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Background: Bioresorbable flow diverters (BRFDs) have the potential to solve several problems associated with conventional permanent flow diverters. We have constructed bare and poly-L-lactic acid (PLLA)-coated magnesium BRFDs (MgBRFDs) using a high-strength corrosion-resistant magnesium alloy. This study aimed to compare bioresorption and biocompatibility between the two types in a rabbit vascular model to determine which is more clinically feasible in humans., Methods: Bare and PLLA-coated MgBRFDs were fabricated by braiding 48 thin magnesium alloy wires. Mechanical testing was conducted. Bare (n=13) and PLLA-coated (n=13) MgBRFDs were implanted into rabbit aortas and harvested 14, 30, and 90 days after implantation. The physical structure of the resolution process was examined using optical coherence tomography (OCT), micro-computed tomography, and scanning electron microscopy (SEM). The biological response of the vascular tissue was examined using SEM and histopathological analysis., Results: The porosity and pore density of the bare MgBRFD were 64% and 16 pores/mm 2 , respectively; corresponding values for the PLLA-coated MgBRFD were 63% and 12 pores/mm 2 , respectively. The OCT attenuation score was significantly higher for the PLLA-coated MgBRFD at all time points (14 days, P=0.01; 30 days, P=0.02; 90 days, P=0.004). OCT, micro-computed tomography, and SEM demonstrated better stent structure preservation with the PLLA-coated MgBRFD. Neointimal thickness did not significantly change over time in either type of MgBRFD (bare, P=0.93; PLLA-coated, P=0.34); however, the number of inflammatory and proliferative cells peaked at 14 days and then decreased., Conclusions: Both bare and PLLA-coated MgBRFDs had excellent biocompatibility. The PLLA-coated MgBRFD has greater clinical feasibility because of its delayed bioresorption., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The Flow Re-direction Endoluminal Device (FRED) X is a next generation flow-diverting stent for treating intracranial aneurysms. Its surface modification (X technology) aims to minimize device thrombogenicity. Early post-market multicenter data from the US are lacking., Methods: We conducted a retrospective multicenter analysis of consecutive FRED X procedures performed to treat unruptured intracranial aneurysms at four US centers (March 2022 to January 2024). Cases with ruptured aneurysms or extracranial aneurysm location were excluded (n=10). We assessed patient and aneurysm characteristics, antithrombotic management, safety events, and both clinical and angiographic (effectiveness) outcomes., Results: In this cohort, 101 patients underwent FRED X stenting for 117 aneurysms. Most aneurysms were saccular in shape (95.7%) and located at the C6-C7 segments of the internal carotid artery (72.6%). Thromboembolic events occurred in 5.9% of the cases, leading to one instance of permanent procedure related morbidity (1.0%). No procedure related mortality (0%) was observed. Device related issues were recorded in 2.0% of cases. At the 6 month follow-up, complete aneurysm occlusion was achieved in 58% of aneurysms. At the last available follow-up (6-12 months), 74.8% of aneurysms were adequately occluded., Conclusions: FRED X stenting for unruptured intracranial aneurysms demonstrated low rates of neurological morbidity and periprocedural complications. Early aneurysm occlusion rates were appropriate, but further mid-term and long term follow-up is required. These findings support the early safety and effectiveness of the FRED X device for intracranial aneurysm treatment., Competing Interests: Competing interests: SH received salary support from MicroVention via an investigator initiated research grant obtained by the senior author OG. NCF received speaking Honoria from NICO. DA is a consultant for Microvention, Stryker, Q’Apel, Synchron, Penumbra, and Cerenovus, and investor of Von Vascular. ARP is a consultant for Microvention, IRRAS, Penumbra, and NICO. JKB is a consultant for Stryker, Medtronic, Cerenovus, Microvention, Q’Apel Medical, BALT, and Siemens. CMS has research grants from Medtronic, Stryker, Penumbra, Cerenovus, Route 92, MIVI, Balt, Microvention, NICO, and NIH/NINDS, consulting agreements with Medtronic, Stryker, Viz.ai, Balt, Microvention, and Werfen, and ownership of NTI and Reist. OG is a consultant for Microvention, Rapid Medical, and Route 92, and received funding from MicroVention. OG received an investigator initiated study research grant from MicroVention., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

The anatomy of vertebrobasilar perforators has been widely studied in human cadavers, with most reports found in the neurosurgical literature. These arterial perforators are extremely hard to visualize consistently with traditional two-dimensional digital subtraction angiography, but are reliably visible with cross sectional cone beam CT techniques. A clear understanding of this specific neurovascular anatomy and pathology is essential for informed treatment decisions. This review analyzes the anatomy of vertebrobasilar perforators with a focus on practical implications for aneurysm treatment, particularly flow diversion., Competing Interests: Competing interests: ER: Consultant for Balt, Cerenovus, Imperative Care, Medtronic, Microvention, Phenox, Qapel, Scientia, Vasorum. Site PI for PROST, Inspire, NECC. Off label use of Pipeline Embolization Device. RDL: Consultant for Imperative Care, Stryker Neurovascular; Scientific Advisory Board Cerenovus. Equity: Synchron, Endostream, Borvo Medical, Von Medical, Vastrax, Precision Health Care. Research Support: Siemens Healthineers, SNIS Foundation, Kaneka Medical., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The posterior communicating artery (PComA) is among the most common intracranial aneurysm locations, but flow diverter (FD) treatment with the widely used pipeline embolization device (PED) remains an off-label treatment that is not well understood. PComA aneurysm flow diversion is complicated by the presence of fetal posterior circulation (FPC), which has an estimated prevalence of 4-29% and is more common in people of black (11.5%) than white (4.9%) race. We present the FD-PComA in-silico trial (IST) into FD treatment performance in PComA aneurysms. ISTs use computational modeling and simulation in cohorts of virtual patients to evaluate medical device performance., Methods: We modeled FD treatment in 118 virtual patients with 59 distinct PComA aneurysm anatomies, using computational fluid dynamics to assess post-treatment outcome. Boundary conditions were prescribed to model the effects of non-fetal and FPC, allowing for comparison between these subgroups., Results: FD-PComA predicted reduced treatment success in FPC patients, with an average aneurysm space and time-averaged velocity reduction of 67.8% for non-fetal patients and 46.5% for fetal patients (P < 0.001). Space and time-averaged wall shear stress on the device surface was 29.2 Pa averaged across fetal patients and 23.5 Pa across non-fetal (P < 0.05) patients, suggesting FD endothelialization may be hindered in FPC patients. Morphological variables, such as the size and shape of the aneurysm and PComA size, did not affect the treatment outcome., Conclusions: FD-PComA had significantly lower treatment success rates in PComA aneurysm patients with FPC. We suggest that FPC patients should be treated with an alternative to single PED flow diversion., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The patency of intracranial stents may not be reliably assessed with either CT angiography or MR angiography due to imaging artifacts. We investigated the potential of ultra-high resolution CT angiography using a photon counting detector (PCD) CT to address this limitation by optimizing scanning and reconstruction parameters., Methods: A phantom with different flow diverters was used to optimize PCD-CT reconstruction parameters, followed by imaging of 14 patients with intracranial stents using PCD-CT. Images were reconstructed using three kernels based on the phantom results (Hv56, Hv64, and Hv72; Hv=head vascular) and one kernel to virtually match the resolution of standard CT angiography (Hv40). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) measurements were calculated. Subjective image quality and diagnostic confidence (DC) were assessed using a five point visual grading scale (5=best, 1=worst) and a three point grading scale (1=best, 3=worst), respectively, by two independent neuroradiologists., Results: Phantom images demonstrated the highest image quality across dose levels for 0.2 mm reconstructions with Hv56 (4.5), Hv64 (5), and Hv72 (5). In patient images, SNR and CNR decreased significantly with increasing kernel sharpness compared with control parameters. All reconstructions showed significantly higher image quality and DC compared with the control reconstruction with Hv40 kernel (P<0.001), with both image quality and DC being highest with Hv64 (0.2 mm) and Hv72 (0.2 mm) reconstructions., Conclusion: Ultra-high resolution PDC-CT angiography provides excellent visualization of intracranial stents, with optimal reconstructions using the Hv64 and the Hv72 kernels at 0.2 mm., Registration: BASEC 2021-00343., Competing Interests: Competing interests: TF is an employee of Siemens Healthcare. HA has received institutional grants from Bayer, Canon, Guerbet, and Siemens. HA received speaker honoraria from Siemens., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Non-ischemic cerebral enhancing (NICE) lesions have been reported as a rare complication of various neuroendovascular procedures, but information on their incidence after flow diversion is scant. It is unclear if specific devices or novel coating technologies may impact their occurrence., Methods: We conducted a multicenter study on the incidence of NICE lesions after flow diverter (FD) implantation for cerebral aneurysm treatment., Results: Eight centers identified 15 patients and provided detailed data. The clinical presentation ranged from asymptomatic to hemiplegia and cognitive impairment. The mean time to diagnosis after treatment was 65.1±101.5 days. Five centers disclosed information on all of their 1201 FD procedures during the inclusion period (2015-2022), during which 12 patients were diagnosed with NICE lesions in these institutions-that is, an incidence of 1%. FD coatings did not increase the incidence (6/591 patients (1%) treated with surface-modified FD vs 6/610 patients (1%) treated with bare FD; P=1.00). Significantly increased rates of 3.7% (6 cases in 161 procedures; P<0.01) and 3.3% (5 cases in 153 procedures; P<0.01) were found with stents of two specific product lines. The use of one product line was associated with a significantly lower incidence (0 cases in 499 procedures (0%); P<0.01)., Conclusions: Novel stent coatings are not associated with an increased incidence of NICE lesions. The incidence rate of 1% suggests that these lesions may occur more often after flow diversion than after other endovascular treatments. We found a concerning accumulation of NICE lesion cases when FDs from two product families were used., Competing Interests: Competing interests: MG: Consultancy agreements with MicroVention, Balt, phenox. Scientific advisory board of Simq. Part of the clinical event committee in a study on a flow diverter sponsored by MicroVention., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Intracavernous carotid aneurysms (ICCAs) are rare, frequently asymptomatic, with a low rupture risk, which, however, can lead to life-threatening epistaxis. The aim of this study was to assess the effect of the treatment of asymptomatic ICCAs with flow diverters (FD) on sphenoid bone erosion or dehiscence in a selected cohort of patients., Methods: We retrospectively reviewed all asymptomatic ICCAs with sphenoid bone erosion or dehiscence detected on cone beam CT (CBCT) and treated with FD between December 2018 and December 2022. Patients were followed-up with CBCT and bone reconstruction was blindly evaluated by two interventional neuroradiologists and classified as unchanged, partial, or complete., Results: A total of 10 patients (women: 90%, mean age 58 years) treated with an FD for an asymptomatic ICCA with associated sphenoid bone erosion or dehiscence were included in this cohort. Sphenoid bone erosion was present in seven patients and dehiscence was observed in the remaining three. After treatment with FD, complete reconstruction of the sphenoid sinus wall occurred in seven cases, and partial reconstruction in two cases. Sphenoid bone erosion remained unchanged after treatment in only one patient., Conclusions: The decision to treat asymptomatic and unruptured ICCAs remains challenging due to their benign natural history and low hemorrhagic risk. The presence of sphenoid sinus erosion or dehiscence should not be overlooked since it could be considered as an indication for prophylactic treatment of life-threatening epistaxis. The mechanisms of bone erosion by the aneurysm and of reconstruction after treatment are still to be fully elucidated., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: A new generation of modified surface flow diverters (FDs) and monotherapy using new antiplatelets may reduce both ischemic and hemorrhagic complications during the treatment of intracranial aneurysms. Previous preliminary safety analysis of distal unruptured intracranial aneurysms treated with the FD p48 MW HPC (phenox-Wallaby, Bochum, Germany) under antiplatelet monotherapy with prasugrel showed promising results. However, the long term outcomes of distal intracranial aneurysms treated with FDs under antiplatelet monotherapy are not known., Methods: This was a single center, prospective, pivotal, open single arm study. The primary (safety) endpoint was absence of any new neurological deficits after treatment until the 24 month follow-up. The primary (efficacy) endpoint