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Introduction: Intracranial atherosclerosis-related acute large vessel occlusion (ICAS-LVO) is the dominant cause of acute middle cerebral artery (MCA) occlusions that can be passed with wire or microcatheter but cannot be completely opened (5-15% of all middle cerebral artery (MCA) infarcts). The major challenge of ICAS-LVO is the tendency of reocclusion or cause a residual, fixed severe stenosis rendering the vessel with suboptimal revascularization. These patients carry a poor functional outcome and high mortality despite mechanical thrombectomy (MT). We aimed to externally validate three preidentified markers of ICAS-LVO on early non-contrast computed tomography (NCCT) and CT Angiogram (absent hyperdense MCA sign (HMCAS), Hounsfield measurements (HU ratio≤1.1 and Delta HU Methods: We conducted a retrospective analysis of 77 consecutive patients presenting with acute M1 occlusions undergoing MT. Based on our previous observational experiences, NCCT and CTA patterns that had been associated with ICAS-LVO included the absent HMCAS, HU ratio and Delta HU between site of occlusion and contralateral MCA and CTA truncal occlusion. ICAS-LVO was identified if an occlusion was difficult to cross, had tendency to reocclude after successful recanalization or demonstrated residual fixed severe stenosis. These markers were also compared with reperfusion rates and functional outcomes at 3 months. Results: Out of 77 patients, 13 (16%) had suspected ICAS-LVO. Absent HMCAS had a sensitivity of 91% and specificity of 90% (AUC 0.91), HU ratio ≤1.1 and delta HU 2) at 3 months. Conclusion: Initial non-contrast CT and CTA markers are highly sensitive and specific in predicting atherosclerotic M1 occlusions and significantly associated with failed reperfusion, and poor functional outcomes after mechanical thrombectomy.

The availability of cone-beam CT perfusion (CBCTP) in angiography suites may improve large-vessel occlusion (LVO) triage and reduce reperfusion times for patients presenting during extended time window. We aim to evaluate the perfusion maps correlation and agreement between multidetector CT perfusion (MDCTP) and CBCTP when obtained sequentially in patients undergoing endovascular therapy.This is a prospective, pilot, single-arm interventional cohort study of consecutive patients with anterior circulation LVO. All patients underwent MDCTP and CBCTP prior to endovascular therapy, generating cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and time-to-maximum/time to peak contrast concentration maps. We compared the two imaging modalities using three different methods: (1) six regions of interest (ROIs) placed in the anterior circulation territory; (2) ROIs placed in all 10 Alberta Stroke Program Early CT Score regions; and (3) ROI drawn around the entire ischemic area. ROI ratios (unaffected/affected area) were compared for all sequences in each method. We used the intraclass correlation coefficient to calculate the correlation between the studies. Bland-Altman plots were also created to measure the degree of agreement. Finally, a sensitivity analysis was done comparing both modalities in patients with low infarct growth rate.Fourteen patients were included (median age 81 years [74-87], 50% males, median National Institutes of Health Stroke Scale 19 [14-22]). Median time between studies was 42 minutes (interquartile range 29-61). Independently of the method used, we found moderate to excellent correlation in CBF, CBV, and MTT between modalities. CBF correlation further improved in patients with low infarct growth.These results demonstrate promising accuracy of CBCTP in evaluating ischemic tissue in patients presenting with LVO ischemic stroke.

Despite advancement in mechanical thrombectomy (MT) techniques, 10–30% of MT for large vessel occlusions (LVO) are unsuccessful. Current prediction models fail to address the association between patient-specific factors and reperfusion. We aimed to evaluate objective, easily reproducible, admission clinical and radiological biomarkers that predict unsuccessful MT. We analyzed consecutive anterior LVO MT patients at two comprehensive stroke centers. The primary outcome was unsuccessful reperfusion defined by a modified thrombolysis in cerebral infarction (mTICI) score of 0–2a. We quantitatively assessed the hyperdense vessel sign by measuring Hounsfield units (HU) on admission computed tomography (CT). Receiver operating characteristic (ROC) curves were plotted to estimate the predictive value of quantitative hyperdense middle cerebral artery (MCA) measurements (delta and ratio) and of the final model for mTICI scores. We performed multivariable logistic regression to analyze associations with outcomes. Out of 348 patients 87 had unsuccessful MT. Smoking, difficult arch, vessel tortuosity, vessel calcification, diminutive vessels, truncal M1 occlusion, delta HU and HU ratio were significantly associated with unsuccessful MT in the univariate analysis. When we fitted two separate multivariate models including all significant variables and a HU measurement; delta HU

Introduction: Carpal tunnel syndrome and ulnar neuropathy are such common maladies affecting the upper extremties that they often become the default diagnosis when patients complain of numbness, pain, or weakness of the hands. While often correct, there are a number of other conditions that can also cause sensory or motor loss of the hands, which should be considered when appropriate, as they can mimic upper extremity entrapment syndromes. Methods: In this review, we will discuss such mimics, including Charcot-Marie-Tooth disease, multifocal motor neuropathy, hereditary neuropathy with pressure palsies, mononeuropathy multiplex, Lewis-Sumner syndrome, brachial plexitis (Parsonage-Turner syndrome), myotonic dystrophy, inclusion body myopathy, and distal myopathy of Welander. We will discuss the clinical presentation, as well as diagnostic testing, treatment (if available), and prognosis. Conclusion: The objective is to provide a differential diagnosis for those patients who do not fit well clinically or respond to usual therapy for entrapment neuropathy of the upper extremities.

Background Unfavorable anatomy can preclude traditional anterograde endovascular interventions. Transcirculation approaches, which consist of primary catheterization of a target artery from the contralateral side or opposite cerebral circulation, can provide alternative pathways for successful treatment of these patients. We aimed to assess the safety, efficacy, and outcomes of endovascular embolization through transcirculation approaches. Methods Nine centers provided retrospective data on patients who underwent transcirculation procedures for embolization of intracranial aneurysms (IAs), dural arteriovenous fistulas (dAVFs), and arteriovenous malformations (AVMs). Raymond-Roy Occlusion Classification (RROC) grades and degree of obliteration were used to evaluate treatment success. Minor/major complications and clinical/angiographic outcomes were also assessed. A review of the literature reporting patients who underwent transcirculation embolizations was also performed. Results Forty patients were included in the study (34 IAs, 3 AVMs, and 3 dAVFs). Most IAs (22/34, 64.7%) were treated electively. Three AVMs and 2 dAVFs presented ruptured. RROC grade I–II was achieved in 97% of IAs. All AVMs and dAVFs were completely obliterated. One patient developed a transient arterial thrombus that was successfully treated with intravenous tirofiban. The most common indications for a transcirculation approach were difficult access angle of the target lesion (42.5%) and occlusion of the parent artery (27.5%). The review of the literature pooled 152 IAs treated via transcirculation approaches. Most common locations were the basilar tip (27%), posterior inferior cerebellar artery (25%), and internal carotid artery (15.1%). The posterior communicating artery was crossed in 60 (39.5%), anterior communicating artery in 48 (31.6%), and vertebral artery in 37 (24.3%) patients. Primary coiling alone was performed in 22 (14.5%), stent-assisted coiling in 67 (44.1%), balloon-assisted coiling in 36 (23.7%), stent-assisted coiling + balloon-assisted coiling in 20 (13.2%) and flow diversion in 7 (4.6%) patients. After intervention, 142 (93.4%) IAs achieved successful RROC grades I–II. Two major complications (1.3%) leading to death were reported, both of which were intraprocedural aneurysmal ruptures with massive subarachnoid hemorrhage and herniation. After a mean angiographic follow-up of 11.3 months, only 6/108 (5.6%) IAs showed intrasaccular filling/recurrence. Conclusions Transcirculation approaches seem to be safe and effective in the treatment of IAs, dAVFs, and AVMs. The most common indication for a transcirculation approach is the presence of a difficult angle to access the target lesion and occlusion of the parent artery.

