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Chronic subdural hematomas (CSDHs) are common in the elderly population and patients taking antiplatelet/anticoagulation medications. Middle meningeal artery (MMA) embolization has become an adjunctive treatment to observation and surgery. Despite many embolization techniques, best practices for optimal CSDH resolution remain unknown.To report a retrospective case series of MMA embolization for CSDHs regarding rate of hematoma improvement and the significance of distal embolic penetration into the falx.Retrospective chart review was performed on all patients who underwent MMA embolization for CSDHs between January 2017 and June 2021. Patient demographics, clinical presentation, anticoagulant use, and radiographic features were collected. Pre-embolization and postembolization computed tomography scans were analyzed for volumetric changes and assessed for midline penetration of embolic material in the falx.MMA embolization was performed in 37 patients and 53 hemispheres. Older patients took longer to obtain complete resolution of CSDHs (r = 0.47, P = .03). Patients with larger pre-embolization (r = 0.57, P = .007) and postembolization (r = 0.56, P = .008) CSDH volumes took longer to completely resolve. Patients who had n-butyl cyanoacrylate embolization with midline penetration, as evidenced by the "bright falx" sign, had faster improvement rates than those who did not (5.64 cm 3 /d vs 1.2 cm 3 /d, P = .02).Distal penetration of embolic material, particularly n-butyl cyanoacrylate, into the falx may lead to more rapid improvement of CSDH.

BackgroundEarly neurological deterioration (END) after endovascular treatment (EVT) in patients with anterior circulation acute ischemic stroke (AIS) is associated with poor outcome. END may remain unexplained by parenchymal hemorrhage (UnEND). We aim to analyze the risk factors of UnEND in the medical management (MM) and EVT arms of the HERMES study.MethodsWe conducted a post-hoc analysis of anterior AIS patients who underwent EVT for proximal anterior occlusions. Risk factors of UnEND, defined as a worsening of ≥4 points between baseline National Institutes of Health Stroke Scale (NIHSS) and NIHSS at 24 hours without hemorrhage, were compared between both arms using mixed logistic regression models adjusted for baseline characteristics. An interaction analysis between the EVT and MM arms for risk factors of UnEND was conducted.ResultsAmong 1723 patients assessable for UnEND, 160 patients experienced an UnEND (9.3%), including 9.1% (78/854) in the EVT arm and 9.4% (82/869) in the MM arm. There was no significant difference in the incidence of UnEND between the two study arms. In the EVT population, independent risk factors of UnEND were lower baseline NIHSS, higher baseline glucose, and lower collateral grade. In the MM population, the only independent predictor of UnEND was higher baseline glucose. However, we did not demonstrate an interaction between EVT and MM for baseline factors as risk factors of UnEND. UnEND was, similarly in both treatment groups, a significant predictor of unfavorable outcome in both the EVT (pConclusionsUnEND is not an uncommon event, with a similar rate which ever treatment arm is considered. In the clinical scenario of AIS due to large vessel occlusion, no patient-related factor seems to increase the risk for UnEND when treated by EVT compared with MM.

Introduction: The Get with the Guidelines - Stroke (GWTG-Stroke) registry has been collecting endovascular thrombectomy (EVT) data on acute stroke interventions since 2015. The key variables associated with EVT, solely based on local site documentation, have never been independently adjudicated. We conducted a detailed analysis of single center EVT data as entered in the GWTG-Stroke registry. Methods: Consecutive EVT cases entered into both GWTG-Stroke and an independent research database at a large academic comprehensive stroke center were sampled from 2020-2022. For each case, the following EMR and PACS imaging variables related to EVT efficacy and safety outcomes were compared between GWTG-Stroke and core lab independent readings, including: site of target occlusion (STO), first-pass time (FPT), time mTICI >=2b50 first documented (reperfusion time), final mTICI score (0, 1, 2a, 2b50, 3; FTICI), presence of post-intervention hemorrhagic transformation (HT), and subtype/extent of HT. Results: The GWTG-Stroke registry EVT-imaging data variables document only 6/30 (20%) of the common data elements (CDEs) recommended by NINDS and 6/34 (18%) recommended by the FDA. Of the 80 cases sampled, 29 (36%) had discrepancies between GWTG-Stroke recorded data and independent core lab findings. In 4 cases (5%), reperfusion time was incorrect. In another 4 cases (5%), FTICI was incorrect, even when using the gross 2b50/3 categories. In 1 case (1.3%) STO was incorrect. In 2 cases (2.5%) patient data was not reported to GWTG-Stroke. In 21 cases (26%), HT was documented as not present, when in fact it was. Of those, 3 cases (4%) were PH2, while 18 cases (23%) were IPH of PH1 or less, SAH or SDH. Conclusions: Detailed analysis of the GWTG-Stroke registry on EVT for acute ischemic stroke reveal major discrepancies in numerous variables. In addition, the majority of variables recommended by NINDS and FDA for routine collection in thrombectomy procedures are not captured in GWTG-Stroke. Even the minority of recommended thrombectomy CDEs currently captured in GWTG-Stroke further contain subject level discrepancies in imaging and angiography outcomes when centrally adjudicated.

