordis, Corindus, EndoStream Medical, Imperative Care, Integra, IRRAS, Medtronic, MicroVention, Minnetronix Neuro, Penumbra, Q’Apel Medical, Rapid Medical, Serenity Medical, Silk Road Medical, StimMed, Stryker Neurovascular, Three Rivers Medical, VasSol, Viz.ai, and W.L. Gore & Associates; payment for participation on the steering committees for the Cerenovus EXCELLENT and ARISE II Trial; Medtronic SWIFT PRIME, VANTAGE, EMBOLISE, and SWIFT DIRECT Trials; MicroVention FRED Trial and CONFIDENCE Study; MUSC POSITIVE Trial; Penumbra 3D Separator Trial, COMPASS Trial, INVEST Trial, MIVI Neuroscience EVAQ Trial; Rapid Medical SUCCESS Trial; InspireMD C-GUARDIANS IDE Pivotal Trial; stock or stock options in Adona Medical, Amnis Therapeutics, Bend IT Technologies, BlinkTBI, Buffalo Technology Partners, Cardinal Consultants, Cerebrotech Medical Systems, Cerevatech Medical, Cognition Medical, CVAID, E8, EndoStream Medical, Imperative Care, Instylla, International Medical Distribution Partners, Launch NY, NeuroRadial Technologies, Neurotechnology Investors, Neurovascular Diagnostics, Perflow Medical, Q’Apel Medical, QAS.ai, Radical Catheter Technologies, Rebound Therapeutics (purchased in 2019 by Integra Lifesciences), Rist Neurovascular (purchased in 2020 by Medtronic), Sense Diagnostics, Serenity Medical, Silk Road Medical, Songbird Therapy, Spinnaker Medical, StimMed, Synchron, Three Rivers Medical, Truvic Medical, Tulavi Therapeutics, Vastrax, VICIS, and Viseon AFD: Consulting fees from Cerenovus, Penumbra, Medtronic, Stryker, Oculus, and Koswire. No relevant relationships RD: No relevant relationships PK: No relevant relationships. VK: No relevant relationships. PL: No relevant relationships SB: No relevant relationships CJS: Participation on the data safety monitoring board or advisory board for Zoll Circulation JK: No relevant relationships PJ: No relevant relationships ST: No relevant relationships FC: No relevant relationships NL: Honoraria for lectures from Cerenovus, Stryker, and CrossMed. MAA: Funding to institution from MicroVention for WEBIT trial; proctoring fees from MicroVention. HHC: No relevant relationships CC: Consulting fees from MicroVention, Stryker, Medtronic, MIVI, and Cerenovus. ABP: Grant to institution from Medtronic; consulting fees from MicroVention, Medtronic, and Q’Apel; workstation for research from Siemens AAD: No relevant relationships, (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Several studies have shown promising outcomes of the Woven EndoBridge (WEB) device for the treatment of wide-necked intracranial bifurcation aneurysms. This is a multicenter study attempts to explore the changes in trends and treatment outcomes over time for WEB embolization of intracranial aneurysms. The WorldWideWEB consortium is a retrospective multicenter collaboration of data from international centers spanning from January 2011 and June 2021, with no limitations on aneurysm location or rupture status. Both bifurcation and sidewall aneurysms were included. These patients were stratified based on treatment year into five treatment intervals: 2011-2015 (N = 66), 2016-2017 (N = 77), 2018 (N = 66), 2019 (N = 300), and 2020-2021 (N = 173). Patient characteristics and angiographic and clinical outcomes were compared between these time intervals. This study comprised 671 patients (median age 61.4 years; 71.2% female) with 682 intracranial aneurysms. Over time, we observed an increasing tendency to treat patients presenting with ruptured aneurysms and aneurysms with smaller neck, diameter, and dome widths. Furthermore, we observed a trend towards more off-label use of the WEB for sidewall aneurysms and increased adoption of transradial access for WEB deployment. Moreover, the proportion of patients with adequate WEB occlusion immediately and at last follow-up was significantly higher in more recent year cohorts, as well as lower rates of compaction and retreatment. Mortality and complications did not differ over time. This learning curve study suggests improved experience using the WEB for the treatment of intracranial aneurysms and has yielded higher rates of adequate occlusion over time., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: The Woven EndoBridge (WEB) device has Food and Drug Administration approval for treatment of wide-necked intracranial bifurcation aneurysms. The WEB device has been shown to result in adequate occlusion in bifurcation aneurysms overall, but its usefulness in the individual bifurcation locations has been evaluated separately only in few case series, which were limited by small sample sizes., Objective: To compare angiographic and clinical outcomes after treatment of bifurcation aneurysms at various locations, including anterior communicating artery (AComA), anterior cerebral artery (ACA) bifurcation distal to AComA, basilar tip, internal carotid artery (ICA) bifurcation, and middle cerebral artery (MCA) bifurcation aneurysms using the WEB device., Methods: A retrospective cohort analysis was conducted at 22 academic institutions worldwide to compare treatment outcomes of patients with intracranial bifurcation aneurysms using the WEB device. Data include patient and aneurysm characteristics, procedural details, angiographic and functional outcomes, and complications., Results: A total of 572 aneurysms were included. MCA (36%), AComA (35.7%), and basilar tip (18.9%) aneurysms were most common. The rate of adequate aneurysm occlusion was significantly higher for basilar tip (91.6%) and ICA bifurcation (96.7%) aneurysms and lower for ACA bifurcation (71.4%) and AComA (80.6%) aneurysms (p=0.04)., Conclusion: To our knowledge, this is the most extensive study to date that compares the treatment of different intracranial bifurcation aneurysms using the WEB device. Basilar tip and ICA bifurcation aneurysms showed significantly higher rates of aneurysm occlusion than other locations., Competing Interests: Competing interests: The following authors serve on the editorial board of JNIS, JDBD, AG, AFD, FCA, and PK., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Data regarding the safety and efficacy of flow diverting stents (FDS) in the treatment of middle cerebral artery (MCA) bifurcation aneurysms are scarce and limited to small single center series, with particular concern for increased risk of ischemic complications with jailing one of the M2 branches., Methods: Prospectively-maintained databases at six North American and European centers were queried for patients harboring MCA bifurcation aneurysms undergoing treatment with FDS (2011-2018). The pertinent clinical and radiographic data were collected and analyzed., Results: 87 patients (median age 60 years, 69% females) harboring 87 aneurysms were included. The majority of aneurysms were unruptured (79%); 75.9% were saccular with a median maximal diameter of 8.5 mm. Radiographic imaging follow-up was available in 88.5% of cases at a