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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: The placement of flow-diverting devices has become a common method of treating unruptured intracranial aneurysms of the internal carotid artery. The progressive improvement of aneurysm occlusion after treatment-with low complication and rupture rates-has led to a dilemma regarding the management of aneurysms in which occlusion has not occurred within 6-24 months. The authors aimed to identify clinical consensus regarding management of intracranial aneurysms displaying persistent filling 6-24 months after flow diversion and to ascertain questions that may drive future investigation., Methods: An international panel of 67 experts was invited to participate in a multistep Delphi consensus process on the treatment of intracranial aneurysms after failed flow diversion., Results: Of the 67 experts invited, 23 (34%) participated. Qualitative analysis of an initial survey with open-ended questions resulted in 51 statements regarding management of aneurysms showing persistent filling after flow diversion. The statements were grouped into 8 categories, and in the second round, respondents rated the degree of their agreement with each statement on a 5-point Likert scale. Flow diverters with surface modifiers did not influence administration of dual-antiplatelet therapy according to 83%. Consensus was also reached regarding the definition of treatment failure at specific time points, including at 6 months if there is aneurysm growth or persistent rapid flow through the entirety of the aneurysm (96%), at 12 months if there is aneurysm growth or symptom onset (78%), and at 24 months if there is persistent filling regardless of size and filling characteristics (74%). Although experts agreed that the degree of intimal hyperplasia or in-device stenosis could not be ascertained by noninvasive imaging alone (83%), only 65% chose digital subtraction angiography as the preferred modality. At 6 and 12 months, retreatment is preferred if there is persistent filling with aneurysm growth (96%, 96%), device malposition (48%, 87%), or a history of subarachnoid hemorrhage (65%, 70%), respectively, and at 24 months if there is persistent filling without reduction in aneurysm size (74%). Experts favored treatment with an additional flow diverter (87%) over aneurysm clipping, applying the same principles for follow-up (83%) and treatment failure (91%) as for the first flow diverter., Conclusions: The authors present the consensus practices of experts in the management of intracranial aneurysms without occlusion 6-24 months after treatment with a flow-diverting device.

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.)

Purpose: Hemorrhagic stroke, particularly occurring from ruptured cerebrovascular malformations, is responsible for 5-12% of all maternal deaths during pregnancy and the puerperium. Whether endovascular treatment is feasible and safe for both the mother and the fetus, is still a matter of debate. The main objective of this case series and systematic review was to share our multi-institutional experience and to assess the feasibility and safety of endovascular treatment during pregnancy, as well as the corresponding maternal and fetal outcomes based on currently available evidence., Methods: We report a case series of 12 pregnant women presenting with hemorrhagic stroke from ruptured cerebrovascular arteriovenous malformations or aneurysms who underwent endovascular treatment prior to delivery. A systematic literature review of pregnant patients with endovascular treated cerebrovascular malformations, published between 1995 and 2022, was performed. Clinical patient information, detailed treatment strategies, maternal and fetal outcomes as well as information on the delivery were collected and assessed., Results: In most patients the course was uneventful and an excellent outcome without significant neurological deficits (mRS ≤ 1) was achieved. Furthermore, the maternal outcome was not worse compared to the general population who underwent endovascular treatment of ruptured vascular brain lesions. Also, in most cases a healthy fetus was born., Conclusion: Endovascular treatment of ruptured cerebrovascular malformations during pregnancy is safe and feasible regarding both aspects, the maternal and fetal outcomes. Still, a stronger knowledge base is needed to correctly approach future cases of intracranial hemorrhage in the pregnant population., (© 2023. The Author(s).)

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: Subtotal coil embolization followed by subsequent flow diversion is often pursued for treatment of acutely ruptured aneurysms. Owing to the need for anti-platelet therapy, the optimal time of safely pursuing flow diversion treatment has not been fully elucidated. In this study, we aim to demonstrate the safety and feasibility of staged treatment of acutely ruptured aneurysms with early coil embolization followed by flow diversion prior to discharge., Methods: A retrospective study to evaluate clinical outcomes of patients who presented with aneurysmal subarachnoid hemorrhage and underwent coil embolization followed by subacute flow diversion treatment during the same hospitalization., Results: A total of 18 patients are included in our case series. Eight patients presented with Hunt-Hess (H-H) grade 2 bleed, 6 patients with H-H grade 3, and 2 patients each with H-H grade 4 and H-H grade 1. Eight patients required placement of an external ventricular drain on admission. After initial coil embolization, 12 achieved Raymond-Roy grade 2 occlusion, and 6 attained grade 3a/b occlusion. The mean duration between coil embolization and subsequent flow diversion was 9.83 days (range: 1-30). There were no instances of re-hemorrhage between initial coil embolization and subsequent flow diversion treatment. Sixteen patients had a minimum of 6-month follow-up, of which 15 were found to have complete occlusion, and 1 required subsequent clipping., Conclusions: Subtotal coil embolization followed by definitive treatment using flow diversion during the same hospitalization is feasible and achieves excellent aneurysm occlusion rates while avoiding dual anti-platelet therapy during the initial hemorrhage period., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Treatment of small-caliber vessel lesions using flow diverters remains challenging because of vasculature's narrow luminal diameter and tortuosity. This in turn makes navigation and delivery of conventional devices with standard microcatheters more difficult. The Silk Vista Baby (SVB, Balt) flow diversion device was designed for ease of use in vessels with a smaller diameter, distal lesions, and 0.017 ″ microcatheter delivery systems., Objective: To report the outcomes of the SVB device on the treatment of posterior inferior cerebellar artery (PICA) aneurysms., Methods: Databases from different centers were retrospectively reviewed for PICA aneurysms treated with SVB. Demographic information, clinical presentation, radiographic characteristics, procedural complications, and immediate postprocedure outcomes were obtained., Results: Fourteen patients harboring 15 true PICA aneurysms were treated between January 2019 and June 2021. Nine were female (n = 9/14; 64.2%), and the mean age was 51 ± 14.9 years. Most patients had previously ruptured aneurysms, treated by another endovascular technique. Six aneurysms were located distally (n = 6/15; 40%). The mean neck size was 3 mm (SD 1.35, range 2.5-5 mm), whereas the mean PICA diameter was 1.6 mm (SD 0.26, range 1.5-1.7 mm). The mean length of follow-up was 6 months (SD 8.28, range 4.5-16 months). Treatment-related adverse events included 1 case of transient hypoesthesia. Two additional events were reported, but adjudicated as unrelated to the procedure. Complete occlusion, measured as Raymond-Roy class I, was achieved in all cases., Conclusion: The SVB device was safely and effectively used in the treatment of PICA aneurysms. The smaller delivery system profile reduces the risk of procedure complications and creates new treatment options for distal lesions., (Copyright © Congress of Neurological Surgeons 2022. All rights reserved.)