Background Most trials have assessed intracranial atherosclerotic disease (ICAD) severity based on angiographic stenosis. However, anatomic stenosis might not accurately identify the actual state of functional post-stenotic flow limitation. Objective To investigate whether angiographic stenosis correlates with physiologic distal flow limitation, measured as trans-stenotic pressure gradients, in ICAD patients. Methods In patients referred for endovascular treatment of anterior circulation symptomatic ICAD who failed maximal medical therapy (MMT) per SAMMPRIS (Stenting versus Aggressive Medical Therapy for Intracranial Arterial Stenosis) criteria, angiographic luminal diameters and percentages of stenosis were correlated with trans-stenotic pressure gradients, calculated as distal/proximal pressure ratios (DPPR) and proximal minus distal pressure gradients (PDPG), by way of Spearman correlation coefficients. Results Nine patients (3 men, 6 women) were evaluated. Atherosclerotic lesions' locations included internal carotid artery in 5 subjects (2 cavernous, 3 supraclinoid) and proximal middle cerebral artery (M1) in 4 patients. Mean percentage of stenosis was 80 ± 8% (range 75%-94%). Minimal lumen diameter at the most stenotic ICAD site ranged from 0.2 to 0.9 mm (0.59 ± 0.41 mm). DPPR ranged from 0.38 to 0.63 (0.56 ± 0.14). PDPG ranged from 35 to 57 mm Hg (50 ± 8 mm Hg). Spearman coefficients showed no correlation between DPPR or PDPG and angiographic minimal luminal diameters or percentages of stenosis. There were no procedural complications related to trans-stenotic pressure measurements. Conclusion Angiographic stenosis does not reflect the physiologic severity of distal flow limitation in patients with ICAD. Hemodynamic assessment using trans-stenotic pressure ratios and gradients may serve as a more reliable predictive biomarker for MMT failure and response to revascularization.

INTRODUCTION Coronavirus disease 2019 (COVID-19) is associated with significant risk of acute thrombosis. We present a case report of a patient with cerebral venous sinus thrombosis (CVST) associated with COVID-19 and performed a literature review of CVST associated with COVID-19 cases. CASE REPORT A 38-year-old woman was admitted with severe headache and acute altered mental status a week after confirmed diagnosis of COVID-19. Magnetic resonance imaging brain showed diffuse venous sinus thrombosis involving the superficial and deep veins, and diffuse edema of bilateral thalami, basal ganglia and hippocampi because of venous infarction. Her neurological exam improved with anticoagulation (AC) and was subsequently discharged home. We identified 43 patients presenting with CVST associated with COVID-19 infection. 56% were male with mean age of 51.8±18.2 years old. The mean time of CVST diagnosis was 15.6±23.7 days after onset of COVID-19 symptoms. Most patients (87%) had thrombosis of multiple dural sinuses and parenchymal changes (79%). Almost 40% had deep cerebral venous system thrombosis. Laboratory findings revealed elevated mean D-dimer level (7.14/mL±12.23 mg/L) and mean fibrinogen level (4.71±1.93 g/L). Less than half of patients had prior thrombotic risk factors. Seventeen patients (52%) had good outcomes (mRS

Background A direct admission to angiosuite (DAA) strategy in transfer patients with large vessel occlusion (LVO) is considered to decrease stroke time metrics and benefit functional outcomes. However, feasibility and effectiveness of DAA have not been established in rural settings. Fast door‐to‐reperfusion times and high‐quality reperfusion are key predictors of outcome in patients with LVO. To reduce treatment times in transferred patients with suspected LVO, we initiated a DAA triage protocol in 2017. Methods We conducted a nested interventional cohort study of adult patients with anterior LVO from January 2015 to August 2019 transferred to our center from an outside hospital. Patients were divided into DAA for mechanical thrombectomy (MT) and patients directly admitted to the emergency department (DAED). DAED was subdivided into patients undergoing MT and patients who did not. Workflow times and clinical and radiographic outcomes were analyzed. Results Forty‐five DAA patients and 241 DAED patients (DAED patients undergoing MT=134 patients and DAED patients not undergoing MT=107 patients) were identified. DAA patients had significantly shorter median door‐to‐arterial‐puncture times (15 versus 71 minutes) and puncture‐to‐recanalization times (27 versus 42.5 minutes). At discharge, DAA patients had a significant decrease in median admission National Institutes of Health Stroke Scale (NIHSS) score (ΔNIHSS score 10 versus 4; P =0.02), and higher rate of dramatic clinical improvement (ΔNIHSS score >10; 48.9% versus 23.5%; P P =0.52), and mortality at 90 days ( P =0.63). When mortality was excluded, DAA patients showed a significant proportion of excellent functional outcome (mRS 0–1; 50% versus 26%) before ( P =0.04) and after ( P =0.02) adjusting for confounders. Conclusions DAA is feasible and can safely reduce reperfusion times in transferred patients with LVO to MT centers in a rural setting. Reducing workflow times may impact the functional recovery of patients undergoing MT.

The Woven EndoBridge (WEB) device, an intrasaccular flow-diverter that does not require long-term antiplatelet use, has recently emerged as an alternative to embolize complex intracranial aneurysms; however, there are limitations to the WEB device. First, it does not immediately secure the aneurysm in most subarachnoid hemorrhage cases. Second, it may not be suitable for embolization of wide-neck aneurysms with an unfavorable aspect ratio. To overcome these limitations, we have used the WEB device in conjunction with stenting and/or coiling. Here, we present a technical note with an illustrated case series and provide a detailed step-by-step description on how the WEB device can be used in adjunct to coiling and/or stenting to achieve successful angiographic results. Accurate sizing of the WEB device before deployment is critical. Larger case series are required to further assess the safety and success of these combined techniques.

