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Background: The two most common approaches to thrombectomy of emergent large vessel occlusion (direct aspiration and primary stent retriever thrombectomy) have been extensively studied; however, the detailed benefit and risk comparison is largely unknown., Objective: To conduct a systematic review and meta-analysis to compare radiographic and clinical outcomes between the use of primary stent retrievers and direct aspiration in management of acute ischemic stroke., Methods: PubMed database was searched for studies between September 1, 2012 and December 31, 2017 with acute ischemic stroke patients., Results: We identified 64 studies with 6875 patients in the primary stent retriever group and 25 studies with 2252 patients in the aspiration group. Primary aspiration alone, without the need of rescue stent retriever devices within the aspiration cohort, was performed in 65% of 2252 patients. There was no difference in the distribution of emergent large vessel occlusion based on occlusion site, age, baseline National Institutes of Health Stroke Scale, or the use of intravenous tPA (P = .19, .051, .23, and .093, respectively). Successful recanalization rates, defined as thrombolysis in cerebral Infarction 2b/3, were significantly higher in the aspiration group than the primary stent retriever group (89% versus 80%, P < .0001). No significant difference in good clinical outcome, defined as modified Rankin scale 0-2 (aspiration 52% versus stent 48%, P = .13), symptomatic intracerebral hemorrhage (aspiration 5.6% versus stent 7.2%, P = .07), and mortality at 3 months (aspiration 15% versus stent 19%, P = .10)., Conclusions: Both aspiration-first (including the subsequent use of stent retriever) and primary stent retriever thrombectomy approaches are equally effective in achieving good clinical outcomes. Our study suggests that direct aspiration with or without subsequent use of stent retriever is a safe and effective alternative to primary stent retriever in acute ischemic stroke., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: The DEFUSE 3 and DAWN trials have shown the benefit of thrombectomy beyond 6 hours of stroke symptom onset in carefully selected patients., Objective: To evaluate the real-world outcomes of stent retriever thrombectomy beyond 6 hours of stroke onset using combined individual patient data from the North American Solitaire Stent Retriever Acute Stroke (NASA) and Trevo Stent-Retriever Acute Stroke (TRACK) registries., Methods: Pooled analysis of individual patient data of all cases of anterior circulation acute ischemic stroke (AIS) from NASA and TRACK was performed to compare outcomes of patients presenting within the first hours 6 or beyond 6 hours of stroke symptom onset., Results: Of 830 patients with anterior circulation AIS from the NASA and TRACK registries, 32.7% (271 patients) underwent thrombectomy beyond the first 6 hours of symptom onset. The rates of good clinical outcome (modified Rankin scale score of 0-2 at 90 days), mortality, and symptomatic intracranial hemorrhage were similar: 48.1%, 20.6%, and 8.0% within 0-6 hours, 46.2%, 21.6%, and 10.9% within 6-16 hours, and 38.9%, 33.3%, and 5% within 16-24 hours (p=0.8, 0.6, and 0.5, respectively). The rates of successful recanalization (Thrombolysis in Cerebral Infarction 2b/3) were 79.4% in patients with stroke within 0-6 hours, 72.6% within 6-16 hours, and 85.0% within 16-24 hours (p=0.04)., Conclusions: Real-world experience with patients with anterior circulation AIS treated with the Solitaire and Trevo thrombectomy devices beyond the first 6 hours of symptom onset proved to be equally safe and effective as for patients with symptom onset within the first 6 hours., Competing Interests: Competing interests: JDE: honoraria from Medtronic, Stryker Neurovascular, and Penumbra. MM: consultant for Cerebrotech, speaker for Penumbra, Canon Medical. RGN, OOZ: consultant/advisory board member for Styker Neurovascular, Covidien., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Competing Interests: Competing interests: JFF is an equity interest holder for Fawkes Biotechnology, LLC, and a consultant for Stream Biomedical and for Medtronic. MM is a consultant for Toshiba (Canon) Medical, Penumbra, and Cerebrotech. MG is a consultant for Medtronic, Stryker, Microvention, and Cerenovus. He has a licensing agreement with GE Healthcare for systems of stroke diagnosis. Stryker has provided an unrestricted research grant tothe University of Calgary. MC is a consultant for Medtronic, Stryker, Penumbra, Genentech, and GE.

Background: Iatrogenic vertebral artery injury is an uncommon but well recognized complication during cervical spine surgery. Intraoperative surgical repair is extremely challenging, and options for endovascular repair are limited because of the lack of proper equipment in the operating room setting., Case Description: A 53-year-old woman who presented with myelopathy underwent anterior cervical diskectomy and fusion of C3-7. A significant laceration injury of the left vertebral artery was encountered during surgery, which was salvaged by intraoperative endovascular repair with a covered stent under portable fluoroscopy guidance. The salvage and repair led to the rest of the surgery being finished as planned preoperatively without any consequences., Conclusions: Vertebral artery injury is an uncommon but severe complication of cervical spine surgery. For uncontrolled bleeding, intraoperative endovascular repair with portable fluoroscopy is warranted and possible. A covered stent can seal the laceration and stop the bleeding completely which enables completion of the surgery., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background and Purpose- The safety and efficacy of mechanical thrombectomy in patients with acute ischemic stroke has been demonstrated. However, the impact of stent retriever size on clinical and angiographic outcomes is not well established. Methods- This was a retrospective ad hoc analysis of data from the STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) registry-a prospective, multicenter study of patients with large vessel occlusion treated with the Solitaire stent retriever. An independent core laboratory, blinded to clinical outcomes, reviewed all procedures and angiographic data to classify stent retriever size, targeted clot location, recanalization after each pass, and the number of stent retriever passes. The primary angiographic end point was first-pass effect (FPE) as determined by a core laboratory and defined as achieving near-complete revascularization (modified Thrombolysis in Cerebral Infarction ≥2c) after the first pass without the use of rescue therapy. Rates of modified FPE were also assessed, defined as meeting all criteria for FPE but achieving modified Thrombolysis in Cerebral Infarction ≥2b after first pass. The primary clinical end point was functional independence (modified Rankin Scale, 0-2) at 3 months as determined on-site. Outcome comparisons were made across the stent retriever size groups and adjusted for baseline characteristics. Results- Of 715 patients, a 4×20 stent retriever was used in 201 (28%) patients, 4×40 was used in 270 (38%) patients, and 6×30 was used in 244 (34%) patients. The 4×40 group had the highest rate of FPE ( P=0.003 versus 6×30) and modified FPE ( P=0.038 versus 4×20; P=0.0001 versus 6×30). Final revascularization was not significantly different across the groups, and there were no significant differences in functional dependence or mortality at 90 days post-procedure. Use of the longer stent retriever (4×40) was an independent predictor of achieving modified FPE ( P=0.037 versus 6×30; P=0.037 versus 4×20). Conclusions- The longer stent retriever (4×40) demonstrated the highest rate FPE and modified FPE compared with larger diameter or shorter stent retrievers, suggesting that their routine use may improve early revascularization success. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT02239640.