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: The anterior communicating artery (AcoA) is the most common location for intracranial aneurysms., Objective: To present occlusion outcomes, complication rate, recurrence rate, and predictors of recurrence in a large cohort with AcoA aneurysms treated primarily with endosaccular embolization. We also attempt to present data on the most effective treatment modality for recurrent AcoA aneurysms., Methods: This is a retrospective, single-center study, reviewing the outcomes of 463 AcoA aneurysms treated endovascularly between 2003 and 2018., Results: The study cohort consisted of 463 patients. Adequate immediate occlusion was achieved in 418 (90.3%). Independent functional status at discharge was observed in 269 patients (58.0%), and the mortality rate was 6.8% (31). At 6 months, adequate occlusion was achieved in 418 (90.4%). Of all the patients, recurrence was observed in 101 cases (21.8%), and of those, 98 (22.4%) underwent retreatment. The combined frequency of retreatment for the coiling group was 42.4%, which was significantly higher than the 0 incident of retreatment in the clipping group (P < .0001). Among the retreatment cohort, there was a significantly higher subsequent retreatment rate in the endovascular group (0% in the clipping group vs 42.4% in the endovascular group, P < .0001)., Conclusion: Coiling with and without stent/balloon assistance is a relatively safe and effective modality for the treatment of AcoA aneurysms; however, in the setting of recurrence, microsurgical reconstruction leads to improved outcomes regarding durable occlusion, thus avoiding the potential for multiple interventions in the future., (Copyright © Congress of Neurological Surgeons 2022. All rights reserved.)

Background: The Woven EndoBridge (WEB) device (Terumno Corp. [parent company of Microvention]) was approved by the U.S. Food and Drug Administration as the first intrasaccular device for intracranial aneurysm treatment in December 2018. Its use has become more common since then, but both trial results and postmarket experiences have raised questions about the efficacy in achieving complete aneurysm obliteration. Retreatment after WEB embolization has not been extensively discussed., Objective: To discuss the incidence and retreatment of aneurysms after initial WEB embolization., Methods: Retrospective review across 13 institutions identified all occurrences of WEB retreatment within neurovascular databases. Details regarding demographics, aneurysm characteristics, treatment considerations, clinical outcomes, and aneurysm occlusion were obtained and analyzed., Results: Thirty aneurysms were retreated in 30 patients in a cohort of 342 WEB-treated aneurysms. The retreatment rate was 8.8%. Endovascular methods were used for 23 cases, and 7 were treated surgically. Two aneurysms presented with rehemorrhage after initial WEB embolization. Endovascular treatments included stent-assisted coiling (12), flow diversion (7), coiling (2), PulseRider (Johnson & Johnson)-assisted coiling (1), and additional WEB placement (1). Surgical treatments included primary clipping (6) and Hunterian ligation (1). There were no major complications within the study group., Conclusion: WEB retreatments were successfully performed by a variety of techniques, including stent-assisted coiling, clipping, and flow diversion as the most common. These procedures were performed safely with subsequent obliteration of most aneurysms. The potential need for retreatment of aneurysms should be considered during primary WEB treatments., (Copyright © Congress of Neurological Surgeons 2022. All rights reserved.)

Background: Using data from the SMART registry, we report on periprocedural safety of the Penumbra SMART Coil System for endovascular coil embolization of saccular intracranial aneurysms., Methods: The SMART registry was a prospective, multi-center registry of site standard of care endovascular coiling procedures performed using at least 75% Penumbra SMART Coil, PC400, and/or POD coils. This subset analysis reports on the periprocedural safety outcomes of the saccular intracranial aneurysm cohort. Predictors of rupture/re-rupture or perforation (RRP), thromboembolic complications, and device- or procedure-related adverse events (AEs) were determined in univariate and multivariate analysis., Results: Between June 2016 and August 2018, 851 saccular aneurysm patients (31.0%, 264/851 ruptured) were enrolled across 66 North American centers. Clinically significant (ie, a serious adverse event) RRP occurred in 2.0% (17/851) of cases - 1.9% (5/264) for the ruptured cohort and 2.0% (12/587) for the un-ruptured cohort. Clinically significant thromboembolic events occurred in 3.1% (26/851) of cases - 5.3% (14/264) for the ruptured cohort and 2.0% (12/587) for the un-ruptured cohort. Multivariate predictors of periprocedural RRP were increased packing density and adjunctive treatment with a balloon. For periprocedural thromboembolic events, multivariate predictors were bifurcation location and ruptured status. For device- or procedure-related AEs, multivariate predictors were bifurcation location and adjunctive treatment with stent or balloon., Conclusion: The low rates of thromboembolic complications and RRP events demonstrate the adequate safety profile of the SMART Coil System to treat cerebral aneurysms in routine clinical practice., Trial Registration Number: NCT02729740., Competing Interests: Competing interests: RMS: research support – NREF, Joe Niekro Foundation, Brain Aneurysm Foundation, Bee Foundation, and National Institute of Health (R01NS111119-01A1) and (UL1TR002736, 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. Consulting – Penumbra, Abbott, Medtronic, InNeuroCo, and Cerenovus. Teaching – Penumbra, Abbott, Medtronic, InNeuroCo, and Cerenovus; MSP: other from Penumbra, during the conduct of the study; CMS: research support –Penumbra. Shareholder – Neurotechnology Investors; RD: personal fees from Penumbra, personal fees from Imperative Care, personal fees from Siemens, and personal fees from Cerenovus, outside the submitted work; DF: consultant – Balt, Marblehead, Medtronic, Stryker, Microvention, Stryker, Penumbra, and Cerenovus. Research support – Cerenovus, Medtronic, Siemens, Stryker, Microvention, and Penumbra; AJY: grants and personal fees from Penumbra, grants and personal fees from Cerenovus, grants from Medtronic, grants from Stryker, and personal fees from Genentech, outside the submitted work. Equity interest in Galaxy Therapeutics and Insera Therapeutics; AMS: consulting for Stryker, Penumbra, and Terumo. Research support Stryker, Penumbra, and Medtronic., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: The Prospective, Multicenter Registry Assessing the Embolization of Neurovascular Lesions Using the Penumbra SMART COIL® System (SMART) is the largest prospective, multicenter, postmarket registry established to gather real-world experience on Penumbra (Alameda, USA) SMART COIL System, PC400, and POD embolization coils. The goal of this study is to report the technical success and efficacy of SMART COIL System coils in treating saccular intracranial aneurysms., Methods: This subgroup analysis from the SMART registry included patients with saccular intracranial aneurysms treated using ≥75% SMART COIL System or PC400 coils. Baseline and procedural data, angiographic data, and clinical outcomes were collected. Predictors of catheter kickout, packing density, and postprocedural angiographic outcome were analyzed using multivariable regression models in saccular aneurysm cases., Results: Between June 2016 and August 2018, the SMART registry enrolled 995 patients at 68 sites, of which 851 of 995 (85.5%) were treated for saccular aneurysms (mean age, 59.9 years). Aneurysms had a mean size of 6.8 mm, were wide neck in 63.1%, and ruptured in 31.0% of patients. Mean aneurysm packing density was 32.3%. Postprocedural Raymond-Roy Occlusion Classification (RROC) I-II was achieved in 80.3% of patients; smaller aneurysms, non-wide-neck aneurysms, and high packing density were predictive of RROC I-II. Overall, mean fluoroscopic time was 43.4 minutes, rate of reaccess attempts because of catheter kickout was 6.2%, and mean procedure time was 83.2 minutes., Conclusions: SMART COIL System coils achieved good technical success and adequate occlusion in treating saccular intracranial aneurysms in a real-world setting., (Copyright © 2021. Published by Elsevier Inc.)

