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Background: Subarachnoid hyperdensity (SAH) after endovascular thrombectomy is a well-known phenomenon. Nevertheless, the clinical significance and natural history of this phenomenon is not well described. In addition, we test previously postulated hypotheses of distal occlusions sites and antithrombotic use to SAH prevalence and extent., Methods: We performed a retrospective analysis of all patients presenting with acute stroke and treated by endovascular thrmbectomy in our tertiary center January 2016 and February 2021. Only patients who underwent CT scan of the brain within 24 h after procedure were included., Results: 394 patients were included in this study. SAH after EVT was evident on CT in18.3% of those. Most of these (10.7%), had non-resolving hyperdensity (persistent SAH) on follow up imaging. A minority (2.6%) had resolving hyperdensity (transient SAH). Only 2% had a combination of subarachnoid hyperdensity and intracerebral hemorrhage (SAH + ICH). Transient and persistent SAH were associated with good functional and imaging outcomes as compared to SAH + ICH patients. Older age, large infarct size, stentretriever use and partial recanalization were correlated with SAH + ICH. Distal occlusions and distal vessel angulations resulting in higher traction potential were more prevalent in persistent SAH group. Higher number of thrombectomy passes was correlated with the extent of persistent SAH. Transient SAH group did not show statistically significant demographic or procedural trends., Discussion: We propose therefore a distinct classification of the post thrombectomy SAH subtypes and discuss the putative pathophysiological mechanisms of the three distinct phenomena and their predictive factors., Competing Interests: Declarations. Ethics approval: The data collection in fully deidentified manner was approved by the institutional ethics board, University Health Network, Toronto. Informed consent: Non applicable for retrospective observational study. Conflicts of interest/Competing interests: Nothing to disclose., (© 2025. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background and Purpose: Dural arteriovenous fistulas (DAVFs) exhibit varied clinical manifestations, and high-grade cases are associated with both a risk of hemorrhage and (in certain cases) dementia. Less known, however, is the association between DAVF and more subtle cognitive changes, which might not be clinically apparent without formal neurocognitive testing. This study prospectively assesses baseline cognitive changes in patients with unruptured DAVFs and looks at the effects of treatment on any such changes., Materials and Methods: A longitudinal prospective study was conducted to formally evaluate the neurocognitive status of patients with unruptured DAVFs undergoing embolization. Pre- and posttreatment assessments included neurologic examinations and cognitive tests (Repeatable Battery for the Assessment of Neuropsychological Status and Trail-Making Test [TMT])., Results: A total of 23 patients were treated, with 78% demonstrating cortical venous reflux at baseline. At baseline, 50% of patients demonstrated cognitive impairment in at least 1 cognitive domain, and this was significantly associated with cortical venous reflux ( P < .05). Following treatment, significant improvements were observed in several cognitive domains. The mean change in Immediate Memory was an increase of 10.5 points (95% CI, 6.2-14.8, P < .001). Visuospatial/Constructional abilities showed a mean increase of 3.8 points (95% CI, 1.1-6.5, P = .008), while Language improved by a mean of 4.2 points (95% CI, 0.9-7.5, P = .015). Attention scores increased by a mean of 6.1 points (95% CI, 2.7-9.5, P < .001). Delayed Memory demonstrated a mean improvement of 7.4 points (95% CI, 3.5-11.3, P < .001), and the Total Repeatable Battery for the Assessment of Neuropsychological Status Score increased by a mean of 8.6 points (95% CI, 5.0-12.2, P < .001). For the TMT, the mean change in TMT-A was a decrease of 9.2 seconds (95% CI, 5.6-12.8, P < .001), indicating faster completion times. TMT-B scores decreased by a mean of 12.7 seconds (95% CI, 8.4-17.0, P < .001). The TMT B-A difference decreased by a mean of 3.5 seconds (95% CI, 0.5-6.5, P = .023), and the TMT B/A ratio showed a mean decrease of 0.18 (95% CI, 0.10-0.26, P = .002). Overall, among the patients with baseline cognitive impairment, 70% showed significant cognitive improvement following endovascular treatment, particularly in memory domains., Conclusions: In our study, 50% of patients with DAVFs had cognitive impairment when assessed with formal neurocognitive testing, with a significant link to cortical venous reflux. This cognitive impairment improved in 70% of those patients following treatment. These findings expand our understanding of how DAVF affects the brain, highlighting cognitive impairment as a critical factor. Consequently, the treatment of DAVFs should perhaps not only focus on hemorrhagic risk but also consider cognitive outcomes as a potential indicator for intervention., (© 2024 by American Journal of Neuroradiology.)

Background/Objectives : MMAE (middle meningeal artery embolization) has emerged as a potential effective treatment for cSDH (chronic subdural hematoma). In this study, MMAE efficiency with regards to cSDH cause and architecture was explored. The comparability of cSDH thickness and volume as parameters for cSDH pre- and post-MMAE assessment was also analyzed. Methods : In this retrospective cohort study, 52 consecutive cSDH patients treated with MMAE in a single tertiary center were included. The cohort was divided into two group pairs pertaining to cSDH cause (spontaneous or traumatic) and cSDH architecture (non-mature or mature). The radiological outcome was compared in each group before and after MMAE and between each group pair using CT imaging. A correlation analysis between cSDH thickness and volume before and after MMAE was also performed. Results : A statistically significant positive linear association between cSDH thickness and volume at admission and at each follow-up interval (1-3, 3-6, 6-12 months) was noticed. cSDH thickness and volume reduction in each group was statistically significant, except for a traumatic cSDH volume reduction at 6-12 months. There was no statistically significant difference between each group pair in the cSDH thickness and volume reduction difference at all the follow-up intervals. Conclusions : A comparable efficiency of MMAE may be achieved in non-mature and mature as well as in spontaneous and traumatic cSDH, with an advantage for spontaneous cSDH at 6-12 months follow-up compared to traumatic cSDH. Traumatic cSDH may require a relatively long-term follow-up post-MMAE. cSDH thickness and volume, as parameters for pre- and post-MMAE cSDH evaluation, appear similar.