Background and Purpose— After large-vessel intracranial occlusion, the fate of the ischemic penumbra, and ultimately final infarct volume, largely depends on tissue perfusion. In this study, we evaluated whether blood pressure reduction and sustained relative hypotension during endovascular thrombectomy are associated with infarct progression and functional outcome. Methods— We identified consecutive patients with large-vessel intracranial occlusion ischemic stroke who underwent mechanical thrombectomy at 2 comprehensive stroke centers. Intraprocedural mean arterial pressure (MAP) was monitored throughout the procedure. ΔMAP was calculated as the difference between admission MAP and lowest MAP during endovascular thrombectomy until recanalization. Sustained hypotension was measured as the area between admission MAP and continuous measurements of intraprocedural MAP (aMAP). Final infarct volume was measured using magnetic resonance imaging at 24 hours, and functional outcome was assessed using the modified Rankin Scale at discharge and 90 days. Associations with outcome were analyzed using linear and ordinal multivariable logistic regression. Results— Three hundred ninety patients (mean age 71±14 years, mean National Institutes of Health Stroke Scale score of 17) were included in the study; of these, 280 (72%) achieved Thrombolysis in Cerebral Infarction 2B/3 reperfusion. Eighty-seven percent of patients experienced MAP reductions during endovascular thrombectomy (mean 31±20 mm Hg). ΔMAP was associated with greater infarct growth ( P =0.036) and final infarct volume ( P =0.035). Mean ΔMAP among patients with favorable outcomes (modified Rankin Scale score, 0–2) was 20±21 mm Hg compared with 30±24 mm Hg among patients with poor outcome ( P =0.002). In the multivariable analysis, ΔMAP was independently associated with higher (worse) modified Rankin Scale scores at discharge (adjusted odds ratio per 10 mm Hg, 1.17; 95% CI, 1.04–1.32; P =0.009) and at 90 days (adjusted odds ratio per 10 mm Hg, 1.22; 95% CI, 1.07–1.38; P =0.003). The association between aMAP and outcome was also significant at discharge ( P =0.002) and 90 days ( P =0.001). Conclusions— Blood pressure reduction before recanalization is associated with larger infarct volumes and worse functional outcomes for patients affected by large-vessel intracranial occlusion stroke. These results underscore the importance of BP management during endovascular thrombectomy and highlight the need for further investigation of blood pressure management after large-vessel intracranial occlusion stroke.

Background The Scepter XC is a dual-lumen balloon catheter that accommodates a 0.014-inch microwire and can be used for balloon-assisted coiling of cerebral aneurysms. We describe our experience with the use of this device. Methods Two high-volume institution neurointerventional databases were retrospectively reviewed for cerebral aneurysms treated with balloon-assisted coiling using the Scepter XC balloon catheter. Patient demographics, aneurysm characteristics, and procedural details were recorded. Major procedure-related neurologic complications were defined as events that caused an increase in modified Rankin Scale that persisted for more than 1 week after the procedure. Follow-up aneurysm occlusion was assessed using the Raymond-Roy classification. Results During the study period, 231 aneurysms were treated in 219 patients (152 women, 67 men) with a mean age of 58.4 ± 12.2 years. Mean aneurysm size was 6.1 ± 3.1 mm, with a mean neck diameter of 3.1 ± 1.3 mm. In total, 77.5% of aneurysms were wide necked, and 39.8% were treated in the setting of subarachnoid hemorrhage. The major complication rate was 0.9% (2/231) per treated aneurysm, including one stroke and one death related to intraoperative aneurysm rupture. Excluding patients who died, angiographic follow up was available for 85.3% (191/224) of aneurysms. During a mean follow up of 17.4 ± 13.0 months (range, 1.7–66.5 months), Raymond-Roy 1 and 2 occlusion rates were 56.5% (108/191) and 35.6% (68/191), respectively. The retreatment rate was 12.6% (24/191). Conclusion Our experience using the coaxial dual-lumen Scepter XC for balloon-assisted coiling demonstrates acceptable aneurysm occlusion and complication rates.

Purpose The purpose of this study is to describe the use of the Penumbra Occlusion Device (POD), which is a coil with an enhanced anchor segment, along with standard coils for carotid and vertebral artery sacrifice, and to assess its feasibility, safety, and efficacy. Methods This is a retrospective chart review of patients with vessel sacrifices who were treated using POD. For the procedure, a balloon test occlusion was performed prior to permanent arterial sacrifice. Following this, a POD was deployed followed by subsequent angiography to confirm occlusion. Secondary PODs or standard coils were deployed as necessary. Results A total of 5 internal carotid arteries and 5 vertebral arteries were treated in 10 patients. The mean vessel diameter of the vessel sacrificed was 4 mm (range 2.9–7.7 mm). The total mean number of coils required for vessel sacrifice was 7 (range 3–17). The mean number of PODs used for vessel sacrifice was 2.4 (range, 1–6). The mean number of additional standard coils used was 4.1 (range, 0–13). 9/10 (90%) parent arteries were successfully occluded. One patient had slow flow distal to the occluded segment. One (10%) of the patients had a delayed ischemic event. There were no immediate periprocedural complications including coil migrations or vessel dissections. 6/10 patients had follow-up imaging and no patients developed recanalization during the follow-up period. Conclusion Parent vessel sacrifice using a combination of PODs and standard coils appear to be a feasible, safe and effective alternative to the traditional vessel sacrifice techniques.

Background and Purpose: Mechanical thrombectomy (MT) is a time-dependent therapy that is only available at a limited number of hospitals. As such, patients that live at a considerable distance of those specialized centers often require rapid interhospital emergent evacuation with Helicopter Emergency Medical Services (HEMS) to be considered for MT. It is not known whether the use of HEMS is equitable across different groups of patients. Methods: Acute ischemic stroke patients emergently transferred to another facility were identified in a retrospective review of a large Medicare claims database. Mode of transportation (HEMS, advanced, or basic ground ambulances) was determined by CPT codes. Distance from patient's residence to the closest center with MT capabilities was calculated. Generalized linear mixed logit models were used to determine the odds of HEMS relative to ground services for Hispanic and non-Hispanic black (NHB) patients relative to non-Hispanic white (NHW) patients while controlling for confounders. Results: A total of 8027 patients that underwent emergent interhospital transportation were analyzed. HEMS utilization was 18.1% for NHB, 20.6% for Hispanics, and 21.6% for NHW (P = .054). In adjusted analyses for confounders, including distance to a MT-capable hospital, Hispanic patients were less likely than NHWs to be transported by HEMS. While that association had marginal significance for the whole United States (OR = .76; 95% CI, .57-1.01; P = .055), it was statistically significant for patients living in the southern region of the United States (OR = .6; 95% CI, .40-.92; P = .019). Discussion: Our findings suggest there is a disparity in the use of HEMS in Hispanic stroke patients compared to NHW. Such a disparity may delay arrival to a MT-capable hospital, delay treatment times, or lead to ineligibility for MT altogether. Given the known benefit of MT and known existing disparities in stroke treatment and outcomes, it is important to further investigate and address disparities in mode of interhospital transportation.