median of 16.3 months post-treatment, showing complete occlusion in 59% and near complete occlusion (90-99%) in 18% of aneurysms. The overall rate of ischemic and hemorrhagic complications was 8% and 1.1%, respectively. Symptomatic and permanent complications were encountered in 5.7% and 2.3% of patients respectively, with retreatment pursued in 2.3% of patients. Jailed branch occlusion was detected in 11.5% of cases, with clinical sequelae in 2.3%. Last follow-up modified Rankin Scale of 0-2 was noted in 96.8% of patients. On multivariate analysis, male sex was the only independent predictor of aneurysmal persistence at last follow-up imaging (p=0.019)., Conclusion: FDS treatment for MCA bifurcation aneurysms is feasible, with comparable safety and efficacy profiles to other available endovascular options when utilized in carefully selected aneurysms. Jailing of M2 branches was not associated with a higher risk of post-procedural ischemic complications., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Purpose: Flow diversion has gradually become a standard treatment for intracranial aneurysms of the anterior circulation. Recently, the off-label use of the flow diverters to treat posterior circulation aneurysms has also increased despite initial concerns of rupture and the suboptimal results. This study aimed to explore the change in complication rates and treatment outcomes across time for posterior circulation aneurysms treated using flow diversion and to further evaluate the mechanisms and variables that could potentially explain the change and outcomes., Materials and Methods: A retrospective review using a standardized data set at multiple international academic institutions was performed to identify patients with ruptured and unruptured posterior circulation aneurysms treated with flow diversion during a decade spanning January 2011 to January 2020. This period was then categorized into 4 intervals., Results: A total of 378 procedures were performed during the study period. Across time, there was an increasing tendency to treat more vertebral artery and fewer large vertebrobasilar aneurysms ( P = .05). Moreover, interventionalists have been increasingly using fewer overlapping flow diverters per aneurysm ( P = .07). There was a trend toward a decrease in the rate of thromboembolic complications from 15.8% in 2011-13 to 8.9% in 2018-19 ( P = .34)., Conclusions: This multicenter experience revealed a trend toward treating fewer basilar aneurysms, smaller aneurysms, and increased usage of a single flow diverter, leading to a decrease in the rate of thromboembolic and hemorrhagic complications., (© 2022 by American Journal of Neuroradiology.)

Background The Woven EndoBridge (WEB) device was explicitly designed for wide-neck intracranial bifurcation aneurysms. Small-scale reports have evaluated the off-label use of WEB devices for the treatment of sidewall aneurysms, with promising outcomes. Purpose To compare the angiographic and clinical outcomes of the WEB device for the treatment of sidewall aneurysms compared with the treatment of bifurcation aneurysms. Materials and Methods A retrospective review of the WorldWideWEB Consortium, a synthesis of retrospective databases spanning from January 2011 to June 2021 at 22 academic institutions in North America, South America, and Europe, was performed to identify patients with intracranial aneurysms treated with the WEB device. Characteristics and outcomes were compared between bifurcation and sidewall aneurysms. Propensity score matching (PSM) was used to match by age, pretreatment ordinal modified Rankin Scale score, ruptured aneurysms, location of aneurysm, multiple aneurysms, prior treatment, neck, height, dome width, daughter sac, and incorporated branch. Results A total of 683 intracranial aneurysms were treated using the WEB device in 671 patients (median age, 61 years [IQR, 53-68 years]; male-to-female ratio, 1:2.5). Of those, 572 were bifurcation aneurysms and 111 were sidewall aneurysms. PSM was performed, resulting in 91 bifurcation and sidewall aneurysms pairs. No significant difference was observed in occlusion status at last follow-up, deployment success, or complication rates between the two groups. Conclusion No significantly different outcomes were observed following the off-label use of the Woven EndoBridge, or WEB, device for treatment of sidewall aneurysms compared with bifurcation aneurysms. The correct characterization of the sidewall aneurysm location, neck angle, and size is crucial for successful treatment and lower retreatment rate. © RSNA, 2022 See also the editorial by Hetts in this issue.

Background: Aneurysmal persistence after flow diversion (FD) occurs in 5% to 25% of aneurysms, which may necessitate retreatment. There are limited data on safety/efficacy of repeat FD-a frequently utilized strategy in such cases., Methods: A series of consecutive patients undergoing FD retreatment from 15 centers were reviewed (2011-2019), with inclusion criteria of repeat FD for the same aneurysm at least 6 months after initial treatment, with minimum of 6 months post-retreatment imaging. The primary outcome was aneurysmal occlusion, and secondary outcome was safety. A multivariable logistic regression model was constructed to identify predictors of incomplete occlusion (90%-99% and <90% occlusion) versus complete occlusion (100%) after retreatment., Results: Ninety-five patients (median age, 57 years; 81% women) harboring 95 aneurysms underwent 198 treatment procedures. Majority of aneurysms were unruptured (87.4%), saccular (74.7%), and located in the internal carotid artery (79%; median size, 9 mm). Median elapsed time between the first and second treatment was 12.2 months. Last available follow-up was at median 12.8 months after retreatment, and median 30.6 months after the initial treatment, showing complete occlusion in 46.2% and near-complete occlusion (90%-99%) in 20.4% of aneurysms. There was no difference in ischemic complications following initial treatment and retreatment (4.2% versus 4.2%; P >0.99). On multivariable regression, fusiform morphology had higher nonocclusion odds after retreatment (odds ratio [OR], 7.2 [95% CI, 1.97-20.8]). Family history of aneurysms was associated with lower odds of nonocclusion (OR, 0.18 [95% CI, 0.04-0.78]). Likewise, positive smoking history was associated with lower odds of nonocclusion (OR, 0.29 [95% CI, 0.1-0.86]). History of hypertension trended toward incomplete occlusion (OR, 3.10 [95% CI, 0.98-6.3]), similar to incorporated branch into aneurysms (OR, 2.78 [95% CI, 0.98-6.8])., Conclusions: Repeat FD for persistent aneurysms carries a reasonable success/safety profile. Satisfactory occlusion (100% and 90%-99% occlusion) was encountered in two-thirds of patients, with similar complications between the initial and subsequent retreatments. Fusiform morphology was the strongest predictor of retreatment failure.