Background: Arteriovenous malformations (AVMs) are uncommon cerebral lesions that can cause significant neurological complications. Surgical resection is the gold standard for treatment, but endovascular embolization and stereotactic radiosurgery (SRS) are viable alternatives., Objective: To compare the outcomes of endovascular embolization versus SRS in the treatment of AVMs with Spetzler-Martin grades I-III., Methods: This study combined retrospective data from 10 academic institutions in North America and Europe. Patients aged 1 to 90 years who underwent endovascular embolization or SRS for AVMs with Spetzler-Martin grades I-III between January 2010 and December 2023 were included., Results: The study included 244 patients, including 84 who had endovascular embolization and 160 who had SRS. Before propensity score matching (PSM), complete obliteration at the last follow-up was achieved in 74.5% of the SRS group compared with 57.8% of the embolization group (OR=0.47; 95% CI 0.26 to 0.48; P=0.01). After propensity score matching, SRS still achieved significantly higher occlusion rates at last follow-up (78.9% vs 55.3%; OR=0.32; 95% CI 0.12 to 0.90; P=0.03).Hemorrhagic complications were higher in the embolization group than in the SRS group, although this difference did not reach statistical significance after PSM (13.2% vs 2.6%; OR=5.6; 95% CI 0.62 to 50.47; P=0.12). Similarly, re-treatment rate was higher in the embolization group (10.5% vs 5.3%; OR=2.11; 95% CI 0.36 to 12.31; P=0.40) compared with the SRS group., Conclusion: Our findings indicate that SRS has a significantly higher obliteration rate at last follow-up compared with endovascular embolization. Also, SRS has a higher tendency for fewer hemorrhagic complications and lower re-treatment rate. Further prospective studies are needed., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Purpose: To evaluate the durability and safety of complete intracranial aneurysm occlusion at one year using the low-profile braided intracranial LVIS EVO stent., Materials and Methods: This is a retrospective, monocentric, observational study of unruptured wide-necked intracranial aneurysms treated with the LVIS EVO stent-through-balloon technique after balloon-assisted hydrocoil embolization. Imaging and clinical data were assessed by two blinded independent neuroradiologists and neurologists, respectively. Primary endpoint was complete angiographic occlusion on day 0 and at 12 months. Secondary endpoints included clinical safety using the modified Rankin scale (mRS), ischemic and hemorrhagic adverse events, parent vessel stenosis > 50% or occlusion and retreatment rate., Results: 103 aneurysms in 103 patients were included (53 years-old, 77% women). Mean aneurysm size and neck were 7 and 4 mm, respectively. Complete occlusion was 97% initially and 90% at 12 months, with pending follow up in 17.5% patients. Five patients (5%) with partially stented necks were retreated with a second stent in a T-configuration. Two stents failed to open initially and were immediately retrieved. Asymptomatic parent vessel occlusion and severe in-stent stenosis occurred in 1% and 3%, respectively. The 12-month procedure-related permanent neurological deficit and mortality rates (mRS 3-6) were 2% and 1%, respectively. There was one fatal bleeding but no large ischemic complications., Conclusion: Delivering the LVIS EVO stent through a dual lumen balloon after balloon-assisted hydrocoil embolization yields a high and stable rate of complete aneurysm occlusion at one year with a reasonable immediate and delayed complication rate., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Purpose: Intracranial aneurysms present significant health risks, as their rupture leads to subarachnoid haemorrhage, which in turn has high morbidity and mortality rates. There are several elements affecting the complexity of an intracranial aneurysm. However, criteria for defining a complex intracranial aneurysm (CIA) in open surgery and endovascular treatment could differ, and actually there is no consensus on the definition of a "complex" aneurysm. This DELPHI study aims to assess consensus on variables defining a CIA., Methods: An international panel of 50 members, representing various specialties, was recruited to define CIAs through a three-round Delphi process. The panelists participated in surveys with Likert scale responses and open-ended questions. Consensus criteria were established to determine CIA variables, and statistical analysis evaluated consensus and stability., Results: In open surgery, CIAs were defined by fusiform or blister-like shape, dissecting aetiology, giant size (≥ 25 mm), broad neck encasing parent arteries, extensive neck surface, wall calcification, intraluminal thrombus, collateral branch from the sac, location (AICA, SCA, basilar), vasospasm context, and planned bypass (EC-IC or IC-IC). For endovascular treatment, CIAs included giant size, very wide neck (dome/neck ratio ≤ 1:1), and collateral branch from the sac., Conclusions: The definition of aneurysm complexity varies by treatment modality. Since elements related to complexity differ between open surgery and endovascular treatment, these consensus criteria of CIAs could even guide in selecting the best treatment approach., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background: Data on the frequency and outcome of mechanical thrombectomy (MT) for large vessel occlusion (LVO) in patients with COVID-19 is limited. Addressing this subject, we report our multicenter experience., Methods: A retrospective cohort study was performed of consecutive acute stroke patients with COVID-19 infection treated with MT at 26 tertiary care centers between January 2020 and November 2021. Baseline demographics, angiographic outcome and clinical outcome evaluated by the modified Rankin Scale (mRS) at discharge and 90 days were noted., Results: We identified 111 out of 11 365 (1%) patients with acute or subsided COVID-19 infection who underwent MT due to LVO. Cardioembolic events were the most common etiology for LVO (38.7%). Median baseline National Institutes of Health Stroke Scale score and Alberta Stroke Program Early CT Score were 16 (IQR 11.5-20) and 9 (IQR 7-10), respectively. Successful reperfusion (mTICI ≥2b) was achieved in 97/111 (87.4%) patients and 46/111 (41.4%) patients were reperfused completely. The procedure-related complication rate was 12.6% (14/111). Functional independence was achieved in 20/108 (18.5%) patients at discharge and 14/66 (21.2%) at 90 days follow-up. The in-hospital mortality rate was 30.6% (33/108). In the subgroup analysis, patients with severe acute COVID-19 infection requiring intubation had a mortality rate twice as high as patients with mild or moderate acute COVID-19 infection. Acute respiratory failure requiring ventilation and time interval from symptom onset to groin puncture were independent predictors for an unfavorable outcome in a logistic regression analysis., Conclusion: Our study showed a poor clinical outcome and high mortality, especially in patients with severe acute COVID-19 infection undergoing MT due to LVO., Competing Interests: Competing interests: MM: Grants or contracts from Balt, Medtronic, MircroVention and Stryker. FD: Consultant for Balt, Cerus Endovascular, Phenox and Cerenovus, honoraria for lectures from Cerenovus, Acandis and Asahi, support for attending meetings from MicroVention, Acandis and Cerus Endovascular, advisory board member for Cerenovus/Johnson & Johnson, associate editor for Journal of NeuroInterventional Surgery. MG: Grants or contracts from Else Kröner Fresenius Stiftung, payment of honoraria for lectures from Phenox, proctoring contract with MircroVention, participation on clinical event committee from MicroVention, chair of ESMINT Examination Committee, received stents from Phenox for research purposes. DK: Grants or contracts from Else Kröner Fresenius Center of Digital Health and Joachim Herz Foundation, spokesman of the “Junge Neuroradiologie” in the German Society of Neuroradiology. CL: Consulting fees, payment of honoraria for lectures and support for attending meetings from Phenox, Penumbra and Acandis. MW: Grants from ab medica, Acandis, Bracco Imaging, Cerenovus, Kaneka Pharmaceuticals, Medtronic, Mentice AB, Microvention, Phenox, Siemens Healthcare and Stryker Neurovascular; Consulting fees from Stryker Healthcare; Payment honoraria for lectures from Stryker Neurovascular. The other authors declare no specific conflict of interest., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The degree of reperfusion is the most important modifiable predictor of 3 month functional outcome and mortality in ischemic stroke patients treated with mechanical thrombectomy. Whether the beneficial effect of reperfusion also leads to a reduction in long term mortality is unknown., Methods: Patients undergoing mechanical thrombectomy between January 2010 and December 2018 were included. The post-thrombectomy degree of reperfusion and emboli in new territories were core laboratory adjudicated. Reperfusion was evaluated according to the expanded Thrombolysis in Cerebral Infarction (eTICI) scale. Vital status was obtained from the Swiss population register. Adjusted hazard ratios (aHRs) using time split Cox regression models were calculated. Subgroup analyses were performed in patients with borderline indications., Results: Our study included 1264 patients (median follow-up per patient 2.5 years). Patients with successful reperfusion had longer survival times, attributable to a lower hazard of death within 0-90 days and for >90 days to 2 years (aHR 0.34, 95% CI 0.26 to 0.46; aHR 0.37, 95% CI 0.22 to 0.62). This association was homogeneous across all predefined subgroups (p for interaction >0.05). Among patients with successful reperfusion, a significant difference in the hazard of death was observed between eTICI2b50 and eTICI3 (aHR 0.51, 95% CI 0.33 to 0.79). Emboli in new territories were present in 5% of patients, and were associated with increased mortality (aHR 2.3, 95% CI 1.11 to 4.86)., Conclusion: Successful, and ideally complete, reperfusion without emboli in new territories is associated with a reduction in long term mortality in patients treated with mechanical thrombectomy, and this was evident across several subgroups., Competing Interests: Competing interests: UF reports grants during the conduct of the study from Medtronic, Stryker, and CSL Behring, unrelated to the submitted work. JG is a global principal investigator of STAR (Solitaire FR Thrombectomy for Acute Revascularisation), Clinical Event Committee member of the PROMISE study (Prospective, Multicenter, Observational, Single-Arm European Registry on the ACE Reperfusion Catheters and the Penumbra System in the Treatment of Acute Ischemic Stroke; Penumbra), and a principal investigator and consultant for the SWIFT DIRECT study (Solitaire With the Intention for Thrombectomy Plus Intravenous tPA Versus DIRECT Solitaire Stent-Retriever Thrombectomy in Acute Anterior Circulation Stroke; Medtronic) and receives Swiss National Science Foundation grants for magnetic resonance imaging in stroke. JK reports grants from the Swiss Academy of Medical Sciences/Bangerter Foundation, Swiss Stroke Society, and Clinical Trials Unit Bern during the conduct of the study. MA reports personal fees from Bayer, Bristol-Myers Squibb, Medtronic, Amgen, Daiichi Sankyo, Nestlé Health Sciences, Boehringer Ingelheim, and Covidien during the conduct of the study. TRM reports research support from the Bangerter Rhyner Foundation, Swiss National Foundation, and the Swiss Heart Foundation. MRH reports research support from the Bangerter Foundation, scientific advisory board honoraria from Amgen, and personal fees from Bayer., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Achieving the best possible reperfusion is a key determinant of clinical outcome after mechanical thrombectomy (MT). However, data on the safety and efficacy of intra-arterial (IA) fibrinolytics as an adjunct to MT with the intention to improve reperfusion are sparse., Methods: We performed a PROSPERO-registered (CRD42020149124) systematic review and meta-analysis accessing MEDLINE, PubMed, and Embase from January 1, 2000 to January 1, 2020. A random-effect estimate (Mantel-Haenszel) was computed and summary OR with 95% CI were used as a measure of added IA fibrinolytics versus control on the risk of symptomatic intracranial hemorrhage (sICH) and secondary endpoints (modified Rankin Scale ≤2, mortality at 90 days)., Results: The search identified six observational cohort studies and three observational datasets of MT randomized-controlled trial data reporting on IA fibrinolytics with MT as compared with MT alone, including 2797 patients (405 with additional IA fibrinolytics (100 urokinase (uPA), 305 tissue plasminogen activator (tPA)) and 2392 patients without IA fibrinolytics). Of 405 MT patients treated with additional IA fibrinolytics, 209 (51.6%) received prior intravenous tPA. We did not observe an increased risk of sICH after administration of IA fibrinolytics as adjunct to MT (OR 1.06, 95% CI 0.64 to 1.76), nor excess mortality (0.81, 95% CI 0.60 to 1.08). Although the mode of reporting was heterogeneous, some studies observed improved reperfusion after IA fibrinolytics., Conclusion: The quality of evidence regarding peri-interventional administration of IA fibrinolytics in MT is low and limited to observational data. In highly selected patients, no increase in sICH was observed, but there is large uncertainty., Competing Interests: Competing interests: Related: UF and JG are global PIs for the SWIFT DIRECT study (Solitaire With the Intention for Thrombectomy Plus Intravenous t-PA Versus DIRECT Solitaire Stent-Retriever Thrombectomy in Acute Anterior Circulation Stroke) supported by Medtronic. Unrelated: JG is a global PI of STAR (Solitaire FR Thrombectomy for Acute Revascularisation Observational study), Clinical Event Committee member of the PROMISE study (European Registry on the ACE Reperfusion Catheters and the Penumbra System in the Treatment of Acute Ischemic Stroke; Penumbra), Consultancy, and receives Swiss National Science Foundation (SNSF) grants for MRI in stroke. UF receives research grants from SNSF and serves as a consultant for Medtronic and Stryker. MA received speaker honoraria from Bayer, Boehringer Ingelheim, and Covidien; advisory board honoraria from Amgen Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Pfizer, Covidien, Daichy Sankyo and Nestlé Health Science; research grant provided by the Swiss Heart Foundation. JK reports grants from SAMW / Bangerter Foundation, the Swiss Stroke Society and non-financial support from Stryker and Pfizer outside the submitted work. DWJD reports funding from the Dutch Heart Foundation, Brain Foundation Netherlands, The Netherlands Organisation for Health Research and Development, Health Holland Top Sector Life Sciences & Health, and unrestricted grants from AngioCare BV, Covidien/EV3®, MEDAC Gmbh/LAMEPRO, Penumbra Inc., Top Medical/Concentric, Stryker, Stryker European Operations BV, Medtronic, Thrombolytic Science, LLC and Cerenovus for research, all paid to institution. MG reports licensing agreement for systems of acute stroke diagnosis for GE Healthcare and Consultancy for Medtronic, Stryker, MicroVention and Mentice as well as unrestricted research grant by Stryker for the UNMASK-EVT study. MDH has a patent Systems and Methods for Assisting in Decision-Making and Triaging for Acute Stroke Patients pending to US patent office number 62/086077 and owns stock in Calgary Scientific, Inc—a company that focuses on medical imaging software., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: Delayed cerebral ischemia (DCI) is a frequent cause of morbidity and mortality in patients with cerebral vasospasm (CV) following aneurysmal subarachnoid hemorrhage (aSAH). Refractory CV remains challenging to treat and often leads to permanent deficits and death despite aggressive therapy. We hereby report the feasibility and safety of stellate ganglion block (SGB) performed with a vascular roadmap-guided technique to minimize the risk of accidental vascular puncture and may be coupled to a diagnostic or therapeutic cerebral angiography., Methods: In addition to a detailed description of the technique, we performed a retrospective analysis of a series of consecutive patients with refractory CV after aSAH that were treated with adjuvant roadmap-guided SGB. Clinical outcomes at discharge are reported., Results: Nineteen SGB procedures were performed in 10 patients, after failure of traditional hemodynamic and endovascular treatments. Each patient received 1 to 3 SGB, usually interspaced by 24 h. In 4 patients, an indwelling microcatheter for continuous infusion was inserted. First SGB occurred on average 7.3 days after aSAH. SGB was coupled to intra-arterial nimodipine infusion or balloon angioplasty in 9 patients. SGB was technically successful in all patients. There were no technical or clinical complications., Conclusion: Adjuvant SGB may be coupled to endovascular therapy to treat refractory cerebral vasopasm within the same session. To guide needle placement, using a roadmap of the supra-aortic arteries may decrease the risk of complications. More prospective data is needed to evaluate the therapeutic efficacy, durability, and safety of SGB compared with the established standard of care., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Spinal imaging is essential to identify and localize cerebrospinal fluid (CSF) leaks in spontaneous intracranial hypotension (SIH) patients when targeted treatment is necessary., Purpose: Provide an in-depth presentation of the conventional dynamic myelography (CDM) technique for localizing spinal CSF leaks in SIH patients., Material and Methods: Consecutive SIH patients with a CSF leak confirmed on CDM and postmyelography computed tomography (CT) investigated at our institution between 2013 and 2019 were retrospectively analyzed. Intraoperative reports were reviewed to confirm the accuracy of CDM., Results: In total, 62 patients (mean age 45 years) were included; 48 with a ventral dural tear, 12 with a meningeal diverticulum, and in 2 patients positive for spinal longitudinal extradural CSF collection the site remained unclear. The leak was identified during the first and the second CDM in 43 and 17 patients, respectively. The use of CDM correctly identified the site of the CSF leak in all but one patient undergoing surgical closure (45/46, 98%). The mean fluoroscopy time was 7.8 min (range 1.8-14.4 min) with a radiation dose for a single examination of 310 mGy (range 28-1237 mGy)., Conclusion: The CDM procedure has a high accuracy for spinal CSF leak localization including dural tears and spinal nerve diverticula. It is the technique with the highest temporal resolution, is robust to breathing artifacts, allows great flexibility regarding patient positioning, compares favorably to other dynamic examinations with respect to the radiation dose and does not require general anesthesia. For CSF venous fistulas, however, other dynamic examinations, such as digital subtraction myelography, seem more appropriate., (© 2020. The Author(s).)