Background The hyperdense middle cerebral artery sign on computed tomography indicates proximal middle cerebral artery occlusion. Recent reports suggest an association between the hyperdense sign and successful reperfusion. The prognostic value of the hyperdense middle cerebral artery sign in patients receiving mechanical thrombectomy has not been extensively studied. Aims Our study aims to evaluate the association between the hyperdense middle cerebral artery sign and functional outcome in patients with M1 occlusions that had undergone mechanical thrombectomy. Methods We conducted a single-center retrospective observational cohort study of 102 consecutive patients presenting with acute M1 occlusions that had undergone mechanical thrombectomy. Patients were stratified into cohorts based on the presence of hyperdense middle cerebral artery sign visually assessed on computed tomography by two readers. The outcomes of interests were functional disability measured by the ordinal Modified Rankin Scale (mRS) at 90 days, mortality, reperfusion status and hemorrhagic conversion. Results Out of the 102 patients with M1 occlusions, 71 had hyperdense middle cerebral artery sign. There was no significant difference between the cohorts in age, baseline mRS, NIHSS, ASPECTS, and time to reperfusion. The absence of hyperdense middle cerebral artery sign was associated with increased odds of being dependent or dying (higher mRS) (OR: 3.24, 95% CI: 1.30–8.06, p = 0.011) after adjusting for other significant predictors, including age, female sex, hypertension, presenting serum glucose, ASPECTS, CTA collateral score, and successful reperfusion. Conclusion The absence of hyperdense middle cerebral artery sign is associated with worse functional outcome in patients presenting with M1 occlusions undergoing thrombectomy.

Endovascular coiling has become the preferred treatment of many centers for the management of both ruptured and unruptured aneurysms. Coil migration is a rare complication that can lead to vessel occlusion in 90% of the cases. Endovascular techniques for coil retrieval have shown less complication rates than open surgery. Stent retriever devices have been successfully used for the retrieval of proximally migrated coils, however, distally migrated coils still represent a challenge with greater risk of complications. In the present technical video 1, we demonstrate the successful retrieval of a distally M3 migrated coil using a 3 mm Trevo XP ProVue stent riever (Stryker Neurovascular, Fremont, CA, USA) in combination with proximal aspiration. neurintsurg;13/9/860/V1F1V1Video 1.

Despite advancement in mechanical thrombectomy (MT) techniques, 10-30% of MT for large vessel occlusions (LVO) are unsuccessful. Current prediction models fail to address the association between patient-specific factors and reperfusion. We aimed to evaluate objective, easily reproducible, admission clinical and radiological biomarkers that predict unsuccessful MT.We analyzed consecutive anterior LVO MT patients at two comprehensive stroke centers. The primary outcome was unsuccessful reperfusion defined by a modified thrombolysis in cerebral infarction (mTICI) score of 0-2a. We quantitatively assessed the hyperdense vessel sign by measuring Hounsfield units (HU) on admission computed tomography (CT). Receiver operating characteristic (ROC) curves were plotted to estimate the predictive value of quantitative hyperdense middle cerebral artery (MCA) measurements (delta and ratio) and of the final model for mTICI scores. We performed multivariable logistic regression to analyze associations with outcomes.Out of 348 patients 87 had unsuccessful MT. Smoking, difficult arch, vessel tortuosity, vessel calcification, diminutive vessels, truncal M1 occlusion, delta HU and HU ratio were significantly associated with unsuccessful MT in the univariate analysis. When we fitted two separate multivariate models including all significant variables and a HU measurement; delta HU6 (odds ratio, OR = 2.07, 95% confidence intervals, CI 1.09-3.92) and HU ratio ≤1.1 (OR = 2.003, 95% CI 1.05-3.81) were independently associated with failed MT after adjustment for smoking, diminutive vessels, vessel tortuosity, and difficult arch. The area under the curve AUC9 of the final model was 0.717.Novel radiological biomarkers on CT, CT angiography (CTA) and digital subtraction angiography (DSA) may help identify patients refractory to standard MT and prepare interventionalists for using additional alternative methods. Quantitative assessment of HU (delta and ratio) may be important in developing objective prediction tools for unsuccessful MT.

Background and Purpose Despite advancement in technique, around 30% of mechanical thrombectomies (MT) for acute large vessel occlusion (LVO) are unsuccessful. Current prediction models fail to address the association between patient’s specific factors and post-procedural reperfusion. In the present study, we aim to evaluate pre-thrombectomy clinical and radiological features and their association with failed MT. Methods We retrospectively analyzed consecutive, adult, MT patients with anterior circulation LVO (2012–2017) treated at two large comprehensive stroke centers. We collected clinical and procedural data and reviewed imaging features from non-contrast enhanced head computed tomography (CT), CT angiography (CTA) and digital subtraction angiography (DSA). We performed a quantitative assessment of hyperdense vessel on CT, measuring Hounsfield unit (HU) in the occluded side and its counterpart. The primary outcome was unsuccessful recanalization measured by the Thrombolysis in Cerebral Infarction (TICI) score (0-2A). We utilized univariate and multivariate logistic regression to examine these associations. Results Out of 348 anterior LVO patients, 87 had failed MT. In univariate analysis, smoking, difficult arch, vessel tortuosity, vessel calcification specifically matching the LVO location, diminutive vessels, truncal M1 occlusion and quantitative measures for hyperdense MCA (delta HU and HU ratio) were significantly associated with failed MT. When we fitted 2 separate multivariate models delta HU or HU ratio; both delta HU Conclusions Quantitative assessment of HU utilizing delta HU and HU ratio may help identify patients refractory to standard thrombectomy strategies. Disclosures S. Ortega Gutierrez: 2; C; MEDTRONIC, STRYKER. C. Zevallos: None. F. Siddiqui: None. S. Dandapat: None. A. Dajles: None. K. Ume: None. M. Weber: None. D. Quispe: None. M. Farooqui: None. S. Ansari: None.