Background: During the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The study's objective was to examine whether subarachnoid haemorrhage (SAH) hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines., Methods: We conducted a cross-sectional, retrospective, observational study across 6 continents, 37 countries and 140 comprehensive stroke centres. Patients with the diagnosis of SAH, aneurysmal SAH, ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases, 10th Revision, codes. The 3-month cumulative volume, monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before (1 year and immediately before) and during the pandemic, defined as 1 March-31 May 2020. The prior 1-year control period (1 March-31 May 2019) was obtained to account for seasonal variation., Findings: There was a significant decline in SAH hospitalisations, with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic, representing a relative decline of 22.5% (95% CI -24.3% to -20.7%, p<0.0001). Embolisation of ruptured aneurysms declined with 1170-1035 procedures, respectively, representing an 11.5% (95%CI -13.5% to -9.8%, p=0.002) relative drop. Subgroup analysis was noted for aneurysmal SAH hospitalisation decline from 834 to 626 hospitalisations, a 24.9% relative decline (95% CI -28.0% to -22.1%, p<0.0001). A relative increase in ruptured aneurysm coiling was noted in low coiling volume hospitals of 41.1% (95% CI 32.3% to 50.6%, p=0.008) despite a decrease in SAH admissions in this tertile., Interpretation: There was a relative decrease in the volume of SAH hospitalisations, aneurysmal SAH hospitalisations and ruptured aneurysm embolisations during the COVID-19 pandemic. These findings in SAH are consistent with a decrease in other emergencies, such as stroke and myocardial infarction., Competing Interests: Competing interests: TNN: PI CLEAR study (Medtronic). DCH: Stryker, Vesalio, Cerenovus consultant. AEH: consultant and speaker for Medtronic, Stryker, Microvention, Penumbra, Balt, Scientia, Genentech and GE Healthcare. PJ: Medtronic, Microvention, Balt, Cerenovus consultant. SO-G: Medtronic, Stryker consultant. DSL: Cerenovus, Genentech, Stryker, Medtronic consultant. TGJ: advisor/investor for Anaconda, Route92, FreeOx, and Blockade Medical; Medtronic grants, DAWN, AURORA PI (Stryker). WJM: consultant: Rebound Therapeutics, Viseon Imperative Care, Q’Apel, Stryker, Stream Biomedical, Spartan Micro; Investor: Cerebrotech, Endostream, Q’Apel, Viseon, Rebound, and Spartan Micro. RGN: Stryker; Cerenovus/Neuravi; Anaconda, Cerebrotech, Ceretrieve, Vesalio (Advisory Board); Imperative Care., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Flow diversion is a common endovascular treatment for cerebral aneurysms, but studies comparing different types of flow diverters are scarce., Objective: To perform a propensity score matched cohort study comparing the Pipeline Embolization Device (PED) and Flow Redirection Intraluminal Device (FRED) for posterior circulation aneurysms., Methods: Consecutive aneurysms of the posterior circulation treated at 25 neurovascular centers with either PED or FRED were collected. Propensity score matching was used to control for age, duration of follow-up imaging, adjunctive coiling, and aneurysm location, size, and morphology; previously ruptured aneurysms were excluded. The two devices were compared for the following outcomes: procedural complications, aneurysm occlusion, and functional outcome., Results: A total of 375 aneurysms of the posterior circulation were treated in 369 patients. The PED was used in 285 (77.2%) and FRED in 84 (22.8%) procedures. Aneurysms treated with the PED were more commonly fusiform and larger than those treated with FRED. To account for these important differences, propensity score matching was performed resulting in 33 PED and FRED unruptured aneurysm pairs. No differences were found in occlusion status and neurologic thromboembolic or hemorrhagic complications between the two devices. The proportion of patients with favorable functional outcome was higher with FRED (100% vs 87.9%, p=0.04)., Conclusion: Comparative analysis of PED and FRED for the treatment of unruptured posterior circulation aneurysms did not identify significant differences in aneurysm occlusion or neurologic complications. Variations in functional outcomes warrant additional investigations., Competing Interests: Competing interests: Ajith Thomas: DSMB SCENT trial by STRYKER. Funds paid to institution.Ramesh Grandhi: Consultant for Medtronic neurovascular, BALT neurovascular and Cerenovus.Christoph Griessenauer: Consultant for Stryker and received research funding from Medtronic.Naci Kocer: Consultant and proctoring agreement with MicroVention.Philipp Taussky:Reply: Consultant for Medtronic, Stryker, Cerenovus.Peter Kan: Consultant for Stryker, Medtronic, MicroVention, and Cerenovus.Vincent Tutino: Co-founder of Neurovascular Diagnostics, Inc.Monika Killer: Research grant from MicroVention/Terumo.Waleed Brinjikji: Microvention and Cerenovus consultant.Tom Marotta: Medtronic proctoring.Timo Krings: Consultant for Stryker, Medtronic, Penumbra, Cerenovus. stockholder in Marblehead Inc, royalties from Thieme.Clemens Schirmer: Research Support from Penumbra. Shareholder in Neurotechnology Investors.Giuseppe Lanzino: Consultant for Superior Medical Editing and Nested Knowledge.Christian Ulfert: Consulting fees from Johnson & Johnson.Charles Matouk: Consultant for Medtronic, Penumbra, Silk Road MedicalMarkus Mohlenbruch: Consultant for Medtronic, MicroVention, Stryker. Grants/grants pending: Balt (money paid to the institution), MicroVention (money paid to the institution). Payment for lectures includings service on speakers bureaus: Medtronic, MicroVention, and Stryker.Marshall Cress: Consulting for Cannon and Cerenovus.None related to this study and none are declared for the reminder of the authors., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Y-stenting is an effective but challenging approach for wide-neck aneurysms. PulseRider (PR) (Pulsar/Cerenovus) is a new device designed to provide scaffolding during coiling but has never been compared with other techniques., Objective: To compare the immediate and 6-mo results of Y-stenting vs PR assisted coiling., Methods: A total of 105 consecutive patients were retrospectively divided into 2 groups (73 Y-stenting and 32 PR). All underwent angiographic 6-mo follow-up. We evaluated if some anatomical features could influence treatment results., Results: The groups were homogeneous. Immediate adequate occlusions as well as complication rates were similar in Y-stenting and PR group (94.5% vs 96.9% and 8.2% vs 6.2%, respectively). At 6 mo, adequate occlusion was 93.1% after Y-stenting and 84.3% after PR (P = .28), complete occlusion was significantly higher after Y-stenting: 90.3% vs 62.5% (P = .0017). Occlusion grade worsening occurred in 6.9% of Y-stenting and 18.7% of PR patients (P = .09).Neck size was associated with occlusion grade in both groups. Maximal aneurysm size was associated with occlusion grade in the PR group (P = .023) but not in the Y-stenting group (P = .06). After PR, 6-mo occlusion rate was higher in small (< 10 mm) than in large aneurysms (P = .0094); this was not observed after Y-stenting (P = .54).Location did not significantly affect the mid-term occlusion rate in both the groups. After PR, occlusion was more stable in basilar than anterior or middle cerebral artery aneurysms., Conclusion: Y-stenting and PR are both effective with similar immediate and mid-term results. However, treatment stability seems higher after Y-stenting. Aneurysm size seems to negatively affect PR results., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Background: Partially thrombosed intracranial aneurysms (PTIA) represent a unique subset of intracranial aneurysms with an ill-defined natural history, posing challenges to standard management strategies. This study aims to assess the efficacy of flow diversion in the treatment of this pathology., Methods: A retrospective review of patients with flow-diverted PTIA at 6 cerebrovascular centers was performed. Clinical and radiographic data were collected from the medical records, with the primary outcome of aneurysmal occlusion and secondary outcomes of clinical status and complications., Results: Fifty patients with 51 PTIA treated with flow diversion were included. Median age was 56.5 years. Thirty-three (64.7%) aneurysms were saccular and 16 (31.4%) were fusiform/dolichoectatic. The most common location was the internal carotid artery (54.9%) followed by the vertebral and basilar arteries (17.7% and 17.7%, respectively). Last imaging follow-up was performed at a median of 25.1 (interquartile range, 12.8-43) months. Complete occlusion at last radiographic follow-up was achieved in 37 (77.1%) aneurysms. Pretreatment aneurysm thrombosis of >50% was associated with a significantly lower rate of complete aneurysm occlusion (58.8 vs. 87.1%, P = 0.026) with a trend toward better functional outcome (modified Rankin scale <2) at last follow-up in patients with <50% pretreatment aneurysm thrombosis (96.8 vs. 82.4; P = 0.08). Ischemic complications occurred in 5 (9.8%) patients, producing symptoms in 4 (7.8%) and resultant mortality in 2 (4.2%) patients., Conclusions: Flow diversion treatment of PTIA has adequate efficacy along with a reasonable safety profile. Aneurysms harboring large amounts of pretreatment thrombus were associated with lower rates of complete occlusion., (Copyright © 2019. Published by Elsevier Inc.)

Flow diverter devices have gained wide acceptance for the treatment of unruptured intracranial aneurysms. Most studies are based on the treatment of large aneurysms harboring on the carotid syphon. However, during the last years the "off-label" use of these stents has widely grown up even if not supported by randomized studies. This review examines the relevant literature concerning "off-label" indications for flow diverter devices, such as for distal aneurysms, bifurcation aneurysms, small aneurysms, recurrent aneurysms, and direct carotid cavernous fistulas., (© Congress of Neurological Surgeons 2019.)

Background: Flow diversion for anterior communicating artery aneurysms required further investigation., Purpose: Our aim was to analyze outcomes after treatment of anterior communicating artery aneurysms with flow-diverter stents., Data Sources: A systematic search of 3 data bases was performed for studies published from 2008 to 2018., Study Selection: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we included studies reporting anterior communicating artery aneurysms treated with flow diversion., Data Analysis: Random-effects meta-analysis was used to pool the following: aneurysm occlusion rate, complications, and factors influencing the studied outcomes., Data Synthesis: We included 14 studies and 148 unruptured saccular anterior communicating artery aneurysms treated with flow diversion. The long-term complete/near-complete (O'Kelly-Marotta C-D) occlusion rate was 87.4% (91/105; 95% CI, 81.3%-93.6%; I 2 = 0%) (mean radiologic follow-up of 11 months). The treatment-related complication rate was 8.6% (14/126; 95% CI, 4%-13.1%; I 2 = 0%), with morbidity and mortality rates of 3.5% (5/126; 95% CI, 2%-7%; I 2 = 0%) and 2.5% (2/148; 95% CI, 0.3%-5%; I 2 = 0%), respectively. Most complications were periprocedural (12/126 = 7%; 95% CI, 3%-11%; I 2 = 0%). Thromboembolic events were slightly higher compared with hemorrhagic complications (10/126 = 6%; 95% CI, 2%-10%; I 2 = 0% and 4/126 = 3%; 95% CI, 1%-6%; I 2 = 0%). Branching arteries (A2 or the recurrent artery of Heubner) covered by the stent were occluded in 16% (7/34; 95% CI, 3.5%-28%; I 2 = 25%) of cases. Pre- and posttreatment low-dose and high-dose of antiplatelet therapy was not associated with significantly different complication and occlusion rates., Limitations: We reviewed small and retrospective series., Conclusions: Flow diversion for unruptured saccular anterior communicating artery aneurysms appears to be an effective alternative treatment for lesions difficult to treat with coiling or microsurgical clipping. The treatment-related complication rate was relatively low. However, larger studies are needed to confirm these results., (© 2019 by American Journal of Neuroradiology.)