was the incidence of complete aneurysm occlusion 24 months after treatment. The secondary (efficacy) endpoints were any incidence of aneurysm dome reduction 24 months after treatment., Results: 21 patients harboring 27 distal aneurysms of the anterior circulation were included. No patient had neurologic deficits in the time from treatment to the 24 month follow-up. Complete aneurysm occlusion occurred in 20 (74%) of 27 aneurysms at the 24 month follow-up. Four aneurysms (14.8%) had dome reduction, and three aneurysms (11.1%) remained unchanged., Conclusions: In this pilot trial, treatment of distal unruptured intracranial aneurysms with an FD under monotherapy with prasugrel, followed by monotherapy with aspirin, appeared to be safe and effective. Randomized studies with long term follow-up are needed to confirm these results., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The Pipeline Vantage Embolization Device (PEDV) is the fourth-generation pipeline flow diverter for intracranial aneurysm treatment. There are no outcome studies for the second PEDV version. We aimed to evaluate safety and efficacy outcomes. Primary and secondary objectives were to determine outcomes for unruptured and ruptured cohorts, respectively., Methods: In this multicenter retrospective and prospective study, we analyzed outcome data from eight centers using core laboratory assessments. We determined 30-day and ≥3-month mortality and morbidity rates, and 6- and 18-month radiographic aneurysm occlusion rates for procedures performed during the period July 2021-March 2023., Results: We included 121 consecutive patients with 131 aneurysms. The adequate occlusion rate for the unruptured cohort at short-term and medium-term follow up, and also for the ruptured cohort at short-term follow up, was >90%. Two aneurysms (1.5%) underwent retreatment. When mortality attributed to a palliative case in the unruptured cohort, or subarachnoid hemorrhage in the ruptured cohort, was excluded then the overall major adverse event rate in respective cohorts was 7.5% and 23.5%, with 0% mortality rates for each. When all event causes were included on an intention-to-treat basis, the major adverse event rates in respective cohorts were 8.3% and 40.9%, with 0.9% and 22.7% mortality rates., Conclusions: For unruptured aneurysm treatment, the second PEDV version appears to have a superior efficacy and similar safety profile to previous-generation PEDs. These are acceptable outcomes in this pragmatic and non-industry-sponsored study. Analysis of ruptured aneurysm outcomes is limited by cohort size. Further prospective studies, particularly for ruptured aneurysms, are needed., Competing Interests: Competing interests: Microvention core laboratory for neurointerventional study: payment to TCB. Siemens Healthineers Speakers Bureau Educational lecture on brain tumours, not related to aneurysms: payment to TCB. Medtronic Speakers Bureau Educational lecture on an independent non-industry-sponsored study published in AJNR 2019 on Pipeline Flow Diverter device: payment to TCB. Bayer Speakers Bureau Educational lecture on Explainability in AI, not related to aneurysms: payment to TCB. Consulting and proctoring agreement with Medtronic, Stryker, Balt, and Cerenovus: payment to TP. Microvention, Balt, and Medtronic support to attend meetings: payment to TM., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Treatment of intracranial aneurysms is currently limited to invasive surgical and endovascular modalities, and some aneurysms are not treatable with these methods. Identification and targeting of specific molecular pathways involved in the pathogenesis of aneurysms may improve outcomes. Low frequency somatic variants found in cancer related genes have been linked to intracranial aneurysm development. In particular, mutations in the PDGFRB gene lead to constitutively activated ERK and nuclear factor κB signaling pathways, which can be targeted with tyrosine kinase inhibitors. In this review, we describe how low frequency somatic variants in oncogenic and other genes affect the pathogenesis of aneurysm development, with a focus on gene therapy applications, such as endovascular in situ delivery of chemotherapeutics., Competing Interests: Competing interests: MRL: unrestricted educational grants from Medtronic and Stryker; consulting agreement with Medtronic, Aeaean Advisers, Metis Innovative, and Genomadix; equity interest in Proprio, Stroke Diagnostics, Apertur, Stereotaxis, Fluid Biomed, and Hyperion Surgical; editorial board of Journal of NeuroInterventional Surgery and data safety monitoring board of Arsenal Medical. BR: founder, shareholder, and board member of Healionics; founder, shareholder, and board member of Kuleana Technology., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The pipeline embolization device (PED) has been increasingly used to treat brain aneurysms; however, concerns have been raised about braid stability with newer drawn filled tubing technology devices., Objective: To evaluate braid stability of PED early generations using data from the PREMIER trial., Methods: All consecutive intracranial aneurysms treated with PED (Classic and Flex) within the PREMIER trial were reviewed for braid stability (fish mouthing, foreshortening, braid bump, braid collapsing). Immediate postprocedure cone-beam CT and angiography were compared with 1- and 2- years' follow-up. Analyses included safety, measured with the modified Rankin Scale (mRS) score, including +1 mRS point and a good clinical outcome (mRS score 0-2), vessel stenosis ≥50%, effectiveness measured with Raymond-Roy Scale, and re-treatment rates., Results: 133/141 aneurysms had a complete dataset. 8/133 (6%) aneurysms showed braid deformations. Inter-reader agreement was excellent (κ=0.83). Braid deformations were statistically significantly associated with in-stent vessel stenosis >50% (P=0.029), without impact on effectiveness or safety. Fish mouthing was found in 1/133 (0.75%) at 1 year, causing >50% vessel stenosis. Foreshortening occurred in 6/133 (4.5%), and braid bump in 1/133 (0.75%) associated with severe in-stent stenosis. Four other cases (3.0%) of asymptomatic in-stent stenosis due to neointimal hyperplasia were seen without braid changes. No new braid stability deformations were found at the 2-year follow-up., Conclusion: Our study demonstrates excellent braid stability among patients treated with the PED Classic and Flex in the PREMIER trial. Within the uncommon braid changes observed, none affected the PED safety or efficacy., Trial Registration Number: NCT02186561., Competing Interests: Competing interests: DKL is a consultant for Asahi, Medtronic, and Stryker; has received honoraria from Siemens, Medtronic, Stryker, and Phenox. DFK received research support from Cerenovus, Sensome, Neurogami Medical, Insera Therapeutics, Medtronic, Microvention, Balt, Monarch Biosciences, Brainomix, MiVi, Stryker, and NIH; royalties from Medtronic; is on the DSMB of NoNO Inc and Vesalio; is a stockholder Nested Knowledge, Superior Medical Experts, Marblehead Medical, and Conway Medical. JF: research support: German Ministry of Science & Education (BMBF) and of Economy and Innovation (BMWi), German Research Foundation (DFG), European Union (EU), Hamburgische Investitions, and Förderbank (IFB), Medtronic, Microvention, Route92, Stryker; consultant for: Acandis, Cerenovus, Medtronic, Microvention, Penumbra, Phenox, Roche, Stryker, TG Med, Tonbridge. Stockholder: Tegus Medical, Vastrax, Eppdata. RAH is a consultant for Medtronic, Stryker, Cerenovus, Microvention, Balt, Phenox, Rapid Medical, and Q’Apel; he is on the advisory board for MiVI, eLum, Three Rivers, Shape Medical, and Corindus; he has received unrestricted research grants from NIH, Interline Endowment, Microvention, Stryker, CNX; he is an investor/stockholder for InNeuroCo, Cerebrotech, eLum, Endostream, Three Rivers Medical Inc, Scientia, RisT, BlinkTBI, and Corindus., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Intracranial dissecting aneurysms present clinical challenges, demanding immediate intervention due to their high bleeding risk. While traditional treatments have limitations, the potential of flow diverters shows promise but remains a subject of ongoing debate for optimal management. The aim of this study was assess the safety and efficacy of flow diverters in the treatment of intracranial dissecting aneurysms., Methods: A systematic review and meta-analysis was performed following established guidelines. The search encompassed PubMed, Scopus, Web of Science, and Embase databases up to July 20, 2023. Eligible studies reporting outcomes of interest were included, and relevant data were extracted and analyzed using R software., Results: The analysis, based on data pooled from 20 included studies involving 329 patients, revealed a favorable functional outcome rate of 89.7% at the last follow-up. The mortality rate during the follow-up period was 2.4%, decreasing to 0.9% when excluding the outlier study. In the final angiographic follow-up, a complete occlusion rate of 71.7% and an adequate occlusion rate of 88.3% were observed. Notably, studies with longer angiographic follow-up times exhibited lower rates of complete (P=0.02) and adequate (P<0.01) occlusion. A minimal aneurysm recurrence/rebleeding rate of 0.1% was noted, while in-stent stenosis/thrombosis occurred at a rate of 1.14%. Additionally, ischemic events/infarctions were seen in 3.3% of cases. The need for retreatment was minimal, with a rate of 0.9%, and the technical success rate was impressively high at 99.1%., Conclusion: This study highlights the safety and efficacy of flow diverters in treating intracranial dissecting aneurysms. Further research, encompassing larger multicenter studies with extended follow-up periods, is crucial for comprehending occlusion dynamics, refining treatment strategies, improving long-term outcomes, and addressing methodological limitations., Competing Interests: Competing interests: DFK holds equity in Nested Knowledge, Superior Medical Editors, Conway Medical, Marblehead Medical, and Piraeus Medical. He receives grant support from MicroVention, Medtronic, Balt, and Insera Therapeutics. Additionally, he has served on the Data Safety Monitoring Board for Vesalio and has received royalties from Medtronic., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Intrasaccular flow diversion is a new endovascular option for managing unruptured intracranial aneurysms.1-6 However, catheter ejection can occur during placement of an intrasaccular flow diverter, especially in tortuous vasculature that creates unfavorable angles between the aneurysm neck and the parent vessel.5 The Bendit steerable microcatheter (Bendit Technologies, Petah Tikva, Israel) can dynamically change its tip angle and may mitigate these placement concerns.7-9 Here, we report the placement of an intrasaccular flow diverter for the treatment of an unruptured internal carotid artery sidewall aneurysm at an unfavorable neck angle using the Bendit microcatheter (video 1). The Bendit was navigated around the 180° turn of the carotid siphon and held a stable position during device delivery. The device was sequentially deployed as the Bendit was progressively straightened and was successfully placed within the aneurysm. No neurological complications were experienced and the patient was asymptomatic on follow-up 3 months later. neurintsurg;16/10/1066/V1F1V1Video 1Placement of an intrasaccular flow diverter in an intracranial sidewall aneurysm using the Bendit articulating microcatheter., Competing Interests: Competing interests: JTF: Leadership or fiduciary role in other board, society, committee or advocacy group, paid or unpaid: Society of NeuroInterventional Surgery Board of Directors; stock of stock options: ownership of Bendit Technologies stock., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Although flow diverters (FDs) have benefited from several technical improvements, recently concerns have arisen regarding the braid stability after implantation. Thus, we investigated frequency, predictive factors, and clinical impact of the phenomenon of FD braid deformation (FDBD)., Methods: Consecutive intracranial aneurysms (IAs) treated with various FDs, between January 2018 and July 2023, were reviewed to identify FDBD (defined as the deformation of a FD without any external force applied to it). Patient, aneurysm, procedural, and FD characteristics were retrieved and analyzed using univariate and multivariable analyses. Morbidity is defined as a score of +1 in the modified Rankin Scale at 3 months., Results: In total, 245 FD procedures (271 FDs implanted; 25 multiple IAs treated with 1 FD) in 228 patients; FDBD was observed in 36/245 cases (14.7%), mainly at follow-up angiography (32/36, 88.9%); fish-mouthing was the most frequent FDBD. Morbidity was related to fish-mouthing and braid collapse and was significantly higher in the FDBD group after retreatment (p=0.04). Drawn filled tubing with platinum (DFT) (adjusted odds ratio (aOR)=7.0, 95% CI 3.0 to 17.5; p<0.001) and FD diameter (aOR=2.2, 95% CI 1.3 to 4.1; p<0.01) were identified as independent predictors of FDBD. The metal alloy composing the FD (p=0.13) and coated surfaces were not significantly associated with FDBD (p=0.54 in multivariable analysis)., Conclusions: FDBD is a frequent phenomenon observed in about 15% of cases, and it was responsible for higher morbidity. Only FD characteristics (DFT and FD diameter) were independent determinants of FDBD. Future research should focus on the impact of novel braid configurations and materials on braid stability., Competing Interests: Competing interests: JCo received research grants from Medtronic, Phenox, and Microvention; and received honoraria for lectures from Balt. DFK received research support from Cerenovus, Sensome, Neurogami Medical, Insera Therapeutics, Medtronic, Microvention, Balt, Monarch Biosciences, Brainomix, MiVi, Stryker, and National