Endovascular intervention has become the mainstay of treatment for subclavian artery stenosis in many centers, with high technical success and low complication rates.1,2 However, potential embolization during proximal subclavian artery intervention can lead to catastrophic posterior circulation ischemic complications.3-5 Although considered a rare complication, the presence of a contralateral hypoplastic vertebral artery with persisting anterograde vertebral blood flow on the affected side is likely to increase the risk of embolization.3 The use of embolic protection devices, such as filters and noncompliant balloons, has been previously described.3,6,7 However, there is still a risk of distal embolization and vessel injury with the use of these devices.7 We present a technical video of a patient in their 80s with left subclavian stenosis who underwent subclavian stent-assisted percutaneous transluminal angioplasty (SAPTA) using an anterograde-retrograde access technique with a dual-lumen compliant balloon catheter (Scepter XC; MicroVention, Aliso Viejo, California) placed at the proximal segment of the left vertebral artery. With this approach, the compliant balloon provides adequate protection while minimizing the risk of endothelial injury and distal embolization. Written informed consent was obtained for the procedure. Patient consent was waived because all health information was deidentified.

Endovascular treatment of intracranial aneurysms (IAs) has evolved considerably over the past decades. The technological advances have been driven by the experience that coils fail to completely exclude all IAs from the blood circulation, the need to treat the diseased parent vessel segment leading to the aneurysm formation, and expansion of endovascular therapy to treat more complex IAs. Stents were initially developed to support the placement of coils inside wide neck aneurysms. However, early work on stent-like tubular braided structure led to a more sophisticated construct that then later was coined as a flow diverter (FD) and found its way into clinical application. Although FDs were initially used to treat wide-neck large and giant internal carotid artery aneurysms only amenable to surgical trap with or without a bypass or endovascular vessel sacrifice, its use in other types of IAs and cerebrovascular pathology promptly followed. Lately, we have witnessed an explosion in the application of FDs and subsequently their modifications leading to their ubiquitous use in endovascular therapy. In this review we aim to compile the available FD technology, evaluate the devices’ peculiarities from the authors’ perspective, and analyze the current literature to support initial and expanded indications, recognizing that this may be outdated soon.

Background Contrast-induced neurotoxicity (CIN) is an infrequent complication of endovascular procedures, and its understanding remains poor. We aimed to study and characterize the clinical and imaging features of a case series of CIN after neurointerventional surgery. Methods We reviewed all neuroendovascular consecutive procedures from September 2014 to November 2018. CIN was defined as new onset of neurologic deficits that occurred postoperatively after excluding other conditions. All demographic, clinical, procedural, and radiologic data were retrospectively analyzed and collected. Results Eleven cases of CIN in 1587 patients were identified out of 2510 procedures. The median age was 76 years (interquartile range [IQR], 65–81). The most common comorbidity was hypertension (82%). Median procedure time was 100 minutes (IQR, 80–130.5 minutes). All patients showed wide variability in intraprocedural blood pressure (BP) recordings with fluctuations from the baseline BP. Systolic BP ranged from 83 mm Hg below the patient baseline to 80 mm Hg above baseline. The median symptom onset was 4 hours (IQR, 0.8–9.5 hours). The CIN signs and symptoms presented gradually, initially with encephalopathy and later with focal signs. All patients had an initial computed tomography scan, which showed ipsilateral cerebral edema in 82% of patients. Two had contrast enhancement. Complete resolution of CIN symptoms was obtained in a median time of 3 days (IQR, 2.5–3 days). Conclusions CIN should be considered in the context of the progressive onset of neurologic deficits after neuroendovascular procedures. A distinct imaging pattern of ipsilateral hemisphere edema in the absence of ischemia is usually identified. Variability in procedural BP might be a predisposing factor.

Background and Purpose Prior literature suggests after-hours delay leads to poor functional outcomes in stroke patients undergoing thrombectomy. We aimed to evaluate the impact of time of presentation on mechanical thrombectomy (MT) metrics and its association with long-term functional outcome in an Interventional Radiology (IR) suite equipped operating room (OR) setting. Methods Retrospective review of prospectively maintained database on all stroke patients undergoing mechanical thrombectomy between January 2015 and December 2018 at our CSC. Work hours were defined by official OR work hours (Monday-Friday 7 AM and 5 PM) and after-hours as between 5 PM and 7 AM during weekdays and weekends as well as official hospital holidays. Primary outcome was 90-day modified Rankin Scale (mRS). Secondary outcomes included door to groin puncture time and procedural complications. Results A total of 315 patients were included in the analyses. 209 (66.4%) received mechanical thrombectomy after hours and 106 (33.6%) during work hours. There was no difference in the shift distribution of functional outcome on the mRS at 90 days (OR: 1.14, CI: 0.72-1.78, p=0.58) and the percentage of patients achieving functional independence (mRS 0-2) at 90 days (43.1% vs. 41.3%; p=0.83) between the after hour and work hour groups respectively. Similarly, there was no difference in median door to groin times and procedural complications among both groups, with significant year on year improvement in overall time metrics. Conclusions Our study showed that undergoing MT during off-hours had similar functional outcomes when compared to MT during working hours in an OR setting. The after-hours deleterious effect might disappear when MT is performed in a system with 24-hours in-house Anesthesia and IR tech services.

Background: Transcirculation approaches, which consist of primary catheterization of a target artery from the contralateral side or opposite cerebral circulation, provide alternate endovascular routes when anterograde interventions are not feasible. We aimed to assess the safety and efficacy of mechanical thrombectomy (MT) through a transcirculation route. Methods: Six centers provided retrospective data on acute ischemic stroke (AIS) patients who underwent MT via transcirculation approaches. Demographics and technical details of the endovascular intervention were collected. Recanalization rates, peri-procedural complications and clinical/angiographic outcomes immediately after the procedure and at last available follow-up were assessed. A review of the literature reporting on AIS patients whom underwent transcirculation MT was also performed. Results: Our multicenter study included 14 AIS patients treated through transcirculation routes. Mean age was 57.8 ± 11.9 years, and 10 (71.4%) were men. Mean NIHSS at admission was 18.4 (range 8–27). TICI 2b-3 recanalization was achieved in 10/14 (71.4%) patients. Three patients died after intervention: one due to late recanalization, one due to acute in-stent thrombosis, and one due to a procedure-related thromboembolic brainstem infarct. Of 11 surviving patients with follow-up available (mean 9.7 months), mRS 0–2 was achieved in 6 (54.5%) cases. Our review of the literature pooled a total of 37 transcirculation MT cases. Most common occlusions were tandem lesions (ICA + MCA = 64.9%) and BA + bilateral VA (18.9%). ACOM and PCOM were crossed in 18 (48.6%) cases each; one patient required a combined ACOM-PCOM approach. Primary recanalization technique included intra-arterial (IA) thrombolytics alone in 10 (27%), angioplasty ± stenting in 6 (16.2%), stent-retriever in 8 (21.6%), contact aspiration in 6, and combined (MT ± IA-thrombolytics) in 6 cases. Twenty-eight (75.7%) AIS patients achieved successful TIMI 2-3/TICI 2b-3 recanalization. After a mean follow-up of 6.7 months, 23/31 (74.2%) patients achieved a favorable functional outcome. Conclusions: Transcirculation approaches may be used to access the target lesion when the parent artery cannot be crossed through conventional antegrade routes. These techniques are feasible but should be reserved as a bailout maneuver when anterograde MT is not possible. Newer endovascular devices have improved neurological and angiographic outcomes in transcirculation cases.