Objective: Flow diversion for posterior circulation aneurysms performed using the Pipeline embolization device (PED) constitutes an increasingly common off-label use for otherwise untreatable aneurysms. The safety and efficacy of this treatment modality has not been assessed in a multicenter study., Methods: A retrospective review of prospectively maintained databases at 8 academic institutions was performed for the years 2009 to 2016 to identify patients with posterior circulation aneurysms treated with PED placement., Results: A total of 129 consecutive patients underwent 129 procedures to treat 131 aneurysms; 29 dissecting, 53 fusiform, and 49 saccular lesions were included. At a median follow-up of 11 months, complete and near-complete occlusion was recorded in 78.1%. Dissecting aneurysms had the highest occlusion rate and fusiform the lowest. Major complications were most frequent in fusiform aneurysms, whereas minor complications occurred most commonly in saccular aneurysms. In patients with saccular aneurysms, clopidogrel responders had a lower complication rate than did clopidogrel nonresponders. The majority of dissecting aneurysms were treated in the immediate or acute phase following subarachnoid hemorrhage, a circumstance that contributed to the highest mortality rate in those aneurysms., Conclusions: In the largest series to date, fusiform aneurysms were found to have the lowest occlusion rate and the highest frequency of major complications. Dissecting aneurysms, frequently treated in the setting of subarachnoid hemorrhage, occluded most often and had a low complication rate. Saccular aneurysms were associated with predominantly minor complications, particularly in clopidogrel nonresponders.

Background: Y-stent-assisted coiling for wide-neck intracranial aneurysms required further investigation., Purpose: Our aim was to analyze outcomes after Y-stent placement in wide-neck aneurysms., Data Sources: We performed a systematic search of 3 data bases for studies published from 2000 to 2018., Study Selection: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we included studies reporting Y-stent-assisted coiling of wide-neck aneurysms., Data Analysis: Random-effects meta-analysis was used to pool the following: aneurysm occlusion rate, complications, and factors influencing the studied outcomes., Data Synthesis: We included 27 studies and 750 aneurysms treated with Y-stent placement. The immediate complete/near-complete occlusion rate was 82.2% (352/468; 95% CI, 71.4%-93%; I 2 = 92%), whereas the long-term complete/near-complete occlusion rate was 95.4% (564/598; 95% CI, 93.7%-97%; I 2 = 0%) (mean radiologic follow-up of 14 months). The aneurysm recanalization rate was 3% (20/496; 95% CI, 1.5%-4.5%; I 2 = 0%), and half of the recanalized aneurysms required retreatment. The treatment-related complication rate was 8.9% (63/614; 95% CI, 5.8%-12.1%; I 2 = 44%). Morbidity and mortality after treatment were 2.4% (18/540; 95% CI, 1.2%-3.7%; I 2 = 0%) and 1.1% (5/668; 95% CI, 0.3%-1.9%; I 2 = 0%), respectively. Crossing Y-stent placement was associated with a slightly lower complication rate compared with the kissing configuration (56/572 = 8.4%; 95% CI, 5%-11%; I 2 = 46% versus 4/30 = 12.7%; 95% CI, 3%-24%; I 2 = 0%). Occlusion rates were quite comparable among Enterprise, Neuroform, and LVIS stents, whereas the Enterprise stent was associated with lower rates of complications (8/89 = 6.5%; 95% CI, 1.6%-11%; I 2 = 0%) compared with the others (20/131 = 14%; 95% CI, 5%-26%; I 2 = 69% and 9/64 = 11%; 95% CI, 3%-20%; I 2 = 18%)., Limitations: This was a small, retrospective series., Conclusions: Y-stent-assisted coiling yields high rates of long-term angiographic occlusion, with a relatively low rate of treatment-related complications. Y-stent placement with a crossing configuration appears to be associated with better outcomes. Although Y-configuration can be obtained using many types of stents with comparable occlusion rates, the Enterprise stent is associated with lower complication rates., (© 2019 by American Journal of Neuroradiology.)

Background: Flow diversion for basilar apex aneurysms has rarely been reported., Objective: To assess flow diversion for basilar apex aneurysms in a multicenter cohort., Methods: Retrospective review of prospectively maintained databases at 8 academic institutions was performed from 2009 to 2016 to identify patients with basilar apex aneurysms treated with flow diversion. Clinical and radiographic data were analyzed., Results: Sixteen consecutive patients (median age 54.5 yr) underwent 18 procedures to treat 16 basilar apex aneurysms with either the Pipeline Embolization Device (Medtronic Inc, Dublin, Ireland) or Flow Redirection Endoluminal Device (Microvention, Tustin, California). Five aneurysms (31.3%) were treated in the setting of subarachnoid hemorrhage. Seven aneurysms (43.8%) were treated with flow diversion alone, while 9 (56.2%) underwent flow diversion and adjunctive coiling. At a median follow-up of 6 mo, complete (100%) and near-complete (90%-99%) occlusion was noted in 11 (68.8%) aneurysms. Incomplete occlusion occurred more commonly in patients treated with flow diversion alone compared to those with adjunctive coiling. Patients with partial occlusion were significantly younger. Retreatment with an additional flow diverter and adjunctive coiling occurred in 2 aneurysms with wide necks. There was 1 mortality in a patient (6.3%) who experienced posterior cerebral artery and cerebellar strokes as well as subarachnoid hemorrhage after the placement of a flow diverter. Minor complications occurred in 2 patients (12.5%)., Conclusion: Flow diversion for the treatment of basilar apex aneurysms results in acceptable occlusion rates in highly selected cases. Both primary flow diversion and rescue after failed clipping or coiling resulted in a modified Rankin Scale score that was either equal or better than at presentation and the technology represents a viable alternative or adjunctive option.

