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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.)

Background: The Surpass flow diverter was developed to treat intracranial aneurysms not amenable to standard treatment. Indications for use allow placement in the internal carotid artery to the terminus, including the communicating artery segment., Methods: The Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide Neck Aneurysms (SCENT) trial is an international, multicenter, prospective, non-randomized trial comparing the outcomes of Surpass flow diverter treatment with historic control designed to evaluate the effectiveness and safety of Surpass for the treatment of wide neck (≥4 mm) large or giant intracranial aneurysms ≥10 mm. The primary effectiveness endpoint is the percentage of subjects with 100% aneurysm occlusion without significant stenosis of the parent artery and without retreatment of the target aneurysm at 12 months. The primary safety endpoint is the percentage of subjects experiencing neurologic death or major ipsilateral stroke at 12 months. We report the effectiveness and safety of flow diversion in the subgroup of posterior communicating artery (PComA) aneurysms., Results: Of the 180 patients treated, 38 harbored a PComA aneurysm. Mean aneurysm size was 12.2 mm and mean neck width was 4.8 mm. The mean number of Surpass devices used was 1.1 per procedure, with 94.7% of aneurysms treated with one flow diverter. The 12 month primary effectiveness rate was 73.7% (28/38). At 36 months, 68.4% (26/38) of aneurysms remained completely occluded. The 12 month major ipsilateral stroke or neurological death rate was 10.5%. No patients with PComA occlusion after flow diverter placement (54.5%) had clinical sequelae., Conclusions: SCENT demonstrated acceptable 12 month effectiveness of flow diversion in PComA aneurysms. Despite associated PComA occlusions in many cases, arterial occlusions were clinically silent., Trial Registration Number: URL: https://www., Clinicaltrials: gov. Unique identifier: NCT01716117., Competing Interests: Competing interests: PK: consultant for Stryker and Cerenovus, and stockholder of InNeuroCo; editorial board member of Journal of NeuroInterventional Surgery; and education chair of the Society of NeuroInterventional Surgery. PMM: consultant for Stryker, Medtronic, and Penumbra. ALC: consultant for Stryker, Medtronic, Microvention, and InNeuroCo. AKW: research grant from Philips Medical; serves as a consultant for Stryker; is a stockholder of InNeuroCo, NovaSignal, Rist, Analytics 4 Life, and ThrombX; and is on the speakers’ bureau for the SCENT trial (Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide Neck Aneurysms) presentations. JD: consultant for Stryker and Evasc. KE: consultant for Stryker and Microvention. RAH: research grant from Medtronic, Stryker, Microvention, and Cerenovus; consultant for Stryker, Medtronic, Cerenovus, and Microvention; stockholder in Neurvana, Elum, EndoStream, Three Rivers Medical Inc, Rist, Cerebrotech, and InNeuroCo; scientific advisor for MIVI, Elum, Three Rivers Medical Inc, and Shape Medical. PT: consultant for Medtronic, Cerenovus, and Stryker., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Mycotic aneurysms represent a rare type of intracranial aneurysm. Treatment options usually consist of coiling, clipping, or liquid embolization. Data regarding outcomes after flow diversion of mycotic aneurysms are sparse., Objective: To present a single-center case series regarding our experience with FD as definitive treatment for ruptured mycotic aneurysms initially treated with coil embolization., Methods: We retrospectively reviewed a prospectively maintained database of all cerebrovascular procedures performed at a single institution between 2017 and 2021 for cases that used FD for the management of intracranial mycotic aneurysms. Prospectively collected data included patient demographics, medical history, rupture status, aneurysm morphology, aneurysm location, and periprocedural complications. The main outcomes included neurological examination and radiographic occlusion rate on cerebral digital subtraction angiography., Results: Three patients with 4 ruptured mycotic aneurysms that were initially treated with coil embolization were identified that required retreatment. The aneurysms were located along the middle cerebral artery bifurcation (n = 2), posterior cerebral artery P1/2 junction (n = 1), and basilar artery apex (n = 1), which all demonstrated recurrence after initial coil embolization. Successful retreatment using flow diverting stents was performed in all 3 patients. At the last angiographic follow-up, all aneurysms demonstrated complete occlusion. No patients suffered new periprocedural complications or neurological deficits after FD., Conclusion: Flow-diverting stents may be an effective treatment option for intracranial mycotic aneurysms that are refractory to previous endovascular coiling. Future studies are warranted to establish the associated long-term safety and clinical efficacy., (Copyright © Congress of Neurological Surgeons 2022. All rights reserved.)