Institutes of Health (NIH); royalties from Medtronic; is on the Data Safety Monitoring Board (DSMB) of NoNO Inc. and Vesalio; is a stockholder in Nested Knowledge, Superior Medical Experts, Marblehead Medical, and Conway Medical. JCa received honoraria from Balt, Cerenovus, and Medtronic for lectures. LS is a consultant for Microvention, Balt, Phenox, Stryker, and Medtronic; DSMB or Advisory Board for CHOICE Study, INSPIRE Study, CLEVER study, and COATING study; grant or contract from Philips with institution., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Here we present a fusiform, partially thrombosed, previously ruptured aneurysm in the posterior cerebral artery that was treated with parent vessel sacrifice after a micro-WADA and micro-balloon test occlusion (video 1). These aneurysms pose treatment challenges due to their deep location, morphology, and potentially eloquent distal supply.1 2 Primary coiling, stent assisted coiling, or microsurgical clipping are often not viable options, whereas flow diversion, parent vessel sacrifice,3 or trapping with bypass are usually employed. Pharmacological provocative testing via a micro-WADA4 5 with or without a micro-balloon test occlusion is critical to establish whether the territory at risk has functional eloquence, although specific reports for using these techniques are limited. We describe the patient presentation, initial treatment attempt and failure, and our protocol for performing a micro-WADA/balloon test occlusion test.neurintsurg;jnis-2024-022058v1/V1F1V1Video 1 Micro wada for PCA aneurysm., Competing Interests: Competing interests: IJA: consultant for Balt, Rapid Medical, Imperative Care, IschemaView, Von Medical, and Remedy Robotics; equity in Hyperion, Von Medical, and Remedy Robotics; and grant funding from CNS Foundation. RMS: research supported by NREF, Joe Niekro Foundation, Brain Aneurysm Foundation, Bee Foundation, and National Institutes 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; unrestricted research grant, consulting, and teaching agreement with Medtronic; consulting and teaching agreement with Penumbra, Abbott, InNeuroCo, and Cerenovus., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Intracranial hemorrhage is the major safety concern of standard-dose ticagrelor (90 mg twice daily) based dual antiplatelet therapy (DAPT). The bleeding avoidance strategy through dose de-escalation has been investigated in interventional cardiology. However, the preserved antithrombotic efficacy and better safety of half-dose (45 mg twice daily) ticagrelor remains unverified in patients undergoing stent-assist coiling (SAC) or flow diversion (FD) treating unruptured intracranial aneurysms (UIA)., Methods: A single-center, prospective, cohort study was conducted to compare DAPT with aspirin 100 mg daily plus half-dose ticagrelor vs standard-dose clopidogrel (75 mg daily) in UIA patients. The adenosine diphosphate inhibition (ADPi) rate was utilized to quantify the antagonization of adenosine diphosphate (ADP)-induced platelet aggregation. The patients were followed-up at 6 month after discharge. The primary efficacy outcome was the major adverse cardiovascular and cerebrovascular events (MACCE), and the primary safety outcome was major bleeding. The secondary outcome was minor hemorrhage., Results: Our study included 322 UIA patients, of which 254 patients were eventually enrolled after propensity score matching. The ADPi of half-dose ticagrelor (51.56%±31.46%) was comparable (P=0.089) to that of clopidogrel (57.44%±22.76%). The outcomes were also comparable. Five (3.94%) patients in the ticagrelor group and eight (6.30%) patients in the clopidogrel group reported MACCE (P=0.393). One patient in the ticagrelor group was diagnosed with asymptomatic intracranial hemorrhage 1 month after stenting. There were 36 (28.35%) minor hemorrhagic events in the ticagrelor group and 35 (27.56%) in the clopidogrel group, (P=0.889)., Conclusion: Half-dose ticagrelor was effective and safe as a potential alternative to clopidogrel in the DAPT regimen for patients undergoing SAC/FD for UIA., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Flow diversion (FD: flow diversion, flow diverter) is an endovascular treatment for many intracranial aneurysm types; however, limited reports have explored the use of FDs in bifurcation aneurysm management. We analyzed the safety and efficacy of FD for the management of intracranial bifurcation aneurysms., Methods: A systematic review identified original research articles that used FD for treating intracranial bifurcation aneurysms. Articles with >4 patients that reported outcomes on the use of FDs for the management of bifurcation aneurysms along the anterior communicating artery (AComA), internal carotid artery terminus (ICAt), basilar apex (BA), or middle cerebral artery bifurcation (MCAb) were included. Meta-analysis was performed using a random effects model., Results: 19 studies were included with 522 patients harboring 534 bifurcation aneurysms (mean size 9 mm, 78% unruptured). Complete aneurysmal occlusion rate was 68% (95% CI 58.7% to 76.1%, I 2 =67%) at mean angiographic follow-up of 16 months. Subgroup analysis of FD as a standalone treatment estimated a complete occlusion rate of 69% (95% CI 50% to 83%, I 2 =38%). The total complication rate was 22% (95% CI 16.7% to 28.6%, I 2 =51%), largely due to an ischemic complication rate of 16% (95% CI 10.8% to 21.9%, I 2 =55%). The etiologies of ischemic complications were largely due to jailed artery hypoperfusion (47%) and in-stent thrombosis (38%). 7% of patients suffered permanent symptomatic complications (95% CI 4.5% to 9.8%, I 2 =6%)., Conclusion: FD treatment of bifurcation aneurysms has a modest efficacy and relatively unfavorable safety profile. Proceduralists may consider reserving FD as a treatment option if no other surgical or endovascular therapy is deemed feasible., Competing Interests: Competing interests: MB is a consultant for Cerenovus, consultant for Integra, and a member of the advisory board for Stryker. GT is a consultant for Dynamed and a Steering Committee member for Medtronic. GT is an Associate Editor for Journal of Neurointerventional Surgery. All other authors have no conflicts of interest to report., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Flow-diverting stents (FDs) for the treatment of cerebrovascular aneurysms are revolutionary. However, these devices require systemic dual antiplatelet therapy (DAPT) to reduce thromboembolic complications. Given the risk of ischemic complications as well as morbidity and contraindications associated with DAPT, demonstrating safety and efficacy for FDs either without DAPT or reducing the duration of DAPT is a priority. The former may be achieved by surface modifications that decrease device thrombogenicity, and the latter by using coatings that expedite endothelial growth. Biomimetics, commonly achieved by grafting hydrophilic and non-interacting polymers to surfaces, can mask the device surface with nature-derived coatings from circulating factors that normally activate coagulation and inflammation. One strategy is to mimic the surfaces of innocuous circulatory system components. Phosphorylcholine and glycan coatings are naturally inspired and present on the surface of all eukaryotic cell membranes. Another strategy involves linking synthetic biocompatible polymer brushes to the surface of a device that disrupts normal interaction with circulating proteins and cells. Finally, drug immobilization can also impart antithrombotic effects that counteract normal foreign body reactions in the circulatory system without systemic effects. Heparin coatings have been explored since the 1960s and used on a variety of blood contacting surfaces. This concept is now being explored for neurovascular devices. Coatings that improve endothelialization are not as clinically mature as anti-thrombogenic coatings. Coronary stents have used an anti-CD34 antibody coating to capture circulating endothelial progenitor cells on the surface, potentially accelerating endothelial integration. Similarly, coatings with CD31 analogs are being explored for neurovascular implants., Competing Interests: Competing interests: CTZ and AAB declare no competing interests. JM: (1) Consultant for Viseon, Endostream, RIST, Synchron, Perflow, Viz.ai, CVAid, Imperative Care, and Mendaera. Investor in Endostream, Imperative Care, Echovate, Viseon, BlinkTBI, Serenity, NTI Managers, RIST, Viz.ai, Synchron, Songbird, Tulavi, Vastrax, Neurolutions, Sim&Cure, Neurolutions, Bend-it, Myra Medical, Q’Apel, Instylla, Viseon, Adona, Tulavi, Radical, E8, Borvo, and Spinaker; (2) Research funding from PCORI, Microvention, Penumbra, and Stryker Neurovascular; (3) President of SNIS. NWD: (1) Consultancy and speaker honoraria from Balt, Medtronic, Stryker and Microvention; (2) Research funding from Medtronic, Stryker and Microvention; (3) Proctoring for Microvention. MJG: (1) Consultant on a fee-per-hour basis for Alembic, Astrocyte Pharmaceuticals, BendIt Technologies, Cerenovus, Imperative Care, Jacob’s Institute, Medtronic Neurovascular, Mivi Neurosciences, phenox GMbH, Q’Apel, Route 92 Medical, Scientia, Simcerre, Stryker Neurovascular, Stryker Sustainability Solutions, Wallaby Medical; holds stock in Imperative Care, InNeuroCo, Galaxy Therapeutics, Kapto, Neurogami and Synchron; (2) Research support from the NIH, the United States–Israel Binational Science Foundation, Anaconda, ApicBio, Arsenal Medical, Axovant, Balt, Cerenovus, Ceretrieve, CereVasc, Cook Medical, Galaxy Therapeutics, Gentuity, Gilbert Foundation, Imperative Care, InNeuroCo, Insera, Jacob’s Institute, Magneto, MicroBot, Microvention, Medtronic Neurovascular, MIVI Neurosciences, Naglreiter MDDO, Neurogami, Q’Apel, Philips Healthcare, Progressive Medical, Pulse Medical, Rapid Medical, Route 92 Medical, Scientia, Stryker Neurovascular, Syntheon, ThrombX Medical, Wallaby Medical, the Wyss Institute and Xtract Medical; (3) Associate Editor of Basic Science on the JNIS Editorial Board., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: This study reports a multicenter experience of using hydrophilic polymer-coated (HPC) flow diverters with prasugrel single antiplatelet therapy to treat ruptured aneurysms with subarachnoid hemorrhage (SAH)., Methods: Patients treated for intracranial aneurysms within 30 days after SAH with a p64/p48 MW HPC flow diverter were prospectively identified. Clinical presentation and outcomes, periprocedural and postprocedural complications, and degree of occlusion at follow-up were evaluated., Results: A total of 84 patients were treated in 88 sessions (54.5% women; mean age 53.3 years). Four patients (4.7%) experienced flow diverter-dependent complications. No cases of aneurysm re-rupture or hemorrhagic complications related to antiplatelet therapy were recorded. Immediate complete occlusion was achieved in 27.4% of cases (23/84). The rate of complete occlusion among survivors was 83% in early follow-up, 90.2% in mid-term follow-up, and 92.3% in the latest possible follow-up., Conclusion: p64/p48 MW HPC flow diverters with prasugrel single antiplatelet therapy were associated with safety from aneurysm re-rupture and high occlusion rates at medium- and long-term follow-up in managing ruptured aneurysms. Adequate management of single antiplatelet therapy with prasugrel is crucial, particularly with higher doses than usual, to avoid both ischemic and hemorrhagic complications., Competing Interests: Competing interests: HH: Consulting and proctoring for Wallaby Phenox GmbH, co-owner of CONTARA GmbH., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Flow diversion (FD) embolization of intracranial cerebral aneurysms is an increasingly common modality where treatment success depends on adequate vessel wall apposition of the device. This study aimed to investigate off-label use of the Comaneci device for augmenting vessel wall apposition in post-deployed flow diversion stents (FDS)., Methods: Over a 20- month period, all FD cases for the treatment of internal carotid artery (ICA) aneurysms were reviewed. Cases in which the Comaneci device was used to augment vessel wall apposition were analyzed. Data including patient demographics, case characteristics, and procedural outcomes were collected and analyzed as counts., Results: From a total of 74 ICA FD cases, the Comaneci device was used to improve vessel wall apposition in 22 cases (29.7%) . Of these cases, 91% were female with a mean patient age of 64.9±11.3 years, and an average aneurysm size of 4.5±2.5 mm. Comaneci device deployment and retrieval was successful in all (100%) cases, with an average fluoroscopy time of 27.3±7.8 min, an average contrast usage of 25.8±13.2 mL, and an average radiation exposure of 915.1±320.8 mGy. Only two cases (9%) required subsequent balloon angioplasty after Comaneci deployment to improve vessel wall apposition throughout the FDS., Conclusion: Our experience with this technique demonstrates the feasibility of using the Comaneci device for augmentation of FDS vessel wall apposition with 100% success in the deployment and retrieval of the Comaneci device., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Flow diverting stents (FDS) have transformed the treatment of intracranial aneurysms; however, their metallic structure associated with their intra-luminal positioning hamper angiographic and clinical outcomes. Therefore, there is a need to develop FDS with optimized surfaces that reduce thrombogenicity while promoting the healing process and endothelialization., Methods: P8RI, a peptide mimicking the CD31 protein, was previously developed and grafted onto Silk Vista (SV) FDS. P8RI-SV and bare-SV were used in vitro in a blood loop model to test their hemocompatibility using human whole blood and in vivo using the rabbit elastase model for optical coherence tomography (OCT) comparisons of neointimal formation at day 5 and day 28., Results: After blood loop incubation, P8RI-SV