Introduction: Distal anterior cerebral artery aneurysms (DACAA) are a rare and difficult entity to manage. Endovascular treatment has evolved for safe and durable treatment of these lesions. The objective of this study is to report the safety, efficacy, and outcomes of endovascular treatment of DACAA., Methods: A retrospective review of DACAA endovascularly treated at 5 different institutions was performed. Data included demographics, rupture status, radiographic features, endovascular technique, complication rates, and long-term angiographic and clinical outcomes. A primary endpoint was a good clinical outcome (modified Rankin scale 0-2). Secondary endpoints included complications and radiographic occlusion at follow-up., Results: A total of 84 patients were reviewed. The mean age was 56, and 64 (71.4%) were female. Fifty-two (61.9%) aneurysms were ruptured. A good functional outcome was achieved in 59 patients (85.5%). Sixty (71.4%) aneurysms were treated with primary coiling, and the remaining 24 were treated with flow diversion. Adequate occlusion was achieved in 41 (95.3%) aneurysms treated with coiling, and 17 (89.5%) with flow diversion. There were total 11 (13%) complications. In the flow diversion category, there were 2, both related to femoral access. In the coiling category, there were 9: 5 thromboembolic, 3 ruptures, and 1 related to femoral access., Conclusion: Endovascular treatment, and in particular, flow diversion for DACAA, is safe, feasible, and associated with good long-term angiographic and clinical outcomes., (Published by Elsevier Inc.)

Objective: There is a reported elevated risk of cerebral aneurysms in patients with intracranial dural arteriovenous fistulas (dAVFs). However, the natural history, rate of spontaneous regression, and ideal treatment regimen are not well characterized. In this study, the authors aimed to describe the characteristics of patients with dAVFs and intracranial aneurysms and propose a classification system., Methods: The Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) database from 12 centers was retrospectively reviewed. Analysis was performed to compare dAVF patients with (dAVF+ cohort) and without (dAVF-only cohort) concomitant aneurysm. Aneurysms were categorized based on location as a dAVF flow-related aneurysm (FRA) or a dAVF non-flow-related aneurysm (NFRA), with further classification as extra- or intradural. Patients with traumatic pseudoaneurysms or aneurysms with associated arteriovenous malformations were excluded from the analysis. Patient demographics, dAVF anatomical information, aneurysm information, and follow-up data were collected., Results: Of the 1077 patients, 1043 were eligible for inclusion, comprising 978 (93.8%) and 65 (6.2%) in the dAVF-only and dAVF+ cohorts, respectively. There were 96 aneurysms in the dAVF+ cohort; 10 patients (1%) harbored 12 FRAs, and 55 patients (5.3%) harbored 84 NFRAs. Dural AVF+ patients had higher rates of smoking (59.3% vs 35.2%, p < 0.001) and illicit drug use (5.8% vs 1.5%, p = 0.02). Sixteen dAVF+ patients (24.6%) presented with aneurysm rupture, which represented 16.7% of the total aneurysms. One patient (1.5%) had aneurysm rupture during follow-up. Patients with dAVF+ were more likely to have a dAVF located in nonconventional locations, less likely to have arterial supply to the dAVF from external carotid artery branches, and more likely to have supply from pial branches. Rates of cortical venous drainage and Borden type distributions were comparable between cohorts. A minority (12.5%) of aneurysms were FRAs. The majority of the aneurysms underwent treatment via either endovascular (36.5%) or microsurgical (15.6%) technique. A small proportion of aneurysms managed conservatively either with or without dAVF treatment spontaneously regressed (6.2%)., Conclusions: Patients with dAVF have a similar risk of harboring a concomitant intracranial aneurysm unrelated to the dAVF (5.3%) compared with the general population (approximately 2%-5%) and a rare risk (0.9%) of harboring an FRA. Only 50% of FRAs are intradural. Dural AVF+ patients have differences in dAVF angioarchitecture. A subset of dAVF+ patients harbor FRAs that may regress after dAVF treatment.

Objective: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is a pressing public health issue. Although most cases do not result in severe illness requiring hospitalization, there is increasing evidence that SARS-CoV-2-induced inflammation can exacerbate pre-existing diseases. We sought to describe the characteristics of patients with aneurysmal subarachnoid hemorrhage who were actively or very recently infected with SARS-CoV-2., Methods: We reviewed subarachnoid hemorrhage cases of patients who also were positive for SARS-CoV-2 at 5 high-volume cerebrovascular centers in the United States from March 2020 to January 2021. Cases of aneurysmal subarachnoid hemorrhage were analyzed., Results: A total of 10 patients were identified, consisting of 5 women (50%) and 5 men (50%). Median age was 38.5 years. Four of the 10 patients (40%) were asymptomatic with respect to SARS-CoV-2-related symptoms, 3 patients (30%) had mild-to-moderate symptoms, and 3 patients (30%) had severe coronavirus disease 2019 (COVID-19), with pneumonia and sepsis. Of the 10 cases, 4 had dissecting pseudoaneurysms (40%), 3 in the posterior circulation and 1 in the anterior circulation. Among 6 saccular/blister aneurysms, 4 (67%) were ≤4 mm in largest diameter., Conclusions: Our experience with aneurysmal subarachnoid hemorrhage in patients positive for COVID-19 reveals a possibly distinct pattern compared with traditional aneurysmal subarachnoid hemorrhage, namely a high frequency of small aneurysms, dissecting pseudoaneurysms, and young patients., (Copyright © 2021 Elsevier Inc. All rights reserved.)

A number of studies have demonstrated that the radial artery is a safer access site than the femoral artery for endovascular procedures.1-4 In the prospective randomized studies comparing transradial and transfemoral approaches for cardiac procedures, there was a 60% reduction in access site complications as well as significant decreases in all-cause mortality with the transradial approach as compared to transfemoral, which has led to the adoption of a radial first strategy.5-7 Neurointerventional studies have demonstrated similar safety benefits as well as improved patient preference.8-14 In this video, a patient presented with an unruptured anterior communicating artery aneurysm and consented to a transradial artery diagnostic cerebral angiogram. This technical video demonstrates the key preprocedural preparation, room setup, patient positioning, steps for radial artery, and distal radial artery puncture and sheath placement. Distal transradial artery access is our preferred approach for diagnostic cerebral angiography because of an improved safety profile and procedural ergonomics. In cases in which a larger radial artery is advantageous such as for neurointerventions requiring larger systems, a standard transradial approach may be performed.9 In this video, a full 6-vessel cerebral angiogram is performed, followed by our arteriotomy closure technique using our standard equipment including a 10-cm 5 French Glidesheath Slender (Terumo, Japan), 100-cm hydrophilic coated 5 French Simmons 1 catheter (Merit OEM), 0.035 hydrophilic coated guidewire, and SafeGuard closure device (Merit, Salt Lake City, Utah)., (© Congress of Neurological Surgeons 2021.)