Objective: Intracranial aneurysms are present in up to 18% of arteriovenous malformations (AVMs) and increase the risk of intracranial hemorrhage. No consensus exists on the optimal treatment strategy for AVM-associated aneurysms. The goal of this study was to systematically review endovascular treatment methods of AVM-associated intracranial aneurysms, radiographic outcomes, and periprocedural complications., Methods: A systematic review was performed in accordance with PRISMA guidelines to identify studies that investigated the use of endovascular treatments for management of patients with AVM-associated aneurysms. Collected variables included aneurysm and AVM location, aneurysm size and characteristics, AVM and aneurysm treatment modality, periprocedural complications, and long-term clinical and radiographic outcomes., Results: Eight studies with 237 patients and 314 AVM-associated intracranial aneurysms were included. Two-hundred and twenty-four aneurysms were flow-related (71.3%), 80 were intranidal (25.5%), and 10 were unrelated (3.2%). Complete occlusion was 56.3% (18/32) for aneurysmal coil embolization and 99% (104/105) for parent vessel sacrifice. Of the 13 aneurysms treated with ethanol sclerotherapy, 8 were successfully obliterated (8/13; 61%) using ethanol sclerotherapy alone and the rest required adjunct endovascular embolization for obliteration of the artery and associated aneurysm. The periprocedural complication rate was approximately 12% and consisted of ischemic symptoms, intracranial hemorrhage, and coiling complications., Conclusions: Endovascular management options of AVM-associated intracranial aneurysms are limited and mostly comprised primary aneurysmal coil embolization or parent vessel sacrifice using coils or liquid embolics. Embolization strategy depends on factors such as AVM angioarchitecture, rupture status, and adjunct AVM treatments., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Flow diversion has revolutionized endovascular treatment for cerebral aneurysms. The Surpass Streamline flow diverter (SSFD) has shown promise for expanding flow diversion device options for aneurysm treatment. SSFD differs from earlier stents by maintaining high porosity with increased pore density to ensure appropriate flow disruption. Given the delivery system's increased dimension options and potential greater flow-diverting properties, SSFD is poised to extend the anatomic and pathologic reaches of flow diversion therapy., Methods: Data pertaining to SSFD-treated aneurysms were gathered retrospectively between 2019 and 2020, including aneurysm location, size, symptoms, complications, and occlusions rates at follow-up. Size was categorized as small (<10 mm), large (10-25 mm), and giant (>25 mm) according to SCENT (Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide Neck Aneurysms) criteria. Aneurysm occlusion on follow-up imaging was characterized by Simple Measurement of Aneurysm Residual after Treatment (SMART) grading with adequate occlusion defined as grades 3 and 4. Imaging was performed at time of treatment and 6-month and 1-year follow-up., Results: There were 42 aneurysms treated with SSFD throughout the cerebrovascular system: 3 cervical, 4 posterior, and 35 intracranial anterior circulation. Complete occlusion rates at 6 months and 1 year were 48% and 57% with adequate occlusion achieved in 89.6% and 85.7%, respectively. Rates of complete occlusion were higher for small (69%) compared with large (38%) aneurysms., Conclusions: Our data suggest comparable complete occlusion rates compared with SCENT (66.1% vs. 57% in our center) and adequate occlusion rates. Similar occlusion rates to prior studies despite broadened inclusion criteria and diversity of treated aneurysms demonstrate favorable generalizability of flow-diverting technology to a wide array of aneurysmal pathology., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Introduction: The low-profile Neuroform Atlas stent received FDA Humanitarian Device Exemption status (HDE) in January 2018 for stent-assisted coil embolization of wide-necked saccular aneurysms. We review and report our results with the Atlas stent in our institution within the first year after its HDE approval., Methods: Our retrospective chart review identified patients treated with the Atlas stent. We analyzed the patient demographics, aneurysm characteristics, stent parameters and configuration, complications, angiographic, and clinical outcomes at discharge., Results: From January to December 2018, 76 Atlas stents were deployed in 58 patients (average 1.3 stents/patient). Median patient age was 63.5 (IQR 56-71) years. Fifty-six (96.6%) patients had elective embolization of unruptured aneurysms, while two (3.4%) patients underwent embolization of a ruptured aneurysm