showed significant reduction in fibrin binding (p=0.004) and platelet adhesion (p=0.041) compared with bare-SV. Similarly, derivative markers measured in blood, thromboxane B2 (platelet activation) and Thrombin-Antithrombin III complexes (coagulation activation), were also significantly reduced in the P8RI-SV group (both p=0.002). In vivo, complete or near-complete occlusion was reached in all aneurysms (n=6) at day 28. Excellent rate of stent-coverage ratio was obtained at day 5 (89.3% (79.1%-98.7%)) comparable to the observation at day 28 (91.8% (79.1%-100%); p=0.44). These rates were significantly higher compared with bare-SV at day 5 (77.8% (58.3%-86.8%); p<0.001) and at day 28 (67.7% (52.6%-88.9%); p<0.0001)., Conclusion: In vitro results confirm enhanced hemocompatibility with a significant anti-thrombotic effect of the P8RI-SV. In vivo results provide evidence of rapid neo-intimal growth reaching near-complete tissue healing as early as day 5 in a rabbit model., Competing Interests: Competing interests: JC received an educational grant from Medtronic, Phenox and Microvention; and received honoraria for lectures from Balt. LS is a consultant for Microvention, Balt, Phenox, Stryker, Medtronic. AR received honoraria for lectures from Balt. CM received honoraria for lectures from Balt., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Endovascular treatment for vertebral artery dissecting aneurysms (VADAs) includes overlapping stents and flow diverters. This study compared the safety and effectiveness of overlapping stents and flow diverters for unruptured VADAs., Methods: We retrospectively enrolled patients with unruptured VADAs who underwent overlapping stents or flow diverters at two tertiary hospitals in South Korea. The primary clinical outcome was the occurrence of stroke. The primary angiographic outcomes (>12 months) were categorized as regression, no decrease in size, recanalization, or stent occlusion, of which only regression was defined as a favorable angiographic outcomes., Results: Of the 146 patients with VADAs, 25 (17.1%) had flow diverters and 121 (82.9%) had overlapping stents. For the primary angiographic outcomes over 12 months, the rate of favorable angiographic outcomes for flow diverters was 81.8% and for overlapping stents (triple stents) was 98.8% (P=0.006). In the multivariale analysis, after adjusting for partially thrombosed aneurysms, aneurysm shape, non-dominant vessel, posterior inferior cerebellar artery involvement, and procedure type, overlapping stents (triple stents) was not associated with favorable angiographic outcomes compared with flow diverters (OR 7.040, 95% CI 0.549 to 90.294; P=0.134), but partially thrombosed aneurysms was inversely associated with favorable angiographic outcomes (OR 0.056, 95% CI 0.005 to 0.589; P=0.016). The primary clinical outcome followed up to the last angiography did not occur in all patients., Conclusion: There was no difference in safety and effectiveness between overlapping stents and flow diverters in unruptured VADAs. Further endovascular treatment studies are needed regarding the association of partially thrombosed aneurysms with unfavorable angiographic outcomes., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Surface-modified flow diverters are increasingly used in clinical settings. However, their safety profiles and additional benefits over non-coated devices still need to be explored. In this meta-analysis, we aimed to investigate and compare the clinical outcomes of the uncoated Phenox and coated Phenox HPC flow diverters., Methods: A systematic literature review was performed using PubMed, Scopus, Embase, and Web of Science databases. Collected data were pooled and corresponding 95% confidence intervals (CI) were calculated. Outcomes of interest included aneurysm occlusion (>6 months) and complication rates. Additionally, the safety outcomes of prophylactic single (SAPT) and dual antiplatelet treatment (DAPT) approaches were compared for patients treated with coated Phenox HPC flow diverters., Results: We included 17 studies with 1238 patients. The overall complete occlusion rates were 80% (95% CI 74.01% to 86.56%) for Phenox HPC and 71.3% (95% CI 59.71% to 85.20%) for non-coated Phenox flow diverters (p=0.24). Ischemic complication rates were 7.3% (95% CI 4.6% to 11.39%) with the Phenox HPC and 5.3% (95% CI 4.07% to 6.91%) with the Phenox (p=0.24). For patients treated with Phenox HPC, the SAPT (5.5%; 95% CI 2.83% to 10.85%) and DAPT (7.1%; 95% CI 1.23% to 41.45%) approaches resulted in comparable ischemic complication rates (p=0.79). The DAPT group (4.8%; 95% CI 1.46% to 16.24%) had higher hemorrhagic complication rates than the SAPT group (1.7%; 95% CI 0.52% to 6.09%), but the difference was not statistically significant for patients treated with Phenox HPC (p=0.25)., Conclusions: Our findings indicate that Phenox HPC is equally as safe and effective as non-coated Phenox devices. Additionally, our results suggest that prasugrel monotherapy might effectively prevent ischemic complications in patients treated with Phenox HPC flow diverters., Competing Interests: Competing interests: AAO is supported by American Heart Association Grant Number 23PRE1012781. RK received research support from Cerenovus Inc, Medtronic, Endovascular Engineering, Frontier Bio, Sensome Inc, Endomimetics, Ancure LLC, Neurogami Medical, MIVI Biosciences, Monarch Biosciences, Stryker, Conway Medical, Piraeus Medical, and Bionaut Labs. WB holds equity in Nested Knowledge, Superior Medical Experts, Piraeus Medical, Sonoris Medical, and MIVI Neurosciences; he receives royalties from Medtronic; he receives consulting fees from Medtronic, Stryker, Imperative Care, Microvention, MIVI Neurosciences, Cerenovus, Asahi, and Balt; he serves in a leadership or fiduciary role for MIVI Neurosciences, Marblehead Medical LLC, Interventional Neuroradiology (editor in chief), Piraeus Medical, and WFITN. DFK holds equity in Nested Knowledge, Superior Medical Experts, and Conway Medical, Marblehead Medical, and Piraeus Medical; he received grant support from Microvention, Medtronic, Neurogami, Cerenovus, Brainomix, MIVI Neurosciences, Stryker, Balt, and Insera Therapeutics; has served on the Data Safety Monitoring Board for Vesalio and NoNo Inc.; and received royalties from Medtronic. The remaining authors report no conflicts of interest concerning the materials or methods used in the manuscript., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Flow diverters carry the risk of thromboembolic complications (TEC). We tested a coating with covalently bound heparin that activates antithrombin to address TEC by locally downregulating the coagulation cascade. We hypothesized that the neuroimaging evidence of TEC would be reduced by the coating., Methods: 16 dogs were implanted with overlapping flow diverters in the basilar artery, separated into two groups: heparin-coated (n=9) and uncoated (n=7). Following implantation, high-frequency optical coherence tomography (HF-OCT) was acquired to quantify acute thrombus (AT) formation on the flow diverters. MRI was performed postoperatively and repeated at 1, 2, 3, 4, and 8 weeks, consisting of T1-weighted imaging, time-0f-flight (ToF), diffusion weighted imaging (DWI), susceptibility weighted imaging (SWI), and fluid attenuated inversion recovery (FLAIR) sequences. Neurological examinations were performed throughout the 8-week duration of the study., Results: The mean AT volume on coated devices was lower than uncoated (0.014 vs 0.018 mm 3 ); however, this was not significant (P=0.3). The mean number of foci of magnetic susceptibility artifacts (MSAs) on SWI was significantly different between the uncoated and coated groups at the 1-week follow-up (P<0.02), and remained statistically different throughout the duration of the study. The AT volume showed a direct linear correlation with the MSA count and 80% of the variance in the MSA could be explained by the AT volume (P<0.001). Pathological analysis showed evidence of ischemic injury at locations of MSA., Conclusions: Heparin-coated flow diverters significantly reduced the number of new MSAs after 1 week follow-up, showing the potential to reduce TEC., Competing Interests: Competing interests: AP: consultant for Medtronic Neurovascular, Stryker Neurovascular, Balt, Q’Apel Medical, Cerenovus, Microvention, Imperative Care, Agile, Merit, CereVasc, and Arsenal Medical; research grants from NIH, Microvention, Cerenovus, Medtronic Neurovascular, and Stryker Neurovascular; holds stocks in InNeuroCo, Agile, Perfuze, Galaxy and NTI. JMA and ABB are employees of Stryker Neurovascular. ASA: Consultant for Arsenal, Balt, Johnson and Johnson, Medtronic, Microvention, Penumbra, Scientia, Siemens, Stryker. Research support from Balt, Medtronic, Microvention, Penumbra and Siemens. Shareholder Azimuth, Bendit, Cerebrotech, Endostream, Magneto, Mentice, Neurogami, Neuros, Revbio, Scientia, Serenity, Synchron, Tulavi, Vastrax, VizAI. DF: Consultant: Medtronic, Cerenovous, Microvention, Stryker, Balt USA, MENTICE-Vascular Simulations, Neurogami, Marblehead, RAPID.AI, RAPID Medical, Qapel Medical, Arsenal Medical, Phenox Medical, Scientia Medical, Perfuze; Research Support: Microvention, Stryker, Balt USA, Siemens; Scientific Advisory Boards: Scientia Medical, NVMed, Perfuze; Holds Stock in: MENTICE-Vascular Simulations, Neurogami, Marblehead, Scientia Medical, NVMed, Perfuze. MJG: Has been a consultant on a fee-per-hour basis for Alembic LLC, Astrocyte Pharmaceuticals, BendIt Technologies, Cerenovus, Imperative Care, Jacob’s Institute, Medtronic Neurovascular, Mivi Neurosciences, phenox GMbH, Q’Apel, Route 92 Medical, Stryker Neurovascular, Stryker Sustainability Solutions, Wallaby Medical; holds stock in Imperative Care, InNeuroCo, Galaxy Therapeutics and Neurogami; and has received research support from the National Institutes of Health (NIH), the United States – Israel Binational Science Foundation, Anaconda, ApicBio, Arsenal Medical, Axovant, Balt, Cerenovus, Ceretrieve, CereVasc LLC, Cook Medical, Galaxy Therapeutics, Gentuity, Gilbert Foundation, Imperative Care, InNeuroCo, Insera, Jacob’s Institute, Magneto, MicroBot, Microvention, Medtronic Neurovascular, MIVI Neurosciences, Naglreiter MDDO, Neurogami, Philips Healthcare, Progressive Medical, Pulse Medical, Rapid Medical, Route 92 Medical, Scientia, Stryker Neurovascular, Syntheon, ThrombX Medical, Wallaby Medical, the Wyss Institute and Xtract Medical. MJG is Associate Editor of Basic Science on the JNIS Editorial Board., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Multiple studies and meta-analyses have described the technical and clinical outcomes in large cohorts of aneurysm patients treated with flow diverters (FDs). Variations in evaluation methodology complicate making comparisons among studies, hinder understanding of the device behavior, and pose an obstacle in the assessment of further advances in FD therapy., Methods: A multidisciplinary panel of neurointerventionalists, imaging experts, and neuroradiologists convened with the goal of establishing consensus recommendations for the standardization of image analyses in FD studies., Results: A standardized methodology is proposed for evaluating and reporting radiological outcomes of FD treatment of intracranial aneurysms. The recommendations include general imaging considerations for clinical studies and evaluations of longitudinal changes, such as neointimal lining and stenosis. They cover standards for classification of aneurysm location, morphology, measurements, as well as the assessment of aneurysm occlusion, wall apposition, and neck coverage. These reporting standards further define four specific braid deformation patterns: foreshortening, fish-mouthing, braid bump deformation, and braid collapse, collectively termed 'F2B2'., Conclusions: When widely applied, standardization of methods of measuring and reporting outcomes will help to harmonize the assessment of treatment outcomes in clinical studies, help facilitate communication of results among specialists, and help enable research and development to focus on specific aspects of FD techniques and technology., Competing Interests: Competing interests: JF: Research support: German Ministry of Science & Education (BMBF) and of Economy and Innovation (BMWi), German Research Foundation (DFG), European Union (EU), Hamburgische Investitions- und Förderbank (IFB), Medtronic, Microvention, Route92, Stryker. Consultant for: Acandis, Cerenovus, Medtronic, Microvention, Penumbra, Phenox, Roche, Stryker, TG Med, Tonbridge. Stockholder: Tegus Medical, Vastrax, Eppdata. DF: Medtronic – Consulting, Proctoring, Cerenovous – Consulting, Microvention – Consulting, Proctoring, Research Support, Penumbra – Consulting, Research Support, Stryker – Consulting, Research Support, Balt USA – Consulting, Research Support, Siemens – Research Support, MENTICE-Vascular Simulations – Consultant, Neurogami – Stockholder, Consultant, RAPID. AI – Consultant, RAPID Medical – Consultant, Qapel Medical –Consultant, Arsenal Medical – Consultant, Phenox Medical – Consultant, Scientia Medical – SAB, Consultant, Stockholder, NVMed – SAB, Stockholder, Perfuze – SAB, Consultant, Stockholder, Vesalio - ConsultantIS: Consulting and proctoring agreement with Medtronic & Microvention. SH: Consulting and proctoring agreement with Medtronic & Microvention. Stocks: Neuravention Inc., Vesalio Inc., Synchron Inc., Bend It Technologies, Sim & Size Inc., Borvo Medical Inc., Prometheus Inc., Piraeus Inc., Neuros Medical Inc. MJG: (1) Consultant on a fee-per-hour basis for Alembic, Astrocyte Pharmaceuticals, BendIt Technologies, Cerenovus, Imperative Care, Jacob’s Institute, Medtronic Neurovascular, Mivi Neurosciences, Phenox GMbH, Q’Apel, Route 92 Medical, Scientia, Simcerre, Stryker Neurovascular, Stryker Sustainability Solutions, Wallaby Medical; holds stock in Imperative Care, InNeuroCo, Galaxy Therapeutics, Kapto, Neurogami and Synchron; (2) Research