Background and Purpose: Quality of visualization of treatment devices during critical stages of endovascular interventions, can directly impact their safety and efficacy. Our aim was to compare the visualization of neurointerventional procedures and treatment devices using a 194-μm pixel flat panel detector mode and a 76-μm pixel complementary metal oxide semiconductor detector mode (high definition) of a new-generation x-ray detector system using a blinded-rater study., Materials and Methods: Deployment of flow-diversion devices for the treatment of internal carotid artery aneurysms was performed under flat panel detector and high-definition-mode image guidance in a neurointerventional phantom simulating patient cranium and tissue attenuation, embedded with 3D-printed intracranial vascular models, each with an aneurysm in the ICA segment. Image-sequence pairs of device deployments for each detector mode, under similar exposure and FOV conditions, were evaluated by 2 blinded experienced neurointerventionalists who independently selected their preferred image on the basis of visualization of anatomic features, image noise, and treatment device. They rated their selection as either similar, better, much better, or substantially better than the other choice. Inter- and intrarater agreement was calculated and categorized as poor, moderate, and good., Results: Both raters demonstrating good inter- and intrarater agreement selected high-definition-mode images with a frequency of at least 95% each and, on average, rated the high-definition images as much better than flat panel detector images with a frequency of 73% from a total of 60 image pairs., Conclusions: Due to their higher resolution, high-definition-mode images are sharper and visually preferred compared with the flat panel detector images. The improved imaging provided by the high-definition mode can potentially provide an advantage during neurointerventional procedures., (© 2019 by American Journal of Neuroradiology.)

Objective: With the increasing use of flow diversion as treatment for intracranial aneurysms, there is a concomitant increased vigilance in monitoring complications. The low porosity of flow diverters is concerning when the origins of vessels are covered, whether large circle of Willis branches or critical perforators. In this study, the authors report their experience with flow diverter coverage of the lenticulostriate vessels and evaluate their safety and outcomes., Methods: The authors retrospectively reviewed 5 institutional databases of all flow diversion cases from August 2012 to June 2018. Information regarding patient presentation, aneurysm location, treatment, and outcomes were recorded. Patients who were treated with flow diverters placed in the proximal middle cerebral artery (MCA), proximal anterior cerebral artery, or distal internal carotid artery leading to coverage of the medial and lateral lenticulostriate vessels were included. Clinical outcomes according to the modified Rankin Scale were reviewed. Univariate and multivariate analyses were performed to establish risk factors for lenticulostriate infarct., Results: Fifty-two patients were included in the analysis. Postprocedure cross-sectional images were available in 30 patients. Two patients experienced transient occlusion of the MCA during the procedure; one was asymptomatic, and the other had a clinical and radiographic ipsilateral internal capsule stroke. Five patients had transient symptoms without radiographic infarct in the lenticulostriate territory. Two patients experienced in-stent thrombosis, leading to clinical MCA infarcts (one in the ipsilateral caudate) after discontinuing antiplatelet therapy. Discontinuation of dual antiplatelet therapy prior to 6 months was the only variable that was significantly correlated with stroke outcome (p < 0.01, OR 0.3, 95% CI 0-0.43), and this significance persisted when controlled for other risk factors, including age, smoking status, and aneurysm location., Conclusions: The use and versatility of flow diversion is increasing, and safety data are continuing to accumulate. Here, the authors provide early data on the safety of covering lenticulostriate vessels with flow diverters. The authors concluded that the coverage of these perforators does not routinely lead to clinically significant ischemia when dual antiplatelet therapy is continued for 6 months. Further evaluation is needed in larger cohorts and with imaging follow-up as experience develops in using these devices in more distal circulation.

Background: Aneurysmal subarachnoid hemorrhage secondary to ruptured small dissecting fusiform aneurysms of the posterior inferior cerebellar artery (PICA) is rare and particularly challenging. Different treatment strategies have been reported in these rare cases. We report 2 patients treated with a novel endovascular approach., Case Description: Two patients presented with subarachnoid hemorrhage secondary to very small (3 mm and 4 mm) ruptured fusiform aneurysms of the proximal section of the PICA trunk. Both patients were treated by coil embolization combined with parent artery preservation by microcatheter auto-assistance. Both coiling procedures were uneventful, and the patients remained asymptomatic. Long-term follow-up angiography in both patients showed complete occlusion of aneurysms with patency of PICA., Conclusions: There is no single treatment strategy suitable for all PICA aneurysms. Our proposed method may be best applied to small dissecting fusiform aneurysms located on a small (≤1 mm in diameter) PICA distally to its origin., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Introduction: Neurothrombectomy frequency is increasing, and a better understanding of the neurothrombectomy call burden is needed., Methods: Neurointerventional physicians at nine participating stroke centers prospectively recorded time requirements for all neurothrombectomy (NT) consultations over 30 consecutive 24 hour call periods., Results: Data were collected from a total of 270 days of call. 214 NT consultations were reported (mean 0.79 per day), including 130 'false positive' consultations that ultimately did not lead to thrombectomy (mean 0.48 per day). 84 NT procedures were performed at the nine centers (0.32 per day, or 1 every 3 days). Most (59.8%) consultations occurred between 5pm and 7am. 30% of thrombectomy procedures resulted in delays in scheduled cases; treating physicians had to emergently travel to the hospital for 51.2% of these cases. A median of 27 min was spent on each false positive consultation and 171 min on each thrombectomy. Overall, the median physician time spent on NT responsibilities per 24 hour call period was 69 min (mean 85 min; IQR 16-135 min)., Conclusions: NT consultations are frequent and often disrupt physician schedules, requiring physicians to commute in from home after hours in the majority of cases. As procedural and consultation volumes increase, it is crucial to understand the significant burden of call on neurointerventional physicians and develop strategies that reduce the potential for burnout. Importantly, this study was performed prior to the completion of the DAWN and DEFUSE3 trials; NT consultations are expected to continue to increase in the future., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

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

Competing Interests: Competing interests: JFF is an equity interest holder for Fawkes Biotechnology, LLC, and a consultant for Stream Biomedical. SWH is a consultant for Medina and Neuravi, and has research contracts with Stryker Neurovascular, Siemens, MicroVention Terumo. JTF has research grants from Stryker and Microvention, equity interest in Endostream, Cerebrotech, and The Stroke Project, and has consulted for Stryker and Penumbra. MM is a consultant for Toshiba (Canon) Medical. All other authors report no relevant conflicts of interest.

Background: The development of new revascularization devices has improved recanalization rates and time, but not clinical outcomes. We report a prospectively collected clinical experience with a new technique utilizing a direct aspiration first pass technique with large bore aspiration catheter as the primary method for vessel recanalization., Methods: 98 prospectively identified acute ischemic stroke patients with 100 occluded large cerebral vessels at six institutions were included in the study. The ADAPT technique was utilized in all patients. Procedural and clinical data were captured for analysis., Results: The aspiration component of the ADAPT technique alone was successful in achieving Thrombolysis in Cerebral Infarction (TICI) 2b or 3 revascularization in 78% of cases. The additional use of stent retrievers improved the TICI 2b/3 revascularization rate to 95%. The average time from groin puncture to at least TICI 2b recanalization was 37 min. A 5MAX demonstrated similar success to a 5MAX ACE in achieving TICI 2b/3 revascularization alone (75% vs 82%, p=0.43). Patients presented with an admitting median National Institutes of Health Stroke Scale (NIHSS) score of 17.0 (12.0-21.0) and improved to a median NIHSS score at discharge of 7.3 (1.0-11.0). Ninety day functional outcomes were 40% (modified Rankin Scale (mRS) 0-2) and 20% (mRS 6). There were two procedural complications and no symptomatic intracerebral hemorrhages., Discussion: The ADAPT technique is a fast, safe, simple, and effective method that has facilitated our approach to acute ischemic stroke thrombectomy by utilizing the latest generation of large bore aspiration catheters to achieve previously unparalleled angiographic outcomes., (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.)