within 2 weeks of subarachnoid hemorrhage. Forty (69.0%) patients were treated with a single stent, 15 (25.9%) with a Y-stent, and three (5.2%) with X-stent configuration. All stent deployments were technically successful. Most stents (82.9%) were the smallest 3 mm diameter devices. Procedural complications included transient stent-associated thrombosis in three (5.2%) patients and aneurysm rupture in one (1.7%). None had distal embolization, associated cerebral infarction, or permanent neurological deficits. Immediate Raymond-Roy 1 occlusion was achieved in 41 (70.7%) patients. Median hospital length of stay for elective aneurysm embolization was 1 day. Excellent outcomes with median National Institute of Health Stroke Scale score 0 (IQR 0-0) and modified Rankin Score 0 (IQR 0-1) were seen for elective patients at discharge., Conclusion: The Neuroform Atlas stent provided a reliable technical and safety profile for the treatment of intracranial wide-neck aneurysms. Further experience is needed to determine long-term durability and safety of this device., Competing Interests: Competing interests: MB is a consultant for Rebound Therapeutics and Stryker Neurovascular. MSH is a consultant for Cerenovus. PAR is on the Medical Advisory Board for Mehana Medical, Stryker Neurovascular, Medtronic Neurovascular, Perflow Medical, and has an Equity Position in Mehana Medical, Perflow Medical, and Bard Neurovascular. GT is a consultant for Dynamed EBSCO., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Anterior inferior cerebellar artery (AICA) aneurysms are rare lesions whose treatment can involve microsurgical and/or endovascular techniques. Such treatment can be challenging and may carry a significant risk of neurological morbidity., Objective: To demonstrate a case involving a complex AICA aneurysm that was treated with a unique microsurgical approach involving trapping the aneurysm and performing in Situ bypass from the posterior inferior cerebellar artery (PICA) to the distal AICA. The nuances of AICA aneurysms and revascularization strategies are discussed., Methods: The aneurysm and the distal segments of AICA and PICA were exposed with a retrosigmoid and far lateral approach. A side-to-side anastomosis was performed between the adjacent caudal loops of PICA and AICA. The AICA aneurysm was then treated by trapping the aneurysm-bearing segment of the parent vessel between 2 clips., Results: A postoperative angiogram demonstrated a patent PICA-AICA bypass and complete occlusion of the AICA aneurysm. There were no complications, and the patient made an excellent recovery., Conclusion: The combination of parent vessel sacrifice and bypass remains an excellent option for certain difficult-to-treat aneurysms. This case involving PICA-AICA bypass to treat an AICA aneurysm serves as an example of the neurosurgeon's ability to develop unique solutions that take advantage of individual anatomy.

Delivery wire fracture of flow-diverter stents are rare but have been described. We describe a video case of a successful technique to retrieve such a fractured delivery wire by using a balloon microcatheter and the intermediate catheter when other proven methods may fail.

Purpose: Blood blister-like aneurysms (BBA) are small, friable, broad-based aneurysms that represent high risk for rerupture. Treatment of BBA is challenging, and may include surgical wrapping, clipping, multiple overlapping stents, and/or coiling. Flow diversion is a rapidly evolving treatment strategy for intracranial aneurysms, but the evidence for its use in cases of BBA is scarce., Methods: A retrospective review of flow-diverter-treated, ruptured BBA cases at our tertiary care institution was undertaken. Clinical, imaging, procedural, and mid-term follow-up data on the patients were collected., Results: Eight patients underwent flow-diverter stent treatment for ruptured BBA. Median age at time of treatment was 49 years (interquartile range [IQR] 42-57) with five females (62.5%). The most common location of the BBA was the supraclinoid segment of the internal carotid artery. The median Hunt-Hess score was 2 (IQR 1.7-3.2). All patients were treated with dual anti-platelet therapy. Good clinical outcomes (modified Rankin score 0-2) were seen in 6/7 (85.7%) patients with available follow-up at 1 year. Complete occlusion of the aneurysm on latest angiogram (7) or MRI (1) was seen in 6/8 (75%) patients (at a median of 8 months). No patient had rerupture, retreatment, or recurrence of the aneurysm., Conclusion: Flow-diverter stents may be a feasible treatment option for BBAs. They offer high occlusion and low retreatment rates with good mid-term outcomes, but the long-term efficacy remains unknown. Also, dual anti-platelet therapy in the acute ruptured setting can be challenging.