Intracranial aneurysm (IA) is one of the most challenging vascular lesions in the brain for clinicians. It was reported that 1%-6% of the world's population is affected by IAs. Owing to serious complications arising from these lesions, much attention has been paid to better understand their pathophysiology. Non-coding RNAs including short non-coding RNAs and long non-coding RNAs, have critical roles in modulating physiologic and pathological processes. These RNAs are emerging as new fundamental regulators of gene expression, are related with the progression of IA. Non-coding RNAs act via multiple mechanisms and be involved in vascular development, growth and remodeling. Furthermore, these molecules are involved in the regulation of inflammation, a key process in the formation and rupture of IA. Studying non-coding RNAs can yield a hypothetical mechanism for better understanding IA. The present study aims to focus on the role of these non-coding RNAs in the pathogenesis of IA., (Copyright © 2018. Published by Elsevier Inc.)

Background: During carotid endarterectomy (CEA), significant amplitude decrement of somatosensory evoked potentials (SEPs) is associated with post-operative neurological deficits., Objective: To investigate the association between an incomplete circle of Willis and/or contralateral ICA occlusion and subsequent changes in intra-operatively monitored SEPs., Methods: We performed a retrospective analysis of a single center, prospective cohort of consecutive patients undergoing CEA over a 42-month period after reviewing the collateral arterial anatomy on pre-operative radiological imaging. The primary endpoint was an intra-operative decline in SEPs > 50% compared to the baseline value during arterial cross-clamping. Univariate and multivariate logistic regression analyses were performed to investigate a potential association between contralateral ICA occlusion, incomplete circle of Willis, and subsequent alteration in SEPs., Results: A total of 140 consecutive patients were included, of which 116 patients (82.9%) had symptomatic carotid stenosis of at least 50% according to the classification used in the North American Carotid Surgery Trial (NASCET) (Stroke 22:711-720, 1991). Six patients (4.3%) showed contralateral ICA occlusion, 22 patients (16%) a missing/hypoplastic anterior communicating artery (Acom) or A1 segment, and 79 patients (56%) a missing ipsilateral posterior communicating artery (Pcom) or P1 segment. ICA occlusion and missing segments of the anterior circulation (missing A1 and/or missing Acom) were associated with the primary endpoint (p = 0.003 and p = 0.022, respectively)., Conclusion: Contralateral ICA occlusion and missing anterior collaterals of the circle of Willis increase the risk of intra-operative SEP changes during CEA. Pre-operative assessment of collateral arterial anatomy might help identifying patients with an increased intra-operative risk.

Background: Wide-necked bifurcation aneurysms remain a challenge for endovascular surgeons. Dual-stent-assisted coiling techniques have been defined to treat bifurcation aneurysms with a complex neck morphology. However, there are still concerns about the safety of dual-stenting procedures. Stent plus balloon-assisted coiling is a recently described endovascular technique that enables the coiling of wide-necked complex bifurcation aneurysms by implanting only a single stent., Objective: To investigate the feasibility, efficacy, safety, and durability of this technique for the treatment of wide-necked bifurcation aneurysms., Methods: A retrospective review was performed of patients with wide-necked intracranial bifurcation aneurysms treated with stent plus balloon-assisted coiling. The initial and follow-up clinical and angiographic outcomes were assessed. Preprocedural and follow-up clinical statuses were assessed using modified Rankin scale., Results: A total of 61 patients (mean age: 54.6 ± 10.4 yr) were included in the study. The immediate postprocedural digital subtraction angiography revealed complete aneurysm occlusion in 86.9% of the cases. A periprocedural complication developed in 11.5% of the cases. We observed a delayed ischemic complication in 4.9%. There was no mortality in this study. The permanent morbidity rate was 3.3%. The follow-up angiography was performed in 55 of 61 patients (90.1%) (the mean follow-up period was 25.5 ± 27.3 mo). The rate of complete aneurysm occlusion at the final angiographic follow-up was 89.1%. The retreatment rate was 1.8%., Conclusion: The results of this study showed that stent plus balloon-assisted coiling is a feasible, effective, and relatively safe endovascular technique for the treatment of wide-necked bifurcation aneurysms located in the posterior and anterior circulation., (© Congress of Neurological Surgeons 2021.)

Objective: To investigate the association between endovascular therapy (EVT) start time in acute ischemic stroke (AIS) and midterm functional outcome., Methods: This retrospective cohort study included all patients with AIS treated with EVT from 2 stroke center registries from January 2012 to December 2018. The primary outcome was the score on the modified Rankin Scale (mRS) and the utility-weighted mRS (uw-mRS) at 90 days. A proportional odds model was used to calculate the common odds ratio (OR) as a measure of the likelihood that the intervention at a given EVT start time would lead to lower scores on the mRS (shift analysis)., Results: A total of 1,558 cases were equally allotted into 12 EVT start time periods. The primary outcome favored EVT start times in the morning at 08:00-10:20 and 10:20-11:34 (OR, 0.53; 95% confidence interval [CI], 0.38 to 0.75; p < 0.001; OR, 0.62; 95% CI, 0.44 to 0.87; p = 0.006, respectively), while it disfavored EVT start times at the end of the working day at 15:55-17:15 and 18:55-20:55 (OR, 1.47; 95% CI, 1.03-2.09; p = 0.034; OR, 1.49; 95% CI, 1.03-2.15; p = 0.033). Symptom onset to EVT start time was significantly higher and use of IV tissue plasminogen activator significantly lower between 10:20 and 11:34 ( p < 0.004 and p = 0.012, respectively)., Conclusion: EVT for AIS in the morning leads to better midterm functional outcome, while EVT at the end of the work day leads to poorer midterm functional outcome. Difference in baseline factors, standard workflow, and technical efficacy metrics could not be identified as potential mediators of this effect., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Background and Purpose: Current demographic changes indicate that more people will be care-dependent due to increasing life expectancy. Little is known about impact of preexisting dependency on stroke outcome after endovascular treatment (EVT)., Methods: We compared prospectively collected baseline and outcome data of previously dependent vs. independent stroke patients (prestroke modified Rankin Scale score of 3-5 vs. 0-2) treated with EVT. Outcome measures were favorable 3-month outcome (mRS ≤ 3 for previously dependent and mRS ≤ 2 for independent patients, respectively), death and symptomatic intracranial hemorrhage (sICH)., Results: Among 1247 patients, 84 (6.7%) were dependent before stroke. They were older (81 vs. 72 years of age), more often female (61.9% vs. 46%), had a higher stroke severity at baseline (NIHSS 18 vs. 15 points), more often history of previous stroke (32.9% vs. 9.1%) and more vascular risk factors than independent patients. Favorable outcome and mortality were to the disadvantage of independent patients (26.2% vs. 44.4% and 46.4% vs. 25.5%, respectively), whereas sICH was comparable in both cohorts (4.9% vs. 5%). However, preexisting dependency was not associated with clinical outcome and mortality after adjusting for outcome predictors (OR 1.076, 95% CI 0.612-1.891; p = 0.799 and OR 1.267, 95% CI 0.758-2.119; p = 0.367, respectively)., Conclusion: Our study underscores the need for careful selection of care-dependent stroke patients when considering EVT, given a less favorable outcome observed in this cohort. Nonetheless, EVT should not systematically be withheld in patients with preexisting disability, since prior dependency does not significantly influence outcome.

An alternative intracranial aneurysm embolic agent is emerging in the form of hydrogels due to their ability to be injected in liquid phase and solidify in situ . Hydrogels have the ability to fill an aneurysm sac more completely compared to solid implants such as those used in coil embolization. Recently, the feasibility to implement photopolymerizable poly(ethylene glycol) dimethacrylate (PEGDMA) hydrogels in vitro has been demonstrated for aneurysm application. Nonetheless, the physical and mechanical properties of such hydrogels require further characterization to evaluate their long-term integrity and stability to avoid implant compaction and aneurysm recurrence over time. To that end, molecular weight and polymer content of the hydrogels were tuned to match the elastic modulus and compliance of aneurysmal tissue while minimizing the swelling volume and pressure. The hydrogel precursor was injected and photopolymerized in an in vitro aneurysm model, designed by casting polydimethylsiloxane (PDMS) around 3D printed water-soluble sacrificial molds. The hydrogels were then exposed to a fatigue test under physiological pulsatile flow, inducing a combination of circumferential and shear stresses. The hydrogels withstood 5.5 million cycles and no significant weight loss of the implant was observed nor did the polymerized hydrogel protrude or migrate into the parent artery. Slight surface erosion defects of 2-10 μm in depth were observed after loading compared to 2 μm maximum for non-loaded hydrogels. These results show that our fine-tuned photopolymerized hydrogel is expected to withstand the physiological conditions of an in vivo implant study., Competing Interests: AS was a shareholder at Lumendo SA to which the intellectual property was licensed. Lumendo SA was not involved in the study design, collection, analysis, interpretation of data, the writing of this article, or the decision to submit it for publication. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Poupart, Conti, Schmocker, Pancaldi, Moser, Nuss, Sakar, Dobrocky, Grützmacher, Mosimann and Pioletti.)