Background: The development of new revascularization devices has improved recanalization rates and time but not clinical outcomes. We report our initial results with a new technique utilizing a direct aspiration first pass technique with a large bore aspiration catheter as the primary method for vessel recanalization., Methods: A retrospective evaluation of a prospectively captured database of 37 patients at six institutions was performed on patients where the ADAPT technique was utilized. The data represent the initial experience with this technique., Results: The ADAPT technique alone was successful in 28 of 37 (75%) cases although six cases had large downstream emboli that required additional aspiration. Nine cases required the additional use of a stent retriever and one case required the addition of a Penumbra aspiration separator to achieve recanalization. The average time from groin puncture to at least Thrombolysis in Cerebral Ischemia (TICI) 2b recanalization was 28.1 min, and all cases were successfully revascularized. TICI 3 recanalization was achieved 65% of the time. On average, patients presented with an admitting National Institutes of Health Stroke Scale (NIHSS) score of 16.3 and improved to an NIHSS score of 4.2 by the time of hospital discharge. There was one procedural complication., Discussion: This initial experience highlights the fact that the importance of the technique with which new stroke thrombectomy devices are used may be as crucial as the device itself. The ADAPT technique is a simple and effective approach to acute ischemic stroke thrombectomy. Utilizing the latest generation of large bore aspiration catheters in this fashion has allowed us to achieve excellent clinical and angiographic outcomes., (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.)

Background: Understanding how many patients are eligible for endovascular therapy can help develop more effective stroke systems of care., Objective: To determine the proportion of patients eligible for endovascular therapy., Methods: In this single center retrospective cohort study, we identified patients with acute ischemic stroke from large vessel occlusion (LVO) from January 2014 to December 2015. Selection criteria including LVO location, Alberta stroke program early computed tomography score (ASPECTS) range, hospital arrival time, and the use of intravenous thrombolysis were applied to calculate proportions of patients eligible for endovascular therapy., Results: Of 989 patients with acute ischemic stroke, LVO was identified in 224 (23%) cases. Eighty-four percent of patients admitted within 6 h, 75% of patients admitted within 6 to 12 h, and 77% of patients with M1 and internal carotid artery occlusions admitted within 12 to 24 h had favorable ASPECTS for thrombectomy, defined as ASPECTS ≥ 6. Severity of NIHSS (National Institutes of Health Stroke Scale) was predictive of favorable ASPECTS (odds ratio [OR] 0.20, 95% confidence interval [CI] 0.04-0.74; P = .014 for NIHSS > 10 and OR 0.30, 95% CI 0.12-0.80; P = .014 for NIHSS > 20), whereas time of hospital arrival was not (OR 1.73, 95% CI 0.76-4.03; P = .26). Using all class I, Level of Evidence A American Heart Association guidelines criteria, 4% of patients with acute ischemic stroke were eligible for endovascular therapy. Up to 20% of patients were eligible for endovascular therapy with less restrictive criteria (Class IIb; Level of Evidence C)., Conclusion: Depending on the sets of selection criteria, between 4% (the most restrictive criteria) and 20% (the least restrictive criteria) of patients with LVO are potentially eligible for endovascular therapy.

Background: The pipeline embolization device (PED) is frequently used in the treatment of anterior circulation aneurysms, especially around the carotid siphon, with generally excellent results. However, treatment of posterior inferior cerebellar artery (PICA) aneurysms with flow diversion (FD) has not been specifically described or discussed. While there are reports of treating PICA aneurysms using placement of FD stents in the vertebral artery, there are no reports of treating these lesions by placement of flow diverting stents in the PICA vessel itself. Due to the unique anatomy and morphology of these aneurysms, it requires special attention. We assessed our multi-institutional experience treating these lesions, including the first reported cases of the PED placed within the PICA., Methods: Institutional databases of neuroendovascular procedures were reviewed for cases of intracranial aneurysms treated with the PED. Patient and aneurysm data as well as angiographic imaging were reviewed for all cases of PICA aneurysms treated with the PED. PICA aneurysms were defined as aneurysms that involved the PICA. Vertebral aneurysms without disease in the PICA were excluded from the study., Results: 10 PICA aneurysms were treated during the study period. These were classified based on their morphology and location into two main types and five total subtypes for consideration of treatment with flow diversion. All aneurysms were successfully treated, with 8/10 completely obliterated and 2 with a partial reduction in size. Three patients had the PED placed entirely in the PICA and no patient suffered from a medullary or cerebellar stroke. All PEDs were patent and all patients were independent at the last follow-up., Conclusions: The PED may be used successfully to treat select aneurysms of the PICA. We present the first described cases of successful PED treatment of PICA aneurysms with direct placement of the PED in the PICA vessel itself. The proposed classification system aids in that selection., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: Anterior choroidal artery (AChA) aneurysms represent a small subset of cerebral aneurysms. The Pipeline Embolization Device (PED) has been successfully applied to various aneurysms of the supraclinoid internal carotid artery (ICA). The treatment of these aneurysms requires special attention due to the eloquent territory supplied by the AChA. We report the largest and first dedicated series of flow diversion treatment of AChA aneurysms., Methods: Four institutional neurointerventional databases were reviewed for cases of intracranial aneurysms treated with PED. Patient and aneurysm data as well as angiographic imaging were reviewed for all cases of AChA aneurysms treated with PED. AChA aneurysms were defined as aneurysms distal to the AChA and proximal to the ICA terminus, with or without the incorporation of the AChA., Results: Eighteen AChA aneurysms were treated during the study period. All aneurysms were successfully treated with a mean follow-up of 19.1 months. The large majority of aneurysms (15/18, 83.3%) were completely obliterated. No patients suffered from intra- or post-procedural complications. A1 stenosis was a common occurrence, seen in 10 of 16 (62.5%) covered anterior cerebral arteries (ACAs), although all were asymptomatic. All AChAs remained patent at last follow-up., Conclusions: The PED can be used successfully in AChA aneurysms with a good safety and efficacy profile. All AChAs remained patent. Collateral flow networks, especially for the ACA, affect long-term branch vessel patency. Treatment with PED for AChA aneurysms appears to be a reasonable option to consider and should be evaluated in a larger cohort., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: Recent randomized clinical trials (RCTs) demonstrated the efficacy of mechanical thrombectomy using stent-retrievers in patients with acute ischemic stroke (AIS) with large vessel occlusions; however, it remains unclear if these results translate to a real-world setting. The TREVO Stent-Retriever Acute Stroke (TRACK) multicenter Registry aimed to evaluate the use of the Trevo device in everyday clinical practice., Methods: Twenty-three centers enrolled consecutive AIS patients treated from March 2013 through August 2015 with the Trevo device. The primary outcome was defined as achieving a Thrombolysis in Cerebral Infarction (TICI) score of ≥2b. Secondary outcomes included 90-day modified Rankin Scale (mRS), mortality, and symptomatic intracranial hemorrhage (sICH)., Results: A total of 634patients were included. Mean age was 66.1±14.8 years and mean baseline NIH Stroke Scale (NIHSS) score was 17.4±6.7; 86.7% had an anterior circulation occlusion. Mean time from symptom onset to puncture and time to revascularization were 363.1±264.5 min and 78.8±49.6 min, respectively. 80.3% achieved TICI ≥2b. 90-day mRS ≤2 was achieved in 47.9%, compared with 51.4% when restricting the analysis to the anterior circulation and within 6 hours (similar to recent AHA/ASA guidelines), and 54.3% for those who achieved complete revascularization. The 90-day mortality rate was 19.8%. Independent predictors of clinical outcome included age, baseline NIHSS, use of balloon guide catheter, revascularization, and sICH., Conclusion: The TRACK Registry results demonstrate the generalizability of the recent thrombectomy RCTs in real-world clinical practice. No differences in clinical and angiographic outcomes were shown between patients treated within the AHA/ASA guidelines and those treated outside the recommendations., Competing Interests: Competing interests: IL is consultant for Metronic, Stryker, Penumbra, and Cordis. MM is consultant for Claret Medical, Nogueira-Stryker Neurovascular (Trevo-2 Trial Principal Investigator – modest; DAWN Trial Principal Investigator – no compensation, TREVO Registry Steering Committee – no compensation), Medtronic (SWIFT Trial Steering Committee – modest; SWIFT-Prime Trial Steering Committee – no compensation; STAR Trial Angiographic Core Lab – significant), Penumbra (3D Separator Trial Executive Committee – no compensation), Neuravi (ARISE-2 Steering Committee – no compensation), Genentech (Physician Advisory Board – modest), Allm Inc (Physician Advisory Board – no compensation), Editor-In-Chief Interventional Neurology Journal (no compensation). SRS is a consultant for Stryker Neurovascular. OOZ is overall PI for TRACK – no compensation, Arise II – modest, Co-PI Therapy Trial – modest, Steering committee STRATIS registry – modest., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: The concept of a Hybrid Angio-Surgical Suite (HASS) has emerged as a solution to the complexity of cerebrovascular surgery and the need for immediate intraoperative feedback. When to use it, what cases are suitable for its use, who can use it and how to use it remain debatable., Objective: Provide the information regarding the application of the HASS for hospital, neurosurgeon and interventionalist., Methods: We review the literatures of case reports and studies on the use of the hybrid angio-sugical suite along with application of HASS in our own practice., Results: Indications for using HASS on different types of cerebral vascular disease, including cerebral aneurysm, AVM, DAVF, carotid and vertebral stenosis/occlusion, are addressed. The application of HASS for other non-cerebral vascular diseases, such as trauma, spine and skullbase cases, is reviewed and discussed., Conclusion: HASS has made many surgical procedures safer and many difficult or previously untreatable conditions much more tractable and cost-effective. Other than used in cerebral vascular disease, HASS has much more applications, such as trauma, spine and other neurosurgical diseases., Competing Interests: Competing interestsThe authors declare that they have no competing interests., (© The Author(s) 2018.)