support from the National Institutes of Health (NIH), the United States–Israel Binational Science Foundation, Anaconda, ApicBio, Arsenal Medical, Axovant, Balt, Cerenovus, Ceretrieve, CereVasc, Cook Medical, Galaxy Therapeutics, Gentuity, Gilbert Foundation, Imperative Care, InNeuroCo, Insera, Jacob’s Institute, Magneto, MicroBot, Microvention, Medtronic Neurovascular, MIVI Neurosciences, Naglreiter MDDO, Neurogami, Q’Apel, Philips Healthcare, Progressive Medical, Pulse Medical, Rapid Medical, Route 92 Medical, Scientia, Stryker Neurovascular, Syntheon, ThrombX Medical, Wallaby Medical, the Wyss Institute, Xtract Medical; and (3) Associate Editor of Basic Science on the JNIS Editorial Board., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Physician variablity in preoperative planning of endovascular implant deployment and associated inaccuracies have not been documented. This study aimed to quantify the variability in accuracy of physician flow diverter (FD) planning and directly compares it with PreSize Neurovascular (Oxford Heartbeat Ltd) software simulations., Methods: Eight experienced neurointerventionalists (NIs), blinded to procedural details, were provided with preoperative 3D rotational angiography (3D-RA) volumetric data along with images annotated with the distal landing location of a deployed Surpass Evolve (Stryker Neurovascular) FD from 51 patient cases. NIs were asked to perform a planning routine reflecting their normal practice and estimate the stent's proximal landing using volumetric data and the labeled dimensions of the FD used. Equivalent deployed length estimation was performed using PreSize software. NI- and software-estimated lengths were compared with postprocedural observed deployed stent length (control) using Bland-Altman plots. NI assessment agreement was assessed with the intraclass correlation coefficient (ICC)., Results: The mean accuracy of NI-estimated deployed FD length was 81% (±15%) versus PreSize's accuracy of 95% (±4%), demonstrating significantly higher accuracy for the software (p<0.001). The mean absolute error between estimated and control lengths was 4 mm (±3.5 mm, range 0.03-30.2 mm) for NIs and 1 mm (±0.9 mm, range 0.01-3.9 mm) for PreSize. No discernable trends in accuracy among NIs or across vasculature and aneurysm morphology (size, vessel diameter, tortuousity) were found., Conclusions: The study quantified experienced physicians' significant variablity in predicting an FD deployment with current planning approaches. In comparison, PreSize-simulated FD deployment was consistently more accurate and reliable, demonstrating its potential to improve standard of practice., Competing Interests: Competing interests: ATR, SB: consulting agreement Stryker, Cerenovus, Microvention. JD: PI for Oxford Heartbeat Multicentre Prospective Oxford Heartbeat PreSize study; consulting agreement Stryker, Phenox, Microvention, Oxford Endovascular. VCdN, CG: consulting agreement Stryker, Medtronic. RR: consulting agreement Stryker, Balt, Medtronic, Microvention, Acandis. JP, TP, MS, JDP: no disclosures., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Flow diversion has become a standard treatment for cerebral aneurysms. However, major drawbacks include the need for dual antiplatelet therapy after implant and delayed complete occlusion of the aneurysm, which occurs when new tissue growth excludes the aneurysm from the parent artery. Biomimetic surface modifications such as the phosphorylcholine polymer (Shield surface modification) represent major advances in reducing thrombogenicity of these devices. However, in vitro studies have raised concerns that this modification may also delay endothelialization of flow diverters., Methods: Bare metal Pipeline, Pipeline Shield, and Vantage with Shield devices were implanted in the common carotid arteries (CCAs) of 10 rabbits (two in the left CCA, one in the right CCA). Following implant and at 5, 10, 15, and 30 days, the devices were imaged with high-frequency optical coherence tomography and conventional angiography to evaluate tissue growth. At 30 days the devices were explanted and their endothelial growth was assessed with scanning electron microscopy (SEM) at five locations along their length using a semi-quantitative score., Results: The average tissue growth thickness (ATGT) was not different between the three devices. Neointima was apparent at 5 days and all devices demonstrated similar ATGT at each time point. On SEM, no difference was found in the endothelium scores between the device types., Conclusion: In vivo, neither the Shield surface modification nor the device design (Vantage) altered the longitudinal healing of the flow diverter., Competing Interests: Competing interests: CTZ, RMK, ME, and VA declare no competing interests. MJG: (1) Consultant on a fee-per-hour basis for Alembic LLC, Astrocyte Pharmaceuticals, BendIt Technologies, Cerenovus, Imperative Care, Jacob’s Institute, Medtronic Neurovascular, Mivi Neurosciences, phenox GMbH, Q’Apel, Route 92 Medical, Scientia, Simcerre, Stryker Neurovascular, Stryker Sustainability Solutions, Wallaby Medical; holds stock in Imperative Care, InNeuroCo, Galaxy Therapeutics, Neurogami and Synchron. (2) Research support from the NIH, the United States – Israel Binational Science Foundation, Anaconda, ApicBio, Arsenal Medical, Axovant, Balt, Cerenovus, Ceretrieve, CereVasc, Cook Medical, Galaxy Therapeutics, Gentuity, Gilbert Foundation, Imperative Care, InNeuroCo, Insera, Jacob’s Institute, Magneto, MicroBot, Microvention, Medtronic Neurovascular, MIVI Neurosciences, Naglreiter MDDO, Neurogami, Q’Apel, Philips Healthcare, Progressive Medical, Pulse Medical, Rapid Medical, Route 92 Medical, Scientia, Stryker Neurovascular, Syntheon, ThrombX Medical, Wallaby Medical, the Wyss Institute and Xtract Medical. (3) Associate Editor of Basic Science on the JNIS Editorial Board. MJG is the guarantor of the study., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Intrasaccular devices have become increasingly popular in the treatment of cerebral aneurysms, particularly at the bifurcation. Here we evaluate the Contour Neurovascular System, an intrasaccular device for the endovascular treatment of cerebral aneurysms, in a multicenter cohort study, the largest to the best of our knowledge., Methods: Consecutive patients with intracranial aneurysms treated with the Contour Neurovascular System between February 2017 and October 2022 at 10 European neurovascular centers were prospectively collected and retrospectively reviewed. Patient and aneurysm characteristics, procedural details, and angiographic and clinical outcomes were evaluated., Results: During the study period, 279 aneurysms (median age of patients 60 years, IQR 52-68) were treated with Contour. In 83.2% of patients the device was placed electively, whereas the remaining patients were treated in the setting of acute subarachnoid hemorrhage. The most common locations were the middle cerebral artery (26.5%) followed by the anterior communicating region (26.2%). Median aneurysm dome and neck size were 5.2 mm (IQR 4.2-7) and 3.9 mm (IQR 3-5). Contour size 7 (39%) and 9 (25%) were most used. Thromboembolic and hemorrhagic complications occurred in 6.8% and 0.4% of aneurysms, respectively. Raymond-Roy 1 and 2 occlusions at last follow-up were achieved in 63.2% and 28.3%, respectively, resulting in adequate occlusion of 91.5% of aneurysms., Conclusion: This is the largest multicenter study reporting the outcome on the Contour Neurovascular System. At 1 year, the self-evaluated data on safety and efficacy are comparable to data of existing intrasaccular devices. Contour is a promising technology in the treatment of cerebral aneurysms., Competing Interests: Competing interests: Please see uploaded ICMJE forms from co-authors., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Flow diverter devices (FDs) are increasingly used for treating unruptured intracranial aneurysms (UIAs), but limited studies compared different FDs., Objective: To conduct a propensity score matched analysis comparing the Pipeline embolization device (PED) and Tubridge embolization device (TED) for UIAs., Methods: Patients with UIAs treated with either PED or TED between July 2016 and July 2022 were included. Propensity score matching was performed to adjust for age, sex, comorbidities, smoking, drinking, aneurysm size, morphology, neck, location, parent artery diameter, adjunctive coiling, and angiographic follow-up duration. Perioperative complications and clinical and angiographic outcomes were compared after matching., Results: 735 patients treated by PED and 290 patients treated by TED were enrolled. Compared with the PED group, patients in the TED group had a greater number of women and patients with ischemia, a smaller proportion of vertebrobasilar and non-saccular aneurysms, a smaller size and neck, and fewer adjunctive coils and overlapping stents, but a larger parent artery diameter and lumen disparities. After adjusting for these differences, 275 pairs were matched. No differences were found in perioperative complications (4.4% vs 2.5%, P=0.350), in-stent stenosis (16.0% vs 15.6%, P>0.999), or favorable prognosis (98.9% vs 98.5%, P>0.999). However, PED showed a trend towards better complete occlusion over a median 8-month angiographic follow-up (81.8% vs 75.3%, P=0.077)., Conclusion: Compared with PED, TED provides a comparable rate of perioperative and short-term outcomes. Nevertheless, a better occlusion status in the PED group needs to be further verified over a longer follow-up period., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Flow diverters are the first-line treatment for specific intracranial aneurysms (iA). Surpass Evolve (SE) is a new-generation 64-wire flow diverter with a high braid angle. Current literature on the SE is limited. We aimed to report the first international real-world experience evaluating the safety and effectiveness of the SE., Methods: The Safety and Effectiveness Assessment of the Surpass Evolve (SEASE) was a multicenter retrospective international post-marketing cohort study including consecutive patients treated with SE for iAs between 2020 and 2022. Demographic, clinical, and angiographic data were collected. Primary effectiveness was independent core lab adjudicated complete occlusion rates (Raymond-Roy Class 1) at last follow-up. Primary safety were major ischemic/hemorrhagic events and mortality., Results: In total, 305 patients with 332 aneurysms underwent SE implantation. The patients had a median age of 59 [50-67] years, and 256 (83.9%) were female. The baseline modified Rankin scale score was 0-2 in 291 patients (96.7%). Most aneurysms were unruptured (285, 93.4%) and saccular (309, 93.1%). Previous treatment was present in 76 (22.9%) patients. The median aneurysm size was 5.1 [3.4-9.0] mm, and the median neck width was 3.6 [2.7-5.1] mm. Most aneurysms were in the internal carotid artery C6 ophthalmic segment (126, 38.0%), followed by the communicating segment (58, 17.5%). At median 10.2 [6.4-12.9] months follow-up, 233 (73.0%) aneurysms achieved complete occlusion. After adjusting for confounders, complete occlusion remained consistent. Major stroke and procedure-related mortality were reported in 6 (2%) and 2 (0.7%) cases, respectively., Conclusion: These results demonstrate that SE has a consistently high effectiveness and favorable safety for the treatment of iAs., Competing Interests: Competing interests: Vivanco-Suarez – None; Dibas – None; Klee Lopes – Consultant: Asahi, Stryker, Corindus, Siemens, and Medtronic. Honoraria: Cerenovus, Medtronic, and Stryker. Advisory Board: INFINITY [trial]. Grants: Mentice. Leadership role: WLNC and Advocate Health. Stock: Syncron, Three Rivers Inc., Q’apel, VIZ.AI, Methinks, Vastrax, Borvo, BendIT, Collavidence, NDI, Prometheus, NextGen, Galaxy, Global Intervention, and Sim&Cure. Hanel – Consultant: Medtronic, Stryker, Cerenovous, Microvention, Balt, Phenox, Rapid Medical, and Q’Apel. Advisory board: MiVI, eLum, Three Rivers Medical Inc., Shape Medical, and Corindus. Grants: from NIH, Interline Endowment, Microvention, Stryker, and CNX. Investor/Stoker: InNeuroCo, Cerebrotech, eLum, Endostream, Three Rivers Medical Inc., Scientia, RisT, BlinkTBI, and Corindus. Martinez-Galdamez – Consultant: Medtronic. Rodriguez-Calienes – None; Cortez – None; Fifi – Consultant: Penumbra, Stryker, Microvention, and Cerenovus. Grants: Viz. Investor/Stoker: Imperative care and Cerebrotech. Devarajan – None; Toth – Consultant: Medtronic and Dynamed. Patterson – None; Altschul – Consultant: Microvention, Stryker, and Von Vascular Inc. Pereira – Consultant: Stryker, Medtronic, Penumbra, Neurovasc, and Balt. Liu – None; Puri – Consultant: Medtronic, Stryker, Cerenovus, Microvention, Agile, Merit, Corindus, Q’apel, Arsenal, and Imperative Care. Grants: Medtronic, Stryker, and Cerenovus. Kühn – None; Guerrero – None; Khandelwal – Consultant: Stryker and Medtronic. Bach – None; Kan – Consultant: Stryker, Imperative Care, Cerenovus, and Microvention. Grants: NIH, Siemens, Joe Niekro, and Medtronic. Editorial board: Journal of NeuroInterventional Surgery. Edhayan – None; Given – Consultant: Stryker and Medtronic. Gross – Consultant: Medtronic, Microvention, and Stryker. Farooqui – None; Galecio-Castillo – None; Derakhshani – None; Ortega-Gutierrez – Grants: NIH-NINDS (R01NS127114-01, RO3NS126804-01), Stryker, Medtronic, Microvention, Methinks, Viz.ai. Consulting fees: Medtronic, Stryker Neurovascular., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Flow diverters (FDs) have become an integral part of treatment for brain aneurysms., Aim: To summarize available evidence of factors associated with aneurysm occlusion (AO) after treatment with a FD., Methods: References were identified using the Nested Knowledge AutoLit semi-automated review platform between January 1, 2008 and August 26, 2022. The review focuses on preprocedural and postprocedural factors associated with AO identified