Introduction: Incidentally discovered cerebral aneurysms are increasingly common as patients are more frequently imaged. To aid in this management, we developed an aneurysm alert system. Here we describe the effectiveness and outcomes of our Incidental Aneurysm Alert System (IAAS). Methods: IAAS received MRA and CTA reports from our Radiology department. Reports were parsed using natural language processing to identify ‘aneurysm’, automatically generating alerts for the interventional neuroradiologists. Background demographics, referral patterns, risk factors and management were then assessed. Results: From March to December 2020, 145 consecutive reports were reviewed. A 87% cerebral aneurysm detection accuracy rate resulted after excluding duplicates and non-vascular lesions, resulting in 117 unique cases. Median age was 65 and 65% were female. Most frequent races were 53% non-Hispanic White, 19% other, 9% Asian, 6% Black; 26% were of Hispanic ethnicity. The most common indication was acute stroke (29%). Of the detected aneurysms, 49% resulted in consultation with an interventionalist. Neurology was the most common referring specialty (37%). Of those referred, 49% underwent diagnostic and/or therapeutic angiography. Sixty eight percent who underwent cerebral angiography were intervened upon immediately or within 2 years of discovery. Seven percent were ruptured on discovery. Aneurysms were most frequently treated with flow diversion (37%), coiling (37%), and clipping (16%).Mean PHASES score of referred patients was 4.3, conferring 0.9-1.3% 5-year rupture risk. Asians and Hispanics had higher PHASES scores on presentation of 6.1 (1.7% 5-year rupture risk) and 5.2 (1.3% 5-year rupture risk) respectively, compared to Non-Hispanic Caucasians of 3.8 (0.9% 5-year rupture risk). For Hispanics, mean age was 55 and mean aneurysm size 9.8 mm as compared to 66 and 5.6 mm in non-Hispanic Caucasians. There were no significant differences in aneurysm risk factors. Conclusions: IAAS is an effective alerting system. Hispanics were younger with larger aneurysms on detection. IAAS may have potential value in connecting general physicians with cerebrovascular specialists, improving the management of incidentally discovered cerebral aneurysms.

Background and Purpose: DWI-FLAIR mismatch is used to determine thrombolytic eligibility in patients with acute ischemic stroke (AIS) when time-to-stroke symptom (TSS) is unknown. Advances in artificial intelligence and machine learning (ML) techniques have shown promising results in automated assessment of TSS. We aimed to use the e-Stroke software (Brainomix, Oxford, UK) to automatically classify DWI-FLAIR mismatch in a cohort of patients with AIS and in a comparative analysis with an expert neuroradiologist. Methods: In this retrospective study, consecutive patients with AIS who had pretreatment MRI, and known TSS were included. DWI-FLAIR mismatch was evaluated by an expert neuroradiologist blinded to TSS. e-Stroke software, which uses a combination of statistical methods and ML classification techniques was used to automatically classify DWI-FLAIR status. TSS was dichotomized using a 4.5 hr cutoff to assess the diagnostic performance of the radiologist vs. e-Stroke software. Results: Thus far 113 patients are included, 53 female, age (mean ± SD): 68.9 ± 17. TSS was 371±249 min (mean ± SD) and the infarct volume was 16.4±26.5 ml (mean ± SD). A total of 60 patients had TSS > 4.5 hrs while 53 had TSS < 4.5 hrs. Diagnostic performance (sensitivity/specificity/accuracy in %) for determination of TSS using DWI-FLAIR mismatch was 75/58.5/66.7 for the radiologist and 43/85/64 for e-Stroke software; without statistical difference (AUC: 0.66 for radiologist, 0.64 for e-Stroke; Delong test, p= 0.59). Subgroup analysis of infarctions of at least 1mL or higher, improved the diagnostic performance for both radiologist (83.8/59.4/71.6) and e-Stroke software (66.7/75.0/71.0), without statistical difference (AUC: 0.71 for radiologist and 0.71 for e-Stroke; Delong test, p= 0.96). Conclusions: Results show that fully automated quantitative approach for DWI-FLAIR mismatch provides similar diagnostic accuracies to expert neuroradiologist in determination of TSS.

Introduction: With successful reperfusion (SR, mTICI 2b-3) now being achieved in the great preponderance of patients undergoing endovascular thrombectomy (EVT), prevention of blood-brain barrier disruption and reperfusion injury is an emerging therapeutic target. For trials of agents to reduce BBB injury, the hyperintense acute reperfusion marker (HARM) sign is a potentially useful physiologic biomarker. However, past studies of HARM have generally failed to disaggregate non-EVT patients, EVT patients without SR, and EVT patients with SR. Methods: In a prospectively maintained database, we analyzed consecutive patients with SR (mTICI 2b-3) after EVT for anterior circulation large vessel occlusion undergoing post-gadolinium MRI scans at 3-6h and 24h after thrombectomy. Results: Among 48 SR patients meeting study entry criteria, the HARM sign was present in 65%. Patients with HARM sign, compared to those without, did not differ in age or NIHSS, but were more often female (54% vs 10%), more often had history of hypertension (65% vs 47%), and had higher initial SBP (156 vs 144). Patients with HARM sign more often received IV TPA (39% vs 29%), had longer time from onset to achievement of SR (median 352 vs 264 mins), underwent more passes (2.5 vs 1.9), and less often had complete (mTICI 3) reperfusion (13% vs 41%). With regard to outcomes, HARM patients more often had radiologic hemorrhage (75% vs 24%), less often were ambulatory at discharge (23% vs 59%), had less functional independence (mRS 0-2) at 90d (33% vs 59%), and had higher in-hospital mortality (16% vs 0%). Conclusion: The HARM sign is present in two-thirds of EVT patients with successful reperfusion; is associated with higher blood pressure, IV lytic therapy, longer time to reperfusion, more procedure manipulations, and less than complete macro-reperfusion; and is strongly associated with hemorrhagic transformation and worse clinical outcomes. The HARM sign is a promising biomarker for use in trials of treatments to avert reperfusion injury.