Objective: To assess technical success and clinical and imaging outcomes of flow diversion (FD) treatment of multiple, tandem intracranial aneurysms., Methods: Retrospective analysis was performed of patients treated with FD for tandem intracranial aneurysms., Results: Twenty female patients with a mean (±SD) age of 60 (±12) years were included. One patient was treated after subarachnoid hemorrhage. In 22 separate procedures, 47 aneurysms, all located in the intracranial internal carotid artery, were treated. In 3 cases, treatment was performed for aneurysm recurrence after previous endovascular treatment. All aneurysms were successfully treated in 1 session. A single stent was used in most (82%) cases, with no adjunctive coiling. There were no intraprocedural complications. Three patients experienced mild, transient neurologic symptoms after the procedure with no long-term neurologic deficits. Follow-up imaging with digital subtraction angiography and/or contrast-enhanced magnetic resonance angiography was available in 18/20 (90%) patients at an average (±SD) of 18.8 (±11.2) months. Of 40 aneurysms with follow-up imaging, 34 (85%) were completely occluded. Clinical follow-up, available in 20/20 (100%) patients, showed that 19/20 (95%) achieved a modified Rankin Scale score of 0-2. There were no cases of aneurysm rupture after treatment, and no patients required retreatment at last available follow-up., Conclusions: FD appears technically feasible, safe, and effective for treatment of tandem intracranial aneurysms, with potential advantages over traditional endovascular or surgical treatment modalities. Larger studies are needed to confirm these findings., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Introduction: Intracranial vertebral dissecting pseudoaneurysms are a rare, but increasingly recognized, cause of subarachnoid hemorrhage and ischemic stroke. The risks of aneurysm re-rupture and associated morbidity are high. The use of flow diverter stents for the treatment of these aneurysms has not been well studied., Objective: To report our data and provide a summarized review of literature using flow diverter stents for the treatment of intracranial vertebral artery dissecting pseudoaneurysms., Methods: We performed a retrospective analysis of flow diverter stents used for the treatment of intracranial vertebral artery dissecting pseudoaneurysms. Clinical, imaging, procedural, and follow-up data were collected., Results: We identified eight vertebral dissecting pseudoaneurysms in seven patients (5 (71.4%) female; median age 47 years (IQR 46-52)) who had undergone treatment with flow diverter stents. In 4/7 patients (57.1%) the aneurysm had ruptured; however, only one was treated in the acute phase. Median size of the largest diameter of the aneurysm was 6.3 mm (IQR 4.2-8.8), and 7/8 aneurysms (87.5%) were treated with a single flow diverter device. Three aneurysms were concurrently coiled. Angiographic complete occlusion was seen in 6/8 (75%) aneurysms at a median follow-up of 14 months (IQR 7.7-20.2). Two patients had periprocedural strokes with transient neurologic deficits. All patients had a good clinical outcome (modified Rankin Scale score ≤2). There were no re-treatments or aneurysm ruptures during the follow-up period., Conclusions: Our experience suggests that flow diverter stent treatment of intracranial vertebral artery dissecting pseudoaneurysms is safe, and associated with good occlusion rates and favorable clinical outcomes., Competing Interests: Competing interests: MB: Codman and Stryker consultant. Clinical Events Committee for the BARREL trial. MSH: Pulsar Inc, Clinical Events Committee. PR: Medtronic Neurovascular—Scientific Advisory Board; Genentech—consultant/honorarium; Nervive Medical—Scientific Advisory Board and stock holder; Perflow Medical—Scientific Advisory Board and stock holder; Stryker Neurovascular—Scientific Advisory Board. GT: Data Safety Monitoring Board for the COMPASS trial., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background: Patients with Moyamoya or other intracranial steno-occlusive disease are at risk for developing aneurysms associated with flow through collateral vessels. Because these lesions are rare, the optimal management remains unclear. Here, we describe 2 cases of microsurgical repair of ruptured collateral vessel aneurysms associated with middle cerebral artery (MCA) occlusion., Case Description: The first patient was a 61-year-old man who presented with right frontal and intraventricular hemorrhage. Angiography revealed chronic right M1 occlusion and a 3-mm spherical lenticulostriate aneurysm. The frontal lobe hematoma was evacuated to reveal the aneurysm, which was safely cauterized and resected by coagulating and dividing the lenticulostriate