Introduction: There are few published data evaluating the incidence of mechanical thrombectomy among stroke centers or the times at which they occur., Methods: A multicenter retrospective study was performed to identify all patients undergoing emergent thrombectomy for acute ischemic stroke during a 3-month period (June through August 2016). Consultations that did not undergo thrombectomy were not included., Results: Ten institutions participated in the study. During the 92-day study period, a total of 189 patients underwent mechanical thrombectomy. The average number of procedures per hospital over the study period was 18.9 (average of 0.2 cases per day per or 75.6 cases per year). This ranged from 0.09 cases per day at the lowest volume center to 0.49 cases per day at the highest volume center. Procedures were more common on weekdays (p<0.001) and during non-work hours (p<0.001). The most common period for thrombectomy procedures was between 20:00 and 21:00 hours. The median time from notification to groin puncture was 84 min (IQR 56-145 min) and from puncture to closure was 57 min (IQR 33-80 min). The median time from imaging completion to procedural start was 52 min longer for non-work hours than during work hours (p<0.001). There were no differences in procedural length based on day of the week or time of day., Conclusions: These findings indicate that the majority of mechanical thrombectomy cases occur during non-work hours, with associated off-hours delays, which has important operational implications for hospitals implementing stroke call coverage., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Competing Interests: Competing interests: Dr Chen reports being a consultant for Medtronic, Penumbra, Stryker and Genentech Dr Fraser is an equity interest holder for Fawkes Biotechnology, LLC, and a consultant for Stream Biomedical. Dr Hetts reports being a consultant for Medina and Neuravi, as well as research contracts with Stryker Neurovascular, Siemens, Micro Vention Terumo. Dr. Klucznik reports being a proctor and speaker for Medtronic. Dr Mocco reports the following: Consultant: Rebound Therapeutics, TSP Inc., Cerebrotech, Lazarus Effect, Pulsar, Medina. investor: Blockade Medical, TSP Inc., Lazarus effect, Medina PI/CO-PI for the following trials: THERAPY (PI), FEAT (PI), INVEST (Co-PI), COMPASS (Co-PI), LARGE (Co-PI), COAST (Co-PI), POSITIVE (Co-PI). Steering committee for the MAPS trial. Dr Prestigiacomo reports the following: Consultant, Codman Neurovascular (serving on DSMB) Dr Pride reports the following: Consultant, Sequent Medical (DSMB for Web-IT study) Dr Sunenshine reports protctoring for Medtronic, and is an investigator in STRATIS (Medtronic) and CARE (Penumbra) studies. All other authors report no relevant conflicts of interest.

Background: The Pipeline Embolization Device (PED) is increasingly used for both on- and off-label purposes for treatment of intracranial aneurysms. The device gradually slows flow of blood into the aneurysm, but the high metal coverage of PED promotes endothelialization of the device. Occasionally, this leads to in-stent stenosis that is clinically well tolerated. We present a multi-institutional Pipeline series that includes three cases of gradual asymptomatic occlusion within the PED and parent vessel., Methods: Institutional databases at each participating center were searched for patients treated with the PED. Patients with at least 50% stenosis or occlusion were selected and all relevant clinical and radiographic data were reviewed., Results: A total of 326 cases performed by five neurointerventionalists across four institutions were reviewed. Among these there were three cases of complete occlusion and two cases of stenosis of more than 50%, for an occlusion rate of 0.9%. All patients were clinically asymptomatic., Conclusions: A gradual tourniquet-like occlusion can occur following placement of the PED, leading to vessel occlusion. This has been clinically well tolerated by patients in our series due to the formation of pial collaterals as the stenosis progresses, likely due to ischemic preconditioning. Small parent vessel, pre-existing stenosis, fusiform pathology, overlapping devices, and suboptimal antiplatelet therapy seem to be predisposing factors. Further experience and follow-up will allow us to characterize the risk factors and optimize post-procedural therapy for these patients., Competing Interests: Competing interests: PK is a consultant for Stryker and Medtronic. PK and VMS receive grant/research support from Microvention. AP has received grant/research support from and serves as a consultant to Codman, Covidien, and Stryker Neurovascular., (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: Recent surveys have failed to examine cerebrovascular aneurysm treatment practices among US physicians., Objective: To survey physicians who are actively involved in the care of patients with cerebrovascular aneurysms to determine current aneurysm treatment preferences., Methods: A 25-question SurveyMonkey online survey was designed and distributed electronically to members of the Society of NeuroInterventional Surgery, Society of Vascular and Interventional Neurology, and the American Association of Neurological Surgeons/Congress of Neurological Surgeons Combined Cerebrovascular Section., Results: 211 physicians completed the survey. Most respondents recommend endovascular treatment as the first-line management strategy for most ruptured (78%) and unruptured (71%) aneurysms. Thirty-eight per cent of respondents indicate that they routinely treat all patients with subarachnoid hemorrhage regardless of grade. Most physicians use the International Study of Unruptured Intracranial Aneurysms data for counseling patients on natural history risk (80%); a small minority (11%) always or usually recommend treatment of anterior circulation aneurysms of <5 mm. Two-thirds of respondents continue to recommend clipping for most middle cerebral artery aneurysms, while most (51%) recommend flow diversion for wide-necked internal carotid artery aneurysms. Follow-up imaging schedules are highly variable. Neurosurgeons at academic institutions and those practicing longer were more likely to recommend clipping surgery for aneurysms (p<0.05)., Conclusions: This survey demonstrates considerable variability in patient selection for intracranial aneurysm treatment, preferred treatment strategies, and follow-up imaging schedules among US physicians., Competing Interests: Competing interests: None declared., (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 strokes from M2 segment middle cerebral artery (MCA) occlusion have been underrepresented in recent randomized trials of endovascular therapy., Objective: To better understand the clinical, imaging, and procedural predictors of successful recanalization and clinical outcomes in this population of patients., Methods: We performed a multicenter retrospective analysis of consecutive patients with acute MCA M2 segment occlusion who underwent thrombectomy with stent retrievers or primary aspiration thrombectomy (including A Direct Aspiration First Pass Technique approach). We correlated clinical and radiographic outcomes with demographic, clinical, and technical characteristics., Results: One hundred and seventeen patients were included in analysis (median admission National Institutes of Health stroke scale [NIHSS] score 15, mean age 67.0 ± 14.5, 42% females). Good clinical outcome at 3 months (modified Rankin scale [mRS] ≤ 2) was achieved in 56% of patients. Treatment beyond 6 h of symptoms onset (P = .69, OR 0.80, 95% CI 0.38-1.73) and age over 80 (P = .47, OR 0.65, 95% CI 0.25-1.70) were not predictive of poor outcome. NIHSS > 15 was a strong predictor of clinical outcome, based on mRS distribution at 3 months (P = .0085, OR 0.35, 95% CI 0.16-0.74). Direct aspiration and primary stent retriever thrombectomy approaches showed similar radiographic and clinical success rates., Conclusion: Advanced age and time to treatment beyond 6 h from symptom onset were not predictive of clinical outcome with thrombectomy. NIHSS score above 15 was a strong predictor of outcome. Direct aspiration and primary stent retriever thrombectomy showed similar efficacy., (Copyright © 2017 by the Congress of Neurological Surgeons)