Introduction: Application of machine learning (ML) algorithms has shown promising results in estimating ischemic core volumes using routine non-contrast CT (NCCT). We aimed to assess the performance of the e-Stroke Suite software (Brainomix, Oxford, United Kingdom) in assessing ischemic core volumes on NCCT compared to CTP in patients with acute ischemic stroke. Methods: In this retrospective study, consecutive patients with anterior circulation large vessel occlusions who underwent pretreatment NCCT and CTP and posttreatment MRI were included. Ischemic core volumes were automatically calculated on NCCTs using e-Stroke Suite (Brainomix) which uses a combination of traditional 3D graphics and ML classification techniques to identify ischemic core voxels. Estimated ischemic core volumes were also automatically calculated from CTP using Olea Sphere (Olea Medical SAS, SP23) using a combination of rCBF5 sec. Estimated core volumes were compared against the final infarct volume on posttreatment MRI in patients who achieved successful reperfusion (mTICI ≥2b). Results: 83 patients [52 female; age (mean ± SD): 73.1 ±15.3] were included. The estimated ischemic core volumes (mean ± SD) were 18.9 ± 13.5 mL on NCCT and 17.5 ± 16.5 mL on CTP, not significantly different (p=0.54) and demonstrated significant correlation (r=0.51, pFigure 1 ). Among patients with successful recanalization (n=49), there was no significant difference in estimated ischemic core volume between NCCT vs. CTP (p=0.80) and NCCT vs. MRI (p=0.38). There was significant correlation between estimated ischemic core volume on NCCT vs. CTP (r=0.75, p Conclusions: Results show estimated ischemic core volumes obtained automatically by ML-based approach (Brainomix) on NCCT correlates well with ischemic core volumes on acute CTP and with post-treatment MR infarct volume.

Supplemental Digital Content is available in the text., Background and Purpose: This study investigates clinical outcomes after mechanical thrombectomy in adult patients with baseline Alberta Stroke Program Early CT Score (ASPECTS) of 0 to 5. Methods: We included data from the STRATIS Registry (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) from patients who underwent mechanical thrombectomy within 8 hours of symptom onset and had available ASPECTS data adjudicated by an independent core laboratory. Angiographic and clinical outcomes were collected, including successful reperfusion (modified Thrombolysis in Cerebral Infarction ≥2b), functional independence (modified Rankin Scale score 0–2), 90-day mortality, and symptomatic intracranial hemorrhage at 24 hours. Outcomes were stratified by ASPECTS scores and age. Results: Of the 984 patients enrolled, 763 had available ASPECTS data. Of these patients, 57 had ASPECTS of 0 to 5 with a median age of 63 years (interquartile range, 28–100), whereas 706 patients had ASPECTS of 6 to 10 with a median age of 70 years of age (interquartile range, 19–100). Ten patients had ASPECTS of 0 to 3 and 47 patients had ASPECTS of 4 to 5 at baseline. Successful reperfusion was achieved in 85.5% (47/55) in the ASPECTS of 0 to 5 group. Functional independence was achieved in 28.8% (15/52) in the ASPECTS of 0 to 5 versus 59.7% (388/650) in the 6 to 10 group (P75 years with ASPECTS of 0 to 5 (0/12) achieved functional independence versus 44.8% (13/29) of those age ≤65 (P=0.005). Conclusions: Patients 75 years of age. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02239640.

Background and importance Aneurysms of the posterior cerebral artery (PCA) are uncommon, estimated at less than 1% of all cerebral aneurysms, and less than half occur distal to the P1/2 junction. Unfortunately, the conventional bypass approach for PCA aneurysms-primarily occipital artery to distal PCA cortical branches-has a history of unsatisfying results. Clinical presentation A 42-yr-old female presented with Fisher 3 Hunt-Hess 2 subarachnoid hemorrhage secondary to ruptured distal PCA aneurysm. She was initially evaluated by the endovascular service, but due to recent subarachnoid hemorrhage, endovascular treatment with flow diversion and/or vessel sacrifice was felt to be relatively contraindicated and the patient was referred for surgical evaluation for possible bypass. The patient subsequently underwent surgery for trapping of aneurysm and concomitant superficial artery to distal PCA bypass. Conclusion A novel approach for the treatment of a ruptured distal PCA aneurysm is described, consisting of posterior transpetrosal exposure and division of the tentorium with superficial temporal artery to P3 bypass.

BackgroundTargeted eloquence-based tissue reperfusion within the primary motor cortex may have a differential effect on disability as compared with traditional volume-based (thrombolysis in cerebral infarction, TICI) reperfusion after endovascular thrombectomy (EVT) in the setting of acute ischemic stroke (AIS).MethodsWe explored the impact of eloquent reperfusion (ER) within primary motor cortex (PMC) on clinical outcome (modified Rankin Scale, mRS) in AIS patients undergoing EVT. ER-PMC was defined as presence of flow on final digital subtraction angiography (DSA) within four main cortical branches, supplying the PMC (middle cerebral artery (MCA) – precentral, central, postcentral; anterior cerebral artery (ACA) – medial frontal branch arising from callosomarginal or pericallosal arteries) and graded as absent (0), partial (1), and complete (2). Prospectively collected data from two centers were analyzed. Multivariate analysis was conducted to assess the impact of ER-PMC on 90-day disability (mRS) among patients with anterior circulation occlusion who achieved partial reperfusion (TICI 2a and 2b).ResultsAmong the 125 patients who met the study criteria, ER-PMC distribution was: absent (0) in 19/125 (15.2%); partial (1) in 52/125 (41.6%), and complete (2) in 54/125 (43.2%). TICI 2b was achieved in 102/125 (81.6%) and ER-PMC was substantially higher in those patients (PConclusionsEloquent PMC-tissue reperfusion is a key determinant of functional outcome, with a greater impact than volume-based (TICI) degree of partial reperfusion alone. PMC-targeted revascularization among patients with partial reperfusion may further diminish post-stroke disability after EVT.