Background and Purpose: Post hoc analyses of randomized controlled clinical trials evaluating mechanical thrombectomy have suggested that admission-to-groin-puncture (ATG) delays are associated with reduced reperfusion rates. Purpose of this analysis was to validate this association in a real-world cohort and to find associated factors and confounders for prolonged ATG intervals., Methods: Patients included into the BEYOND-SWIFT cohort (Bernese-European Registry for Ischemic Stroke Patients Treated Outside Current Guidelines With Neurothrombectomy Devices Using the Solitaire FR With the Intention for Thrombectomy; https://www.clinicaltrials.gov; Unique identifier: NCT03496064) were analyzed (n=2386). Association between baseline characteristics and ATG was evaluated using mixed linear regression analysis. The effect of increasing symptom-onset-to-admission and ATG intervals on successful reperfusion (defined as Thrombolysis in Cerebral Infarction [TICI] 2b-3) was evaluated using logistic regression analysis adjusting for potential confounders., Results: Median ATG was 73 minutes. Prolonged ATG intervals were associated with the use of magnetic resonance imaging (+19.1 [95% CI, +9.1 to +29.1] minutes), general anesthesia (+12.1 [95% CI, +3.7 to +20.4] minutes), and borderline indication criteria, such as lower National Institutes of Health Stroke Scale, late presentations, or not meeting top-tier early time window eligibility criteria (+13.8 [95% CI, +6.1 to +21.6] minutes). There was a 13% relative odds reduction for TICI 2b-3 (adjusted odds ratio [aOR], 0.87 [95% CI, 0.79-0.96]) and TICI 2c/3 (aOR, 0.87 [95% CI, 0.79-0.95]) per hour ATG delay, while the reduction of TICI 2b-3 per hour increase symptom-onset-to-admission was minor (aOR, 0.97 [95% CI, 0.94-0.99]) and inconsistent regarding TICI 2c/3 (aOR, 0.99 [95% CI, 0.97-1.02]). After adjusting for identified factors associated with prolonged ATG intervals, the association of ATG delay and lower rates of TICI 2b-3 remained tangible (aOR, 0.87 [95% CI, 0.76-0.99])., Conclusions: There is a great potential to reduce ATG, and potential targets for improvement can be deduced from observational data. The association between in-hospital delay and reduced reperfusion rates is evident in real-world clinical data, underscoring the need to optimize in-hospital workflows. Given the only minor association between symptom-onset-to-admission intervals and reperfusion rates, the causal relationship of this association warrants further research. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03496064.

Data on infarcts in new territory (INT) in patients undergoing endovascular stroke treatment for acute large-vessel occlusions are sparse. Aim of this study was to assess the prevalence, risk factors, and clinical relevance of INT. For this purpose, all patients in a single-center prospective registry who underwent endovascular stroke treatment and received pre- and post-interventional diffusion-weighted imaging were included (N = 259). Using an established scoring system, INT were classified according to size (I-III, ≤2 mm, >2 mm ≤20 mm, >20 mm) and likelihood of being related to the intervention (A, high likelihood; B, low likelihood). Additionally, a new type of infarct, that occurred in a territory distal to the occlusion, but was initially not hypoperfused, was defined as an infarct in initially not hypoperfused territory (IINHT). A total of 180 INT and 38 IINHT were observed in 32.8% (N = 85/259) of patients. In most patients, INT were angiographically occult (90.2%), and 13 patients had INT/IINHT larger than 2 cm (type III). Absence of protection during stent-retrieval and a cardio-embolic stroke origin were associated with higher incidence of INT/IINHT, whereas pretreatment with IV tPA showed no association, even when different bolus timing was considered. INT/IINHT were associated with lower rates of functional independence with increasing size type after adjusting for confounders (adjusted Odds Ratio per size group increase 0.63, 95% confidence interval 0.46-0.86). In conclusion, INT and IINHT are not rare, are associated with poor outcome with increasing size, and they may serve as a surrogate endpoint for safety evaluation of new devices and endovascular techniques. Further research on associated factors is warranted.

Intracranial aneurysms are increasingly being treated with endovascular therapy, namely coil embolization. Despite being minimally invasive, partial occlusion and recurrence are more frequent compared to open surgical clipping. Therefore, an alternative treatment is needed, ideally combining minimal invasiveness and long-term efficiency. Herein, we propose such an alternative treatment based on an injectable, radiopaque and photopolymerizable polyethylene glycol dimethacrylate hydrogel. The rheological measurements demonstrated a viscosity of 4.86 ± 1.70 mPa.s, which was significantly lower than contrast agent currently used in endovascular treatment ( p = 0.42), allowing the hydrogel to be injected through 430 μm inner diameter microcatheters. Photorheology revealed fast hydrogel solidification in 8 min due to the use of a new visible photoinitiator. The addition of an iodinated contrast agent in the precursor contributed to the visibility of the precursor injection under fluoroscopy. Using a customized light-conducting microcatheter and illumination module, the hydrogel was implanted in an in vitro silicone aneurysm model. Specifically, in situ fast and controllable injection and photopolymerization of the developed hydrogel is shown to be feasible in this work. Finally, the precursor and the polymerized hydrogel exhibit no toxicity for the endothelial cells. Photopolymerizable hydrogels are expected to be promising candidates for future intracranial aneurysm treatments., (Copyright © 2020 Poupart, Schmocker, Conti, Moser, Nuss, Grützmacher, Mosimann and Pioletti.)

Background and Purpose- Guidelines regarding blood pressure (BP) management during endovascular therapy (EVT) for anterior circulation strokes are questionable since the optimal BP target is a matter of debate. To evaluate the importance of hemodynamic control during EVT, we investigated the impact of dynamic and steady BP parameters during EVT on functional outcome (part 1) and according to the collateral status (CS; part 2). Methods- We performed a post hoc analysis of the ASTER trial (Contact Aspiration Versus Stent Retriever for Successful Recanalization). BP was measured noninvasively during EVT and CS assessed on the angiographic run before EVT. We studied dynamic BP parameter using BP variability (coefficient of variation) and steady BP parameter (hypotension time defined as systolic BP <140 mm Hg and mean arterial pressure <90 mm Hg). The primary outcome was favorable outcome defined as a 3-month modified Rankin Scale score between 0 and 2. Results- Among the 381 patients of the ASTER study, 172 patients were included in part 1 and 159 in part 2. Systolic BP, diastolic BP, and mean arterial pressure variability were negatively associated with favorable outcome regardless of CS: per 10-unit increase, adjusted odds ratios were 0.45 (95% CI, 0.20-0.98), 0.37 (95% CI, 0.19-0.72), and 0.35 (95% CI, 0.16-0.76), respectively. According to CS, the hypotension time with periprocedural mean arterial pressure <90 mm Hg was negatively associated with favorable outcome in patients with poor CS (adjusted odds ratio, 0.88 [95% CI, 0.72-1.09]) but not in patients with good CS (adjusted odds ratio, 1.24 [95% CI, 0.91-1.67]; P het =0.047). Conclusions- The CS did not modify the association between dynamic parameters and functional outcomes, but some findings suggest that the CS modifies the association between steady parameter and functional outcomes. Hypotension time according to the CS was not statistically predictive of poor outcomes but displayed a trend toward worse outcomes for patients with poor CS only.

An increasing number of centers not necessarily equipped with biplane (BP) angiosuites are performing mechanical thrombectomy (MT) in acute ischemic stroke patients. We assessed whether MT performed on single-plane (SP) is equivalent in terms of safety, effectiveness, radiation and contrast agent exposure. Consecutive patients treated by MT in four high volume centers between January 2014 and May 2017 were included. Demographic and MT characteristics were assessed and compared between SP and BP. Of 906 patients treated by MT, 576 (64%) were handled on a BP system. After multivariate analysis, contrast load and fluoroscopy duration were significantly lower in the BP group [100vs200mL, relative effect 0.85 (CI: 0.79-0.92), p = 0.0002; 22 vs 27 min, relative effect 0.84 (CI: 0.76-0.93), p = 0.0008, respectively]. There was no difference in recanalization (modified Thrombolysis-In-Cerebral-Infarction 2b-3), good clinical outcome (modified Rankin Scale 0-2), complications rates, procedure duration or radiation exposure. A three-vessel diagnostic angiogram performed prior to MT led to a significant increase in procedure duration (15% increase, p = 0.05), radiation exposure (33% increase, p < 0.0001) and contrast load (125% increase, p < 0.0001). Mechanical neuro-thrombectomy seems equally safe and effective on a single or biplane angiography system despite increased contrast load and fluoroscopy duration on the former.

Importance: Achieving complete reperfusion is a key determinant of good outcome in patients treated with mechanical thrombectomy (MT). However, data on treatments geared toward improving reperfusion after incomplete MT are sparse., Objective: To determine whether administration of intra-arterial urokinase is safe and improves reperfusion after failed or incomplete MT., Design, Setting, and Participants: This observational cohort study included a consecutive sample of patients treated with second-generation MT from January 1, 2010, through August 4, 2017. Data were collected from the prospective registry of a tertiary care stroke center. Of 1274 patients screened, 69 refused to participate, and 993 met the observational studies inclusion criteria of a large vessel occlusion in the anterior circulation. Data were analyzed from September 1, 2017, through September 20, 2019., Intervention: One hundred patients received intra-arterial urokinase after failed or incomplete MT using manual microcatheter injections., Main Outcomes and Measures: Primary safety outcome was the occurrence of symptomatic intracranial hemorrhage (sICH) according to the Prolyse in Acute Cerebral Thromboembolism II criteria. Secondary end points included 90-day mortality and 90-day functional independence (defined as modified Rankin Scale score of ≤2). Efficacy was evaluated angiographically, applying the Thrombolysis in Cerebral Infarction (TICI) scale., Results: After exclusion of patients with posterior circulation strokes and those treated with intra-arterial thrombolytics only, 993 patients were included in the final analyses (median age, 74.6 [interquartile range, 62.6-82.2] years; 505 [50.9%] women). Additional intra-arterial urokinase was administered in 100 patients (10.1%). The most common reason for administering intra-arterial urokinase was incomplete reperfusion (TICI<3) after MT (53 [53.0%]). After adjusting for baseline characteristics underlying case selection, intra-arterial urokinase was not associated with an increased risk of sICH (adjusted odds ratio [aOR], 0.81; 95% CI, 0.31-2.13) or 90-day mortality (aOR, 0.78; 95% CI, 0.43-1.40). Among 53 cases of partial or near-complete reperfusion and treated with intra-arterial urokinase, 32 (60.4%) had early reperfusion improvement, and 18 of 53 (34.0%) had an improvement in TICI grade. Correspondingly, patients treated with intra-arterial urokinase had higher rates of functional independence after adjusting for the selection bias favoring a priori poor TICI grades in the intra-arterial urokinase group (aOR, 1.93; 95% CI, 1.11-3.37)., Conclusions and Relevance: In selected patients, adjunctive treatment with intra-arterial urokinase during or after MT was safe and improved angiographic reperfusion. Systemic evaluation of this approach in a multicenter prospective registry or a randomized clinical trial seems warranted.

Background and Purpose: Mechanical thrombectomy is an effective recanalization technique in acute ischemic stroke patients with large vessel occlusions; however, it is unclear to what extent stent retriever thrombectomy may be applicable to occlusions of smaller peripheral cerebral vessels. The outcome of patients with isolated M2 occlusions treated with the Mindframe Capture low profile (LP) stent retriever was reviewed., Material and Methods: A retrospective review of prospectively collected data on all consecutive patients treated for isolated M2 occlusions between June 2013 and December 2017 using the Mindframe Capture LP was performed. Technical aspects of the recanalization procedure, recanalization rate, complication rate, and clinical outcome were analyzed., Results: Mechanical thrombectomy with the Mindframe Capture LP was performed in 38 patients (median age 79 years) with an isolated M2 occlusion. The median National Institutes of Health Stroke Scale (NIHSS) score on admission was 7.5 (interquartile range, IQR 5-12) and successful reperfusion modified Thrombolysis in Cerebral Infarction (mTICI 2b or 3) was achieved in 28 patients (74%). A compensated/adjusted modified Rankin Scale (mRS) 0-2 at 3 months was observed in 65% when taking pre-stroke disability into account. Symptomatic intracranial hemorrhage (sICH) occurred in 1 patient (2.6%). Asymptomatic intracranial hemorrhage (aICH) was noted in 8 patients (21%) and a small subarachnoid hemorrhage (SAH) in the immediate vicinity of the target vessel was apparent in 8 patients (21%)., Conclusion: The Mindframe Capture LP is a technically effective thrombectomy device for the treatment of isolated M2 occlusions. The lower profile of the device is advantageous when targeting peripheral intracranial occlusions.