Purpose of Review: Cerebral cavernous malformations (CCMs) are common vascular abnormalities often discovered on imaging as an incidental finding. The most common clinical presentations of CCMs include seizure, headache, focal neurological deficits, and intracranial hemorrhage. This article discusses the most recent guidelines including imaging diagnostic criteria and radiographic standards of CCMs and reviews the utility of currently available imaging techniques., Recent Findings: Gradient echo T2*-weighted imaging and susceptibility-weighted imaging are the recommended imaging protocols for evaluation of suspected CCMs. Diffusion tensor imaging-based tractography provides visualization of the eloquent white matter tracks in the brain. This imaging is increasingly used in clinical practice to assist in selecting the optimal surgical approach, especially for brainstem lesions. Quantitative susceptibility mapping and dynamic contrast-enhanced quantitative perfusion are presently considered experimental. Its proposed value might prove helpful in the future to monitor disease activity and response to treatments. The choice of imaging modality of CCMs depends on the goals the clinician expects to achieve, such as establishing the initial diagnosis, follow-up and monitoring disease activity, preoperative, intraoperative, and postoperative evaluation, or research and experimental work on patients with CCM.

Background: Vessel perforation during stent retriever thrombectomy is a rare complication; typically only single instances have been reported., Objective: To report on a series of patients whose stent retriever thrombectomy was complicated by intraprocedural vessel perforation and discuss its potential mechanisms, rescue treatment strategies, and clinical significance., Methods: Cases with intraprocedural vessel perforation, where a stent retriever was used either as a primary treatment approach or as a part of a direct aspiration first pass technique (ADAPT), were included in the final analysis. Clinical data, procedural details, radiographic and clinical outcomes were collected from nine participating centers., Results: Intraprocedural vessel perforation during stent retriever thrombectomy occurred in 16 (1.0%) of 1599 cases. 63% of intraprocedural perforations occurred at distal locations. Endovascular rescue techniques (most commonly, intracranial balloon occlusion for tamponade) were attempted in 50% of cases. Procedure was aborted without any rescue attempts in 44% of cases. Mortality during hospitalization and at 3 months was 56% and 63%, respectively. 25% of patients achieved good functional outcome at 3 months after the procedure., Conclusions: Intraprocedural perforations during stent retriever thrombectomy were rare, but when they occurred were associated with high mortality. Perforations most commonly occurred at distal occlusion sites and were often characterized by difficulty traversing the occlusion with a microcatheter or microwire, or while withdrawing the stent retriever. Nevertheless, 25% of patients had a favorable functional outcome, suggesting that in some patients with this complication good neurological recovery is achievable., (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: The clot burden score (CBS) was developed as a tool to evaluate the extent of intracranial thrombus burden in patients with anterior circulation acute ischemic stroke. CBS is based on the presence or absence of contrast opacification on CT angiography (CTA). Its value in predicting radiographic and clinical outcomes in patients given endovascular stroke therapy remains unknown., Objective: To evaluate the relationship between CBS and outcomes after stent retriever thrombectomy in the interventional arm of the SWIFT PRIME trial., Methods: CBS was calculated for the endovascular arm (IV tissue plasminogen activator plus Solitaire stent retriever) of SWIFT PRIME using baseline CTA. The cohort of 69 patients was divided into three groups according to their CBS values: CBS 0-5 (n=14), CBS 6-7 (n=23), and CBS 8-9 (n=32)., Results: The mean age of the 69 patients who formed the study cohort was 63.2±13.1 years, mean National Institutes of Health Stroke Scale score was 16.8±4.5, and 55% of the patients were male. There was no difference in clinical characteristics among the three groups, except for the baseline Alberta Stroke Program Early CT Score (p=0.049). The site of proximal occlusion varied significantly among the three groups (p<0.001). Rates of successful recanalization (TICI 2b/3), complete recanalization (TICI 3 only) and of good clinical outcome at 3 months were similar among the three groups (p=0.24, p=0.35, and p=0.52, respectively)., Conclusions: The combination of IV thrombolysis and stent retriever thrombectomy with the Solitaire device is highly effective in achieving successful recanalization and a good clinical outcome throughout the entire range of CBS values., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background and Purpose: The ASPECTS (Alberta Stroke Program Early CT Score) is a quantitate score that measures the extent of early ischemic changes. Our aim was to investigate how measurement of ASPECTS using Hounsfield unit (HU) values on initial noncontrast head computerized tomography (CT) correlates with the extent of final infarct on follow-up imaging., Methods: Cases of acute stroke from the middle cerebral artery M1 occlusion in which complete recanalization (TICI [Thrombolysis in Cerebral Infarction] 3) was achieved were included for analysis. Using HU ratio (HU affected/HU control hemisphere) and HU difference (HU control-HU affected hemisphere) values, ASPECTS was measured on initial CT imaging and correlated with final ASPECTS at 24 hours. The study cohort consisted of 41 patients with acute stroke from the M1 occlusion. The mean time from stroke symptoms onset to baseline head CT imaging was 264 minutes and from CT to TICI 3 recanalization was 142 minutes., Results: HU ratio within the 0.94 to 0.96 ranges showed the highest correlation coefficient and lowest mean and median errors with the final ASPECTS. The difference of 2.0 HU between the 2 hemispheres demonstrated the higher correlation coefficient ( r =0.71; P <0.0001) and the lowest mean and median absolute errors (1.4 and 1, respectively)., Conclusions: We established a simple algorithm for rapid and accurate assessment of ASPECTS on baseline CT imaging to predict the extent of final stroke in patients with emergent large vessel occlusion who undergo endovascular revascularization., (© 2017 American Heart Association, Inc.)

The Pipeline Embolization Device (PED) was approved for the treatment of intracranial aneurysms from the petrous to the superior hypophyseal segment of the internal carotid artery. However, since its approval, its use for treatment of intracranial aneurysms in other locations and non-sidewall aneurysms has grown tremendously. The authors report on a cohort of 15 patients with 16 cerebral aneurysms that incorporated an end vessel with no significant distal collaterals, which were treated with the PED. The cohort includes 7 posterior communicating artery aneurysms, 5 ophthalmic artery aneurysms, 1 superior cerebellar artery aneurysm, 1 anterior inferior cerebellar artery aneurysm, and 2 middle cerebral artery aneurysms. None of the aneurysms achieved significant occlusion at the last follow-up evaluation (mean 24 months). Based on these observations, the authors do not recommend the use of flow diverters for the treatment of this subset of cerebral aneurysms.