Background and Purpose: We aimed to delineate the determinants of the initial speed of infarct progression and the association of speed of infarct progression (SIP) with procedural and functional outcomes. Methods: From a prospectively maintained stroke center registry, consecutive anterior circulation ischemic stroke patients with large artery occlusion, National Institutes of Health Stroke Scale score ≥4, and multimodal vessel, ischemic core, and tissue-at-risk imaging within 24 hours of onset were included. Initial SIP was calculated as ischemic core volume at first imaging divided by the time from stroke onset to imaging. Results: Among the 88 patients, SIP was median 2.2 cc/h (interquartile range, 0–8.7), ranging most widely within the first 6 hours after onset. Faster SIP was positively independently associated with a low collateral score (odds ratio [OR], 3.30 [95% CI, 1.25–10.49]) and arrival by emergency medical services (OR, 3.34 [95% CI, 1.06–10.49]) and negatively associated with prior ischemic stroke (OR, 0.12 [95% CI, 0.03–0.50]) and coronary artery disease (OR, 0.32 [95% CI, 0.10–1.00]). Among the 67 patients who underwent endovascular thrombectomy, slower SIP was associated with a shift to reduced levels of disability at discharge (OR, 3.26 [95% CI, 1.02–10.45]), increased substantial reperfusion by thrombectomy (OR, 8.30 [95% CI, 0.97–70.87]), and reduced radiological hemorrhagic transformation (OR, 0.34 [95% CI, 0.12–0.94]). Conclusions: Slower SIP is associated with a high collateral score, prior ischemic stroke, and coronary artery disease, supporting roles for both collateral robustness and ischemic preconditioning in fostering tissue resilience to ischemia. Among patients undergoing endovascular thrombectomy, the speed of infarct progression is a major determinant of clinical outcome.

Background Mechanical thrombectomy (MT) is the standard of care for the treatment of acute ischemic stroke (AIS) caused by anterior circulation large-vessel occlusion. However, the true safety and efficacy of MT in medium-size vessel occlusions such as the M2 segment of the middle cerebral artery have yet to be completely defined. In this study, we analyze the safety and efficacy of MT in M2 occlusions compared with M1 occlusions. Methods A retrospective analysis was performed of patients with AIS secondary to M1 and M2 occlusions between 2011 and 2018. The inclusion criteria were 1) AIS secondary to M1 or M2 occlusion, 2) MT performed by stentrieval technique alone, aspiration technique, or combined stentrieval–aspiration techniques. Basic patient characteristics, number of passages, first passage recanalization success (≥TICI [Thrombolysis in Cerebral Ischemia] grade 2b), total recanalization success, hemorrhagic complications (including intracerebral hemorrhage [ICH] and subarachnoid hemorrhage), and clinical outcomes were compared between both groups. Results Two hundred and sixty patients met the inclusion criteria; 171 patients had M1 occlusion versus 89 with M2 occlusion. First passage recanalization success rate was significantly higher in the M2 group (55.1% vs. 39.2%; P = 0.015). Total recanalization success rate was higher in the M2 group but did not reach significance (83% vs. 75%; P = 0.128). Subarachnoid hemorrhage rate was significantly higher in the M2 group (25% vs. 12%; P = 0.010) but there was no difference for ICH complications (14.6% vs. 16.4%; P = 0.711). Conclusions MT for M2 occlusions has similar overall efficacy to that for M1 occlusions, but with higher first-pass successful recanalization rates. MT for M2 occlusions has a higher risk of associated subarachnoid hemorrhage.

BackgroundRouting patients directly to endovascular capable centers (ECCs) would decrease time to mechanical thrombectomy (MT), but may delay intravenous thrombolysis (IVT).ObjectiveTo study the clinical outcomes of patients with a stroke transferred directly to ECCs compared with those transferred to ECCs from non-endovascular capable centers (nECCs).MethodsData from the STRATIS registry were analyzed to evaluate process and clinical outcomes under five routing policies: (1) transport to nearest nECC; (2) transport to STRATIS ECC over any distance or (3) within 20 miles; (4) transport to ideal ECC (iECC), over any distance or (5) within 20 miles.ResultsAmong 236 patients, 117 (49.6%) were transferred by ground, of whom 62 (53%) were transferred within 20 miles. Median MT start time was accelerated in all direct transport models. IVT start was prolonged with direct transport across all distances, but accelerated with direct transport to iECC ≤20 miles. With bypass limited to ≤20 miles, the median modeled EMS arrival to IVT interval decreased for both iECCs and ECCs (by 12 min and 6 min, respectively), and median EMS arrival to puncture time decreased by up to 94 min. In this cohort, no patient would have become ineligible for IVT. Bypass to iECC modeling under 20 miles showed a significant reduction in the level of disability at 3 months, with freedom from disability (modified Rankin Scale score 0–1) at 3 months increased by 12%.ConclusionsDirect routing of patients with a large vessel occlusion to ECCs, especially when within 20 miles, may lead to better clinical outcomes by accelerating the start of MT without any delay of IVT.Clinical trial registration numberhttp://www.clinicaltrials.gov. Unique identifier: NCT02239640.

Introduction: Intracranial artery calcification (ICAC) is a common finding on CTA in patients presenting with LVO acute ischemic stroke and could potentially serve as a useful biomarker of intracranial atherosclerosis and altered intracranial vessel pliability in patients undergoing endovascular thrombectomy (EVT). However, ICAC frequency, determinants, and outcome associations have not been well delineated. Methods: In a prospectively maintained database, we analyzed consecutive patients undergoing CTA immediately prior to EVT from Mar 2016 - Aug 2020. Extent of ICAC in the intracranial ICA or VA proximal to the target vessel was scored using a validated grading scale (Babiarz et al, AJNR 2003: 5 levels for greatest calcific thickness and 5 levels for greatest circumferential extent). Example cases in Figure 1. Patients were stratified into low (0-2), medium (3-4), and high (5-6) ICAC groups. Results: Among 91 patients, mean age was 73, 54% female, and mean NIHSS 17. Median ICAC score was 3 [IQR 0-4]. Baseline characteristics associated with higher ICAC scores were: CAD (3.8 vs. 2.4, p = 0.02), HTN (3.1 vs. 2.1, p = 0.07), and age ( r = 0.50, p < 0.001). There was a U-shaped association between ICAC score and successful reperfusion (mTICI 2b-3): 90.9%, 65.7%, and 95.0% in low, medium, and high ICAC score groups, respectively ( p = 0.006). Need for rescue intervention (angioplasty/stenting, IA thrombolysis, or GpIIb/IIIa inhibitor) was higher in the high ICAC group: 5.9% vs. 5.6% vs. 28.6% ( p = 0.01). Functional independence (mRS 0-2) at discharge (29.4% vs. 22.2% vs. 19.0%, p = 0.64) or 90 days (40.0% vs. 30.0% vs. 21.4%, p = 0.22) did not differ, nor did symptomatic intracranial hemorrhage ( p = 0.96). Conclusions: Calcification of intracranial vessels is frequently seen on CTA in LVO patients and is associated with age and vascular risk factors. Degree of calcification has important associations with rates of successful reperfusion and need for rescue intervention during EVT.