Background: Blood blister aneurysms (BBA) are a rare subset of intracranial aneurysms that represent a therapeutic challenge from both a surgical and endovascular perspective., Objective: To report multicenter experience with flow diversion exclusively for BBA, located at non-branching segments along the anteromedial wall of the supraclinoidal internal carotid artery (ICA)., Methods: Consecutive cases of BBA located at non-branching segments along the anteromedial wall of the supraclinoidal ICA treated with flow diversion were included in the final analysis., Results: 49 patients with 51 BBA of the ICA treated with devices to achieve the flow diversion effect were identified. 43 patients with 45 BBA of the ICA were treated with the pipeline embolization device and were included in the final analysis. Angiographic follow-up data were available for 30 patients (32 aneurysms in total); 87.5% of aneurysms (28/32) showed complete obliteration, 9.4% (3/32) showed reduced filling, and 3.1% (1/32) persistent filling. There was no difference between the size of aneurysm (≤2 mm vs >2 mm) or the use of adjunct coiling and complete occlusion of the aneurysm on follow-up (P=0.354 and P=0.865, respectively). Clinical follow-up data were available for 38 of 43 patients. 68% of patients (26/38) had a good clinical outcome (modified Rankin scale score of 0-2) at 3 months. There were 7 (16%) immediate procedural and 2 (5%) delayed complications, with 1 case of fatal delayed re-rupture after the initial treatment., Conclusions: Our data support the use of a flow diversion technique as a safe and effective therapeutic modality for BBA of the supraclinoid ICA., Competing Interests: Competing interests: ASA: consultant for Covidien, Johnson and Johnson, Siemens, Stryker, and Terumo; grants from Siemens and Terumo. BWB: personal fees from Penumbra Inc, Stryker, Medtronic, Route 92 Medical, and Pulsar. MIC: consultant for Penumbra, Medtronic, Microvention, Codman, Pulsar Vascular, Q’Apel, Rebound Medical, and Blockade Medical. GD: consultant for Proctor; speakers bureau for Medtronic and Microvention; shareholder in Medina Medical, InNeuroCo, and Stryker/Surpass. LE: consultant for Stryker Neurovascular, Microvention, and Codman Neurovascular. RH: consultant for Covidien, Stryker, Codman, and MicroVention. PK: consultant for Stryker Neurovascular, Covidien, and MicroVention. EIL: shareholder/ownership interests in Intratech Medical Ltd, Blockade Medical LLC, and Medina Medical; principal investigator in Covidien US SWIFT PRIME Trials; honoraria for training and lecturing from Covidien; consultant for Pulsar, Medina Medical, and Blockade Medical; other financial support from Abbott for carotid training for physicians. IL: consultant and speaker bureau for Covidien, Codman, and Stryker. DKL: consultant for Covidien and Stryker; shareholder/ownership in Penumbra and Blockade Medical; advisory board for Siemens; principal investigator for Liberty Trial (Penumbra). VMP: consultant for Medtronic, Stryker, Penumbra, and BALT; research grant from Philips. MM: consultant for Toshiba (Canon) Medical. ASP: consultant for Medtronic Neurovascular and Stryker Neurovascular; research grants from Medtronic Neurovascular and Stryker Neurovascular. AJR: consultant for Stryker, MicroVention, and Covidien/ev3. AHS: grants from National Institutes of Health/NINDS/NIBIB, University at Buffalo–none related to present study; financial interests in Hotspur, Intratech Medical, StimSox, Valor Medical, Blockade Medical, and Lazarus Effect; consultant for Codman & Shurtleff Inc, Concentric Medical, ev3/Covidien Vascular Therapies, GuidePoint Global Consulting, Penumbra, Stryker, Pulsar Vascular, MicroVention, Lazarus Effect, and Blockade Medical; speakers bureau for Codman & Shurtleff Inc; National Steering Committee for Penumbra Inc 3D Separator Trial, Covidien SWIFT PRIME trial, and MicroVention FRED trial; advisory boards for Codman & Shurtleff and Covidien Neurovascular; honoraria from Abbott Vascular, Codman & Shurtleff, and Penumbra Inc. AST: consultant for Stryker, Codman, Penumbra, and Microvention; research grants (not related to the present study) from Stryker, Codman, Micorvention, Penumbra, and Covidien; financial interests in Medina Medical, Lazarus Effect, Pulsar Vascular, and Blockade Medical. RDT: consultant for Penumbra, Medtronic, Microvention, Codman, Pulsar Vascular, Q’Apel, Rebound Medical, and Blockade Medical. AKW: consultant for Stryker Neurovascular; research grants from Philips Healthcare, and Wyss Institute; speaker for Harvard Postgraduate Course and Miami Cardiovascular Institute. BGW: consultant for Stryker and Medtronic., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Objective: The safety and efficacy of flow diversion for distal circulation aneurysms of the cerebral vasculature has not been well evaluated. The objective of this study was to assess the use of flow diversion for distal circulation aneurysms (defined as at or beyond the M1, P1, and A1 segments of the middle cerebral artery, posterior cerebral artery, and anterior cerebral artery, respectively) in an international multicenter cohort., Methods: Clinical and radiologic records from all patients undergoing flow diversion treatment of distal circulation aneurysms at 3 academic centers (2 in the USA and 1 in Europe) from 2014 until 2017 were retrospectively reviewed., Results: Forty-six patients (mean age, 58.2 years; 33 women) harboring 46 aneurysms who underwent treatment with either the Pipeline Embolization Device (Medtronic Inc., Dublin, Ireland) or the Flow Re-Direction Endoluminal Device (MicroVention, Tustin, California, USA) were included in these analyses. Thirty-four aneurysms (74%) were located in the anterior circulation and 12 (26%) were located in the posterior circulation. With a mean follow-up of 13.0 months, complete (100%) and near-complete (90%-99%) occlusion was noted in 36 aneurysms (78.2%). Angiographic evidence of side branch or perforator vessel coverage was present in 35 aneurysms (76.1%) but was not associated with failure to occlude at follow-up (P = 0.06). All patients had good functional outcomes after treatment (modified Rankin Scale score 0-2). There were 2 cases (4.3%) of perforator vessel stroke and no hemorrhagic complications., Conclusions: Flow diversion for aneurysms beyond the circle of Willis has occlusion rates comparable to alternative treatments and low morbidity. The clinical significance of flow limitation through covered side branches requires further investigation., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background and Purpose: Flow diversion with the Pipeline Embolization Device is increasingly used for endovascular treatment of intracranial aneurysms due to high reported obliteration rates and low associated morbidity. While obliteration of covered branches in the anterior circulation is generally asymptomatic, this has not been studied within the posterior circulation. The aim of this study was to evaluate the association between branch coverage and occlusion, as well as associated ischemic events in a cohort of patients with posterior circulation aneurysms treated with the Pipeline Embolization Device., Materials and Methods: A retrospective review of prospectively maintained databases at 8 academic institutions from 2009 to 2016 was performed to identify patients with posterior circulation aneurysms treated with the Pipeline Embolization Device. Branch coverage following placement was evaluated, including the posterior inferior cerebellar artery, anterior inferior cerebellar artery, superior cerebellar artery, and posterior cerebral artery. If the Pipeline Embolization Device crossed the ostia of the contralateral vertebral artery, its long-term patency was assessed as well., Results: A cohort of 129 consecutive patients underwent treatment of 131 posterior circulation aneurysms with the Pipeline Embolization Device. Adjunctive coiling was used in 40 (31.0%) procedures. One or more branches were covered in 103 (79.8%) procedures. At a median follow-up of 11 months, 11% were occluded, most frequently the vertebral artery (34.8%). Branch obliteration was most common among asymptomatic aneurysms ( P < .001). Ischemic complications occurred in 29 (22.5%) procedures. On multivariable analysis, there was no significant difference in ischemic complications in cases in which a branch was covered ( P = .24) or occluded ( P = .16)., Conclusions: There was a low occlusion incidence in end arteries following branch coverage at last follow-up. The incidence was higher in the posterior cerebral artery and vertebral artery where collateral supply is high. Branch occlusion was not associated with a significant increase in ischemic complications., (© 2018 by American Journal of Neuroradiology.)