Background: The management of unruptured intracranial aneurysms (UIAs) has evolved significantly over the last few decades. Our objective was to evaluate the 100 most cited UIA articles by bibliometric analysis to identify nature, content and shifts over time., Methods: Elsevier's Scopus database was interrogated for the 100 most cited articles that focused on UIA. Older versus newer articles were compared, with categorical data analyzed using Pearson's Chi-square, and continuous data analyzed using Wilcoxon's rank-sum test., Results: The 100 most cited articles were published between 1975 and 2015, with the majority of these reporting patient clinical outcomes (n=69). There were 47/69 (68%) articles that described surgical intervention, with 38/47 (81%) and 18/47 (38%) including endovascular and open approaches, respectively . Publications peaked in 2004 (n=8), and the most common country of correspondence was the United States (n=59). Compared to older articles, newer articles had statistically higher citation rates (P<0.01), higher number of authors (P<0.01) with more multiple institution collaborations (P=0.01), greater disclosures of funding (P<0.01), more focus on endovascular treatments (P=0.04), in more journals with a clinical, non-surgical focus (P<0.01) published under open access policies (P<0.01)., Conclusions: In the 100 most cited articles about UIAs to date, there is a distinct shift towards more co-authored efforts utilizing multi-institutional efforts focused on endovascular approaches supported by funding. The emergence of endovascular techniques has refreshed the need for more contemporary rupture risk prediction models and natural history data to validate current attitudes towards clinical management after these minimally invasive procedures for UIAs., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Currently, there are no large-scale studies in the neurointerventional literature comparing safety between transradial (TRA) and transfemoral (TFA) approaches for flow diversion procedures. This study aims to assess complication rates in a large multicenter registry for TRA versus TFA flow diversion., Methods: We retrospectively analyzed flow diversion cases for cerebral aneurysms from 14 institutions from 2010 to 2019. Pooled analysis of proportions was calculated using weighted analysis with 95% CI to account for results from multiple centers. Access site complication rate and overall complication rate were compared between the two approaches., Results: A total of 2,285 patients who underwent flow diversion were analyzed, with 134 (5.86%) treated with TRA and 2151 (94.14%) via TFA. The two groups shared similar patient and aneurysm characteristics. Crossover from TRA to TFA was documented in 12 (8.63%) patients. There were no access site complications in the TRA group. There was a significantly higher access site complication rate in the TFA cohort as compared with TRA (2.48%, 95% CI 2.40% to 2.57%, vs 0%; p=0.039). One death resulted from a femoral access site complication. The overall complications rate was also higher in the TFA group (9.02%, 95% CI 8.15% to 9.89%) compared with the TRA group (3.73%, 95% CI 3.13% to 4.28%; p=0.035)., Conclusion: TRA may be a safer approach for flow diversion to treat cerebral aneurysms at a wide range of locations. Both access site complication rate and overall complication rate were lower for TRA flow diversion compared with TFA in this large series., Competing Interests: Competing interests: RMS research is supported by the NREF, Joe Niekro Foundation, Brain Aneurysm Foundation, Bee Foundation, and by National Institute of Health (R01NS111119-01A1) and (UL1TR002736, 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. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH. RMS has consulting and teaching agreements with Penumbra, Abbott, Medtronic, InNeuroCo and Cerenovus. DRY: Medtronic Neurovascular: Consultant, Cerenovus: Consultant, Rapid Medical and Neuralanalytics: consultant. ECP: Stryker Neurovascular: Consultant, Penumbra: Consultant, RIST Neurovascular: Stockholder, Medtronic Neurovascular: Consultant, Cerenovus: Consultant. MRL: Grants: National Institutes of Health (R01NS105692, R01NS088072, U24NS100654); American Heart Association (18CDA34110295); The Aneurysm and AVM Foundation. Unrestricted educational grants: Stryker Neurovascular, Medtronic, Philips Volcano. Equity interest: eLoupes Inc, Cerebrotech, Synchron. AS: Penumbra: consulting, research support, Stryker: consulting, Cerenovus: consulting. CMS: NTI stockholder, AANS honoraria. ASA: Consultant for Johnson and Johnson, Medtronic, Microvention, Penumbra, Scientia, Siemens, Stryker. Research support from Balt, Cerenovus, Medtronic, Microvention, Penumbra, Siemens, and Stryker. Shareholder in Bendit, Cerebrotech, Endostream, Magneto, Marblehead, Neurogami, Serenity, Synchron, Triad Medical, Vascular Simulations. JWO: Disclosures: consultant for Terumo, Medtronic, Microvention. Royalties: Caeli Vascular, inc., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The Pipeline Vantage Embolization Device with Shield Technology is a next generation flow diverter developed to improve aneurysm occlusion and implant endothelialization in addition to lowering thrombogenicity. We report here the in vivo biocompatibility and in vitro hemocompatibility performance of the Pipeline Vantage Embolization Device with Shield Technology (Vantage) compared with the Pipeline Flex Embolization Device (Flex)., Methods: Biocompatibility (via histology), aneurysm occlusion and vessel patency (via angiography), and endothelial coverage (via scanning electron microscopy (SEM)) for the Vantage and Flex devices were assessed in the rabbit elastase aneurysm model at 90 days (n=29) and 180 days (n=27). In vitro thrombogenicity for Flex and Vantage (n=16) was assessed using a human blood flow loop model at low heparin concentration (0.6 U/mL) with thrombin generation, platelet activation and thrombus visualization as outputs., Results: Raymond Roy Occlusion Classification grade 1 was higher for Vantage (61%) compared with Flex (46%), but was not statistically significant (p>0.05). All branch vessels were patent. Histological measures for both devices were similar (p>0.05). Endothelial coverage of the implant was significantly better for Vantage compared with Flex (p<0.05). In vitro measurements of thrombin generation (thrombin-antithrombin complex (µg/mL): Vantage 0.49±0.45; Flex 10.57±9.84) and platelet activation (β-thromboglobulin (IU/µl): Vantage 0.41±0.19; Flex 4.14±2.38) were both statistically lower (p < 0.05) for Vantage compared with Flex. High resolution microscopy showed less accumulation of thrombus on Vantage as compared with Flex., Conclusion: Vantage improved aneurysm occlusion and implant endothelialization and had significantly lower thrombogenicity as compared with Flex, while preserving the biocompatibility safety profile of Flex., Competing Interests: Competing interests: RMS and JT are employees of University of Miami. AP, RJ, GG, JMW, MFW, AC are employees of Medtronic. RMS research is supported by the NREF, Joe Niekro Foundation, Brain Aneurysm Foundation, Bee Foundation, and by the National Institute of Health (R01NS111119-01A1) and (UL1TR002736, 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. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH. RMS has consulting and teaching agreements with Penumbra, Abbott, Medtronic, InNeuroCo and Cerenovus., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: A dramatic improvement in obliteration rates of large, wide-necked aneurysms has been observed after the FDA approved the Pipeline Embolization Device (PED) in 2011., Objective: To assess the predictors of complications, morbidity, and unfavorable outcomes in a large cohort of patients with aneurysms treated with PED., Methods: A retrospective chart review of a prospectively maintained database for subjects treated with flow diversion from 2010 to 2019., Results: A total of 598 aneurysms were treated during a period extending from 2010 to 2019 (84.28% females, mean age 55.5 yr, average aneurysm size 8.49 mm). Morbidity occurred at a rate of 5.8% and mortality at a rate of 2.2%. Ischemic stroke occurred at a rate of 3%, delayed aneurysmal rupture (DAR) at 1.2%, and distal intraparenchymal hemorrhage (DIPH) at 1.5%. On multivariate analysis, the predictor of stroke was aneurysm size >15 mm. Predictors of DAR were previous subarachnoid hemorrhage (SAH), increasing aneurysm size, and posterior circulation aneurysm. Predictors of DIPH were using more than 1 PED and baseline P2Y12 value. Predictors of in-stent stenosis were the increasing year of treatment and balloon angioplasty, whereas increasing age and previous treatment were negatively associated with in-stent stenosis. Predictors of morbidity were posterior circulation aneurysms, increasing aneurysm size, and hypertension, and incidental aneurysm diagnosis was protective for morbidity., Conclusion: Flow diversion is a safe and effective treatment option for aneurysms. A better understanding of predictive factors of complications, morbidity, and functional outcomes is of high importance for a more accurate risk assessment., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Background: Following publication of the International Subarachnoid Aneurysm Trial (ISAT), treatment paradigms for cerebral aneurysms (CAs) shifted from open surgical clipping to endovascular embolization as primary therapy in a majority of cases. However, comprehensive analyses evaluating more recent CA diagnosis patterns, patient populations and outcomes as a function of treatment modality remain rare., Methods: The National Inpatient Sample from 2004 to 2014 was reviewed. Aneurysmal subarachnoid hemorrhages (aSAHs) and unruptured intracranial aneurysms (UIAs) with a treatment of surgical clipping or endovascular therapy (EVT) were identified. Time trend series plots were created. Linear and logistic regressions were utilized to quantify treatment changes., Results: 114 137 aSAHs and 122 916 UIAs were reviewed. aSAH (+732/year, p=0.014) and UIA (+2550/year, p<0.0001) discharges increased annually. The annual caseload of surgical clippings for aSAH decreased (-264/year, p=0.0002) while EVT increased (+366/year, p=0.0003). For UIAs, the annual caseload for surgical clipping remained stable but increased for EVT (+615/year, p<0.0001). The rate of incidentally diagnosed UIAs increased annually (+1987/year; p<0.0001). Inpatient mortality decreased for clipping (p<0.0001) and EVT in aSAH (p<0.0001) (2004 vs 2014-clipping 13% vs 11.7%, EVT 15.8% vs 12.7%). Mortality rates for clipped UIAs decreased over time (p<0.0001) and remained stable for EVT (2004 vs 2014-clipping 1.57% vs 0.40%, EVT 0.59% vs 0.52%)., Conclusion: Ruptured and unruptured CAs are increasingly being treated with EVT over clipping. Incidental unruptured aneurysm diagnoses are increasing dramatically. Mortality rates of ruptured aneurysms are improving regardless of treatment modality, whereas mortality in unruptured aneurysms is only improving for surgical clipping., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: Inflammation plays an integral role in the formation, growth, and progression to rupture of unruptured intracranial aneurysms (UIAs). Animal and human studies have suggested that, due to its antiinflammatory effect, aspirin (ASA) may decrease the risks of growth and rupture of UIAs. High-resolution vessel wall imaging (HR-VWI) has emerged as a noninvasive method to assess vessel wall inflammation and UIA instability. To the authors' knowledge, to date no studies have found a significant correlation between patient use of ASA and contrast enhancement of UIAs on HR-VWI., Methods: The University of Iowa HR-VWI Project database was analyzed. This database is a compilation of data on patients with UIAs who prospectively underwent HR-VWI on a 3T Siemens MRI scanner. The presence of aneurysmal wall enhancement was objectively defined using the aneurysm-to-pituitary stalk contrast ratio (CRstalk). This ratio was calculated by measuring the maximal signal intensity in the aneurysmal wall and the pituitary stalk on postcontrast T1-weighted images. Data on aneurysm size, morphology, and location and patient demographics and comorbidities were collected. Use of ASA was defined as daily intake of ≥ 81 mg during the previous 6 months or longer. Univariate and multivariate logistic regression analyses were performed to determine factors independently associated with increased contrast enhancement of UIAs on HR-VWI., Results: In total, 74 patients harboring 96 UIAs were included in the study. The mean patient age was 64.7 ± 12.4 years, and 60 patients (81%) were women. Multivariate analysis showed that age (OR 1.12, 95% CI 1.05-1.19), aneurysm size ≥ 7 mm (OR 21.3, 95% CI 4.88-92.8), and location in the anterior communicating, posterior communicating, and basilar arteries (OR 10.7, 95% CI 2.45-46.5) were significantly associated with increased wall enhancement on HR-VWI. On the other hand, use of ASA was significantly associated with decreased aneurysmal wall enhancement on HR-VWI (OR 0.22, 95% CI 0.06-0.83, p = 0.026)., Conclusions: The study results establish a correlation between use of ASA daily for ≥ 6 months and significant decreases in wall enhancement of UIAs on HR-VWI. The findings also demonstrate that detection of wall enhancement using HR-MRI may be a valuable noninvasive method for assessing aneurysmal wall inflammation and UIA instability.