Background Accurate estimation of ischemic core on baseline imaging has treatment implications in patients with acute ischemic stroke (AIS). Machine learning (ML) algorithms have shown promising results in estimating ischemic core using routine noncontrast computed tomography (NCCT). Objective We used an ML-trained algorithm to quantify ischemic core volume on NCCT in a comparative analysis to pretreatment magnetic resonance imaging (MRI) diffusion-weighted imaging (DWI) in patients with AIS. Methods Patients with AIS who had both pretreatment NCCT and MRI were enrolled. An automatic segmentation ML approach was applied using Brainomix software (Oxford, UK) to segment the ischemic voxels and calculate ischemic core volume on NCCT. Ischemic core volume was also calculated on baseline MRI DWI. Comparative analysis was performed using Bland–Altman plots and Pearson correlation. Results A total of 72 patients were included. The time-to-stroke onset time was 134.2/89.5 minutes (mean/median). The time difference between NCCT and MRI was 64.8/44.5 minutes (mean/median). In patients who presented within 1 hour from stroke onset, the ischemic core volumes were significantly (p = 0.005) underestimated by ML-NCCT. In patients presented beyond 1 hour, the ML-NCCT estimated ischemic core volumes approximated those obtained by MRI-DWI and with significant correlation ( r = 0.56, p Conclusion The ischemic core volumes calculated by the described ML approach on NCCT approximate those obtained by MRI in patients with AIS who present beyond 1 hour from stroke onset.

IntroductionSuccessful treatment of intracranial aneurysms after flow diversion (FD) is dependent on the flow modulating effect of the device. We aimed to investigate the intra-aneurysmal and parent vessel hemodynamic changes, as well as the incidence of silent emboli following treatment with various FD devices.MethodsWe evaluated the appearance of the eclipse sign in nine distinct phases of cerebral angiography before and immediately after FD placement in correlation with aneurysm occlusion. Angiographic and clinical data of consecutive procedures were analyzed retrospectively. Patients who had successful FD procedure without adjunctive coiling, visible eclipse sign on post embolization angiography, and reliable follow-up angiographic data were included in the analysis. Detailed analysis of hemodynamic data from transcranial doppler after FD was performed in selected patients, such as monitoring for silent emboli.ResultsAmong all patients (N = 65) who met inclusion criteria, complete aneurysm occlusion at 12 months was achieved in 89% (58/65). Eclipse sign prior to FD was observed in 42% (27/65) with unchanged appearance in 4.6% (3/65) of the treated patients. None of these three patients achieved complete aneurysm occlusion. Among all analyzed variables, such as aneurysm size, device type used, age, and appearance of the eclipse sign pre- and post-FD, the most reliable predictor of permanent aneurysm occlusion at 12 months was earlier, prolonged, and sustained eclipse sign visibility in more than three angiographic phases in comparison to the baseline (p < 0.001). Elevation in flow velocities within the ipsilateral vascular territory was noted in 70% (9/13), and bilaterally in 54% (7/13) of the treated patients. None of the patients had silent emboli.ConclusionsIntra-aneurysmal and parent vessel hemodynamic changes after FD can be reliably assessed by the cerebral angiography and transcranial doppler with important implications for the prediction of successful treatment.

This meeting abstract was removed due to the OA licensing requirements of this journal. The full abstract is listed here : https://www.svin.org/files/SVIN_2021_Abstracts_for_Web.pdf

Sodium MR imaging has the potential to complement routine proton MR imaging examinations with the goal of improving diagnosis, disease characterization, and clinical monitoring in neurologic diseases. In the past, the utility and exploration of sodium MR imaging as a valuable clinical tool have been limited due to the extremely low MR signal, but with recent improvements in imaging techniques and hardware, sodium MR imaging is on the verge of becoming clinically realistic for conditions that include brain tumors, ischemic stroke, and epilepsy. In this review, we briefly describe the fundamental physics of sodium MR imaging tailored to the neuroradiologist, focusing on the basics necessary to understand factors that play into making sodium MR imaging feasible for clinical settings and describing current controversies in the field. We will also discuss the current state of the field and the potential future clinical uses of sodium MR imaging in the diagnosis, phenotyping, and therapeutic monitoring in neurologic diseases.

Background and Purpose: The benefits of mechanical thrombectomy (MT) in vertebrobasilar artery occlusions have not been well-studied. We compared clinical, procedural, and safety outcomes of MT for posterior circulation (PC) vs. anterior circulation (AC) occlusions among patients in the STRATIS registry.Methods: Data from STRATIS including patient demographics, procedural characteristics, and outcomes including symptomatic intracranial hemorrhage (sICH) at 24 h, serious adverse events (SAE), substantial reperfusion [modified thrombolysis in cerebral infarction (mTICI) 2b/3], 90-day functional independence [modified Rankin Scale (mRS) 0–2], and 90-day mortality were analyzed. Univariate logistic regression was used to calculate predictors of good clinical outcome.Results: Of 984 STRATIS patients, 43 (4.4%) patients with PC occlusions [mean age 63.0 ± 13.6, 25.6% (11/43) female] and 932 (94.7%) with AC occlusions [mean age 68.5 ± 14.8, 46.9% (437/932) female] were included for analysis. Median National Institutes of Health Stroke Scale (NIHSS) scores at baseline were 17.0 (13.0, 12.0) for the AC group and 12.0 (11.0, 24.0) for the PC group. Time from onset to procedure end was longer for the PC group [median (IQR): 322.0 min (255.0–421.0) vs. 271.0 min (207.0–360.0); p = 0.007]. PC and AC groups had similar rates of substantial reperfusion [89.2% (33/37) vs. 87.7% (684/780)], procedure-related SAE [0.0% (0/43) vs. 1.7% (16/932)], sICH [0.0% (0/38) vs. 1.5% (12/795)], 90-day functional independence [66.7% (26/39) vs. 55.9% (480/858)] and mortality [12.8% (5/39) vs. 15.8% (136/861)]. National Institutes of Health Stroke Scale score and patient sex were significant univariate predictors of good clinical outcome (p < 0.05).Conclusions: Despite longer reperfusion times, MT in PC stroke has similar rates of 90-day functional independence with no significant difference in procedure-related SAE, sICH, or mortality, supporting the use of MT in PC acute ischemic stroke (AIS).Clinical Trial Registration:https://www.clinicaltrials.gov, Identifier: NCT02239640.