Introduction: The hyper-dense middle cerebral artery sign (HMCAS) on computed tomography (CT) is associated with ischemic stroke involving the middle cerebral artery (MCA) territory. While its presence is indicative of acute thromboembolic disease, the clinical implications of its absence in patients presenting with M1 occlusions have not been widely studied. Methods: We retrospectively analyzed104 consecutive patients presenting with acute M1 occlusions undergoing mechanical thrombectomy. Pertinent clinical/radiological variables were obtained from the electronic medical records and review of angiographic images. Presence of HMCAS was defined as a difference of >5 Hounsfield units (HU) between the occlusion site and the corresponding contralateral MCA segment. Patients were stratified based on the presence (HD group) vs. absence (nHD group) of HMCAS. Primary outcomes included mortality, reperfusion status (TICI), and 3-month Modified Rankin Scale (mRS). Other relevant clinical variables were statistically analyzed and compared. Statistical analyses were two-tailed and considered significant if p Results: Out of the 104 patients with M1 occlusions, 78 had a measurable HMCAS (HD group), while 22 patients did not (nHD group). 4 patients were excluded due to CT artifacts. Age (69.2 ± 16.0), presenting NIHSS (15.8 ± 5.1), and time to groin (347.0 ± 282.6 min) were similar in the two groups. Mortality and 3-month mRS were 50% and 4.4 (±1.9) in the nHD group versus 27% and 3.1 (±2.2) in the HD group, both significant, with p=0.0201. and p=0.0152, respectively. The nHD patients had significantly higher incidence of diabetes (40.9% vs. 19.2%, p=0.0178). TICI score was unfavorable (2A, 1, or 0) in 31.8% of the nHD- and 24.4% of the HD patients, although not statistically significant. Lesions were presumed to be atherosclerotic (based on cerebral angiography) in 40.9% of nHD- and 7.7% of HD cases (p=0.00006). Conclusion: Absent HMCAS - defined as a

Introduction: Decreases in blood pressure (BP) during endovascular therapy (EVT) are associated with infarct progression and poor outcome. The largest BP reductions are thought to occur during induction. The frequency and clinical relevance of late BP decreases after partial reperfusion has been achieved remain unknown. In this study, we aimed to characterize the timing of BP reductions during EVT and to assess their association with functional outcome. Methods: We retrospectively studied patients with LVO stroke who underwent EVT at two comprehensive stroke centers. BP was continuously monitored throughout the procedure and averaged for selected time points. Maximum BP drop was calculated as the difference between admission systolic BP (SBP) and lowest SBP during EVT and assigned to one of three intervals: 1) arrival to angiography suite to groin puncture, 2) groin puncture to first pass, and 3) first pass to recanalization. Functional outcome was assessed using the modified rankin scale (mRS) at 90 days. Associations with the outcome were analyzed using ordinal logistic regression and adjusted for the size of the maximum drop in SBP. Results: 401 patients (age 71.3±14, 57% female, mean NIHSS 17) were included. Mean SBP for all patients decreased from EVT start to first procedural angiogram and then stabilized (Figure 1A). While the majority of blood pressure reductions occurred during interval 1 and 2 (n=253, 70%), 30% took place after first pass. We found no relation between timing of BP reduction and outcome (p=0.780, Figure 1B). Decreases in SBP during all intervals were significantly associated with 90-day outcome (OR per 10 mmHg 1.2, p=0.013; OR 1.1, p=0.025; and OR 1.3, p=0.011 for interval 1-3, respectively). Conclusions: BP drops occur throughout EVT, including between first pass and recanalization. Regardless of when these drops occur, they associate with poor outcome and thus underline the importance of blood pressure management throughout the procedure.

Carotid stenting (CAS) has been shown to be equivalent to carotid endarterectomy in symptomatic patients; however its optimal timing remains unclear. In this study, we aim to evaluate the safety of CAS when performed within the first 48 hours of symptom onset. We performed a retrospective analysis of a prospectively collected database of consecutive CAS patients admitted to our comprehensive stroke center with TIA/stroke and ipsilateral symptomatic carotid stenosis >50% from 2014 to 2019. Medical records were retrospectively reviewed for demographic, clinical and procedural data and outcomes. Acute and delayed treatment were defined as ≤48 and >48 hours from last known well (LKW) respectively. The primary endpoint was procedure-related major complications (stroke with NIHSS increase of ≥4, myocardial infarction, parenchymal hemorrhage type 2 or death) ≤30 days after CAS. Secondary endpoints were procedure-related minor neurological (stroke with NIHSS increase of

Unsuccessful recanalization rates in acute ischemic stroke patients range between 8-18%. Currently, there are no models to predict thrombectomy reperfusion success with current thrombectomy techniques. We aimed to describe the clinical and radiological features of patients with unsuccessful thrombectomy (UT) and its association with intracranial atherosclerosis (ICAD). A cohort of 413 consecutive, adult, thrombectomy patients admitted to two comprehensive stroke centers were reviewed from 2014 to 2017. Patients with anterior circulation large vessel occlusions (LVOs) and a thrombolysis in cerebral infarction (TICI) score of ≤2a were selected. Demographics, clinical and imaging data were obtained from electronic medical records. Head CT, CT angiography and digital subtraction angiography (DSA) images were reviewed by one independent investigator to evaluate ASPECTS score, vessel calcifications, clot burden score and CTA and DSA collateral score. Proposed causes of UT were categorized based on angiography evaluation by two independent neurointerventionalists. Analysis was performed using descriptive frequency analysis and univariate logistic regression models. A total of 87 low TICI score (≤2a) patients from 413 procedures were included. The median age was 74 years (IQR 58.5-84) and 58% were female. The most common comorbidity was hypertension (73.5%), followed by hyperlipidemia (46%). TICI score of 0 was found in 23% (N=20), 1 in 9.2% (N=8), and 2a in 67.8% (N=59). The inpatient mortality rate was 19.5% (17/87). Out of the remaining 70 patients, 78.5% (N=55) had a 3-month follow up modified Rankin Scale (mRS) of 3-6. The most common proposed cause of poor revascularization in our study was presence of ICAD [29.9% (n=32) of patients]. In our cohort of UT patients with ICAD, 68.8% (N=22) had TICI 2a score with majority (96.8%) having a 3 months mRS of 3-6. Patients with ICAD had 7.3% increased odds of having angiographic collateral score of 5 (p=0.035) and 15.2% increased odds of having an absence of hyperdense MCA in noncontrast CT scan (p=0.003). ICAD is frequently found in patients that undergo UT. Identification of radiological predictors of ICAD may be helpful to consider alternative revascularization strategies for LVOs.