Background: Flow-diverting stents had gained prominence among neurointerventionalists. Aneurysms originating from distal vessels, particularly dissecting or fusiform, pose more technical challenges. The aim of the following single center large series was to report the safety, efficacy, and functional outcome of flow diversion for aneurysms originating from small caliber vessel and compare to proximal vessels group., Methods: A retrospective chart review of a prospectively maintained database for subjects treated with flow diversion from 2010-2019., Results: A total of 598 aneurysms were treated during a period extending from 2010-2019 (87.8% large caliber group versus 12.20% small caliber group); 84.28% (N.=504) were females and the average age was 55.5 years. Ischemic stroke occurred at a rate of 2.99% with a non-significant difference between both groups. Delayed aneurysmal rupture and distal intraparenchymal bleed occurred at a rate of 3.70% with a non-significant difference between both groups. Complete aneurysms occlusion was seen at a rate of 75.3% with a non-significant difference between both groups. Morbidity rate occurred at a rate of 5.8% with non-significant difference between both groups. Multivariate logistic regression showed that small vessel was an independent predictor of aneurysm obliteration with a 2.6-fold-higher likelihood., Conclusions: Flow-diverting stents are being used to treat diverse types of aneurysms and in various locations, in distal small caliber vessels where other treatment options pose a considerable risk. Small caliber group had similar complication and occlusion rates compared to proximal vessel group.