Introduction/Purpose Catheterization of brain arteriovenous malformations (AVMs) can be challenging when small arterial feeders arise with sharp angles. We report the use of the Comaneci device to catheterize a small feeder with hyperacute angle, along with 3-D in-vitro model reconstruction and experimentation of balloon vs Comaneci stent micro-catheterization. We also developed a 3-D model of the arterial anatomy to compare Comaneci vs balloon assisted catheterization of small feeders. Methods and Methods Patient is a 37-year-old man who presented with sudden onset of severe headache and left sided weakness. Initial CT head and MRA showed left basal ganglia hemorrhage associated with left thalamic AVM. Using a 3D model of the AVM, 30 iterations of micro-catheterization was performed with balloon (Hyperform 4x7mm), Comaneci Petit (24mm length) stent, and without any device assistance (10 each). Results During the embolization procedure, Comaneci stent provided adequate support distal to the origin of the arterial feeder to the AVM, and the microcatheter was successfully navigated into the small sharply angled feeder (figure 1A). Experimental model showed similar effectiveness of balloon and Comaneci stent with 3/10 first-attempt success rate for micro-catheterization, and 0/10 without any device (figure 1B). Patient tolerated the procedure well with no ischemic or hemorrhagic complications. Conclusion Comaneci stent showed similar efficacy compared to a balloon for distal micro catherization without distal flow-arrest. Our technical report along with the 3-D model experiments provide insights into the utility of Comaneci vs balloon assisted micro-catherization of the small sharply angled feeders in AVM embolization. Disclosures H. Saber: None. N. Kaneko: None. S. Tateshima: 2; C; Medtronic, Stryker, Cerenovus. G. Colby: 2; C; Stryker, MicroVention, Medtronic. V. Szeder: None. M. Nour: None. G. Duckwiler: 2; C; Medtronic. R. Jahan: 2; C; Medtronic, Balt.

Introduction/Background Advancements in endovascular therapies have significantly impacted cerebral aneurysm management in recent years. Recent release of the National Inpatient Sample (NIS) data for 2017 provides the opportunity to explore novel population-based insights into outcomes following surgical clipping vs endovascular embolization of ruptured and unruptured cerebral aneurysms. Materials and Methods This is an analysis of US National Inpatient Sample of hospitalizations with non-traumatic subarachnoid hemorrhage (SAH) or unruptured cerebral aneurysms from January 1, 2017 to December 31, 2017. Baseline patient demographics, open vs endovascular treatment modalities and the associated hospitalization outcomes were analyzed. Primary outcomes included in-hospital mortality and favorable discharge disposition defined as discharge to home. Results Among 56,165 hospitalizations with unruptured aneurysms, 13,090 (23.3%) underwent endovascular embolization (median age 59, IQR 51-68; Female 74.9% ) and 4105 (7.3%) had surgical clipping (median age 58, IQR 51-65; Female 74.1%). In-hospital mortality occurred in 1.45% in endovascular vs 1.83% in clipping group (p=0.17), whereas favorable discharge outcome was achieved in 87.5% in endovascular vs 74.8% in clipping group (p Conclusion In 2017 in US, about 75% of patients were discharged home after clipping and 90% were discharged home after endovascular treatment of an unruptured cerebral aneurysm. About 1 in 7 patients died following clipping and 1 in 8 following endovascular treatment for aneurysmal SAH. Endovascular therapy remains associated with better in-hospital outcomes, including the younger age population with ruptured or unruptured aneurysms. Disclosures H. Saber: None. M. Jafari: None. A. Desai: None. N. Kaneko: None. G. Colby: 2; C; Medtronic, Stryker, MicroVention. V. Szeder: None. R. Jahan: 2; C; Medtronic. G. Duckwiler: 2; C; Medtronic. S. Tateshima: 2; C; Medtronic, Stryker, Cerenovus.

There are currently no imaging criteria to identify patients who would benefit from endovascular recanalization of posterior circulation strokes. Applying the Posterior Circulation Alberta Stroke Program Early Computed Tomography Score (pc-ASPECTS) to magnetic resonance imaging (MRI) has been demonstrated to be an accurate predictor of functional outcome. Here, we aimed to evaluate the accuracy of the pc-ASPECTS with preintervention MRI as a predictor of functional outcome in a cohort undergoing endovascular recanalization.This is a 15-year retrospective study of patients undergoing endovascular recanalization of posterior circulation with baseline MRI or computed tomography. We analyzed baseline imaging, clinical data, and type and timing of intervention to the functional outcome at 90 days. Using MRI pc-ASPECTS, we evaluated interrater reliability and accuracy in predicting functional outcome and compared them to the use of single-anatomic location for this function.Door-to-recanalization time in the MRI cohort was significantly longer (median: 8.7 vs. 2.7 hours, P = 0.03); however, functional outcome was not different. Within the MRI cohort, pc-ASPECTS and National Institutes of Health Stroke Scale were the only factors that were significantly different between the groups with good and bad functional outcome (P0.001). The area under the receiver operating characteristic curve for the pc-ASPECTS and good functional outcome was 0.96, with the optimal threshold of ≥8 resulting in positive predictive value of 90% and negative predictive value of 100%.Despite longer time to intervention with MRI as the initial imaging modality in posterior circulation strokes, it does not negatively affect the functional outcome. Pc-ASPECTS is an easy to use and accurate prognostic tool for the real-time evaluation of preintervention MRI in this population.