OBJECTIVE The Pipeline embolization device (PED) is frequently used in the treatment of anterior circulation aneurysms, especially around the carotid siphon, with generally excellent results. However, the PED has its own unique technical challenges, including the occurrence of device foreshortening or migration leading to prolapse into the aneurysm. The authors sought to determine the incidence of this phenomenon, the rescue strategies, and outcomes. METHODS Four institutional databases of neuroendovascular procedures were reviewed for cases of intracranial aneurysms treated with PEDs. Patient and aneurysm data as well as angiographic imaging were reviewed for all cases involving device prolapse into the aneurysm. RESULTS A total of 413 intracranial aneurysms were treated with PEDs during the study period, by 5 neurointerventionalists. Large and giant aneurysms (≥ 2 cm) accounted for 32 of these aneurysms. Among these 32 PEDs, prolapse into the aneurysm occurred in 3 patients, with 1 of these PEDs successfully rescued and the other 2 left in situ. No patients suffered any severe complications. The 2 patients in whom the PEDs were left in situ remained on antiplatelet therapy. CONCLUSIONS The PED may foreshorten or migrate during or after deployment, leading to prolapse into the aneurysm. This phenomenon appears to be associated with large and giant aneurysms, vessel tortuosity, short landing zones, and use of balloon angioplasty. Future study and follow-up is needed to further evaluate this phenomenon, but some of the observations and techniques described in this paper may help to prevent or salvage prolapsed devices.

Background: Favorable imaging profile according to the Alberta Stroke Program Early CT Score (ASPECTS) on non-contrast head CT is a key criterion for the selection of patients with ischemic stroke from large vessel occlusion (LVO) for IA revascularization therapies., Objective: To analyze factors associated with changes in ASPECTS during inter-hospital transfer and to determine how deterioration of ASPECTS affects eligibility for endovascular procedures., Methods: We analyzed factors associated with changes in ASPECTS during inter-hospital transfer and their potential impact on eligibility for IA stroke therapies in patients with anterior circulation ischemic strokes. Clinical and demographic characteristics between patients with favorable (ASPECTS ≥6) and unfavorable (ASPECTS <6) imaging on repeat CT were compared., Results: Stroke evolution towards unfavorable ASPECTS occurred in 13/42 (31%) patients who initially had a favorable imaging profile at outside hospitals. A higher National Institutes of Health Stroke Scale (NIHSS) score was the only significant predictor of ASPECTS decay, whereas other clinical characteristics, such as the use of IV thrombolysis and site of LVO, were similar between the two groups., Conclusions: In our cohort, one out of three patients became ineligible for IA thrombectomy because of unfavorable ASPECTS 'decay' following inter-hospital transfer. Except for NIHSS severity, baseline clinical factors could not identify which patients were at risk for ASPECTS deterioration., (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/.)

Introduction: The definition of stroke has changed over time, from a clinical only-based diagnosis to a more complex classification, including both clinical and imaging-based criteria, in part due to widespread use of magnetic resonance imaging (MRI). The increasing number of transcatheter aortic valve replacement (TAVR) procedures in patients with severe aortic valvular stenosis who are considered high-risk surgical candidates has influenced our view on the diagnosis, interpretation, and significance of perioperative stroke during these procedures. Areas covered: In this perspective, we summarize changes in the definition and diagnostic criteria for stroke and transient ischemic attacks. We examine how the introduction of MRI and standardized cognitive tests has affected our understanding of the safety of TAVR procedures. Finally, we review the growing evidence regarding the role of cerebral protection technology during TAVR procedures on cognitive function. Expert commentary: Standardized MRI-based protocols and prospective evaluation of neurologic deficits with a battery of cognitive assessment tests are needed to ensure accurate recognition of postprocedural clinical events in patients undergoing TAVR procedures and to confirm the effectiveness of embolic protection technology.

Background and Purpose: Computed tomography perfusion imaging can estimate the size of the ischemic core, which can be used for the selection of patients for endovascular therapy. The relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) thresholds chosen to identify ischemic core influence the accuracy of prediction. We aimed to analyze the accuracy of various rCBV and rCBF thresholds for predicting the 27-hour infarct volume using RAPID automated analysis software from the SWIFT PRIME trial (Solitaire With the Intention for Thrombectomy as Primary Endovascular Treatment) data., Methods: Patients from the SWIFT PRIME study who achieved complete reperfusion based on time until the residue function reached its peak >6 s perfusion maps obtained at 27 hours were included. Patients from both the intravenous tissue-type plasminogen activator only and endovascular groups were included in analysis. Final infarct volume was determined on magnetic resonance imaging (fluid-attenuated inversion recovery images) or computed tomography scans obtained 27 hours after symptom onset. The predicted ischemic core volumes on rCBV and rCBF maps using thresholds ranging between 0.2 and 0.8 were compared with the actual infarct volume to determine the most accurate thresholds., Results: Among the 47 subjects, the following baseline computed tomography perfusion thresholds most accurately predicted the actual 27-hour infarct volume: rCBV=0.32, median absolute error (MAE)=9 mL; rCBV=0.34, MAE=9 mL; rCBF=0.30, MAE=8.8 mL; rCBF=0.32, MAE=7 mL; and rCBF=0.34, MAE=7.3., Conclusions: Brain regions with rCBF 0.30 to 0.34 or rCBV 0.32 to 0.34 thresholds provided the most accurate prediction of infarct volume in patients who achieved complete reperfusion with MAEs of ≤9 mL., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01657461., (© 2017 American Heart Association, Inc.)

OBJECTIVE Intracranial atherosclerotic disease (ICAD) accounts for approximately 10% of ischemic strokes. The recent Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) study demonstrated a high incidence of perioperative complications (15%) for treatment of ICAD with stenting. Although the incidence of stroke was lower in the medical arm, recurrent stroke was found in 12% of patients despite aggressive medical management, suggesting that intervention may remain a viable option for ICAD if perioperative risk is minimized. Angioplasty without stenting represents an alternative and understudied revascularization treatment for ICAD. Submaximal angioplasty limits the risks of thromboembolism, vessel perforation, and reperfusion hemorrhage that were frequently reported with stenting in the SAMMPRIS trial. The authors conducted a prospective Phase I trial designed to assess the safety of submaximal angioplasty in patients with symptomatic ICAD. METHODS This study was approved by the local institutional review board. Demographic and clinical data were prospectively collected. Angioplasty was performed with a balloon undersized to approximately 50%-70% of the nondiseased vessel diameter in patients with symptomatic ICAD who had angiographically significant stenosis of ≥ 70%. The primary outcome measure was the incidence of periprocedural complications (combined rate of death, stroke, and hemorrhage occurring within 30 days and at 1 year). RESULTS Among the 65 patients with symptomatic ICAD who were screened, 24 had significant angiographic stenosis that met the inclusion criteria of this study. The mean age was 64.08 years (median 65 years; SD ± 11.24 years), most were men (62.5%), and most were white (66.67%). Many patients had concomitants of vascular disease, including hypertension (95.8%), hyperlipidemia (70.83%), smoking history (54.1%), and diabetes mellitus (50.0%). Coronary artery disease (41.66%) and previous stroke or transient ischemic attack (45.83%) were frequently present. Most patients (75%) had anterior circulation stenosis. The mean preprocedure stenosis was 80.16% (median 80%, range 70%-95%). Submaximal angioplasty was performed in patients who met the inclusion criteria, with a mean postangioplasty stenosis rate of 54.62% (median 55.5%, range 31%-78%). Rates of ischemic stroke in the territory of the treated artery were 0% within 30 days and 5.55% (in the only patient who presented with recurrent stroke) at 1 year. The mortality and hemorrhage rates in this series were 0%. CONCLUSIONS This study demonstrates the safety of the submaximal angioplasty technique, with no permanent periprocedural complications in 24 treated patients.