in logistic regression analysis. Studies were included if they met the inclusion criteria of study details (ie, study design, sample size, location, (pre)treatment aneurysm details). Evidence levels were classified by variability and significancy across studies (eg, low variability ≥5 studies and significance in ≥60% throughout reports)., Results: Overall, 2.03% (95% CI 1.22 to 2.82; 24/1184) of screened studies met the inclusion criteria for predictors of AO based on logistic regression analysis. Predictors of AO with low variability in multivariable logistic regression analysis included aneurysm characteristics (aneurysm diameter), particularly complexity (absence of branch involvement) and younger patient age. Predictors of moderate evidence for AO included aneurysm characteristics (neck width), patient characteristics (absence of hypertension), procedural (adjunctive coiling) and post-deployment variables (longer follow-up; direct postprocedural satisfactory occlusion). Variables with a high variability in predicting AO following FD treatment were gender, FD as re-treatment strategy, and aneurysm morphology (eg, fusiform or blister)., Conclusion: Evidence of predictors for AO after FD treatment is sparse. Current literature suggests that absence of branch involvement, younger age, and aneurysm diameter have the highest impact on AO following FD treatment. Large studies investigating high-quality data with well-defined inclusion criteria are needed for greater insight into FD effectiveness., Competing Interests: Competing interests: JF: research support from the German Ministry of Science and Education (BMBF), German Ministry of Economy and Innovation (BMWi), German Research Foundation (DFG), European Union (EU), Hamburgische Investitions-/Förderbank (IFB), Medtronic, Microvention, Philips, Stryker; consultancy appointments; Acandis, Bayer, Boehringer Ingelheim, Cerenovus, Covidien, Evasc Neurovascular, MD Clinicals, Medtronic, Medina, Microvention, Penumbra, Route92, Stryker, Transverse Medical; stock holdings for Tegus, JNIS associate editor. KMK: works for, and holds equity in, Nested Knowledge, works for Conway Medical, and holds equity in Piraeus Medical and Superior Medical Experts. TNN: reports research support from Medtronic and SVIN. KZ: support under the operational program Integrated Infrastructure for the project: TENSION—complementary project, IMTS: 313011W875, co-financed by the European Regional Development Fund. AR: consultant for Balt and Medtronic. LM: received financial compensation as a speaker for Balt Prime. MM-G: JNIS associate editor. The other authors report no conflict of interest., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Current imaging algorithms for post-device evaluation are limited by either poor representation of the device or poor delineation of the treated vessel. Combining the high-resolution images from a traditional three-dimensional digital subtraction angiography (3D-DSA) protocol with the longer cone-beam computed tomography (CBCT) protocol may provide simultaneous visualization of both the device and the vessel content in a single volume, improving the accuracy and detail of the assessment. We aim here to review our use of this technique which we termed "SuperDyna"., Methods: In this retrospective study, patients who underwent an endovascular procedure between February 2022 and January 2023 were identified. We analyzed patients who had both non-contrast CBCT and 3D-DSA post-treatment and collected information on pre-/post-blood urea nitrogen, creatinine, radiation dose, and the intervention type., Results: In 1 year, SuperDyna was performed in 52 (of 1935, 2.6%) patients, of which 72% were women, median age 60 years. The most common reason for the addition of the SuperDyna was for post-flow diversion assessment (n=39). Renal function tests showed no changes. The average total procedure radiation dose was 2.8 Gy, with 4% dose and ~20 mL of contrast attributed to the additional 3D-DSA needed to generate the SuperDyna., Conclusions: The SuperDyna is a fusion imaging method that combines high-resolution CBCT and contrasted 3D-DSA to evaluate intracranial vasculature post-treatment. It allows for more comprehensive evaluation of the device position and apposition, aiding in treatment planning and patient education., Competing Interests: Competing interests: ER is stock owner of Siemens, proctor of Microvention, and consultant for Medtronic and Balt. MS is consultant for Medtronic and Balt. DHS is consultant for Siemens, Microvention, Balt and Medtronic., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Dual antiplatelet therapy (DAPT) is necessary to prevent thromboembolic complications after stent-assisted coiling (SAC) or flow-diversion (FD) for cerebral aneurysms, but the optimal antiplatelet regimen remains unclear., Objective: To determine the optimal DAPT duration in patients with SAC/FD., Methods: This multicenter cohort study enrolled patients who received SAC/FD for cerebral aneurysms at seven Japanese institutions between January 2010 and December 2020. The primary outcome was the time from procedure to the occurrence of a composite of target vessel-related thromboembolic events, procedure-unrelated major bleeding events, or death. The cumulative event-free survival rates were analyzed using a Kaplan-Meier curve, and the differences in each outcome between the groups dichotomized by the duration of DAPT were analyzed using the log-rank test., Results: Of 632 patients (median observational period, 646 days), primary outcome occurred in 63 patients (10.0%), most frequently within 30 days after the procedure. The cumulative event-free survival rates at 30 days, 1 year, and 2 years after the procedure were 93.3% (91.4 to 95.3%), 91.5% (89.3 to 93.7%), and 89.5% (87.0 to 92.0%), respectively. The cumulative event-free survival rates after switching to monotherapy were similar for the >91 and <90 days DAPT groups in the population limited to patients who were switched from DAPT to monotherapy without major clinical events., Conclusions: Thromboembolic events rarely occurred beyond 30 days after SAC/FD. The duration of DAPT may be shortened if patients have a periprocedural period without events. Further prospective studies are warranted to determine the optimal duration of antiplatelet therapy., Trial Registration Number: UMIN000044122 :https://center6.umin.ac.jp/cgi-open-bin/ctr&#95;e/ctr&#95;view.cgi?recptno=R000050384., Competing Interests: Competing interests: YEn received a research grant from Sysmex; a lecture fee from Stryker, Medtronic, Johnson and Johnson, Daiichi-Sankyo and Otsuka Pharmaceutical. AI received a lecture fee feom Medtronic, Stryker, Terumo, Johnson and Johnson, Medico's Hirata, Kaneka, Daiichi-Sankyo and Otsuka Pharmaceutical; a research glant from Fuji film. MS received a lecture fee from Medtronic. KSu received a lecture fee from Stryker and Daiichi-Sankyo. IN received a lecture fee from Terumo, Kaneka and Daiichi-Sankyo. TH received a lecture fee from Stryker, Medtronic, Johnson and Johnson, Daiichi-Sankyo and Abbott; a research grant from Stryker, Medtronic, Asahi Intec, Kaneka, Medico's Hirata, Boehringer Ingelheim and Eisai. SY recieved a research grant from Asahi Intec, Biomedical Solution, Medico's Hirata, Medtronic, Otsuka Pharmaceutical, Stryker and Terumo; a lecture fee from Stryker, Medtronic, Johnson and Johnson, Kaneka, Daiichi-Sankyo, Bayer and Bristol-Meyers Squibb., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Studies reporting spontaneous delayed migration or shortening (SDMS) after treatment with the Pipeline Embolization Device (PED) are limited. This study aimed to evaluate the incidence of SDMS after PED treatment, propose management strategies, and identify the risk factors contributing to its occurrence., Methods: We retrospectively reviewed consecutive patients with an intracranial aneurysm (IA) treated with PEDs at three institutions. SDMS was classified as type I or II based on whether the PED covered the aneurysm neck., Results: The total cohort comprised 790 patients. SDMS was identified in 24 (3.04%) patients. Eighteen of the 24 patients had type I SDMS and did not require retreatment, while the remaining six patients had type II SDMS and all received retreatment. Multivariate logistic regression showed that the difference between the proximal and distal parent artery diameters (DPAD) (adjusted OR 2.977; 95% CI 1.054 to 8.405; P=0.039) and device tortuosity index (DTI) (adjusted OR 8.059; 95% CI 2.867 to 23.428; P<0.001) were independent predictors of SDMS after PED treatment, while the difference in length (DL) (adjusted OR 0.841; 95% CI 0.738 to 0.958; P=0.009) and PED plus coiling (adjusted OR 0.288; 95% CI 0.106 to 0.785; P=0.015) were protective factors., Conclusion: The incidence of SDMS after PED treatment of IA was 3.04%. For patients with type I SDMS with incomplete aneurysm occlusion we recommend continuous imaging follow-up while, for patients with type II SDMS, we recommend aggressive retreatment. The DPAD and DTI were independent risk predictors of SDMS after PED treatment, while the DL and PED plus coiling were protective factors., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: This multicenter study evaluated the safety and efficacy of coated flow diverters (cFDs) for the treatment of ruptured intracranial aneurysms., Methods: Consecutive patients treated with different cFDs for ruptured aneurysms under tirofiban at eight neurovascular centers between 2016 and 2023 were retrospectively analyzed. The majority of patients were loaded with dual antiplatelet therapy after the treatment. Aneurysm occlusion was determined using the O'Kelly-Marotta (OKM) grading scale. Primary outcome measures were major procedural complications and aneurysmal rebleeding during hospitalization., Results: The study included 60 aneurysms (posterior circulation: 28 (47%)) with a mean size of 5.8±4.7 mm. Aneurysm morphology was saccular in 28 (47%), blister-like in 12 (20%), dissecting in 13 (22%), and fusiform in 7 (12%). Technical success was 100% with a mean of 1.1 cFDs implanted per aneurysm. Adjunctive coiling was performed in 11 (18%) aneurysms. Immediate contrast retention was observed in 45 (75%) aneurysms. There was 1 (2%) major procedural complication (a major stroke, eventually leading to death) and no aneurysmal rebleeding. A good outcome (modified Rankin Scale 0-2) was achieved in 40 (67%) patients. At a mean follow-up of 6 months, 27/34 (79%) aneurysms were completely occluded (OKM D), 3/34 (9%) had an entry remnant (OKM C), and 4/34 (12%) had residual filling (OKM A or B). There was 1 (3%) severe in-stent stenosis during follow-up that was treated with balloon angioplasty., Conclusions: Treatment of ruptured aneurysms with cFDs was reasonably safe and efficient and thus represents a valid treatment option, especially for complex cases., Competing Interests: Competing interests: CK serves as consultant for Acandis GmbH (Pforzheim, Germany) and as proctor for MicroVention Inc./Sequent Medical (Aliso Viejo, CA, USA). TL previously served as proctor for MicroVention Inc./Sequent Medical (Aliso Viejo, CA, USA), CERUS Endovascular (Fremont, CA, USA), Phenox (Bochum, Germany), Stryker (Kalamazoo, MI, USA), and Medtronic (Dublin, Ireland). DZ is on the speaker’s bureau of Philips (Amsterdam, The Netherlands) and lecturer for Amboss GmbH (Cologne, Germany). FD serves as consultant/ proctor for MicroVention Inc./Sequent Medical, Balt (Irvine, CA, USA), Cerenovus/Johnson&Johnson (Irvine, CA, USA); received speakers honoraria from Cerenovus/ Johnson&Johnson, Acandis, Asahi (Tokyo, Japan), Q Apel (Fremont, CA, USA), Penumbra (Alameda, CA, USA), Medtronic, Stryker; received scientific grants from Cerenovus/ Johnson&Johnson. The other authors declare that they have no competing interests., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Cerebral aneurysms, especially large and giant aneurysms, pose challenges in neurointerventional surgery. Treatment choices involve clinical presentation, aneurysm details, and global resource variations. Neurointerventional methods, while innovative, may be cost restrictive in certain regions. In public healthcare, cost is crucial, notably in countries like Brazil. This study examines the device specific cost estimation of flow diverters (FD) and traditional stent assisted coiling (SAC) for large and giant cerebral aneurysms, providing insights into optimizing neurosurgical interventions within the Brazilian public health system's unique challenges., Methods: A comprehensive retrospective analysis was conducted at our medical center of cases of large and giant aneurysms treated between 2013 and 2023. Determination of the estimated number of coils for aneurysms previously treated with FDs at our center was made, with the cost of each case, and the difference between both treatments was calculated., Results: We investigated the profiles of 77 patients: 40 had large aneurysms (51.9%) and 37 had giant aneurysms (48.1%). Large aneurysms had a mean cost difference of US$274 (standard deviation (SD) $2071), underscoring the device specific cost estimation of FDs over SAC in their treatment. For giant aneurysms, the mean cost difference increased to $6396 (SD $2694), indicating FDs as the more economically sound choice., Conclusion: Our study indicated that, for the treatment of giant aneurysms and some large aneurysms, the FD intervention was more economical than SAC., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The Pipeline Flex embolization device with Shield technology (PED Shield) is the first flow diverter for brain aneurysm treatment approved in the United States using surface-modified technology. The effect of PED Shield on decreasing perioperative diffusion-weighted imaging positive (DWI+) hits, as a marker for in-human decrease thrombogenicity, is unclear., Objective: To determine if the number of periprocedural DWI+ lesions differs between patients