parent vessel. The procedure was carried out with neuronavigation guidance and intraoperative neuromonitoring. The patient was discharged with no neurologic deficits. The second patient was a 53-year-old woman who presented with subarachnoid and intracerebral hemorrhage. Computed tomography angiogram showed a 2-mm saccular MCA aneurysm. Emergency left decompressive hemicraniectomy and hematoma evacuation were performed. The aneurysm, arising from a small collateral type vessel, was safely clipped without complications. Postoperative angiography revealed absence of the superior MCA trunk with a dense network of collateral vessels at the site of the clipped aneurysm. The patient recovered well and was ambulating independently 6 months postoperatively. No rebleeding occurred in the 2 patients., Conclusions: Our experience suggests that patients with MCA occlusion can harbor associated aneurysms related to flow through collateral vessels and can present with hemorrhage. Microsurgical repair of these aneurysms can be performed safely to prevent rebleeding., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: The long-term effect of flow diversion (FD) on aneurysms has not been well studied., Objective: We aimed to assess the effect of the Pipeline embolization device (Covidien, Irvine, California, USA) on large and giant intracranial aneurysms with magnetic resonance imaging (MRI) and digital subtraction angiography (DSA) and then correlate with clinical follow-up., Methods: We conducted a retrospective analysis of aneurysms treated solely with Pipeline without adjunctive therapy. The largest aneurysm diameters were compared with pretreatment and post treatment MRI and correlated with DSA and clinical symptoms., Results: Twelve patients harboring large and giant saccular unruptured aneurysms, treated with Pipeline, were included. Mean follow-up times were as follows: MRI 22.8 months (range 1-57), DSA 18.2 months (range 1-33), and clinical 29 months (range 1-48). Ten (83%) of 12 treated aneurysms decreased in size on MRI, which was first seen at an average of 17 months (range 4-57). In 70% of patients the change was noted on MRI ≤1 year after treatment, at an average of 9.1 months (range 4-12). MRI reduction was more likely in angiographically occluded aneurysms. Five aneurysms with complete occlusion on early angiogram showed size reduction on MRI only at ≥12 months. Mean aneurysm size reduction was 57% (range 19.6-94.2), which correlated well with improvement of cranial neuropathies in 75% and headaches in 100% of patients., Conclusion: Most aneurysms treated with Pipeline decreased in size, correlating with clinical improvement. Some aneurysms remained unchanged on MRI until a later time point despite early DSA occlusion. It may be reasonable to eliminate early postprocedural imaging and start follow-up only as late as 1 year after FD treatment in clinically stable, asymptomatic patients., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: There is scant information on in-stent stenosis after flow diversion treatment of intracranial aneurysms with the Pipeline Embolization Device (PED)., Objective: To assess the incidence, severity, nature, and clinical consequences of in-stent stenosis on angiographic follow-up after treatment with the PED., Methods: A retrospective study of patients who underwent aneurysm treatment with the PED was conducted. In-stent stenosis was assessed on subsequent follow-up angiography. Intimal hyperplasia was defined as a uniform growth process beyond the limits of the metallic mesh at <25%. In-stent stenosis represented an area of parent vessel narrowing, most often focal, graded as mild (25%-50%), moderate (50%-75%), or severe (>75%)., Results: Between June 2011 and April 2015, 80 patients were treated with the PED. Angiographic follow-up was available for 51 patients (representing 76% of available or 64% of all patients). Mean follow-up was 12.5 months. In-stent stenosis was detected in 5 patients (9.8%) at a median of 6 months. Stenosis was mild in 4 of 5 (80%) and moderate in 1 of 5 (20%) patients. There were no cases of severe stenosis. No stenosis caused flow limitation, clinical symptoms, or required re-treatment. Additional follow-up angiography was available in 2 of 5 stenosis patients showing marked improvement. Sixteen patients (31%) had intimal hyperplasia, and 28 patients (55%) had no stenosis. Asymptomatic stent occlusion occurred in 2 patients (4%) related to medication noncompliance., Conclusion: Treatment with the PED was associated with a 9.8% rate of in-stent stenosis, detected on first angiographic follow-up, at a median of 6 months. None were symptomatic or required re-treatment, and they showed significant improvement on follow-up., Abbreviation: FD, flow diverter.