Five recently published randomized trials of endovascular therapy versus medical management, including intravenous thrombolysis, demonstrated strong positive data in support of intra-arterial thrombectomy procedures. The American Heart Association/American Stroke Association released a focused update of the 2013 guidelines on the early management of acute ischemic strokes to specifically incorporate the findings of the 5 "positive" trials. In this review, we examine the key results of those trials and the principal changes in the updated guidelines. We discuss the ongoing and future changes in stroke systems of care, with an emphasis on the role of pre-hospital stroke triage, interhospital transfer, and the 2 main levels of stroke center certification (primary and comprehensive)., (Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Fusiform aneurysms present a unique challenge to traditional microsurgical and endovascular treatment because of the lack of a discernible neck and the involvement of parent vessel. Flow diversion has increasingly become the treatment of choice for fusiform aneurysms in the anterior circulation, but its results in the posterior circulation are variable. We report successful treatment of a giant fusiform upper basilar trunk aneurysm with the Surpass flow diverter in an adolescent, and discuss the potential advantages of this emerging technology in the treatment of fusiform posterior circulation aneurysms., (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/)

OBJECT In this study, the authors used information provided in the Nationwide Inpatient Sample (NIS) to study the impact of transferring stroke patients from one facility to a center where they received some form of active stroke intervention (intravenous tissue plasminogen activator, thrombectomy, or a combination of both therapies). METHODS Patient demographic characteristics and hospital factors obtained from the 2008-2010 acute stroke NIS data were analyzed. Discharge disposition, hospitalization cost, and mortality were the dependent variables studied. Univariate analysis and multivariate binary logistic regression analysis were performed. Data analysis focused on the cohort of acute stroke patients who received some form of active intervention (55,913 of 1,311,511 patients in the NIS). RESULTS When overall outcome was considered, transferred patients had a significantly higher number of other-than-routine (OTR, i.e., other than discharge to home without home health care) discharge dispositions (p < 0.0001). In multivariate regression analysis including pertinent patient and hospital factors, transfer-in patients had significantly worse OTR discharge disposition (p < 0.0001, odds ratio [OR] 2.575, 95% CI 2.341-2.832). Mean hospitalization cost including an intervention was $70,325.11 for direct admissions and $97,546.92 for transferred patients. Transfer from another facility (p < 0.001, OR 1.677, 95% CI 1.548-1.817) was associated with higher hospitalization cost. CONCLUSIONS The study showed that hospital cost for acute stroke intervention is significantly higher for a transferred patient than for a direct admission. Moreover, the frequency of OTR discharge was significantly higher among transferred patients than direct admissions. Future strategies should focus on ways and means of transporting patients appropriately and directly to stroke centers.

Background: Recently, an in vitro cerebrovascular occlusion model of the intracranial circulation was developed for testing thrombectomy devices. The Cover accessory (Lazarus Effect; Campbell, California, USA) is a novel nitinol braided mesh device that surrounds the stent retrieval device and thrombus during the retrieval process to help prevent clot fragmentation and embolization., Methods: Using the in vitro model, after introducing fresh clot into the middle cerebral artery, we compared rates of target vessel recanalization and embolization in new territories (areas in which clot had not been introduced) achieved with the Solitaire Flow Restoration (FR) stent retriever (Covidien, Irvine, California) in conjunction with the use of a conventional guide catheter (control group), a balloon guide catheter (BGC group), and the Cover device (Cover group)., Results: In a total of 51 thrombectomy experiments (20 in the control group, 20 in the BGC group, and 11 in the Cover group), successful recanalization (Thrombolysis in Cerebral Infarction 2b-3) was achieved more frequently in the Cover group than in the control group or in the BGC group (p=0.047 and p=0.020, respectively). Embolization of new (previously unaffected) territories occurred in five (25%) experiments from the control group and in three (15%) experiments from the BGC group, whereas no embolization of new territories was seen with Cover device assisted thrombectomy., Conclusions: Application of the Cover device in this experimental model resulted in higher successful recanalization rates, no embolic events, and was more effective than use of the conventional guide catheter or BGC., (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: Endovascular treatment of wake-up strokes (WUS) has been previously described, mostly with the use of pharmacological thrombolysis or first generation thrombectomy devices., Objective: To describe outcomes of WUS treated with modern endovascular therapy since the Food and Drug Administration approval of stent retrievers, and to identify predictors of good clinical outcome in this population of stroke patients., Methods: We performed a multicenter retrospective analysis of consecutive patients with WUS who underwent thrombectomy with stent retrievers Trevo (Stryker, Kalamazoo, Michigan, USA) and Solitaire FR (Covidien, Irvine, California, USA), or primary aspiration thrombectomy. We correlated favorable clinical outcomes with demographic, clinical, and technical characteristics., Results: 52 patients were included in this study; 46 (88%) cases were treated with stent retrievers and 6 (12%) were treated with primary aspiration thrombectomy alone. Successful recanalization (Thrombolysis in Cerebral Infarction (TICI) 2b/3) was achieved in 36 (69%) patients. Favorable clinical outcome at 3 months, defined as a modified Rankin Scale score of 0-2, was achieved in 25 (48%) patients. Duration of intervention <30 min and its success, defined as TICI 2b/3 recanalization, were strong predictors of favorable clinical outcome at 90 days (p<0.001 and p<0.0001, respectively)., Conclusions: Our study indicates that endovascular treatment of WUS with stent retrievers and aspiration thrombectomy is safe and effective., (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: Acute cerebral venous sinus thrombosis (VST) can be difficult to diagnose because of its diverse clinical presentation. The utility of perfusion imaging for diagnosing VST is not well understood., Summary: We retrospectively reviewed cases of acute VST in patients who underwent whole-brain (320-detector-row) computed tomographic (CT) perfusion imaging in combination with craniocervical CT venography. Perfusion maps that were analyzed included cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time, and time to peak. Among the 10 patients with acute VST included in this study, 9 had perfusion abnormalities. All perfusion abnormalities were localized in areas adjacent to the occluded sinus and did not match typical anterior or posterior circulation arterial territories. Bilateral perfusion deficits were seen in 4 cases. In 2 cases, parenchymal hemorrhage was diagnosed on noncontrast CT imaging; in those cases, focal CBV and CBF were reduced., Key Messages: Whole-brain CT perfusion imaging with 320-detector-row scanners can further assist in establishing the diagnosis of VST by detecting perfusion abnormalities corresponding to venous and not arterial territories. CT perfusion could assist in the differentiation between focal reversible changes, such as those caused by vasogenic edema, and irreversible changes due to infarction.

Background and Purpose: Patients with posterior circulation strokes have been excluded from recent randomized endovascular stroke trials. We reviewed the recent multicenter experience with endovascular treatment of posterior circulation strokes to identify the clinical, radiographic, and procedural predictors of successful recanalization and good neurological outcomes., Methods: We performed a multicenter retrospective analysis of consecutive patients with posterior circulation strokes, who underwent thrombectomy with stent retrievers or primary aspiration thrombectomy (including A Direct Aspiration First Pass Technique [ADAPT] approach). We correlated clinical and radiographic outcomes with demographic, clinical, and technical characteristics., Results: A total of 100 patients were included in the final analysis (mean age, 63.5±14.2 years; mean admission National Institutes of Health Stroke Scale score, 19.2±8.2). Favorable clinical outcome at 3 months (modified Rankin Scale score ≤2) was achieved in 35% of patients. Successful recanalization and shorter time from stroke onset to the start of the procedure were significant predictors of favorable clinical outcome at 90 days. Stent retriever and aspiration thrombectomy as primary treatment approaches showed comparable procedural and clinical outcomes. None of the baseline advanced imaging modalities (magnetic resonance imaging, computed tomographic perfusion, or computed tomography angiography assessment of collaterals) showed superiority in selecting patients for thrombectomy., Conclusions: Time to the start of the procedure is an important predictor of clinical success after thrombectomy in patients with posterior circulation strokes. Both stent retriever and aspiration thrombectomy as primary treatment approaches are effective in achieving successful recanalization., (© 2016 American Heart Association, Inc.)