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., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Although secondary trigeminal neuralgia is usually due to tumors or multiple sclerosis, other major neurologic diseases, such as aneurysms, should be taken into account when the history or the symptoms suggest a secondary origin., Case Description: A 67-year-old lady presented with a 6-month history of trigeminal neuralgia involving exclusively the right ophthalmic division. A dedicated 3-dimensional-magnetic resonance imaging-magnetic resonance angiography study documented rare contact with a wide-necked aneurysm of the superior cerebellar artery, which distorted the trigeminal root. The patient underwent an endovascular treatment by stent-assisted coiling with the complete disappearance of neuralgic pain attacks within 24 hours., Conclusion: The complete relief from the neuralgic paroxysms immediately after endovascular stent-assisted occlusion of a superior cerebellar artery aneurysm demonstrates the crucial role of a pulsating stimulus on the demyelinated nerve fibers in evoking the ectopically generated discharges., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background/objective: PulseRider is a new endovascular stent dedicated to treat bifurcation intracranial aneurysms with a wide neck. Our purpose was to evaluate 6-month clinical and anatomic results of the device when used to facilitate endovascular coiling of wide-neck bifurcation aneurysms., Methods: Unruptured intracranial aneurysms coiled with PulseRider, in 6 European centers and 1 U.S. center, were retrospectively reviewed from June 2014 to October 2015. Immediate and 6-month results were evaluated independently by using the Raymond classification scale. Recanalization was defined as worsening, and progressive thrombosis was defined as improvement on the Raymond scale., Results: Nineteen patients (10 women, 9 men; mean age, 63 years) harboring 19 bifurcation aneurysms (mean dome size, 8.8 mm; mean neck size, 5.8 mm) were included. Immediate angiographic outcome showed 11 complete aneurysm occlusions, 6 neck remnants, and 2 residual aneurysms. Follow-up at 6 months, obtained in all patients, included 12 complete aneurysm occlusions (63.1%), 6 neck remnants (31.6%), and 1 residual aneurysm (5.3%). Adequate occlusion (defined as complete occlusion and neck remnant combined) was observed in 94.7%. Progressive thrombosis was observed in 2 cases (10.6%) and recanalization in 1 case (5.3%). There was no in-stent stenosis or jailed branch occlusion. No bleeding was observed during the follow-up period. Permanent morbidity rate was 5.3% (1/19), and the mortality rate was 0% at 6 months., Conclusions: The PulseRider allows endovascular treatment of wide-neck bifurcation intracranial aneurysms. Larger series are needed to confirm our preliminary results., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Y-stent assisted coiling has been proposed for the treatment of wide-neck bifurcation aneurysms, but there are many technical variations. We report our single-center experience of Y-stent assisted coiling of bifurcation aneurysms with the closed cell Enterprise stent in order to evaluate the safety and long-term results of this technique. The literature on Y-stenting and its hemodynamic effects are reviewed., Methods: Fifty-two consecutive patients with wide-neck bifurcation aneurysms underwent Y-stent assisted coiling with two Enterprise stents. The procedure was completed in 48 cases (92.3%) and technical failure occurred in 4 cases (7.3%). Cases performed with other stents were excluded. All procedures were performed under double antiplatelet therapy. Periodic clinical and neuroradiological follow-up was performed., Results: Mean neuroradiological follow-up time was 26 months. Complete immediate occlusion was obtained in 87.5% of patients. Two remnants had regrown at follow-up and were recoiled, achieving complete occlusion. The late neuroradiological occlusion rate was: complete occlusion 93.6%, neck remnant 4.3%, sac remnant 2.1%. No in-stent stenosis was detected at follow-up. Among the 48 procedures, two complications occurred (4.2%). Mortality was 2.1%. No delayed ischemic stroke occurred., Conclusions: Y-stent assisted coiling has a high immediate occlusion rate and very good long-term stability. The procedure is relatively safe, although the complication and mortality rates are not negligible. Two Enterprise stents can be safely used for Y-stenting and, indeed, offer the advantage of easier catheterization, delivery and deployment into distal and tortuous vessels than open cell stents., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background and Purpose: Assisted coiling with stents or balloons enables a higher percentage of complete occlusions of saccular unruptured intracranial aneurysms to be achieved with a reasonable complication rate. The aim of this study was to compare stent-assisted coiling and the balloon remodeling technique in terms of efficacy, stability, and safety for the treatment of comparable unruptured saccular intracranial aneurysms., Materials and Methods: 268 patients with 286 saccular unruptured wide-necked intracranial aneurysms were treated at our institution with stent- or balloon-assisted coiling and retrospectively reviewed. Statistical analysis was performed to assess significant differences between the two groups., Results: The rate of complete occlusion at the end of the procedure was higher with stent-assisted coiling than with balloon-assisted coiling (86.8% vs 78%) and the same results were also observed after 6 months (92.1% vs 77.6%; p=0.05). About 50% of major recurrences occurred in large to giant aneurysms (p<0.001). The overall complication rate was similar in the stent-assisted and balloon-assisted groups (10.3% vs 9.3%). Independently of the technique, a higher complication rate was observed with bifurcational aneurysms, particularly in the middle cerebral artery (p=0.016)., Conclusions: Stent-assisted coiling achieved better results in terms of complete occlusion and stability than balloon-assisted coiling with a lower rate of recurrence without being associated with a higher risk of intraprocedural complications. Bifurcational and large to giant aneurysms were associated with higher complication rates and higher recurrence rates, respectively, and still represent a challenge for both techniques., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Endovascular treatment of wide-neck bifurcation aneurysms is challenging and often requires adjunctive techniques and devices. We report our experience with the hybrid Y stenting with the waffle-cone technique, combining Y stent-assisted coiling and waffle-cone stenting techniques. This approach has been described only in a single case report using a combination of open and closed cell stents. We describe four cases treated by hybrid Y stenting with the waffle-cone procedure with a variation from the originally reported technique, consisting in deploying two closed cell stents. All patients were successfully treated without complications. We propose hybrid Y stenting with the waffle-cone for the treatment of wide-neck bifurcation aneurysms as a bailout technique after failure of Y stent-assisted coiling.