Background and Purpose- We aimed to determine the safety and mortality after mechanical thrombectomy in patients taking vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs). Methods- In a multicenter observational cohort study, we used multiple logistic regression analysis to evaluate associations of symptomatic intracranial hemorrhage (sICH) with VKA or DOAC prescription before thrombectomy as compared with no anticoagulation. The primary outcomes were the rate of sICH and all-cause mortality at 90 days, incorporating sensitivity analysis regarding confirmed therapeutic anticoagulation. Additionally, we performed a systematic review and meta-analysis of literature on this topic. Results- Altogether, 1932 patients were included (VKA, n=222; DOAC, n=98; no anticoagulation, n=1612); median age, 74 years (interquartile range, 62-82); 49.6% women. VKA prescription was associated with increased odds for sICH and mortality (adjusted odds ratio [aOR], 2.55 [95% CI, 1.35-4.84] and 1.64 [95% CI, 1.09-2.47]) as compared with the control group, whereas no association with DOAC intake was observed (aOR, 0.98 [95% CI, 0.29-3.35] and 1.35 [95% CI, 0.72-2.53]). Sensitivity analyses considering only patients within the confirmed therapeutic anticoagulation range did not alter the findings. A study-level meta-analysis incorporating data from 7462 patients (855 VKAs, 318 DOACs, and 6289 controls) from 15 observational cohorts corroborated these observations, yielding an increased rate of sICH in VKA patients (aOR, 1.62 [95% CI, 1.22-2.17]) but not in DOAC patients (aOR, 1.03 [95% CI, 0.60-1.80]). Conclusions- Patients taking VKA have an increased risk of sICH and mortality after mechanical thrombectomy. The lower risk of sICH associated with DOAC may also be noticeable in the acute setting. Improved selection might be advisable in VKA-treated patients. Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT03496064. Systematic Review and Meta-Analysis: CRD42019127464.

Online supplemental material is available for this article.

Introduction: An adequate recanalization grade is an independent predictor of a good clinical outcome in patients with acute ischemic stroke. It can be obtained with stent retrievers (SR) and contact aspiration (CA). The aim of this ancillary study of the ASTER trial was to investigate the effect of the regular and irregular phenotype of the M1-middle cerebral artery (M1-MCA) segment occlusion on the procedural and clinical outcomes in the ASTER trial population., Methods: The predetermined occlusion phenotype assessment was performed by the core laboratory of the ASTER trial and patients with M1-MCA occlusion were included in this study. Clinical and procedural outcomes were analyzed according to the technique used and to the occlusion phenotype., Results: 188 patients were included in the analysis (95 received SR, 93 CA as first-line treatment). The occlusion phenotypes were graded as irregular in 52.7% of cases (n=99, 95% CI 45.5% to 59.8%). In patients with an irregular occlusion phenotype, complete or adequate recanalization at the end of the first-line strategy was more often achieved with SR than CA (TICI 3: SR 44.1% vs CA 22.5%, OR 0.35, 95% CI 0.14 to 0.89, p=0.027), with a shorter procedure time, a lower number of passes (>2 passes: SR 32.2% vs CA 57.5%, OR 3.31, 95% CI 1.36 to 8.03, p=0.009), and higher rates of favorable clinical outcome (SR 55.2% vs CA 31.6%, OR 0.40, 95% CI 0.16 to 0.97, p=0.042)., Conclusion: Irregular M1-MCA occlusion phenotypes treated with SR as first-line approach were associated with better procedural and clinical outcomes in the ASTER trial population., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Purpose: Acute basilar artery occlusion (BAO) is a devastating disease with a high rate of mortality and morbidity, and early recanalization is crucial to achieve a good prognosis. The best treatment strategy for BAO combined with a proximal stenosis (tandem occlusion) is not yet clear. Our study aimed to evaluate whether and how vertebrobasilar tandem occlusions can be treated effectively and safely compared with isolated BAO., Materials and Methods: Fifty-two patients with acute vertebrobasilar occlusive stroke treated with mechanical thrombectomy were identified in a prospective database from March 2010 to September 2016. We retrospectively analysed the clinical, technical, and functional outcomes of the patients., Results: Of the 52 patients, 15 presented with a tandem occlusion, 14 with a single intracranial occlusion due to an underlying stenosis, and 23 with a single embolic BAO. Successful recanalization was achieved in all of the patients with tandem occlusions (modified Thrombolysis in Cranial Infarction 2b/3) and in 35 of 37 patients with a single BAO (with and without stenosis). A favourable outcome was achieved (modified Rankin Scale ≤2) in 8 of the 15 patients with a tandem occlusion compared with 4 of the 14 patients with a single BAO with underlying stenosis and 5 of the 23 patients with isolated embolic BAO (p=0.18)., Conclusions: We suggest that endovascular treatment of vertebrobasilar tandem occlusions is safe and feasible, with a high rate of good outcome., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Performing mechanical thrombectomy (MT) in patients with basilar artery occlusion (BAO) is currently not evidence-based., Objective: To compare patients' outcome, relative merits of achieving recanalization, and predictors of futile recanalization (FR) between BAO and anterior circulation large vessel occlusion (ACLVO) MT., Methods: In the multicenter BEYOND-SWIFT registry (NCT03496064), univariate and multivariate (displayed as adjusted Odds Ratios, aOR and 95% confidence intervals, 95%-CI) outcome comparisons between BAO (N=165) and ACLVO (N=1574) were performed. The primary outcome was favorable outcome at 90 days (modified Rankin Scale, mRS 0-2). Secondary outcome included mortality, symptomatic intracranial hemorrhage (sICH) and FR. The relative merits of achieving successful recanalization between ACLVO and BAO were evaluated with interaction terms., Results: MT in BAO was more often technically effective and equally safe in regards to mortality and sICH when compared to ACLVO. When adjusting for baseline differences, there was no significant difference between BAO vs ACLVO regarding rates of favorable outcome (aOR 0.986, 95%-CI 0.553 - 1.758). However, BAO were associated with increased rates of FR (aOR 2.146, 95%-CI 1.267 - 3.633). Predictors for FR were age, stroke severity, maneuver count and intracranial stenting. No significant heterogeneity on the relative merits of achieving successful recanalization on several outcome parameters were observed when comparing BAO and ACLVO., Conclusions: In selected patients, similar outcomes can be achieved in BAO and ACLVO patients treated with MT. Randomized controlled trials comparing patient selection and interventional strategies seem warranted to avoid FR., Trial Registration Number: NCT03496064., Competing Interests: Competing interests: UF is a consultant for Medtronic and Stryker and co-principal investigator of the SWIFT DIRECT trial (Medtronic). JG is a global principal investigator of STAR (Solitaire FR Thrombectomy for Acute Revascularisation), clinical event commitee member of the PROMISE study (European Registry on the ACE Reperfusion Catheters and the Penumbra System in the Treatment of Acute Ischemic Stroke; Penumbra), and a principal investigator and consultant for the SWIFT DIRECT study (Medtronic) and receives Swiss National Science Foundation (SNSF) grants for magnetic resonance imaging in stroke. LPi serves as a consultant for Balt, Microvention, and Penumbra. JK has received travel grants from Pfizer and Stryker. MRi serves as a consultant for Medtronic, Stryker, Anaconda, Apta Targets, and Perflow Medical and as a speaker for Neuravi. PMi has received funding for speaker honoraria from Boehringer. He has served on scientific advisory boards also for Boehringer. He has received research grants from Bristol-Myers Squibb, Boehringer, and the Swiss Heart Foundation. VMP is a consultant for Stryker (SC for DAWN trial), Penumbra (SC for PROMISE study), BALT (proctorship of products unrelated to ischemic stroke), Phenox, Rapid Medical, Neurovasc and receives research a grant from Philips. All the other authors have nothing to disclose., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: A new generation of carotid artery stents that use a dual micromesh layer to reduce embolic events during carotid artery stenting has recently been introduced. We aimed to analyze the effectiveness and safety of the new Casper-RX stent in patients experiencing acute ischemic stroke with large vessel intracranial occlusion associated with a tandem lesion (another carotid occlusion or severe stenosis)., Methods: We retrospectively analyzed all consecutive patients treated with carotid Casper-RX stents from our stroke registry. We analyzed clinical, angiographic, and neuroimaging data. Endpoints included acute intra-stent thrombus formation, stent occlusion prior to hospital discharge, 3 month modified Rankin Scale score (mRS), and symptomatic intracranial hemorrhage., Results: 21 patients were included: 10 patients had tandem carotid occlusions and 11 patients had severe carotid stenosis, 8 of whom had a hemodynamically significant stenosis. We observed acute in-stent thrombus formation in 11 patients. No stent occlusion occurred prior to hospital discharge. We report no stroke recurrence at 3 months but symptomatic intracranial hemorrhage in two patients. mRS score at 3 months was 0-2 (favorable) for 15 patients (71%), 3-5 for 3 patients, and 6 for 3 patients., Conclusions: In the present series, we frequently observed clot formation during the procedure with Casper-RX stents, which required periprocedural intravenous infusion of anticoagulant and antiplatelet treatment. This motivated us, in the absence of a prospective randomized controlled study demonstrating the non-inferiority of micromesh dual layer stents compared with the single layer design, to discontinue using this stent type in acute stroke requiring carotid angioplasty., Competing Interests: Competing interests: PM: speaker and consulting fees from Medtronic, Steering committee of PROMISE (Penumbra). All this support goes to the institution and is used for stroke education and research. The other authors report no conflicts., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: The aim of our study was to assess the technical success and the safety of this new low-profile flow diverter Silk Vista Baby (SVB) by evaluating the intraprocedural and periprocedural complication rate., Material/methods: Clinical, procedural, and angiographic data were analyzed., Results: 41 consecutive patients (28 women; age average 50.5 years) with 43 aneurysms were treated with SVB. Aneurysm sizes were classified by their maximum diameter, with an average size of 9.5 mm (range 2-30 mm). Thirty-four cases were unruptured. five aneurysms previously ruptured, had recurrence after the initial coiling. There were two ruptured cases. Aneurysms' locations were: M1 segment (five cases), M2 segment (three cases), M3 segment (one case), middle cerebral artery (MCA) bifurcation (six cases), carotid-T (two cases), anterior communicating artery/A1/A2 (11 cases), pericallosal artery (four cases), supraclinoid ICA (two cases), PCom (one case), V4 segment (three cases), PCA (three cases), SCA (one case), and PICA (one case). We had five intraprocedural complications which resolved without clinical consequences and three events postprocedural events. Initial occlusion rates were: eight aneurysms (18.6%) were completely occluded, five aneurysms (11.6%) showed near-complete occlusion, four cases (9.3%) showed incomplete filling, and 26 cases (60.4%) showed persisting filling. The mRS score at discharge from the hospital did not change from the admission mRS score., Conclusion: Our study demonstrated that the use of the new low-profile flow diverter, SVB device, for the treatment of intracranial aneurysms is feasible and technically safe., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: International dose reference levels are lacking for mechanical thrombectomy in acute ischemic stroke patients with large vessel occlusions. We studied whether radiation dose-reduction systems (RDS) could effectively reduce exposure and propose achievable levels., Materials and Methods: We retrospectively included consecutive patients treated with thrombectomy on a biplane angiography system (BP) in five international, high-volume centers between January 2014 and May 2017. Institutional Review Board approvals were obtained. Technical, procedural, and clinical characteristics were assessed. Efficacy, safety, radiation dose, and contrast load were compared between angiography systems with and without RDS. Multivariate analyses were adjusted according to Bonferroni's correction. Proposed international achievable cutoff levels were set at the 75th percentile., Results: Out of the 1096 thrombectomized patients, 520 (47%) were treated on a BP equipped with RDS. After multivariate analysis, RDS significantly reduced dose-area product (DAP) (91 vs 140 Gy cm 2 , relative effect 0.74 (CI 0.66; 0.83), 35% decrease, p < 0.001) and air kerma (0.46 vs 0.97 Gy, relative effect 0.63 (CI 0.56; 0.71), 53% decrease, p < 0.001) with 75th percentile levels of 148 Gy cm 2 and 0.73 Gy, respectively. There was no difference in contrast load, rates of successful recanalization, complications, or clinical outcome., Conclusion: Radiation dose-reduction systems can reduce DAP and air kerma by a third and a half, respectively, without affecting thrombectomy efficacy or safety. The respective thresholds of 148 Gy cm 2 and 0.73 Gy represent achievable levels that may serve to optimize current and future radiation exposure in the setting of acute ischemic stroke treatment. As technology evolves, we expect these values to decrease., Key Points: • Internationally validated achievable levels may help caregivers and health authorities better assess and reduce radiation exposure of both ischemic stroke patients and treating staff during thrombectomy procedures. • Radiation dose-reduction systems can reduce DAP and air kerma by a third and a half, respectively, without affecting thrombectomy efficacy or safety in the setting of acute ischemic stroke due to large vessel occlusion.