Background: The aim of this paper is to describe our experience with the transradial approach (TRA) for intracranial aneurysms treatment using the Pipeline Embolization device (PED). We also performed a logistic regression comparing outcomes between TR and transfemoral approach (TFA)., Methods: The clinical and imaging characteristics as well as periprocedural outcomes of patients treated for aneurysms using a TRA with PED were analyzed retrospectively., Results: A total of 598 aneurysms were treated with pipeline during a period extending from 2010-2019 (N.=580 [97%] using TFA vs. N.=18 [3%] using TRA). About 84.28% (N.=504) were females, and the average age was 55.5 years. There was no significant difference between both approaches in procedural duration, complication rate, morbidity, and aneurysms obliteration. We did not encounter any access site complication in the TR group compared to 2% in the TF; however, this did not reach statistical significance. One case was converted to TFA due to the need for more support. Multivariate analysis did not show that the access site was an independent predictor of the complications, morbidity, and aneurysms obliteration., Conclusions: The results of this study illustrate that the transradial approach is a safe and effective means of treating intracranial aneurysms with PED. The TRA in selected patients offers better safety with high rates of procedural success.

Background: The transradial approach (TRA) to endovascular procedures decreases access site morbidity and mortality in comparison with the traditional transfemoral technique (TFA). Despite its improved safety profile, there is a concern that TRA is less favorable for neurointerventional procedures that require large coaxial systems to manage the small tortuous cerebral vessels., Objective: To report our experience with TRA for flow diverter placement for treatment of unruptured cerebral aneurysms., Methods: We performed a retrospective review of prospective institutional databases at two high-volume centers to identify 49 patients who underwent flow diversion for aneurysm treatment via primary TRA between November 2016 and November 2018. Patient demographics, procedural techniques, and clinical data were recorded., Results: Of the 49 patients, 39 underwent successful flow diversion placement by TRA. Ten patients were converted to TFA after attempted TRA. There were no procedural complications. Reasons for failure included tortuosity in eight patients and severe radial artery spasm in two., Conclusions: In the largest reported series to date of flow diverter deployment via TRA for aneurysm treatment, we demonstrate the technical feasibility and safety of the method. The most common reason for failure of TRA was an acute angle of left common carotid artery origin or left internal carotid artery tortuosity. Overall, our data suggest that increasing adoption of TRA is merited given its apparent equivalence to the current TFA technique and its documented reduction in access site complications., Competing Interests: Competing interests: BMS is a stockholder in RIST Neurovascular. RMS is a consultant for Medtronic Neurovascular, Cerenovus, and Abbott. DRY is a consultant for Medtronic Neurovascular, Cerenovus, and Rapid Medical and Neural Analytics. JWO is a consultant for Microvention. ECP is a consultant for Stryker Neurovascular, Penumbra, Medtronic Neurovascular, and Cerenovus, and is a stockholder in RIST Neurovascular., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Aneurysmal subarachnoid hemorrhage (SAH) is associated with high mortality (30%-40%) and morbidity with long-term physical, neurologic, and psychological impairments; most patients present with high initial Hunt and Hess grade. In view of the great need for efficacious therapies for high-grade SAH, recent animal studies have demonstrated improved outcomes with administration of mesenchymal stem cells (MSCs) as a potential neuroregenerative strategy. We present the first case of human intravenous administration of MSCs after aneurysmal SAH., Clinical Presentation: An 80-year-old man presented with sudden severe headache with nausea and vomiting. Computed tomography demonstrated SAH with hydrocephalus from a ruptured basilar tip aneurysm. Initial examination of the patient showed Hunt and Hess grade 5 and World Federation of Neurosurgical Societies grade 5. The patient was treated with external ventricular drain placement and coiling of aneurysm. The patient received an infusion of intravenous bone marrow-derived allogeneic MSCs on day 3 postbleed. The patient made a better recovery than anticipated with a modified Rankin Scale score of 3 at 6 months., Conclusions: Several studies using models of ischemic brain injury have found that administration of MSCs may improve functional neurologic recovery and decrease brain lesion volume. Although there have been limited human studies in patients with stroke, the role of stem cell therapy for aneurysmal SAH remains unclear. This is the first case of use of MSCs in a patient for treatment of aneurysmal SAH. In conjunction with the promising results in animal studies, this encouraging preliminary case report supports the need for additional clinical trials., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Cerebral aneurysm rupture is a devastating event resulting in subarachnoid hemorrhage and is associated with significant morbidity and death. Up to 50% of individuals do not survive aneurysm rupture, with the majority of survivors suffering some degree of neurological deficit. Therefore, prior to aneurysm rupture, a large number of diagnosed patients are treated either microsurgically via clipping or endovascularly to prevent aneurysm filling. With the advancement of endovascular surgical techniques and devices, endovascular treatment of cerebral aneurysms is becoming the first-line therapy at many hospitals. Despite this fact, a large number of endovascularly treated patients will have aneurysm recanalization and progression and will require retreatment. The lack of approved pharmacological interventions for cerebral aneurysms and the need for retreatment have led to a growing interest in understanding the molecular, cellular, and physiological determinants of cerebral aneurysm pathogenesis, maturation, and rupture. To this end, the use of animal cerebral aneurysm models has contributed significantly to our current understanding of cerebral aneurysm biology and to the development of and training in endovascular devices. This review summarizes the small and large animal models of cerebral aneurysm that are being used to explore the pathophysiology of cerebral aneurysms, as well as the development of novel endovascular devices for aneurysm treatment.

Background: Intracranial pseudoaneurysms (PSAs) are associated with high rupture and mortality rates and have traditionally been treated by parent vessel sacrifice. There has been recent interest in using flow-diverting devices for treatment of these complex lesions while preserving flow through the parent artery. The objective of this study is to examine the safety and efficacy of these devices in the treatment of intracranial PSA., Methods: We performed a multi-institutional retrospective study of intracranial PSAs treated with the Pipeline Embolization Device (PED) between 2014 and 2017 at 7 institutions. Complications and clinical and radiographic outcomes were reviewed., Results: A total of 19 patients underwent PED placement for intracranial PSA. Iatrogenic injury and trauma comprised most etiologies in our series. The mean pseudoaneurysm diameter was 8.8 mm, and 18 of 19 PSAs (95%) involved the internal carotid artery (ICA). Multiple PEDs were deployed in a telescoping fashion in 7 patients (37%). Of the 18 patients with follow up imaging, 14 (78%) achieved complete pseudoaneurysm obliteration and 2 achieved near-complete obliteration (11%). Two patients (11%) were found to have significant pseudoaneurysm progression on short-term follow-up and required ICA sacrifice. No patients experienced new neurologic deficits or deterioration secondary to PED placement. No patients experienced bleeding or rebleeding from PSA., Conclusions: In well-selected patients, the use of flow-diverting stents may be a feasible alternative to parent vessel sacrifice. Given the high morbidity and mortality associated with PSA, we recommend short- and long-term radiographic follow-up for patients treated with flow-diverting stents., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Endothelial cell (EC) dysfunction is known to contribute to cerebral aneurysm (CA) pathogenesis. Evidence shows that damage or injury to the EC layer is the first event in CA formation. The mechanisms behind EC dysfunction in CA disease are interrelated and include hemodynamic stress, hazardous nitric oxide synthase (NOS) activity, oxidative stress, estrogen imbalance, and endothelial cell-to-cell junction compromise. Abnormal variations in hemodynamic stress incite pathological EC transformation and inflammatory zone formation, ultimately leading to destruction of the vascular wall and aneurysm dilation. Hemodynamic stress activates key molecular pathways that result in the upregulation of chemotactic cytokines and adhesion molecules, leading to inflammatory cell recruitment and infiltration. Concurrently, oxidative stress damages EC-to-EC junction proteins, resulting in interendothelial gap formation. This further promotes leukocyte traffic into the vessel wall and the release of matrix metalloproteinases, which propagates vascular remodeling and breakdown. Abnormal hemodynamic stress and inflammation also trigger adverse changes in NOS activity, altering proper EC mediation of vascular tone and the local inflammatory environment. Additionally, the vasoprotective hormone estrogen modulates gene expression that often suppresses these harmful processes. Crosstalk between these sophisticated pathways contributes to CA initiation, progression, and rupture. This review aims to outline the complex mechanisms of EC dysfunction in CA pathogenesis., Competing Interests: The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper., (© AANS, except where prohibited by US copyright law.)