Five trials that investigated the efficacy of modern endovascular therapies for stroke--MR CLEAN, ESCAPE, SWIFT PRIME, EXTEND IA and REVASCAT--have been published within the past year, changing the landscape of acute stroke management. The trials used a variety of imaging modalities and combinations of treatment approaches, including the mandatory use of intravenous thrombolysis before the initiation of endovascular therapy. All five trials provided strong evidence to support the use of thrombectomy that is initiated within 6 h of stroke onset, prompting worldwide changes in the guidelines for management of acute stroke by endovascular treatment. The benefits of endovascular therapy were observed irrespective of a patient's age, their NIH Stroke Scale score, or whether they received intravenous thrombolysis. In this article, we review the main findings of these recent trials, focusing on key aspects of their designs, and discuss their impact on the future management of patients with acute stroke that results from large-vessel occlusion. We discuss the values of noncontrast CT ASPECTS, perfusion imaging and angiography for selecting patients to receive endovascular interventions. We also consider the role of thrombectomy beyond 6 h after stroke onset, and in patients with posterior circulation strokes.

Diffusion- and perfusion-based imaging studies are regularly used in patients with ischemic stroke. Cerebral venous sinus thrombosis (CVST) is a rare cause of stroke and is primarily treated by systemic anticoagulation. Endovascular intervention can be considered in cases of failed medical therapy, yet the prognostic value of diffusion- and perfusion-based imaging for CVST has not been clearly established. We present a patient with CVST whose abnormal findings on MRI and CT perfusion images were largely reversed after endovascular treatment., (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: Demographics and vascular anatomy may play an important role in predicting periprocedural complications in symptomatic patients undergoing carotid artery stenting (CAS)., Objective: To predict factors associated with increased risk of complications in symptomatic patients undergoing CAS and to devise a CAS scoring system that predicts such complications in this patient population., Methods: A retrospective study was conducted that included patients who underwent CAS for symptomatic carotid stenosis during a 3-year period. Demographics and anatomic characteristics were subsequently correlated with 30-day outcome measures., Results: A total of 221 patients were included in the study. The cumulative rate of periprocedural complications was 7.2%, including stroke (3.2%), myocardial infarction (3.2%), and death (1.4%). Renal disease increased the risk of all complications. National Institutes of Health Stroke Scale score ≥10 at presentation, difficult femoral access, and diseased calcified aortic arch increased the risk of stroke and all complications. Type III aortic arch correlated with increased risk of stroke. Pseudo-occlusion and concentric calcification of the carotid artery increased the risk of myocardial infarction, death, and all complications. Carotid tortuosity and anatomy hostile to the deployment of distal protection devices increased the risk of stroke, myocardial infarction, death, and all complications., Conclusion: Our results suggest that CAS should be avoided in patients with multiple anatomic risk factors. High presenting National Institutes of Health Stroke Scale score and renal disease also increase the complication risk. The CAS scoring system devised here is simple, reproducible, and clinically valuable in predicting complications risk in symptomatic patients undergoing CAS.

Background: Neurointerventionalists do not agree about the optimal imaging protocol when evaluating patients with acute stroke for potential endovascular revascularization. Preintervention cerebrovascular blood volume (CBV) has been shown to predict outcomes in patients undergoing intra-arterial stroke therapies., Objective: To determine whether CBV can predict hemorrhagic transformation and clinical outcomes in patients selected for endovascular therapy for acute ischemic middle cerebral artery (MCA) stroke using a CT perfusion (CTP)-based imaging protocol., Methods: We retrospectively reviewed cases of acute ischemic stroke due to MCA M1 segment occlusion and correlated favorable clinical outcomes (modified Rankin scale (mRS) ≤2) and radiographic outcomes with preintervention CBV values. All patients underwent whole-brain (320-detector-row) CTP imaging, and absolute CBV values of the affected and contralateral MCA territories were obtained separately for the cortical and basal ganglia regions., Results: Relative CBV (rCBV) of the MCA cortical regions was significantly lower in patients with poor clinical outcomes than in those with favorable clinical outcomes (0.87±0.21 vs 1.02±0.09, p=0.0003), and a negative correlation was found between rCBV values and mRS score severity. rCBV of the basal ganglia region was significantly lower in patients with hemorrhagic infarction (p=0.004) and parenchymal hematoma (p=0.04) than in those without hemorrhagic transformation., Conclusions: We found that cortical CBV loss is predictive of poor clinical outcomes, whereas basal ganglia CBV loss is predictive of hemorrhagic transformation but without translation into poor clinical outcomes. Our study findings support published results of baseline preintervention CBV as a predictor of outcomes in patients undergoing intra-arterial stroke therapies., (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.)

Endovascular therapy of cerebral venous thrombosis using modern approaches to intracranial recanalization, such as stent retrievers and aspiration thrombectomy, is not well described. We performed a retrospective review of data for consecutive patients with venous sinus thrombosis who underwent endovascular treatment between 1 January 2010 and 31 December 2013 at participating institutions. We identified a total of 13 patients with a diagnosis of cerebral venous thrombosis. The most frequently utilized type of endovascular intervention was the Penumbra aspiration system (Penumbra Inc., Alameda, California, USA) (nine cases), followed by local infusion of tissue plasminogen activator (bolus and/or drip in six cases) and stent retrievers (Solitaire FR (Covidien, Irvine, California, USA) in three cases and Trevo (Stryker, Kalamazoo, Michigan, USA) in one case). Overall, multimodality treatment (two or more different types of devices or approaches) was performed in 62% of cases. Follow-up data were available for 11 patients; of those, five had a favorable clinical outcome (defined as modified Rankin Scale score of 0-2) and three patients died. Various endovascular approaches are utilized in current clinical practice. A multimodal approach to endovascular therapy for the treatment of cerebral venous thrombosis resulted in partial or complete restoration of flow in all cases, yet the mortality rate of 27% indicates the need for improvement in recanalization strategies for this disorder., (© The Author(s) 2015.)

Unlabelled: A 57-year-old woman with National Institutes of Health Stroke Scale (NIHSS) score of 26 was found to have an acute left carotid occlusion with tandem left M1 thrombus within 1.5 hours of symptom onset. After no neurologic improvement following standard-dose intravenous (IV) recombinant tissue plasminogen activator (rtPA), emergent neuroendovascular revascularization with carotid stenting and intracranial thrombectomy were performed under conscious sedation. Thrombolysis in myocardial infarction (TIMI)-3 flow restoration and symptom resolution were achieved postprocedure; however, complete carotid stent thrombosis was noted on final angiographic runs (25 minutes later), correlating with neurologic decline. Rapid administration of an intraarterial (IA) bolus dose of eptifibatide resulted in TIMI-3 flow restoration, with neurologic improvement. The patient was discharged three days postrevascularization on dual antiplatelet therapy with an NIHSS score of 1. Intraarterial (IA) eptifibatide can be an effective option for acute stent occlusion during emergent neuroendovascular revascularization after IV rtPA administration., Abbreviations: CLEARCombined approach to lysis utilizing eptifibatide and RtPACTcomputed tomographicFrFrenchGPglycoproteinIAintraarterialICAinternal carotid arteryIVintravenousMCAmiddle cerebral arteryNIHSSNational Institutes of Health Stroke ScalertPArecombinant tissue plasminogen activatorTIMIthrombolysis in myocardial infarction.