Background and Purpose: Data on the management of large vessel occlusion in patients with anterior circulation acute ischemic stroke (AIS) due to underlying intracranial stenosis are scarce. The aim of this retrospective study was to compare endovascular treatment and outcome in AIS patients with and without underlying stenosis of the M1 segment., Materials and Methods: A total of 533 acute stroke patients with an isolated M1 occlusion who underwent mechanical thrombectomy between 02/2010 and 08/2017 were included. Underlying intracranial atherosclerotic stenosis (ICAS) was present in 10 patients (1.9%), whereas 523 patients (98.1%) had an embolic occlusion without stenosis., Results: There was no difference in age, admission National Institutes of Health Stroke Scale, risk factors, Alberta stroke program early CT score or collaterals between the groups. Procedure time (155 vs 40 min, P = 0.001) was significantly longer in the ICAS group where rescue stent-angioplasty was performed in all patients. There was no statistical difference in final modified thrombolysis in cerebral infarction score between both groups (70 vs 88%, P = 0.115). Favorable outcome (modified Rankin Scale ≤ 2) at 90 days was less frequent in patients with ICAS than in the embolic group (0 vs 49.4%, P = 0.004). The mortality rate tended to be higher in the ICAS group (44.4 vs 19.4%, P = 0.082)., Conclusion: In patients with AIS, rescue therapy with stent placement to treat underlying ICAS of the M1 segment is technically feasible; however, in our study, a significantly lower rate of favorable outcome was observed in these patients compared to those with thromboembolic M1 occlusions., Level of Evidence: Level 3, non-randomized controlled study.

Importance: Various signs may be observed on brain magnetic resonance imaging (MRI) in patients with spontaneous intracranial hypotension (SIH). However, the lack of a classification system integrating these findings limits decision making in clinical practice., Objective: To develop a probability score based on the most relevant brain MRI findings to assess the likelihood of an underlying spinal cerebrospinal fluid (CSF) leak in patients with SIH., Design, Setting, and Participants: This case-control study in consecutive patients investigated for SIH was conducted at a single hospital department from February 2013 to October 2017. Patients with missing brain MRI data were excluded. Three blinded readers retrospectively reviewed the brain MRI scans of patients with SIH and a spinal CSF leak, patients with orthostatic headache without a CSF leak, and healthy control participants, evaluating 9 quantitative and 7 qualitative signs. A predictive diagnostic score based on multivariable backward logistic regression analysis was then derived. Its performance was validated internally in a prospective cohort of patients who had clinical suspicion for SIH., Main Outcomes and Measures: Likelihood of a spinal CSF leak based on the proposed diagnostic score., Results: A total of 152 participants (101 female [66.4%]; mean [SD] age, 46.1 [14.3] years) were studied. These included 56 with SIH and a spinal CSF leak, 16 with orthostatic headache without a CSF leak, 60 control participants, and 20 patients in the validation cohort. Six imaging findings were included in the final scoring system. Three were weighted as major (2 points each): pachymeningeal enhancement, engorgement of venous sinus, and effacement of the suprasellar cistern of 4.0 mm or less. Three were considered minor (1 point each): subdural fluid collection, effacement of the prepontine cistern of 5.0 mm or less, and mamillopontine distance of 6.5 mm or less. Patients were classified into groups at low, intermediate, or high probability of having a spinal CSF leak, with total scores of 2 points or fewer, 3 to 4 points, and 5 points or more, respectively, on a scale of 9 points. The discriminatory ability of the proposed score could be demonstrated in the validation cohort., Conclusions and Relevance: This 3-tier predictive scoring system is based on the 6 most relevant brain MRI findings and allows assessment of the likelihood (low, intermediate, or high) of a positive spinal imaging result in patients with SIH. It may be useful in identifying patients with SIH who are leak positive and in whom further invasive myelographic examinations are warranted before considering targeted therapy.

Background and Purpose: In acute ischaemic stroke (AIS) of the anterior circulation (AC) treated with mechanical thrombectomy (MT), data point to a decline of treatment effect with increasing time from symptom onset to treatment. However, the magnitude of the decline will depend on the clinical setting and imaging selection used. The aims of this study were (1) to evaluate the clinical effect of time to reperfusion (TTR); and (2) to assess the safety and technical efficacy of MT according to strata of TTR., Methods: Using the retrospective multicentre BEYOND-SWIFT registry data (ClinicalTrials.gov identifier: NCT03496064), we compared safety and efficacy of MT in 1461 patients between TTR strata of 0-180 min ( n = 192), 180-360 min ( n = 876) and >360 min ( n = 393). Clinical effect of TTR was evaluated using multivariable logistic regression analyses adjusting for pre-specified confounders [adjusted odds ratios (aOR) and 95% confidence intervals (95% CI)]. Primary outcome was good functional outcome (modified Rankin Scale: mRS 0-2) at day 90., Results: Every hour delay in TTR was a significant factor related to mRS 0-2 (aOR 0.933, 95% CI 0.887-0.981) with an estimated 1.5% decreased probability of good functional outcome per hour delay of reperfusion, and mRS 0-1 (aOR 0.929, 95% CI 0.877-0.985). Patients with late TTR had lower rates of successful and excellent reperfusion, higher complication rates and number of passes., Conclusions: TTR is an independent factor related to long-term functional outcome. With increasing TTR, interventional procedures become technically less effective. Efforts should be made to shorten TTR through optimized prehospital and in-hospital pathways., Competing Interests: Conflict of interest statement: U. Fischer is a consultant for Medtronic and Stryker and Co-PI of the SWIFT DIRECT trial (Medtronic). J. Gralla is a global principal investigator of STAR (Solitaire FR Thrombectomy for Acute Revascularisation), clinical event committee member of the PROMISE study (European Registry on the ACE Reperfusion Catheters and the Penumbra System in the Treatment of Acute Ischemic Stroke; Penumbra) and a principal investigator and consultant for the SWIFT DIRECT study (Medtronic), and receives Swiss National Science Foundation (SNSF) grants for magnetic resonance imaging in stroke. L. Pierot serves as a consultant for Balt, Microvention, and Penumbra. J. Kaesmacher has received travel grants from Pfizer and Stryker. M. Ribo serves as a consultant for Medtronic, Stryker, Anaconda, Apta Targets and Perflow Medical, and as a speaker for Neuravi. P. Michel has received funding for speaker honoraria from Boehringer. He has served on scientific advisory boards also for Boehringer. He has received research grants from Bristol-Myers Squibb, Boehringer and the Swiss Heart Foundation. V.M. Pereira is a consultant for Stryker (SC for DAWN trial), Penumbra (SC for PROMISE study), BALT (proctorship of products unrelated to ischaemic stroke), Phenox, Rapid Medical and Neurovasc, and receives a research grant from Philips. All other authors have nothing to disclose.

Background: In acute ischemic stroke (AIS) collaterals correlate with infarct size, recanalization rate and clinical outcome. We aimed to identify factors associated with better collateral status in a large series of AIS patients with middle cerebral artery (MCA) occlusion., Methods: In the Acute STroke Registry and Analysis of Lausanne (ASTRAL) from 2003 to 2016, we identified all consecutive AIS with proximal MCA occlusion on CT-angiography performed < 24 h. Collaterals were scored from 0 (absent) to 3 (≥ 100%) and related to multiple demographic, clinical, metabolic and radiological variables in a multivariate regression analysis (MVA)., Results: The 857 included patients had a median age of 72.3 years, 48.4% were female and median admission NIHSS was 16. Better collaterals were associated with younger age (OR 0.99; 95% CI 0.98-1.00), hemineglect (OR 1.35; 95% CI 1.03-1.76), absence of visual field defects (OR 0.64; 95% CI 0.46-0.90), eye deviation (OR 0.58; 95% CI 0.43-0.79) and decreased vigilance (OR 0.62; 95% CI 0.44-0.88). Better collaterals were also associated with dyslipidemia (OR 1.57; 95% CI 1.16-2.13), no previous statin use (OR 0.69; 95% CI 0.50-0.95), and lower creatinine levels (OR 0.99; 95% CI 0.99-1.00). On neuroimaging, better collaterals related to higher ASPECTS score (OR 1.27; 95% CI 1.20-1.35) and higher clot burden score (OR 1.09; 95% CI 1.03-1.14)., Conclusions: Younger age, dyslipidemia and lower creatinine levels were predictors of better collaterals in AIS patients from proximal MCA occlusions. Greater degree of collaterals related to lower stroke severity on admission. On neuroimaging, better collaterals were independently associated with minor early ischemic changes and lower clot burden. These data may add knowledge on pathophysiology of collaterals development and may help to identify patients with better collaterals for late or aggressive recanalization treatments.