Background: Flow diversion has emerged as a highly effective treatment for intracranial aneurysms., Objective: To assess the yield of further angiographic follow-up in aneurysms that have achieved adequate occlusion after treatment with the Pipeline Embolization Device (PED; Medtronic Inc, Dublin, Ireland)., Methods: This is a single-institution, retrospective study. Inclusion criteria were as follows: (1) patients with 1 or more aneurysms treated with PED, (2) available short-term (<12 mo) follow-up digital subtraction angiography (DSA), (3) complete (100%) or near-complete (>95%) occlusion on short-term follow-up DSA, and (4) available further angiographic follow-up (DSA, Magnetic Resonance Angiography (MRA), or Computed Tomography Angiography (CTA))., Results: A total of 146 patients were identified. Aneurysm size was 8.4 ± 5.1 mm on average. Mean angiographic follow-up time was 29.7 ± 12.2 mo. On short-term follow-up DSA images, 132 (90.4%) had complete aneurysm occlusion and 14 (9.6%) had near-complete occlusion. Four patients (3%) had further DSA follow-up alone, 30 patients (21%) had further DSA and MRA/CTA follow-up, and 112 patients (76%) had further MRA/CTA follow-up alone. On further angiographic follow-up (DSA, MRA, and/or CTA), no patient had a decrease in the degree of aneurysm occlusion (recurrence) or required retreatment. Of the 14 patients with near-complete occlusion on initial DSA images, 7 patients (50%) progressed to complete aneurysm occlusion on further angiographic follow-up., Conclusion: This study did not find any diagnostic yield in repeating cerebral angiography in adequately occluded aneurysms with the PED. We do not recommend repeat angiographic follow-up once aneurysms have achieved complete occlusion with the PED unless clinically warranted.

Objective: The objective of this study is to determine the impact of intraventricular hemorrhage (IVH) on the cognitive prognosis of subarachnoid hemorrhage (SAH) due to ruptured cerebral aneurysm, independent of the presence of intraparenchymal hemorrhage, hydrocephalus or vasospasm., Patient and Methods: A Retrospective review of a prospectively collected database of patients with aneurysmal SAH from July 2009 to November 2016 was performed. Patients were included if they had a saccular aneurysm with a Hunt-Hess grade (HHG) 1-3. Those who underwent craniectomy/clipping and those with vasospasm were excluded. Patients with IVH were grouped into 5 groups depending on the blood distribution in the ventricles. Functional outcomes studied were modified Rankin score (mRS) 0-2, cognitive impairment and memory impairment, and the presence of amnesia to the event. A univariate followed by a multivariate analysis ware performed., Results: A total of 443 patients were identified and 124 patients met the criterion. There were no significant differences in the proportion of patients with mRS of 0-2 between patients with IVH and those without IVH but with EVD (external ventricular drain). There was a higher proportion of cognitive deficits in patients with IVH (71.95%), compared to those without (31.58%; p = 0.01). Patients with IVH had a higher rate of anterograde amnesia (100% vs. 4.3% p < 0.0001), lower rate of mRS 0-2 (78% vs 100% p < 0.001), and higher rate of cognitive impairment (71.9% vs. 13% p < 0.0001) compared with those who did not require an EVD. Grade 3 and grade 4 were shown to have lower rate of patients with mRS 0-2 and a higher rate of cognitive impairment. In multivariate analysis, independent predictors of cognitive and memory impairment were increasing HHG (OR = 155.33; P < 0.01), ACOM/A1/ACA/anterior choroidal aneurysms, (OR = 5.24; P = 0.04), increasing Fischer scale (OR = 6.93; P = 0.01), and increasing IVH grade (OR = 6.9; P = 0.01). Only worse HHG (OR = 2704.22; P = 0.01) and IVH grade 2-4 were associated (perfect predictor, OR cannot be extracted) with anterograde amnesia., Conclusion: IVH is an independent prognosticator of SAH cognitive outcomes. The effect of IVH drainage and other intraventricular therapies on SAH course is an attractive topic for further investigation., (Copyright © 2018 Elsevier B.V. All rights reserved.)

OBJECTIVE Endothelin-1, a potent vasoconstrictor, and its receptors may be involved in the pathogenesis of aneurysmal subarachnoid hemorrhage (aSAH), clinical vasospasm, delayed cerebral ischemia (DCI), and functional outcome following aSAH. In the present study, common endothelin single nucleotide polymorphisms (SNPs) and their relation to aSAH were evaluated. METHODS Blood samples from all patients enrolled in the Cerebral Aneurysm Renin Angiotensin System (CARAS) study were used for genetic evaluation. The CARAS study prospectively enrolled patients with aSAH at 2 academic institutions in the US from 2012 to 2015. Common endothelin SNPs were detected using 5' exonnuclease (TaqMan) genotyping assays. Analysis of associations between endothelin SNPs and aSAH and its clinical sequelae was performed. RESULTS Samples from 149 patients with aSAH and 50 controls were available for analysis. In multivariate logistic regression analysis, the TG (odds ratio [OR] 2.102, 95% confidence interval [CI] 1.048-4.218, p = 0.036) and TT genotypes (OR 7.884, 95% CI 1.003-61.995, p = 0.05) of the endothelin-1 T/G SNP (rs1800541) were significantly associated with aSAH. There was a dominant effect of the G allele (CG/GG genotypes; OR 4.617, 95% CI 1.311-16.262, p = 0.017) of the endothelin receptor A G/C SNP (rs5335) on clinical vasospasm. Endothelin SNPs were not associated with DCI or functional outcome. CONCLUSIONS Common endothelin SNPs were found to be associated with presentation with aSAH and clinical vasospasm. Further studies are required to elucidate the relevant pathophysiology and its potential implications in the treatment of patients with aSAH.