Introduction: Intracranial atherosclerosis related occlusions (ICAS-O), occurring in 5-15% of all middle cerebral artery (MCA) infarcts, carry a poor functional outcome and high mortality despite mechanical thrombectomy (MT). We aimed to identify early non-contrast computed tomography (NCCT) predictors for ICAS-O and unfavorable outcomes in patients with M1 occlusions. Methods: We conducted a retrospective analysis of 104 consecutive patients presenting with acute M1 occlusions undergoing MT. Based on our previous observational experience, NCCT patterns that had been associated with atherosclerosis included the absence of visible hyperdense MCA sign, the presence of anterior temporal/insular hypodensity and the presence M1/M2 caliber asymmetry (diminutive vessels). These were used as predictors and were scored (1 for each) to build a 0-3 CT atherosclerosis score (CTAS) which was correlated with findings on cerebral angiogram, reperfusion status (TICI), 3-month Modified Rankin Scale (mRS), mortality, and other clinical variables. Results: CTAS was 3 in 16, 2 in 15, 1 in 41, and 0 in 30 patients. Two patients were excluded for poor quality NCCT. Age (69.1 ± 16.1), presenting NIHSS (15.7 ± 5.1), and time to groin (347.2 ± 281.4 min) were similar across all CTAS scores. Mortality and 3-month mRS both showed significant correlation with increasing CTAS (p=0.0198 and p=0.0111, respectively). CTAS 3 patients did poorly, carrying a mortality of 62.5%, and having a mean 3-month mRS of 5.1. The probability of unfavorable reperfusion (TICI 0, 1, and 2A) also increased with CTAS (p=0.0207). There was a significant correlation between CTAS and the presence of ICAS-O (p Conclusion: Initial non-contrast CT can be used to predict atherosclerotic M1 occlusions, failed reperfusions, and poor functional outcomes after mechanical thrombectomy. Co-existence of the above 3 predictors (CTAS 3) is more than 95% specific for atherosclerotic M1 occlusions and may identify an at-risk population that may be considered for alternative treatment approaches in the future.

Cerebral perfusion evaluation using CT or MR perfusion is the gold standard modality to select large vessel occlusion (LVO) stroke patients presenting >6 hours from symptom onset. The availability of cone beam C-arm CT perfusion (CBCTP) in angiography suites could reduce time to endovascular revascularization. We aimed to evaluate the reliability of using CBCTP when compared to multidetector CT perfusion (MDCTP). In this prospective, single-arm, interventional study, 14 LVO anterior circulation thrombectomy patients underwent both a 128 slice MDCTP in the ED and a CBCTP 2 ) were placed in the anterior arterial territory. In measurement 2, circular ROIs were placed in the ASPECTS regions (cortical 300mm 2 , subcortical 200mm 2 ). In measurement 3, a ROI was drawn around the entire affected area. All ROIs were placed in the basal ganglia and supraganglionic level of both brain sides. Rates (unaffected/affected area) between MDCTP and CBCTP were compared for all sequences. The intraclass correlation coefficient (ICC) was calculated using a single rater, consistency, two-way random-effects model. Measurement 1 found a moderate degree of agreement between MDCTP and CBCTP in CBF, CBV, MTT and TTP rates with ICCs of 0.58 (CI 0.42 - 0.69), 0.65 (CI 0.53 - 0.74), 0.77 (CI 0.68 - 0.83) and 0.52 (CI 0.35 - 0.65). In measurement 2, moderate agreement was found in CBF, CBV and MTT rates; with ICCs of 0.51 (CI 0.32 - 0.65), 0.57 (CI 0.4 - 0.69) and 0.62 (CI 0.47 - 0.73). The results of measurement 3 found an excellent (ICC=0.95, CI 0.88 - 0.98), good (ICC=0.83, CI 0.62 - 0.9) and moderate (ICC=0.7, CI 0.34 - 0.87), degree of agreement in the CBV, MTT and CBF rates, respectively. These results demonstrate promising accuracy of CBCTP in the evaluating ischemic tissue in patient presenting with LVO acute stroke.

BackgroundCombination antiplatelet therapy with clopidogrel and aspirin may reduce the rate of recurrent stroke during the first 3 months after a minor ischemic stroke or transient ischemic attack (TIA). A trial of combination antiplatelet therapy in a Chinese population has shown a reduction in the risk of recurrent stroke. We tested this combination in an international population.MethodsIn a randomized trial, we assigned patients with minor ischemic stroke or high-risk TIA to receive either clopidogrel at a loading dose of 600 mg on day 1, followed by 75 mg per day, plus aspirin (at a dose of 50 to 325 mg per day) or the same range of doses of aspirin alone. The dose of aspirin in each group was selected by the site investigator. The primary efficacy outcome in a time-to-event analysis was the risk of a composite of major ischemic events, which was defined as ischemic stroke, myocardial infarction, or death from an ischemic vascular event, at 90 days.ResultsA total of 4881 patients were enrolled at 269 international sites. The trial was halted after 84% of the anticipated number of patients had been enrolled because the data and safety monitoring board had determined that the combination of clopidogrel and aspirin was associated with both a lower risk of major ischemic events and a higher risk of major hemorrhage than aspirin alone at 90 days. Major ischemic events occurred in 121 of 2432 patients (5.0%) receiving clopidogrel plus aspirin and in 160 of 2449 patients (6.5%) receiving aspirin plus placebo (hazard ratio, 0.75; 95% confidence interval [CI], 0.59 to 0.95; P=0.02), with most events occurring during the first week after the initial event. Major hemorrhage occurred in 23 patients (0.9%) receiving clopidogrel plus aspirin and in 10 patients (0.4%) receiving aspirin plus placebo (hazard ratio, 2.32; 95% CI, 1.10 to 4.87; P=0.02).ConclusionsIn patients with minor ischemic stroke or high-risk TIA, those who received a combination of clopidogrel and aspirin had a lower risk of major ischemic events but a higher risk of major hemorrhage at 90 days than those who received aspirin alone. (Funded by the National Institute of Neurological Disorders and Stroke; POINT ClinicalTrials.gov number, NCT00991029 .).