with an aneurysm treated with PED Flex and PED Shield., Methods: This retrospective study compares the outcomes of consecutive patients with an aneurysm treated with PED Flex and PED Shield. The primary outcome of interest was the occurrence of DWI+ lesions. We also assessed potential predictors of DWI+ lesions and compared the outcomes between on-label and off-label treatment indications., Results: 89 patients were included, 48 (54%) treated with PED Flex and 41 (46%) with PED Shield. After matching, the incidence of DWI+ lesions was 61% and 62% for the PED Flex and PED Shield groups, respectively. Results were consistent across each model with no significant differences in DWI+ lesions between treatment groups, and effect sizes ranging from OR=1.08 (95% CI 0.41 to 2.89) after propensity score matching to OR=1.84 (95% CI 0.65 to 5.47) after multivariable regression. Multivariable models demonstrated reduced DWI+ lesions with balloon-assisted therapies and posterior circulation treatment, while a significant linear relationship was encountered with fluoroscopy time., Conclusion: There was no significant difference in the incidence of perioperative DWI+ lesions between patients with an aneurysm treated with PED Flex and PED Shield. Larger cohorts are likely needed to demonstrate differences between the devices., Competing Interests: Competing interests: RAH is a consultant for Medtronic, Stryker, Cerenovous, Microvention, Balt, Phenox, Rapid Medical, and Q’Apel. He is on the advisory board for MiVI, eLum, Three Rivers, Shape Medical, and Corindus. Unrestricted research grant from NIH, Interline Endowment, Microvention, Stryker, CNX, and Balt. Investor/stockholder for InNeuroCo, Cerebrotech, eLum, Endostream, Three Rivers Medical Inc, Scientia, RisT, BlinkTBI, and Corindus. AA is on an advisory board for iSchema View. JMP is employed by, and holds equity in, Superior Medical Experts and Nested Knowledge. All other authors have nothing to disclose., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Stent assisted coiling (SAC) and flow diverters (FDs) are common endovascular treatments for wide necked cerebral aneurysms, but studies comparing the new generation Atlas SAC and FDs are scarce. We performed a propensity score matched (PSM) cohort study to compare the Atlas SAC and the pipeline embolization device (PED) for proximal internal carotid artery (ICA) aneurysms., Methods: Consecutive ICA aneurysms treated at our institution with either the Atlas SAC or PED were studied. PSM was used to control for age, sex, smoking, hypertension, and hyperlipidemia, and the rupture status, maximal diameter, and neck size of the aneurysm (aneurysms >15 mm and non-saccular aneurysms were excluded). Midterm outcomes and hospital costs were compared between these two devices., Results: A total of 309 patients with 316 ICA aneurysms were included. Following PSM, 178 aneurysms treated with the Atlas SAC and PED were matched (n=89 in each group). Aneurysms treated with the Atlas SAC required a slightly longer procedure time, but had lower hospital costs than those treated with the PED (115.2±24.6 vs 102.4±40.8 min, P=0.012; $27 650.2±$6961.4 vs $34 107.0±$3707.2, P<0.001). Atlas SAC and PED treatments showed equivalent aneurysm occlusion rates (89.9% vs 86.5%, P=0.486), complication rates (5.6% vs 11.2%, P=0.177), and a favorable functional outcome (96.6% vs 97.8%, P=1.0) at follow-up (8.2±3.0 vs 8.4±4.2 months, P=0.652)., Conclusion: In this PSM study, midterm outcomes of the PED and Atlas SAC in the treatment of ICA aneurysms were similar. However, SAC required a longer operation time, and the PED may increase the economic cost of inpatients in Beijing, China., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Despite the growing sophistication of robot-assisted surgery, it is necessary to demonstrate that robots can reliably perform complex procedures on site and then remotely. Although a flow diverter stent is one of the most effective and widely used devices, its placement is sometimes challenging., Objective: To evaluate the feasibility and safety of the CorPath GRX robotic platform for the embolization of cerebral and cervical aneurysms using flow diverter stents., Methods: We performed a single-center technical study of the first 10 flow diverter stent deployments with the CorPath GRX Robotic System (Corindus Inc, Waltham, Massachusetts, USA) for the treatment of cerebral aneurysms between April and October 2022., Results: Ten patients underwent robot-assisted embolization with flow diverter stents: there were nine intracranial aneurysms (paraclinoid n=6; posterior communicating artery aneurysm n=1; anterior communicating artery n=2) and one cervical aneurysm. Four procedures were performed with coils plus a flow diverter stent, one was performed with woven endobridge plus a flow diverter stent and four were performed with flow diverter stents alone. Of these procedures, two were performed with telescoping flow diverters.All flow diverter stents were deployed with robotic assistance, with only one partial conversion to a manual technique (caused by guidewire torquability limitations). No perioperative complications were observed., Conclusion: Robot-assisted flow diverter stent deployment using the CorPath GRX platform is feasible and appears to be safe. Larger, in-depth studies of the technique's safety and benefits are now warranted., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Recurrent intracranial aneurysms (IAs) often present with more complex morphology such as irregular shape, shallow height, and wide neck, which can make for challenging endovascular treatments.1 Initial rupture and interventions are associated with fibrotic changes and considerable alteration in the aneurysm configuration, which limits retreatment options and increases the risk of complications during retreatment.2 The Woven Endobridge (WEB) embolization device has demonstrated high efficacy, flexibility, and safety for the treatment of wide-neck bifurcation IAs, including ruptured and recurrent IAs, as shown in multiple retrospective studies and meta-analyses.3-8 Due to its optimal barrel shape, the WEB device is useful in the setting of previously treated aneurysms, particularly with wide-neck previously coiled aneurysms.1 9 10 In this technical video of four cases (video 1), we describe the technical nuances of WEB embolization for recurrent IAs, which were initially either coiled or clipped and demonstrated progressive growth with a wide-neck presentation on follow-up. neurintsurg;16/3/226/V1F1V1Video 1Management of recurrent intracranial aneurysms via WEB: This video describes four recurrent intracranial aneurysms, which were initially either coiled or clipped but demonstrated progressive growth with a wide-neck presentation on follow-up. All cases were successfully treated via WEB., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Contour (Stryker, Kalamazoo, MI) is a relatively new endosaccular device for the treatment of intracranial aneurysms.1 2 Its unique cup-like shape permits treatment of most lesions, including wide-necked, irregular, and shallowed-shaped aneurysms. The sizing of the device only requires two parameters: neck size and equatorial plane (width). It must be positioned at the neck of the aneurysm with the device proximal marker in the parent artery. In our experience, dual antiplatelet therapy is usually not required for intrasaccular devices and this is also an advantage of the Contour device. We report two illustrative cases of wide-neck aneurysms in the anterior and posterior circulation, respectively (video 1). In this video we demonstrate the feasibility of this treatment in a middle cerebral artery bifurcation with atypical triangular shape and typical tip-basilar aneurysm. neurintsurg;16/3/225/V1F1V1Video 1 ., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Vertebral-basilar artery dissecting aneurysms (VADAs) are an uncommon phenomenon in all fields of cerebrovascular disease. The flow diverter (FD) can be used as an endoluminal reconstruction device that promotes neointima formation at the aneurysmal neck and preserves the parent artery. To date, imaging examinations such as CT angiography, MR angiography, and DSA are the main methods used to evaluate the vasculature of patients. However, none of these imaging methods can reveal the situation of neointima formation, which is of great importance in evaluating occlusion of VADAs, especially those treated with a FD., Methods: Three patients were included in the study from August 2018 to January 2019. All patients underwent preprocedural, postprocedural, and follow-up evaluations with high resolution MRI, DSA, and optical coherence tomography (OCT), as well as the formation of intima on the surface of the scaffold at the 6 month follow-up., Results: Preprocedural, postoperative, and follow-up high resolution MRI, DSA, and OCT of all three cases successfully evaluated occlusion of the VADAs and occurrence of in stent stenosis from different views of intravascular angiography and neointima formation., Conclusions: OCT was feasible and useful to further evaluate VADAs treated with FD from a near pathological perspective, which may contribute toward guiding the duration of antiplatelet medication and early intervention of in stent stenosis., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Flow-diverting stents are not currently indicated for the treatment of bifurcation aneurysms, and some case series have demonstrated low occlusion rates, possibly due to a lack in neck coverage. The ReSolv stent is a unique hybrid metal/polymer stent that can be deployed with the shelf technique in order to improve neck coverage., Methods: A Pipeline, unshelfed ReSolv, and shelfed ReSolv stent were deployed in the left-sided branch of an idealized bifurcation aneurysm model. After determining stent porosity, high-speed digital subtraction angiography runs were acquired under pulsatile flow conditions. Time-density curves were created using two region of interest (ROI) paradigms (total aneurysm and left/right), and four parameters were extracted to characterize flow diversion performance., Results: The shelfed ReSolv stent demonstrated better aneurysm outflow alterations compared to the Pipeline and unshelfed ReSolv stent when using the total aneurysm as the ROI. On the left side of the aneurysm, there was no significant difference between the shelfed ReSolv stent and the Pipeline. On the right side of the aneurysm, however, the shelfed ReSolv stent had a significantly better contrast washout profile than the unshelfed ReSolv stent and the Pipeline stent., Conclusions: The ReSolv stent with the shelf technique demonstrates the potential to improve flow diversion outcomes for bifurcation aneurysms. Further in vivo testing will help to determine whether the additional neck coverage leads to better neointimal scaffolding and long-term aneurysm occlusion., Competing Interests: Competing interests: DM and SG are employed by Fluid Biomed Inc. ME is a shareholder of Fluid Biomed Inc. DF is on the editorial board of the Journal of NeuroInterventional Surgery; has received consulting, proctoring, and/or research support from Balt USA, MicroVention, Prenumbra, and Stryker; and is a shareholder of Marblehead, Mentice Inc, Neurogami Medical Inc., NV Med, and Scientia Medical. JHW is a co-founder and shareholder of Fluid Biomed Inc, and holds patents related to the technology described in this manuscript. CS has received consulting, proctoring, and/or research support from Stryker Neurovascular, Medtronic Neurovascular, Rapid Medical, Balt USA, Siemens Healthineers, and Mentice Inc. APM received research support from Evolve2Innovate, Fluid Biomedical, and Stryker Neurovascular; is a consultant for Cerus Endovascular; is a co-founder and shareholder of Fluid Biomed Inc; and holds patents related to the technology described in this manuscript., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The Willis covered stent (WCS) and pipeline embolization device (PED) have partly overlapping therapeutic indications. However, the differences of effect between these two treatments remain unclear., Objective: To compare clinical outcome, angiographic outcome, and complications following treatment with a WCS versus PED., Methods: Patients with intracranial aneurysms treated by a WCS or PED between January 2015 and December 2020 were included. The primary outcomes were complications, clinical outcome (modified Rankin Scale score >2), and angiographic outcome (incomplete aneurysm occlusion). Propensity score matching was conducted to adjust for potential confounding factors., Results: A total of 94 aneurysms treated by WCS and 698 aneurysms by PED were included. Compared with the PED group, patients in the WCS group are younger, a greater number have a poor condition at admission, a larger proportion of ruptured, non-saccular, and anterior circulation aneurysms, a smaller aneurysm neck width, and less coiling assistance is required. A total of 42 (44.7%) branches were covered by WCS. After adjustment for age, sex, aneurysm type, rupture status, neck size, aneurysm location, and coiling, 50 WCS and PED pairs were examined for internal carotid artery aneurysms. No significant differences were observed in clinical (10.4% vs 2.1%, P=0.206) and angiographic outcomes (12.8% vs 18.2%, P=0.713). However, 27 branches covered by WCS, including 22 ophthalmic arteries and five posterior communicating arteries. Patients in the WCS group had a higher intraoperative complication rate than those in the PED group (28% vs 6%, P=0.008), especially in the occlusion rate of covered branches (51.9% vs 11.1%, P<0.001)., Conclusion: The comparable clinical and angiographic outcomes of WCS or PED demonstrate the therapeutic potential of WCS as a viable alternative for aneurysms. However, the complication of occlusion of covered branches might not be negligible., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The