Background: Flow diverters have been used predominantly for large anterior circulation aneurysms. Data on the safety and efficacy of this treatment for posterior circulation aneurysms are limited., Objective: To present our posterior circulation flow diverter experience, outcomes and morbidity in comparison with recent studies., Methods: A retrospective chart and imaging review of six patients with seven aneurysms in posterior circulation vessels, treated with flow diverter technology was carried out. A literature review was performed using standard online search tools., Results: We included five saccular and two fusiform posterior circulation aneurysms. An average of two flow diverters was placed for each patient. Adjunctive coiling was used in three cases. Follow-up at an average of 14.5 months showed complete angiographic occlusion in 4 (57.1%) cases, including one patient with in-stent thrombosis and major brainstem stroke at 4.5 months, a week after self-discontinuing dual antiplatelet therapy. Two other patients developed small periprocedural strokes but had excellent recovery. One death occurred 18 months after the initial procedure. No aneurysm rupture or parenchymal hemorrhage was seen. Overall, 5 (71%) cases, all with saccular aneurysms, had good clinical outcome (modified Rankin score (mRS) 0-1). Fusiform basilar aneurysms had markedly worse outcomes (mRS 5 and 6). Our literature review yielded six other studies with 100 additional patients. Overall, good outcome was seen in 74.3%, with a 12.3% average mortality and 11% permanent neurologic deficit rate. Complete occlusion varied from 43% to 100%., Conclusions: Flow diversion may be a possible treatment in carefully selected patients with high-risk atypical posterior circulation aneurysms, with poor natural history and no optimal treatment strategy. Symptomatic and fusiform large aneurysms appear to carry the highest risk. Further studies are necessary to assess the role of flow diversion in the posterior circulation., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Unlabelled: Coil embolization of oblong aneurysms is difficult because the majority of commercially available coils are manufactured with a helical or spherical tertiary structure. While adopting framing strategies for oblong aneurysms (aspect ratio ≥ 2: 1), traditional coils may be undersized in the long axis but oversized in the short axis, resulting in increased aneurysmal wall stress, risk of re-rupture, and difficulty creating a basket that respects the aneurysmal neck. We review three cases in which versatile filling coils (VFCs) were used as the initial coils for embolization of oblong aneurysms and report coil distribution characteristics and clinical outcomes. Packing density after VFC implantation was assessed using the software AngioSuite-Neuro edition and AngioCalc., Illustrative Case: a 58-year-old woman experienced a subarachnoid hemorrhage from a ruptured anterior communicating artery aneurysm (7.5 mm × 3.5 mm). A 3-6 mm × 15 cm VFC was selected as the first coil because the flexibility of its wave-loop structure facilitates framing of an irregularly shaped aneurysm. The loop portions of the structures tend to be pressed to the extremes of the aneurysmal sac by the wave component. The VFC was introduced smoothly into the aneurysmal sac without catheter kickback. We were then able to insert detachable filling coils without any adjunctive technique and achieved complete occlusion. Complete occlusion without severe complications was achieved in all three cases in our study. Average packing density after the first coil was 15.63%. VFC coils may have a specific role in framing oblong aneurysms given their complex loop-wave design, allowing spacing of the coils at the dome and neck while keeping sac stress to a minimum.

Background and Importance: Giant fusiform aneurysms of the basilar artery are associated with a high rate of morbidity and mortality. Treatment of these lesions can be difficult, especially when there are poor anatomic collaterals such as posterior communicating arteries. These lesions often have no acceptable treatment. The authors present a case of a patient with a symptomatic, fusiform basilar artery aneurysm successfully treated with a side-by-side (double-barrel), telescoping stent construct., Clinical Presentation: A 56-year-old man presented with chief concerns of dysarthria and left-sided hemiparesis. MRI and conventional catheter-based angiography revealed a dolichoectatic basilar artery with 3 large fusiform aneurysms throughout its length. Flow through the patient's aneurysm was successfully reduced with a side-by-side stent construct and coiling of the proximal aneurysm dilation. The patient experienced stabilization of his ischemic events and neurologic recovery. A total of 6 Neurform-2 4.5 × 30-mm stents were navigated and positioned from the proximal posterior cerebral arteries to the distal vertebral arteries in a side-by-side (double-barrel), telescoping manner. These were deployed simultaneously by 2 operators to oppose the stent struts as well as the arterial wall. Next, the proximal aneurysmal dilation was coiled to near occlusion. Successful flow redirection and aneurysm thrombosis was observed., Conclusion: A novel, endovascular stenting technique for successfully treating symptomatic, giant basilar artery aneurysms is presented. This patient at 4 months was living independently with no further neurologic events or decline.