Background and Purpose- Factors influencing recanalization success in basilar artery occlusions are largely unknown. Preliminary evidence has suggested that flow arrest in the vertebral artery contralateral to the catheter bearing vertebral artery may facilitate recanalization. The aim of this analysis was to assess the impact of anatomic variations and flow conditions on recanalization success in basilar artery occlusion treated with mechanical thrombectomy. Methods- Consecutive basilar artery occlusions treated with second-generation thrombectomy devices at a single-center were retrospectively analyzed. Baseline patients' characteristics, occlusion length, collateral circulation, underlying stenosis, incomplete occlusions, and patency of the vertebral arteries were analyzed with regards to recanalization success. Aplastic or hypoplastic vertebral artery contralateral to the catheter position was defined as contralateral low flow condition. Logistic regression analysis was used to examine the association between anatomic variations and flow conditions in relation to complete recanalization and the modified Rankin Scale score while controlling for several potentially confounding variables. Clinical impact was evaluated using the modified Rankin Scale score of ≤3. Results- One hundred fifteen patients were included (mean age 71.5±12.8, m:f=2:1, median National Institutes of Health Stroke Scale =15, interquartile range =10-22). Complete recanalization was more often observed in patients with contralateral low flow conditions (80.6% versus 50.0%), which remained an independent predictor of complete recanalization in multivariable analysis (adjusted odds ratio, 5.81; 95% CI, 1.97-17.19). Patients with complete posterior recanalization had lower in-hospital mortality (16.4% versus 41.7%) and more often achieved modified Rankin Scale score of ≤3 (49.4% versus 8.3%), even after adjusting for potential confounders (adjusted odds ratio, 15.93; 95% CI, 1.42-179.00). Conclusions- Contralateral low flow condition (vertebral artery aplasia or hypoplasia) seems to be an independent factor for fewer distal emboli and complete recanalization in basilar artery occlusion patients treated by modern endovascular devices. Complete recanalization reflecting the absence of peri-interventional clot fragmentation brings clear clinical benefit. Further studies are warranted to evaluate the need for contralateral flow modulation or ipsilateral balloon guide catheter during posterior circulation thrombectomy in patients with bilaterally patent vertebral arteries.

Purpose To propose a modified dynamic CT myelographic technique to locate cerebrospinal fluid (CSF) leaks, also known as cryptogenic leaks, in patients with spontaneous intracranial hypotension (SIH) in whom previous imaging did not show the dural breach. Materials and Methods This retrospective analysis included 74 consecutive patients with SIH and a myelographically proven CSF leak who were evaluated between February 2013 and October 2017. In 14 patients, dynamic CT myelography in the prone or lateral position showed the exact leakage point after unsuccessful previous imaging. During image analysis, the first time point showing extrathecal contrast material was defined as the site of dural breach point. Results Mean population age was 44 years (range, 25-65 years [nine women; mean age, 44 years; age range, 25-65 years] [five men; mean age, 46 years; age range, 29-61 years]). All patients had previously undergone spine MRI, conventional dynamic myelography, and CT myelography. Subsequent dynamic CT myelography covered a mean range of seven vertebral levels. The leak was caused by a calcified microspur in 10 patients and by a dural tear at the axilla of a spinal nerve root in the remaining four. The mean volume CT dose index of dynamic CT myelography was 107 mGy (range, 12-246 mGy), and the mean dose-length product was 1347 mGy·cm (range, 550-3750 mGy·cm). Conclusion Dynamic CT myelography is a valuable adjunctive tool with which to identify the precise location of a dural tear when other examinations are unsuccessful. © RSNA, 2018 See also the editorial by Dillon in this issue.

Background and Purpose- Sustained successful reperfusion is an important prognostic factor for good clinical outcome in acute ischemic stroke. We aimed to identify the prevalence, clinical impact, and predictors of early reocclusion after initially successful thrombectomies within a prospective cohort. Methods- A total of 711 stroke patients with successful reperfusion (modified Thrombolysis in Cerebral Infarction, 2b/3) followed with magnetic resonance or computed tomographic angiography at 24 to 48 hours were included. Multivariable logistic regression analysis was used to evaluate associated factors and clinical impact. Results are displayed as adjusted odds ratio (aOR) and 95% CI. Improvement in accuracy of additional imaging findings on angiography control runs after the intervention was evaluated by area under the curve. Results- Early reocclusion was observed in 16 of 711 successfully reperfused patients (2.3%; 95% CI, 1.1-3.3; median delay: 20 hours). Suggestive predictors were higher platelets on admission (aOR, 1.01; 95% CI, 1.01-1.02), prestroke functional dependence (aOR, 7.12; 95% CI, 1.49-34.03), and stroke of undetermined or other specified pathogenesis in the TOAST classification (aOR, 7.19; 95% CI, 1.10-47.05 and aOR, 36.50; 95% CI, 4.47-298.11, respectively). When implementing residual embolic fragments or stenosis at the thrombectomy site into the logistic regression model, discrimination between patients with and without reocclusion improved significantly (area under the curve, 0.955 versus 0.854; P=0.023). Early reocclusion was an independent predictor of unfavorable outcome at 90 days (aOR for modified Rankin Scale ≤2, 0.13; 95% CI, 0.03-0.57). Conclusions- Early reocclusion within 48 hours after successful mechanical thrombectomy is rare but associated with poor outcome. Patients with high platelets on admission and residual embolic fragments or stenosis at the thrombectomy site are at high risk for reocclusion, which may be prevented or corrected after carefully re-evaluating the last angiographic run.

Objective: A reperfusion quality of thrombolysis in cerebral infarction (TICI)≥2b has been set as the therapeutic angiography target for interventions in patients with acute ischaemic stroke. This study addresses whether the distinction between TICI2b and TICI3 reperfusions shows a clinically relevant difference on functional outcome., Methods: A systematic literature review and meta-analysis was carried out and presented in conformity with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria to test the primary hypothesis that TICI2b and TICI3 reperfusions are associated with different rates of modified Rankin Scale (mRS) ≤2 at day 90. Secondary endpoints included rates of haemorrhagic transformations, mortality and excellent functional outcome (mRS ≤1). Summary estimates of ORs (sOR) with 95% CI were calculated using the inverse variance heterogeneity model accounting for multiple true effect sizes., Results: Fourteen studies on 2379 successfully reperfused patients were included (1131 TICI3, 1248 TICI2b). TICI3 reperfusions were associated with higher rates of functional independence (1.74, 95% CI 1.44 to 2.10) and excellent functional outcomes (2.01, 95% CI 1.60 to 2.53), also after including adjusted estimates. The safety profile of patients with TICI3 was superior, as demonstrated by lower rates of mortality (sOR 0.59, 95% CI 0.37 to 0.92) and symptomatic intracranial haemorrhages (sOR 0.42, 95% CI 0.25 to 0.71)., Conclusion: TICI3 reperfusions are associated with superior outcome and better safety profiles than TICI2b reperfusions. This effect seems to be independent of time and collaterals. As reperfusion quality is the most important modifiable predictor of patients' outcome, a more conservative definition of successful therapy and further evaluation of treatment approaches geared towards achieving TICI3 reperfusions are desirable., Competing Interests: Competing interests: Unrelated: JG is a global PI of STAR, CEC member of the PROMISE study (Penumbra), Consultancy; is the global PI for the SWIFT DIRECT study (Medtronic), Consultancy; and receives SNSF grants for magnetic resonance imaging in stroke. UF is the global PI for the SWIFT DIRECT study (Medtronic), Consultancy, and receives research grants from the Swiss National Science Foundation (SNSF). All other authors have nothing to disclose., (© 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 and Purpose- Preinterventional reperfusion before endovascular treatment (ET) is a benefit of bridging with intravenous tPA (tissue-type plasminogen activator). However, detailed data on reperfusion quality and rates of obviating ET in a cohort of patients with immediate access to ET is lacking. Purpose of this analysis was to evaluate prevalence and quality of preinterventional reperfusion in mothership patients. Methods- All mothership patients (n=627) from a prospective registry subjected to angiography with an intention to perform ET were reviewed. Preinterventional change of occlusion site (COS) was categorized into COS with Thrombolysis in Cerebral Infarction (TICI) 0/1, COS with TICI ≥2a, COS with TICI ≥2b, and COS with perfusion worsening. Predictors and clinical relevance were evaluated using multivariable logistic regression and results are displayed as adjusted odds ratios (aOR) and corresponding 95% confidence intervals (95% CI). Results- Prevalence of COS in all patients was 10.7% (95% CI, 8.3%-13.1%), subdividing into 2.7% COS with TICI 0/1, 6.2% COS with ≥TICI 2a (including 2.9% with TICI ≥2b), and 1.8% COS with perfusion worsening. Factors related to COS with ≥TICI 2a were intravenous tPA (aOR, 11.98; 95% CI, 4.5-31.6), cardiogenic thrombus origin (aOR, 2.3; 95% CI, 1.1-4.6), and thrombus length (aOR per 1 mm increase 0.926; 95% CI, 0.87-0.99). Additional ET was performed despite COS with ≥TICI 2a in 51.3%. COS with ≥TICI 2a showed a tendency for favorable outcomes (modified Rankin Scale, ≤2; aOR, 2.65; 95% CI, 0.98-7.17). Rates of COS with ≥TICI 2a were particularly low in internal carotid artery and proximal M1 occlusions (2.2%; 95% CI, 0.9%-5%), where intravenous tPA was associated with perfusion worsening (aOR, 4.33; 95% CI, 1.12-16.80). Conclusions- Prevalence of preinterventional reperfusion is non-negligible in patients with direct access to ET and is clearly favored by intravenous tPA treatment. However, it is often incomplete and often requires additional ET. Preinterventional reperfusion of internal carotid artery and proximal M1 occlusions is rare and usually of low quality, where intravenous tPA may also promote perfusion worsening.

Introduction: Since the first landmark randomized trials on unruptured bAVMs were published, there has been emerging concerns about the role of endovascular therapy. For bAVMs considered inoperable, embolization remains an option worth considering, especially in young patients presenting with a rupture. We aimed to review the curative potential of contemporary stand-alone embolization techniques enabling high occlusion rates and their respective short and long term safety profile., Evidence Acquisition: We performed a PubMed search with the terms "curative embolization of brain arteriovenous malformations" and "endovascular cure of brain arteriovenous malformations" focusing on the last ten years (2008-2018) and compliant to the PRISMA reporting guidelines. We then screened the prospective and retrospective studies of pediatric or adult populations that contained patient demographics, ruptured or unruptured presentation, and bAVM grade according to the Spetzler-Martin (SM) classification, exclusive or stand-alone endovascular treatment without previous embolization, micro-, radio- or stereotactic surgery, number of sessions, type of access, technique(s) and embolic agents used, rate of angiographically confirmed complete occlusion at least 3 months after obliteration stratified by AVM grade or subtype, as well as neurological status and treatment-associated outcome based on the modified Rankin scale at admission, discharge and within 12 months following curative embolization, rated by an independent observer., Evidence Synthesis: Given the heterogeneity of the reported data, multiple confounding factors, overwhelming number of unpowered studies, lack of homogenous control groups and poor compliance to PRISMA reporting guidelines in most of the interventional literature, we were unable to obtain solid data and perform a statistical meta-analysis on the safety and effectiveness of curative embolization. Consequently, we decided to cover a selection of salient topics., Conclusions: Stand-alone curative embolization, as well as exclusive microsurgery or radiosurgery each play complementary roles. Hemorrhagic, deep-seated lesions are an interesting subtype of surgically unfavorable bAVMs that may benefit from exclusive transvenous embolization, when carefully selected. Larger randomized trials and prospective registries are needed to establish the place of stand-alone or neoadjuvant endovascular treatment.