Despite the encouraging results obtained with the endovascular treatment of ruptured intracranial aneurysms, few data are available on the effects of the timing of this approach on clinical outcome. The aim of our study was to evaluate the effects of the hyper-early timing of treatment and of pre-treatment and treatment-related variables on the clinical outcome of patients with ruptured intracranial aneurysms. Five hundred and ten patients (167 M, 343 F; mean age 56.45 years) with 557 ruptured intracranial aneurysms were treated at our institution from 2000 to 2011 immediately after their admission. The total population was divided into three groups: patients treated within 12 hours (hyper-early, group A), between 12-48 hours (early, group B) and after 48 hours (delayed, group C). A statistical analysis was carried out for global population and subgroups. Two hundred and thirty-four patients (46%) were included in group A, 172 (34%) in group B and 104 (20%) in group C. Pre-treatment variables (Hunt&Hess, Fisher grades, older age) and procedure-related variable (ischaemic/haemorrhagic complications) showed a significant correlation with worse clinical outcomes. The hyper-early treatment showed no correlation with good clinical outcomes. The incidence of intra-procedural complications was not significantly different between the three groups; 1.2% of pre-treatment rebleedings were observed. The hyper-early endovascular treatment of ruptured intracranial aneurysm does not seem to be statistically correlated with good clinical outcomes although it may reduce the incidence of pre-treatment spontaneous rebleedings without being associated with a higher risk of intra-procedural complications. However, since no significant differences in terms of clinical outcome and pre-treatment rebleeding rate were observed, a hyper-early treatment is not be supported by our data.

Background and Purpose: Fenestration of the vertebrobasilar junction (VBJ) is a rare condition which may be associated with the presence of aneurysms. The endovascular approach is usually the first-line treatment in these cases since the location of the aneurysm may be unsuitable for a surgical approach. This anatomical variation may even influence the endovascular strategy, particularly in those cases in which the sacrifice of a vessel could be avoided. This paper describes an innovative approach of flow diversion in such challenging situations., Methods: Two women were admitted after an occasional diagnosis of an aneurysm arising from a fenestrated VBJ. In both cases the endovascular approach was performed with two flow diverter stents and dual antiplatelet therapy was administered for 6 months., Results: Complete exclusion of the two aneurysms was obtained after 6 and 7 months, respectively, and the clinical outcome was excellent., Conclusions: Endovascular treatment of unruptured aneurysms located on a fenestrated VBJ with flow diverter stents represents a valid therapeutic approach with excellent clinical and radiological outcomes.

Purpose: Neurosurgical and endovascular treatment of fragile and recurrent aneurysms of the non-branching portion of the internal carotid artery, known as blister-like aneurysms, is challenging. The aim of this paper is to describe two cases of ruptured blister-like aneurysms of the internal carotid artery and of the vertebral artery at the origin of the postero-inferior cerebellar artery, which were both treated with flow diverter (FD) stents., Methods: Two patients with a sub-arachnoid hemorrhage secondary to the rupture of a blister-like aneurysm were treated with a Pipeline (ev3, Irvine, California, USA) stent. Digital subtraction angiography and clinical follow-up were carried out., Results: Both patients treated with FD stents had an excellent clinical (modified Rankin Scale, mRS 0) and angiographic outcome. In both cases the aneurysms were completely excluded after 6 months., Conclusions: Although the use of this endovascular approach is still debated because of poor experience and pharmacological limitations, FD stents may represent a valid alternative approach for treatment of this aneurysm subtype.

Endovascular treatment has assumed a role of first choice in the management of ruptured intracranial aneurysms. We describe the clinical and morphological data after the treatment of 258 ruptured intracranial aneurysms in 241 patients, in order to evaluate the safety and the efficacy of the endovascular treatment. Two hundred and forty-one patients with saccular ruptured aneurysms were treated at our institution between 2000 and 2005. After the endovascular treatment a clinical and angiographic follow-up was conducted. The clinical follow-up was carried out with a medical examination and telephonic interviews and mRS was used for evaluation. Two hundred and forty-nine acutely ruptured aneurysms were successfully treated and immediately after the endovascular procedure 81.9% of the aneurysms resulted completely occluded, 12.1% had a residual neck and 6% revealed a residual sac. The evolution of each grade was evaluated at six months and two years. During the follow-up we observed five early and one late re-bleedings. Twenty-four patients underwent a second procedure. After the discharge and up to ten years 73.1% of patients had a good clinical outcome (mRS0-1), 8.9% died and the remainder showed moderate-severe disability (mRS2-3). The long-term stability of the anatomical result is a critic-al issue of this approach because eventual re-bleedings may occur even after several months or years. A careful clinical and radiological follow-up for up to two years after the embolization may prevent recurrences but may not be sufficient.