FRED X flow diverter (FREDX), as the second generation in the FRED series, aims to improve the treatment of cerebral aneurysms. This study compares the efficacy and safety of FREDX with its predecessor, FRED., Methods: This prospective registry included patients treated with FRED and FREDX devices. Efficacy was assessed using digital subtraction angiography with 3D volumetric reconstruction at immediate and 1 year follow-ups. Safety was evaluated by recording complications, analyzed through univariate contrasts, generalized mixed models, and Bayesian network analyses., Results: We treated 287 patients with 385 aneurysms, with 77.9% receiving FRED and 22.1% FREDX. The median age was 55 years (IQR 47-65) and 78.4% were women. The FREDX group showed a higher prevalence of saccular-like aneurysms (70.6% vs 52.7%, P=0.012) and a higher rate of complete occlusion compared with FRED interventions (79.4% vs 59.3%, P=0.022). After adjusting for confounders, these differences represented a 3.04-fold increased likelihood (95% CI 1.44 to 6.41, P=0.003) of achieving complete occlusion at 1 year with FREDX interventions. Regarding safety, two (3.5%) complications (both non-symptomatic) were observed in the FREDX group and 23 (10.4%) in the FRED group (P=0.166). Bayesian network analysis suggested a trend towards fewer complications for FREDX, with a median reduction of 5.5% in the posterior distribution of the prevalence of complications compared with FRED interventions., Conclusions: The FREDX device shows improved complete occlusion rates at 1 year compared with the FRED device while maintaining a favourable safety profile, indicating its potential advantage in the treatment of cerebral aneurysms., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The Pipeline Embolization Device has proven to be a safe and effective device for the treatment of intracranial aneurysms. The Pipeline Vantage Flow Diverter (PVFD) with Shield Technology is the new fourth generation of this implant, with modifications made compared to previous iterations. We aimed to evaluate the mechanical properties and clinical safety and efficacy of this device., Methods: Vanguard is a single arm, single center, prospective study. Between April 2021 and April 2023, all consecutive patients with an unruptured aneurysm treated with Pipeline Vantage flow-diverting stents were included. There were no aneurysm size or location exclusion criteria. Safety (neurological serious adverse events) and efficacy (device deployment and aneurysm occlusion) were independently reviewed. Imaging follow-up data, and immediate, early (<30 days), and delayed (>30 days) neurological serious adverse events were independently assessed., Results: 101 consecutive patients with a total of 115 aneurysms were included. The aneurysms were situated in the anterior (90.4%) or posterior (9.6%) circulations. A total of 124 devices were implanted. The deployment success rate was 100%. In four (4.0%) cases post-deployment angioplasty was required to optimize device wall apposition. Occlusion rates at 1 month were 54.7%, at 3 months 72.1%, and at 6 months 81.7%. Morbidity and mortality were 4.9% and 0%, respectively, at 6 months. Eight cases (6.9%) demonstrated in-stent stenosis, four of which had 'fish mouth' deformity., Conclusion: Initial results of the new generation PVFD for unruptured intracranial aneurysm treatment demonstrate overall satisfactory device performance, safety profile, and effectiveness., Competing Interests: Competing interests: HR and LV: consultants for Medtronic, Stryker, Microvention, Philips, Corindus. No disclosures or competing interests were declared by the remaining authors., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Flow diverter (FD) devices provide a safe and effective treatment option especially for wide-necked intracranial aneurysms. One of the main concerns in patients treated with FD devices is patency of arterial branches jailed by the stent. However, there are no long-term data from magnetic resonance perfusion (MRP) studies regarding jailed branches. In this study we aimed to reveal the MRP findings in patients with jailed middle cerebral artery (MCA) cortical branches during long-term follow-up after flow diversion., Methods: Patients who underwent FD stent treatment for MCA aneurysms with a resulting jailed cortical branch were included. Follow-up clinical, angiographic, and MRP examination findings were recorded. Different MRP parameters were measured in the MCA territory regarding the jailed branches., Results: Eighteen patients treated endovascularly with flow diversion for a total of 20 MCA aneurysms were included. At angiographic follow-up (median 35 months, range 7-95 months) complete occlusion was observed in 13 (65%) aneurysms and partial occlusion was observed in 6 (30%). The mean transit time (MTT) prolongation, MTT ratio, time-to peak (TTP) prolongation, and TTP ratio were 1.34, 1.20, 1.18, and 1.06 s, respectively, when compared with the contralateral side in the MCA territory. MTT, TTP, and cerebral blood volume values of the patients showed statistically significant differences compared with the contralateral side (P<0.05)., Conclusions: Flow diversion treatment of complex bifurcation aneurysms can be effective and safe. MRP examination may reveal perfusion changes in the territory vascularized via a jailed branch, and these changes are rarely accompanied by clinical findings., Competing Interests: Competing interests: CI has a consulting and proctoring agreement with Medtronic, Inc., outside of this work. NK has a consulting and proctoring agreement with MicroVention, Inc. and Medtronic, Inc., outside of this work. OK has a consulting and proctoring agreement with Acandis GmbH and Stryker, Inc., outside of this work. The other authors have no conflicts of interest to declare., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Basilar artery (BA) fenestration aneurysm (BAFA) is a rare phenomenon commonly accompanying other aneurysms. Treatment is challenging, and few cases have been reported. This review investigated the management outcomes of BAFAs., Methods: Publication databases were searched to identify studies evaluating outcomes of endovascular treatment (EVT) and microsurgical treatment of BAFAs from inception through 2021. Outcomes (clinical, angiographic, postoperative complications, and retreatment rates) were collected and analyzed. The authors present their case of a patient treated for a BAFA., Results: Including the authors' case, 184 patients with 209 BAFAs were reported in 68 studies. Most patients (130/175; 74.3%) presented with ruptured aneurysms, most commonly involving the proximal segment of the BA. Most BAFAs were small (52/103, 50.5%) and saccular (119/143, 83.2%). Most patients underwent EVT (143/184, 77.7%); the rest underwent microsurgery. Postoperative complications after EVT occurred in 10 (8.3%) of 120 patients, with 4 of the 10 experiencing strokes. At clinical follow-up, most EVT patients (74/86, 86.0%) showed good outcomes; 3.9% (2/51) had died. Most aneurysms managed with EVT (56/73, 76.7%) showed complete occlusion at follow-up; 7.3% (8/109) were retreated. Postoperative complications occurred in 62.2% (23/37) of microsurgical patients; 5 (21.7%) of the 23 experienced strokes. All patients showed good clinical outcomes at follow-up. Most aneurysms (22/28, 78.6%) treated microsurgically showed complete occlusion at angiographic follow-up, with no retreatment required., Conclusion: BAFAs are often symptomatic; thus, treatment is challenging. By the 2000s, treatment had moved from microsurgical to endovascular modalities, with good clinical and angiographic outcomes., Competing Interests: Competing interests: FCA and AFD are on the editorial board for Journal of NeuroInterventional Surgery. No prior submissions or presentations., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The aim of this study was to evaluate the overall rates of braid changes associated with flow diverter (FD) treatment for intracranial aneurysms (IAs). Additionally, we sought to provide an overview of the currently reported definitions related to these complications., Methods: A systematic search was conducted from the inception of relevant literature up to April 2023, encompassing six databases. The included studies focused on patients with IAs treated with FDs. We considered four main outcome measures as FD braid changes: (1) fish-mouthing, (2) device braid narrowing, (3) device braid collapsing, and (4) device braid deformation. The data from these studies were pooled using a random-effects model., Results: A total of 48 studies involving 3572 patients were included in the analysis. Among them, 14 studies (39%) provided definitions for fish-mouthing. However, none of the included studies offered specific definitions for device braid narrowing, collapsing, or deformation, despite reporting rates for these complications in six, five, and three studies, respectively. The pooled rates for braid changes were as follows: 3% (95% CI 2% to 4%, I 2 =27%) for fish-mouthing, 7% (95% CI 2% to 20%, I 2 =85%) for narrowing, 1% (95% CI 0% to 3%, I 2 =0%) for collapsing, and 1% (95% CI 1% to 4%, I 2 =0%) for deformation., Conclusion: The findings of this study suggest that FD treatment for IAs generally exhibits low rates of fish-mouthing, device braid narrowing, collapsing, and deformation. However, the lack of standardized definitions hinders the ability to compare device outcomes objectively, emphasizing the need for uniform definitions for FD braid changes in future prospective studies on FD., Competing Interests: Competing interests: SO-G: grants from NIH, Stryker, Medtronic, Microvention, MEthinks, IschemiaView, Viz.ai, Siemens; consulting fees from Medtronic and Stryker. HSC receives consulting fees from Medtronic and MicroVention and holds stock or stock options in Neuravention Inc, Vesalio Inc, Bend It Tech, Syncron, Prometheus Inc, Piraeus Inc, Sim Research Support: Microvention, Stryker, Balt USA, Siemens; Scientific Advisory Boards: Scientia Medical, NVMed, Perfuze; holds stock in: MENTICE-Vascular Simulations, Neurogami, Marblehead, Scientia Medical, NVMed, Perfuze. PL receives consulting fees from Medtronic, Cerevasc, and Phenox GmbH (paid to his institution); honoraria from Medtronic (paid to him); and support for attending meetings and/or travel from Cerevasc, Medtronic, and Philips (paid to him); and participates on the Cerevasc data safe monitoring board. VMP is an unpaid consultant for Siemens Healthinners Endovascular Robotics. JF reported compensation from Acandis, Cerenovus, MicroVention, Medtronic, Penumbra, Phenox, Roche, Stryker, Tonbridge and stock holdings in Eppdata GmbH and Tegus Medical outside the submitted work., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The anterior communicating artery (AComm) region is the most common site of intracranial aneurysms, with increased rupture risk compared with other locations. Overall, flow diverters present as a safe and efficacious treatment for intracranial aneurysms, but there is paucity of data for their use in the treatment of unruptured AComm aneurysms. We present the largest multicentric analysis evaluating the outcomes of flow diverters in AComm aneurysm treatment., Methods: Databases from 10 centers were retrospectively reviewed for unruptured AComm aneurysms treated with flow diverters. Demographics, clinical presentation, radiographic characteristics, procedural complications, and outcomes were assessed., Results: A total of 144 patients harboring 147 AComm aneurysms were treated between January 2012 and December 2021. Seventy-four were women (51.4%) and median age was 60 (IQR 50-67) years. All were unruptured AComm aneurysms. Half of the cohort had similar anterior cerebral artery sizes (51.4%). The most common morphology was saccular (94.6%), with a branch involvement in 32.7% of cases. Median vessel diameter was 2.4 mm, and the Pipeline Flex was the most prevalent device (32.7%). Median follow-up time was 17 months, with complete occlusion in 86.4% at the last follow-up. Functional independence (modified Rankin Scale score 0-2) was reported in 95.1%. Intraprocedural complications occurred in 5.6%, and postoperative complications were noted in 9.7% of cases. Combined major complication and mortality rate was 2.1%., Conclusions: Our study suggests that flow diverters are a useful treatment for AComm aneurysms. Mid-term results indicated favorable aneurysm occlusion with a good safety profile. Additional prospective studies with longer follow-up periods and independent adjudication are warranted to better assess these results., Competing Interests: Competing interests: IS is a consultant for Medtronic and Microvention. HSC is a stockholder from Neuravention, Vesalio, Syncron Tech, Bend It Tech, and Sim&Size, and is a consultant for Medtronic and Microvention. NK is a consultant and proctoring for Microvention. CI is a speaker for Microvention, holds patent from 4D G1 coil, and is a stockholder of Neuravention and Bend It. GD has consulting agreements with Microvention, Medtronic, Cerenovus, Stryker, Penumbra, and InNeuroCo. RAH is a consultant for Medtronic, Stryker, Cerenovous, Microvention, Balt, Phenox, Rapid Medical, and Q'Apel, is on the advisory board for MiVI, eLum, Three Rivers, Shape Medical, and Corindus, has unrestricted research grants from NIH, Interline Endowment, Microvention, Stryker, and CNX, and is an investor/stockholder for InNeuroCo, Cerebrotech, eLum, Endostream, Three Rivers Medical, Scientia, RisT, BlinkTBI, and Corindus. VMP serves as a consultant/steering committee member for Stryker, Penumbra, and Balt, a consultant for Medtronic and Neurovasc, and receives a research grant from Philips. DKL reports conflicts of interest with Medtronic and Stryker, being the national PI of the ADVANCE trial, receiving research grants, and being part of their advisory board., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)