Background and Purpose: Patients with embolic large-vessel occlusion may present with additional coincidental acute occlusions within or distant from the involved territory, referred to as multivessel occlusion (MVO). Purpose of this study was to assess prevalence of MVO, associated factors, and clinical relevance in patients undergoing endovascular stroke treatment., Methods: Image data of consecutive endovascular candidates (n=720) with direct access to angiography were extracted from a prospective registry. Prevalence of MVO was assessed with multimodal magnetic resonance imaging/computed tomography and confirmed by intra-arterial angiography. Explorative analysis of associated factors and clinical relevance was evaluated using multivariable logistic regression including variables with P <0.15 in univariate comparison. Good functional outcome was defined as modified Rankin Scale score ≤2 at day 90., Results: MVO was present in 10.7% of patients (95% confidence interval [CI], 6.4%-13.0%). Two, 3, and 4 concomitant occlusions were found in 80.5%, 16.9%, and 2.6% of MVO cases, respectively. Detection rate on initial radiological report was 54.5%. Downstream MVO was present in around one third of MVO (n=27/77, 35.1%), whereas all other MVO (n=50/77, 64.9%) occurred in different territories. Independent factors related to MVO were statin treatment (adjusted odds ratio [aOR], 0.477; 95% CI, 0.276-0.827), higher systolic blood pressure (aOR per mm Hg increase, 1.014; 95% CI, 1.005-1.023), and primary occlusion site M2 (aOR, 1.870; 95% CI, 1.103-3.170). MVO was related to lower rates of successful reperfusion (aOR, 0.549; 95% CI, 0.316-0.953) and lower rates of good functional outcome (aOR, 0.437; 95% CI, 0.207-0.923)., Conclusions: Every tenth patient subjected to angiography for endovascular stroke treatment experienced MVO in our series, and only half were prospectively identified on preinterventional diagnostic imaging. Patients with MVO had higher baseline systolic blood pressure and were less often medicated with statins, an observation that warrants external validation and evaluation regarding causality. Occurrence of MVO has implication for treatment decisions, negatively affects endovascular treatment success, and is predictive of worse clinical outcome., (© 2018 American Heart Association, Inc.)

Introduction: Dual coaxial lumen balloon microcatheters through which small stents can be delivered have recently been described. We report a series of a new type of dual lumen balloon catheter with a parallel lumen design enabling enhanced inflation and deflation properties through which larger stents may be deployed, including flow diverters (FD)., Methods: All aneurysms that were treated with a Copernic 2L (COP2L) dual lumen balloon catheter at our institution between February 2014 and December 2016 were assessed. Patient demographics, aneurysm characteristics, clinical and angiographic follow-up, as well as adverse events were analyzed., Results: A total of 18 aneurysms in 16 patients (14 women) were treated with the COP2L. Mean maximal aneurysm diameter was 6.4 mm, mean neck size was 3.3 mm (min 1; max 6.3), and mean aneurysm height/width was 1.1 (min 0.5; max 2.1). The COP2L was used for balloon-remodeled coiling exclusively in 2 aneurysms; coiling and FD stenting in 8; coiling and braided stent delivery in 3; coiling, braided and FD stenting in 1; and FD stenting without coiling in 4 (stenting alone). The rate of Roy-Raymond 1 (complete occlusion) changed from 22% in the immediate postoperative period to 100% at 3 months (mean imaging follow-up 8.2 months). There were three technical complications (3/16, 18.7%), including a perforation and two thromboembolic asymptomatic events that were rapidly controlled with the COP2L. There was no immediate or delayed morbidity or mortality (modified Rankin Scale score 0-1 in 100% of patients)., Conclusion: The COP2L is a new type of dual lumen balloon catheter that may be useful for balloon and/or stent-assisted coiling of cerebral aneurysms. The same device can be used to deliver stents up to 4.5 mm and to optimize stent/wall apposition or serve as a life-saving tool in case of thromboembolic or hemorrhagic events. Long-term efficacy and safety need to be further assessed with larger case-controlled cohorts., Competing Interests: Competing interests: AG, J-BZ, FP, SH, DCR, JG, PJM, TD, FZ, EIP, RC and RTD report no disclosures relevant to the manuscript. PJM was a consultant and proctor for Balt Extrusion at the time of the manuscript preparation., (© 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.)

Introduction: The interest in measuring brain perfusion with intravoxel incoherent motion (IVIM) MRI has significantly increased in the last 3 years. Our aim was to evaluate the prognostic value for survival of intravoxel incoherent motion perfusion fraction in patients with gliomas, and compare it to dynamic susceptibility contrast relative cerebral blood volume and apparent diffusion coefficient., Methods: Images were acquired in 27 patients with brain gliomas (16 high grades, 11 low grades), before any relevant treatment. Region of maximal perfusion fraction, maximal relative cerebral blood volume, and minimal apparent diffusion coefficient were obtained. The accuracy of all three methods for 2‑year survival prognosis was compared using the area under the receiver operating characteristic curve and Kaplan-Meier survival curves., Results: Death or survival for at least 2 years after imaging could be documented in 22/27 patients. The cutoff values of 0.112 for the perfusion fraction, of 3.01 for the relative cerebral blood volume, and 1033 × 10 -6  mm 2 /s for apparent diffusion coefficient led to an identical sensitivity of 0.889, and a specificity of 0.833, 0.517, and 0.750, respectively for 2 year survival prognosis. The corresponding areas under the receiver operating characteristic curves were 0.84, 076, and 0.86, respectively. All three methods had a significant log rank test considering overall survival (p = 0.001, p = 0.028, and p = 0.002)., Conclusion: In this relatively small cohort, maximal IVIM perfusion fraction, similarly to maximal relative cerebral blood volume and minimal apparent diffusion coefficient, was prognostic for survival in patients with gliomas. Maximal IVIM perfusion fraction and minimal apparent diffusion coefficient performed similarly in predicting survival, and both slightly outperformed maximal relative cerebral blood volume.

Background and Purpose: Endovascular treatment (EVT) is a new standard of care for selected, large vessel occlusive strokes. We aimed to determine frequency of potentially eligible patients for intravenous thrombolysis (IVT) and EVT in comprehensive stroke centers. In addition, predictors of EVT eligibility were derived., Methods: Patients from a stroke center-based registry (2003-2014), admitted within 24 hours of last proof of usual health, were selected if they had all data to determine IVT and EVT eligibility according to American Heart Association/American Stroke Association (AHA/ASA) guidelines (class I-IIa recommendations). Moreover, less restrictive criteria adapted from randomized controlled trials and clinical practice were tested. Maximum onset-to-door time windows for IVT eligibility were 3.5 hours (allowing door-to-needle delay of ≤60 minutes) and 4.5 hours for EVT eligibility (door-to-groin delay ≤90 minutes). Demographic and clinical information were used in logistic regression analysis to derive variables associated with EVT eligibility., Results: A total of 2704 patients with acute ischemic stroke were included, of which 26.8% were transfers. Of all patients with stroke arriving at our comprehensive stroke center, a total proportion of 12.4% patients was eligible for IVT. Frequency of EVT eligibility differed between AHA/ASA guidelines and less restrictive approach: 2.9% versus 4.9%, respectively, of all patients with acute ischemic stroke and 10.5% versus 17.7%, respectively, of all patients arriving within <6 hours. Predictors for AHA-EVT eligibility were younger, shorter onset-to-admission delays, higher National Institutes of Health Stroke Scale (NIHSS), decreased vigilance, hemineglect, absent cerebellar signs, atrial fibrillation, smoking, and decreasing glucose levels (area under the curve=0.86)., Conclusions: Of patients arriving within 6 hours at a comprehensive stroke center, 10.5% are EVT eligible according to AHA/ASA criteria, 17.7% according to criteria resembling randomized controlled trials, and twice as many patients are IVT eligible (36.2%)., (© 2016 American Heart Association, Inc.)

Purpose To evaluate the effectiveness of mechanical thrombectomy with the use of a stent retriever in acute ischemic stroke, performed by using a balloon guide catheter or non-balloon guide catheter. Materials and Methods In accordance with the institutional review board approval obtained at the two participating institutions, retrospective analysis was performed in 183 consecutive patients treated between 2013 and 2014 for occlusions in the middle cerebral artery or carotid terminus by using a stent retriever with a balloon guide catheter (n = 102) at one center and a non-balloon guide catheter (n = 81) at the other center. Data on procedure duration, number of passes, angiographic findings, type of stent retriever used, and expertise of the operators were collected. Successful recanalization was defined as grade 3 or 2b modified Treatment in Cerebral Ischemia recanalization accomplished in up to three passes. Univariate and multivariate subgroup analyses were conducted to control for the confounding variables of prior thrombolysis, location of occlusion, and operator expertise. Results Successful recanalization with the balloon guide catheter was achieved in 89.2% of thrombectomies (91 of 102) versus 67.9% (55 of 81) achieved with the non-balloon guide catheter (P = .0004). The one-pass thrombectomy rate with the balloon guide catheter was significantly higher than for that with the non-balloon guide catheter (63.7% [65 of 102] vs 35.8% [29 of 81], respectively; P = .001). The procedure duration was significantly shorter by using the balloon guide catheter than the non-balloon guide catheter (median, 20.5 minutes vs 41.0 minutes, respectively; P < .0001). Conclusion The effectiveness of mechanical thrombectomy with stent retrievers in acute ischemic stroke in the anterior circulation in terms of angiographic results and procedure duration was improved when performed in combination with the balloon guide catheter. (©) RSNA, 2016.

Introduction: Endovascular treatment of small anterior choroidal artery (AChA) aneurysms can be challenging, especially if the AChA arises from the sac. Preserving its patency during embolization is as important as obliterating the aneurysm. We describe a variant of the "protective microcatheter technique" (PMT) in a series of six patients with AChA aneurysms where the AChA emerged from the sac., Methods: Three different microcatheters (KT) were used. The first microcatheter was placed in the AChA to protect it. A remodeling balloon-catheter was then positioned in the internal carotid artery to stabilize the coils during embolization and to control a potential rupture. The third microcatheter was finally used to coil the aneurysm., Results: Mean sac size of anterior choroidal artery aneurysms was 2×2×2mm. All aneurysms were successfully occluded. There was neither ischemic complication nor ruptured aneurysm during endovascular treatment. A final angiogram demonstrated AChA patency in all cases., Conclusion: The 3KT-PMT for AChA aneurysms appears to be safe and effective to prevent AChA occlusion during aneurysm coiling, especially when the AChA arises from the sac., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)