Background and Importance: Early origin of the middle cerebral artery M2 segment is a normal variant. When such a vessel is occluded proximally, the parenchyma distal to the vessel may become ischemic. Targeted extracranial to intracranial bypass to such a specific branch may preserve perfusion to the end organ. We describe the use of intra-aneurysmal injection of indocyanine green to identify a target middle cerebral artery branch (MCA) for bypass, immediately followed by proximal parent vessel sacrifice via endovascular embolization., Clinical Presentation: A 45-year-old woman presented to an outside hospital with headaches. Magnetic resonance imaging revealed a giant aneurysm of the right MCA. The aneurysm gave rise to an M2 branch that supplied the right anterior frontal operculum, as well as the anterolateral portion of the superior temporal gyri. Balloon test occlusion was nondiagnostic because of the territory involved, and the risk of sizable infarction after vessel sacrifice was thought to be high. Craniotomy and targeted extracranial to intracranial bypass to an M4 opercular branch was performed with intra-aneurysmal injection of indocyanine green. In our combined endovascular/open cerebrovascular suite, an opercular MCA branch that fluoresced during the first-pass arterial circulation of indocyanine green was identified, and a superficial temporal artery to MCA bypass was performed. Angiographic verification of bypass patency was confirmed, followed by embolic occlusion of the giant aneurysm with preservation of flow to the parenchyma at risk through the bypass., Conclusion: Targeted bypass to distal branches is feasible with intra-arterial and intra-aneurysmal injection of indocyanine green, allowing confident preservation of blood supply to areas distal to the sacrificed vessel.

Background and purposeStent-assisted coil embolization using the new generation Neuroform Atlas Stent System has shown promising safety and efficacy. The primary study results of the anterior circulation aneurysm cohort of the treatment of wide-neck, saccular, intracranial, aneurysms with the Neuroform Atlas Stent System (ATLAS trial [Safety and Effectiveness of the Treatment of Wide Neck, Saccular Intracranial Aneurysms With the Neuroform Atlas Stent System]) are presented.MethodsATLAS IDE trial (Investigational Device Exemption) is a prospective, multicenter, single-arm, open-label study of wide-neck (neck ≥4 mm or dome-to-neck ratio 50%) at the target location. The primary safety end point was any major stroke or ipsilateral stroke or neurological death within 12 months. Adjudication of the primary end points was performed by an independent Imaging Core Laboratory and the Clinical Events Committee.ResultsA total of 182 patients with wide-neck anterior circulation aneurysms at 25 US centers were enrolled. The mean age was 60.3±11.4 years, 73.1% (133/182) women, and 80.8% (147/182) white. Mean aneurysm size was 6.1±2.2 mm, mean neck width was 4.1±1.2 mm, and mean dome-to-neck ratio was 1.2±0.3. The most frequent aneurysm locations were the anterior communicating artery (64/182, 35.2%), internal carotid artery ophthalmic artery segment (29/182, 15.9%), and middle cerebral artery bifurcation (27/182, 14.8%). Stents were placed in the anticipated anatomic location in all patients. The study met both primary safety and efficacy end points. The composite primary efficacy end point of complete aneurysm occlusion (Raymond-Roy 1) without parent artery stenosis or aneurysm retreatment was achieved in 84.7% (95% CI, 78.6%-90.9%) of patients. Overall, 4.4% (8/182, 95% CI, 1.9%-8.5%) of patients experienced a primary safety end point of major ipsilateral stroke or neurological death.ConclusionsIn the ATLAS IDE anterior circulation aneurysm cohort premarket approval study, the Neuroform Atlas stent with adjunctive coiling met the primary end points and demonstrated high rates of long-term complete aneurysm occlusion at 12 months, with 100% technical success and