Objective: Cigarette smoke exposure (CSE) is a risk factor for cerebral aneurysm (CA) formation, but the molecular mechanisms are unclear. Although CSE is known to contribute to excess reactive oxygen species generation, the role of oxidative stress on vascular smooth muscle cell (VSMC) phenotypic modulation and pathogenesis of CAs is unknown. The goal of this study was to investigate whether CSE activates a NOX (NADPH oxidase)-dependent pathway leading to VSMC phenotypic modulation and CA formation and rupture., Approach and Results: In cultured cerebral VSMCs, CSE increased expression of NOX1 and reactive oxygen species which preceded upregulation of proinflammatory/matrix remodeling genes (MCP-1, MMPs [matrix metalloproteinase], TNF-α, IL-1β, NF-κB, KLF4 [Kruppel-like factor 4]) and downregulation of contractile genes (SM-α-actin [smooth muscle α actin], SM-22α [smooth muscle 22α], SM-MHC [smooth muscle myosin heavy chain]) and myocardin. Inhibition of reactive oxygen species production and knockdown of NOX1 with siRNA or antisense decreased CSE-induced upregulation of NOX1 and inflammatory genes and downregulation of VSMC contractile genes and myocardin. p47phox -/- NOX knockout mice, or pretreatment with the NOX inhibitor, apocynin, significantly decreased CA formation and rupture compared with controls. NOX1 protein and mRNA expression were similar in p47phox -/- mice and those pretreated with apocynin but were elevated in unruptured and ruptured CAs. CSE increased CA formation and rupture, which was diminished with apocynin pretreatment. Similarly, NOX1 protein and mRNA and reactive oxygen species were elevated by CSE, and in unruptured and ruptured CAs., Conclusions: CSE initiates oxidative stress-induced phenotypic modulation of VSMCs and CA formation and rupture. These molecular changes implicate oxidative stress in the pathogenesis of CAs and may provide a potential target for future therapeutic strategies., (© 2018 American Heart Association, Inc.)

Background: Aspirin is a promising medical therapy for the prevention of intracranial aneurysm (IA) rupture. Recently, we found that men have a better response to aspirin than women. The purpose of this study was to determine whether a sex differential exists in the level of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) in the lumen of human IAs., Methods and Results: Consecutive patients undergoing coiling or stent-assisted coiling for a saccular IA at our institution were enrolled. Two samples (A and B) were collected from IA lumens, and the plasma level of 15-PGDH was measured using an ELISA-based method. The study included 38 patients, with 20 women and 18 men. Women and men were comparable on baseline characteristics. The mean plasma concentration of 15-PGDH did not differ statistically between sample A (62.8±16.2 ng/mL) and sample B (61.8±17.9 ng/mL; 95% confidence interval -6.6 to 9.4). The mean plasma concentration of 15-PGDH in IA lumens of samples A and B was significantly higher in men (73.8±13.5 ng/mL) than women (49.6±7.8 ng/mL; P <0.0001)., Conclusions: Higher enzyme levels of 15-PGDH exist in the lumen of IAs of men compared with women. This observation could explain why aspirin confers better protection against IA rupture in men than in women. The susceptibility of an individual to aspirin may differ according to the level of 15-PGDH., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background: Flow diversion is typically reserved for large, giant, or morphologically complex aneurysms. Coiling remains a first-line treatment for small, morphologically simple aneurysms., Objective: To compare coiling and flow diversion in small, uncomplicated intracranial aneurysms (typically amenable to coiling)., Methods: Forty patients treated with the pipeline embolization device (PED) for small (<10 mm), morphologically simple aneurysms that would have also been amenable to coiling were identified. These patients were matched in a 1:1 fashion with 40 patients with comparable aneurysms treated with coiling. Matching was based on age, gender, aneurysm size, and aneurysm morphology., Results: The 2 groups were comparable with regard to baseline characteristics including age, gender, and aneurysm size. The complication rate did not differ between the 2 groups (2.5% with coiling vs 5% with PED; P = .6). Multivariate analysis did not identify any predictor of complications. Complete occlusion (100%) at follow-up was significantly higher in patients treated with PED (70%) than coiling (47.5%, P = .04). In multivariate analysis, treatment with PED predicted aneurysm obliteration ( P = .04). A significantly higher proportion of coiled patients (32.5%) required retreatment compared with flow diversion (5%, P = .003). In multivariate analysis, coiling predicted retreatment ( P = .006). All patients achieved a favorable outcome (modified Rankin Scale: 0-2) regardless of group., Conclusion: This matched analysis suggests that flow diversion provides higher occlusion rates, lower retreatment rates, and no additional morbidity compared with coiling in small, simple aneurysms amenable to both techniques. These results suggest a potential benefit for flow diversion over coiling even in small, uncomplicated aneurysms., (Copyright © 2017 by the Congress of Neurological Surgeons)

Background: Aneurysm rebleeding following presentation with aneurysmal subarachnoid hemorrhage (aSAH) is associated with high mortality and poor functional outcome. While a substantial genetic contribution to aneurysm formation and rupture is known, the genetic influence on the risk of rebleeding is poorly understood., Objective: To evaluate the role of common endothelin polymorphisms in aneurysm rebleeding., Patients and Methods: Blood sample from all patients enrolled in the CARAS (Cerebral Aneurysm Renin Angiotensin System) study were used for genetic evaluation. The CARAS study prospectively enrolled aSAH patients at two academic institutions in the United States from 2012 to 2015. Common endothelin SNPs were detected using 5'exonnuclease (Taqman) genotyping assays. Analysis of associations between endothelin single nucleotide polymorphisms (SNP) and aneurysm rebleeding was performed., Results: One hundred and forty-nine aSAH patients were included. Acute spontaneous aneurysm rebleeding occurred in 5 (3.4%) patients. Multivariable analysis identified the TT genotype for EDN1 G/T SNP (rs2070699; OR 97.4, 95% CI 3.825-2479.984, p=0.006) as an independent risk factor for aneurysm rebleeding. Aneurysm rebleeding was associated with an unfavorable functional outcome (mRS 3-6) at last follow up in all 5 patients., Conclusion: Aneurysm rebleeding following presentation with aSAH was independently associated with the TT genotype of the EDN1 G/T SNP. All patients with acute spontaneous aneurysm rebleeding suffered a poor functional outcome at last follow up., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: The coincidence of parasellar aneurysms (IAs) and anterior skull base (ASB) lesions, while rare, presents a management challenge. IAs embedded within, or adjacent to, ASB lesions are at risk in the perioperative period and may have unique presentations, natural histories, and outcomes. The objective of this study was to outline management options and nuances in patients with coexisting IAs and ASB lesions., Methods: We retrospectively evaluated all patients who presented for management of IAs and ASB lesions from January 2006 to January 2014. Medical charts and imaging were reviewed for patient, tumor and IA characteristics, pathology, operative findings, complications, and outcomes., Results: Of 13 patients included in the study, 11 had histologically proven or presumed pituitary macroadenomas. The majority of cases presented with visual and endocrine deficits, and the median maximal tumor diameter was 3.1 cm. There were 17 IAs, all located in the parasellar area. Endovascular treatment of the IA was performed before tumor resection in 2 cases. Transsphenoidal resection was performed before IA occlusion in 1 case, and intraoperative vascular injury occurred in 2 cases. The median follow-up was 36 months., Conclusions: Management decisions for patients with coincident IA and ASB lesions require careful, individualized treatment plans. Coil embolization is well tolerated and does not delay surgery, except in cases requiring stent placement. Inadvertent intraoperative rupture of an adjacent IA during anterior skull base surgery may be treated with emergent coil embolization, flow diversion, or carotid sacrifice, but adequate preoperative planning can reduce this risk., (Copyright © 2016 Elsevier Inc. All rights reserved.)