BackgroundThe time–benefit relationship of endovascular thrombectomy (EVT) according to the size of the core infarct has been incompletely explored in prior studies. We investigated whether established infarct core size on baseline imaging modifies the relationship between onset-to-reperfusion time (OTR) and functional outcomes in patients with acute ischemic stroke treated with EVT.MethodsWe analyzed a database containing individual patient data pooled from three prospective Solitaire stent retriever studies. The inclusion criteria were treatment with a Solitaire device and achievement of substantial reperfusion (modified Thrombolysis in Cerebral Infarction 2b–3). Main analyses were performed in patients with baseline Alberta Stroke Program Early CT Scores (ASPECTSs) of 7–10.ResultsAmong the 305 patients (mean age 67±13 years, 58% women), the proportions of patients in different categories of pretreatment infarct extent were: small (ASPECTS 9–10) 52.0%, moderate (ASPECTS 7–8) 37.1%, and large (ASPECTS 0–6) 7.6%. The mean OTR was 297±95 min. At 3 months, 60.1% of the patients achieved a good outcome. For OTRs of 2–8 hours, the rates of good outcomes at all time points were higher with higher baseline ASPECTS but declined with similar steepness. Both baseline ASPECTS (OR 1.23 (95% CI 1.04 to 1.45)) and OTR (every 30 min delay, OR 0.80 (95% CI 0.73 to 0.88)) were independently associated with a good 3-month outcome. No interaction between OTR and baseline ASPECTS was observed.ConclusionsAlthough patients with higher baseline ASPECTS are more likely to have good clinical outcomes at all OTR intervals after 2 hours, this benefit consistently declines with time, even in patients with a small infarct core, reinforcing the need to treat all patients as quickly as possible.

OBJECTIVEMeningiomas that appear hypervascular on neuroimaging could be amenable to preoperative embolization. However, methods for measuring hypervascularity have not been described, nor has the benefit of preoperative embolization been adjudicated. The objective of this study was to show a relationship between flow void volume (measured on MRI) and intraoperative estimated blood loss (EBL) in nonembolized meningiomas.METHODSThe authors performed volumetric analyses of 51 intracranial meningiomas (21 preoperatively embolized) resected at their institution. Through the use of image segmentation software and a voxel-based segmentation method, flow void volumes were measured on T2-weighted MR images. This metric was named the Meningioma Vascularity Index (MVI). The primary outcomes were intraoperative EBL and perioperative blood transfusion.RESULTSIn the nonembolized group, the MVI correlated with intraoperative EBL when controlling for tumor volume (r = 0.55, p = 0.002). The MVI also correlated with perioperative blood transfusion (point-biserial correlation [rpb] = 0.57, p = 0.001). A greater MVI was associated with an increased risk of blood transfusion (odds ratio [OR] 5.79, 95% confidence interval [CI] 1.15–29.15) and subtotal resection (OR 7.64, 95% CI 1.74–33.58). In the embolized group, those relationships were not found. There were no significant differences in MVI, intraoperative EBL, or blood transfusion across groups.CONCLUSIONSThis study clearly shows a relationship between MVI and intraoperative EBL in nonembolized meningiomas when controlling for tumor volume. The MVI is a potential biomarker for tumors that would benefit from embolization.

BackgroundProcedural time in patients with acute ischemic stroke (AIS) undergoing mechanical thrombectomy may affect clinical outcomes. We performed a pooled analysis of the effect of procedural time on clinical outcomes using data from three prospective endovascular treatment trials.ObjectiveTo examine the relationship between endovascular procedural time and clinical outcomes of patients with AIS following endovascular treatment.MethodsWe analyzed data from SWIFT, STAR, and SWIFT PRIME studies, including baseline characteristics: National Institutes of Health Stroke Scale (NIHSS) score on admission, intracranial hemorrhage rates, and modified Rankin Scale score at 3 months. The Thrombolysis in Cerebral Infarction (TICI) scale was used to grade postprocedure recanalization. We recorded two procedural time intervals: (1) symptom onset to groin puncture and (2) groin puncture to angiographic recanalization. A multivariate analysis was performed using a logistic regression model to analyze predictors of unfavorable outcome.ResultsWe analyzed 301 patients who had undergone endovascular treatment and had near-complete or complete recanalization (TICI 2b or 3). At 3 months, 122 patients (40.5%) had unfavorable outcomes. The rate of favorable outcomes was significantly higher when the procedural time was ConclusionProcedural time in patients with stroke undergoing mechanical thrombectomy may be an important determinant of favorable outcomes in those with recanalization.

Background and Purpose— Mechanical thrombectomy has been shown to improve clinical outcomes in patients with acute ischemic stroke. However, the impact of balloon guide catheter (BGC) use is not well established. Methods— STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) was a prospective, multicenter study of patients with large vessel occlusion treated with the Solitaire stent retriever as first-line therapy. In this study, an independent core laboratory, blinded to the clinical outcomes, reviewed all procedures and angiographic data to classify procedural technique, target clot location, recanalization after each pass, and determine the number of stent retriever passes. The primary clinical end point was functional independence (modified Rankin Scale, 0–2) at 3 months as determined on-site, and the angiographic end point was first-pass effect (FPE) success rate from a single device attempt (modified Thrombolysis in Cerebral Infarction, ≥2c) as determined by a core laboratory. Achieving modified FPE (modified Thrombolysis in Cerebral Infarction, ≥2b) was also assessed. Comparisons of clinical outcomes were made between groups and adjusted for baseline and procedural characteristics. All participating centers received institutional review board approval from their respective institutions. Results— Adjunctive technique groups included BGC (n=445), distal access catheter (n=238), and conventional guide catheter (n=62). The BGC group had a higher rate of FPE following first pass (212/443 [48%]) versus conventional guide catheter (16/62 [26%]; P =0.001) and distal access catheter (83/235 [35%]; P =0.002). Similarly, the BGC group had a higher rate of modified FPE (294/443 [66%]) versus conventional guide catheter (26/62 [42%]; P P =0.003). The BGC group achieved the highest rate of functional independence (253/415 [61%]) versus conventional guide catheter (23/55 [42%]; P =0.007) and distal access catheter (113/218 [52%]; P =0.027). Final revascularization and mortality rates did not differ across the groups. Conclusions— BGC use was an independent predictor of FPE, modified FPE, and functional independence, suggesting that its routine use may improve the rates of early revascularization success and good clinical outcomes. Clinical Trial Registration— URL: https://www.clinicaltrials.gov . Unique identifier: NCT02239640.