Background and Purpose Intravenous alteplase (rt-PA) increases the risk of hemorrhagic transformation of acute ischemic stroke. The objective of our study was to evaluate clinical, laboratory, and imaging predictors on forecasting the risk of hemorrhagic transformation following treatment with rt-PA. We also evaluated the factors associated with cerebral microbleeds that increase the risk of hemorrhagic transformation. Methods Consecutive patients with acute ischemic stroke admitted between January 1, 2009 and December 31, 2013 were included in the study if they received IV rt-PA, had magnetic resonance imaging (MRI) of the brain on admission, and computed tomography or MRI of the brain at 24 (18-36) hours later to evaluate for the presence of hemorrhagic transformation. The clinical data, lipid levels, platelet count, MRI, and computed tomography images were retrospectively reviewed. Results The study included 366 patients, with mean age 67 ± 15 years; 46% were women and 88% were white. The median National Institutes of Health Stroke Scale (NIHSS) score was 6 (interquartile range 3-15). Hemorrhagic transformation was observed in 87 (23.8%) patients and cerebral microbleeds were noted in 95 (25.9%). Patients with hemorrhagic transformation tended to be older, nonwhite, have atrial fibrillation, higher baseline NIHSS score, lower cholesterol and triglyceride levels, and cerebral microbleeds and nonlacunar infarcts. Patients with cerebral microbleeds were more likely to be older, have hypertension, hyperlipidemia, previous history of stroke, and prior use of antithrombotics. On multivariate analysis race, NIHSS score, nonlacunar infarct, and presence of cerebral microbleeds were independently associated with hemorrhagic transformation following treatment with rt-PA. Conclusions Presence of cerebral microbleeds is an independent predictor of hemorrhagic transformation of acute ischemic stroke following treatment with rt-PA.

Background Stenting and flow diversion for aneurysmal sub arachnoid hemorrhage (aSAH) require the use of dual antiplatelet therapy (DAPT). Objective To investigate whether DAPT is associated with hemorrhagic complication following placement of external ventricular drains (EVD) in patients with aSAH. Methods Rates of radiographically identified hemorrhage associated with EVD placement were compared between patients who received DAPT for stenting or flow diversion, and patients who underwent microsurgical clipping or coiling and did not receive DAPT by way of a backward stepwise multivariate analysis. Results Four hundred forty-three patients were admitted for aSAH management. Two hundred ninety-eight patients required placement of an EVD. One hundred twenty patients (40%) were treated with stent-assisted coiling or flow diversion and required DAPT, while 178 patients (60%) were treated with coiling without stents or microsurgical clipping and did not receive DAPT. Forty-two (14%) cases of new hemorrhage along the EVD catheter were identified radiographically. Thirty-two of these hemorrhages occurred in patients on DAPT, while 10 occurred in patients without DAPT. After multivariate analysis, DAPT was significantly associated with radiographic hemorrhage [odds ratio: 4.92, 95% confidence interval: 2.45-9.91, P = .0001]. We did not observe an increased proportion of symptomatic hemorrhage in patients receiving DAPT (10 of 32 [31%]) vs those without (5 of 10 [50%]; P = .4508). Conclusion Patients with aSAH who receive stent-assisted coiling or flow diversion are at higher risk for radiographic hemorrhage associated with EVD placement. The timing between EVD placement and DAPT initiation does not appear to be of clinical significance. Stenting and flow diversion remain viable options for aSAH patients.

Background and Purpose: Complex wide-neck intracranial aneurysms are challenging to treat. We report a multicenter experience using the LVIS Jr stent for “Y-stent”-assisted coiling embolization of wide-neck bifurcation aneurysms. Methods: Seven centers provided retrospective data on patients who underwent Y-stenting. Technical complications, immediate posttreatment angiographic results, clinical outcomes, and imaging follow-up were assessed. Results: Thirty patients/aneurysms were treated: 15 basilar tip, 8 middle cerebral artery, 4 anterior communicating artery, 1 pericallosal, and 2 posterior inferior cerebellar artery aneurysms. The mean aneurysm size was 11 mm and the mean dome-to-neck ratio was 1.3 mm. Twenty-four aneurysms were unruptured and treated electively, and 6 were acutely ruptured. Fifty-eight LVIS Jr stents were successfully deployed without any technical issue. One pro­cedural and transient in-stent thrombosis resolved with the intravenous infusion of a glycoprotein IIb/IIIa inhibitor. Five periprocedural complications (within 30 days) occurred: 2 periprocedural neurological complications (1 small temporal stroke that presented with transient aphasia and 1 posterior cerebral artery infarct) and 3 nonneurological periprocedural complications (2 retroperitoneal hematomas, and 1 patient developed a disseminated intravascular coagulopathy). One permanent complication (3.3%) directly related to Y-stenting was reported in the patient who suffered the posterior cerebral artery infarct. Immediate complete obliteration (Raymond-Roy Occlusion Classification [RROC] I–II) was achieved in 26 cases (89.6%). Twenty-four patients had clinical and imaging follow-up (mean 5.2 months). Complete angiographic occlusion (RROC I–II) was observed in 23 patients (96%). A good functional outcome with a modified Rankin Scale score ≤2 was achieved in 26 cases. Conclusions: In this multicenter case series, Y-stent-assisted coiling of wide-neck aneurysms with the LVIS Jr device was feasible and relatively safe. Follow-up imaging demonstrated very low recanalization rates.

Key Clinical Message We report a case of Hashimoto's encephalopathy (HE), who presented with epilepsia partialis continua (EPC) and a frontal lobe lesion. The diagnosis of HE remained elusive until the serum thyroid antibodies became positive 7 months after the onset of EPC. The histopathology of this frontal lesion showed nonvasculitic inflammation.

Introduction: Selecting the appropriate Woven EndoBridge (WEB) device sizing for the treatment of wide-neck bifurcation aneurysms (WNBAs) remains challenging. The aim of this study was to evaluate different volumetric-based imaging methodologies to predict an accurate WEB device size selection to result in a successful implantation. Methods: All consecutive patients treated with WEB devices for intracranial aneurysms from January 2019 to June 2020 were included. Aneurysm dimensions to calculate aneurysm volumes were measured using three different modalities: automated three-dimensional (3D) digital subtraction angiography (DSA), manual 3D DSA, and two-dimensional (2D) DSA. The device–aneurysm volume (DAV) ratio was defined as device volume divided by the aneurysm volume. WEB volumes and the DAV ratios were used for assessing the device implantation success and follow-up angiographic outcomes at six months. Pearson correlation, Wilcoxon Rank Sum test, and density approximations were used for estimating the WEB volumes and the imaging modality volumes for successful implantation. Results: A total of 41 patients with 43 aneurysms were included in the study. WEB device and aneurysm volume correlation coefficient was highest for 3D automatic (r = 0.943), followed by 3D manual (r = 0.919), and 2D DSA (r = 0.882) measurements. Measured median volumes were significantly different for 3D automatic and 2D DSA (p = 0.017). The highest rate of successful implantation (87.5%) was between 0.6 and 0.8 DAV ratio. Conclusion: Pre-procedural assessment of DAV ratios may increase WEB device implantation success. Our results suggest that volumetric measurements, especially using automated 3D volumes of the aneurysms, can assist in accurate WEB device size selection.