Background Extensive evidence supports mechanical thrombectomy using stentrievers (SR) for acute large vessel occlusion (aLVO). Aspiration is also used as a first pass or adjunct technique during clot removal. Here we report technical results from mechanical thrombectomy cases using SR alone, aspiration alone (AD), or a combination of SR and aspiration (SA) as a first pass for aLVO. Methods An institutional stroke database was reviewed for patients presenting to a single academic institution with anterior circulation aLVO and who were treated with mechanical thrombectomy from 2011 to 2017. Patients managed with SR alone, AD, or a combination of these 2 techniques (SA) were identified. The rate of successful recanalization after the first thrombectomy attempt was compared between the 3 groups. Results A total of 353 patients were analyzed, including 215 in SR, 32 in AD, and 106 in SA groups. There was no significant difference for age and admission National Institutes of Health Stroke Scale between the groups. Successful recanalization rates after the first pass were 35.8% in the SR group, 34.4% in aspiration as a first pass technique, and 55.7% in SA, with a statistically significant higher rate of first pass success in the SA group (P = 0.002). Using balloon-guide catheter doubled the rate of successful first pass recanalization from 21.3% to 41.6% in the SR group (P = 0.005); however, the SA technique was more effective for first pass recanalization when compared with an SR and balloon-guide catheter combination (55.7% vs. 41.6%, P = 0.025). Conclusions The combination of SR and catheter aspiration can increase the rate of single pass successful recanalization compared with these techniques individually.

Background and Purpose— Although intracranial thrombectomy represents the standard treatment approach for anterior circulation tandem occlusions, whether the extracranial lesion requires acute stenting remains unclear. Our aim was to investigate differences in clinical and procedural outcomes related to stenting extracranial lesions in a registry of patients undergoing thrombectomy for acute stroke. Methods— Data were analyzed from the STRATIS registry (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke)—a prospective, nonrandomized study of patients undergoing neurothrombectomy with the Solitaire device. A total of 984 patients treated at 55 sites were analyzed. Univariate and multivariable logistic regression was used to assess relationship between outcome and procedural technique. Results— Of 147 (14.9%) patients with tandem lesions treated, stenting of the extracranial lesion during thrombectomy was performed in 80 patients and withheld in 67 patients. There were no differences between groups with respect to age, ASPECTS (Alberta Stroke Program Early CT Score), or intravenous-tPA (tissue-type plasminogen activator) use. However, the patients in the stenting group had lower baseline National Institutes of Health Stroke Scale (16 versus 17.9; P =0.07), shorter onset to arterial puncture time (133.6 versus 163.4 minutes; P =0.04), and lower rates of atrial fibrillation (6.3% versus 25.4%) as compared to the nonstenting group. Good outcomes (modified Rankin Scale, 0–2 at 90 days) were higher in the stenting group (68.5% versus 42.2%; P =0.003) with no difference in mortality or symptomatic hemorrhage. After adjustment for covariates, stenting continued to be associated with superior outcomes. Conclusions— Acute stenting of an extracranial carotid stenosis during neurothrombectomy can be achieved with equal safety compared with no stenting. Carotid stenting in the acute phase may lead to better outcomes; this should ideally be confirmed by randomized trials.

Background and Purpose: Clot fragmentation and distal embolization during endovascular thrombectomy for acute ischemic stroke may produce emboli downstream of the target occlusion or in previously uninvolved territories. Susceptibility-weighted magnetic resonance imaging can identify both emboli to distal territories (EDT) and new territories (ENT) as new susceptibility vessel signs (SVS). Diffusion-weighted imaging (DWI) can identify infarcts in new territories (INT). Methods: We studied consecutive acute ischemic stroke patients undergoing magnetic resonance imaging before and after thrombectomy. Frequency, predictors, and outcomes of EDT and ENT detected on gradient-recalled echo imaging (EDT-SVS and ENT-SVS) and INT detected on DWI (INT-DWI) were analyzed. Results: Among 50 thrombectomy-treated acute ischemic stroke patients meeting study criteria, mean age was 70 (±16) years, 44% were women, and presenting National Institutes of Health Stroke Scale score 15 (interquartile range, 8–19). Overall, 21 of 50 (42%) patients showed periprocedural embolic events, including 10 of 50 (20%) with new EDT-SVS, 10 of 50 (20%) with INT-DWI, and 1 of 50 (2%) with both. No patient showed ENT-SVS. On multivariate analysis, model-selected predictors of EDT-SVS were lower initial diastolic blood pressure (odds ratio, 1.09 [95% CI, 1.02–1.16]), alteplase pretreatment (odds ratio, 5.54 [95% CI, 0.94–32.49]), and atrial fibrillation (odds ratio, 7.38 [95% CI, 1.02–53.32]). Classification tree analysis identified pretreatment target occlusion SVS as an additional predictor. On univariate analysis, INT-DWI was less common with internal carotid artery (5%), intermediate with middle cerebral artery (25%), and highest with vertebrobasilar (57%) target occlusions ( P =0.02). EDT-SVS was not associated with imaging/functional outcomes, but INT-DWI was associated with reduced radiological hemorrhagic transformation (0% versus 54%; P Conclusions: Among acute ischemic stroke patients treated with thrombectomy, imaging evidence of distal emboli, including EDT-SVS beyond the target occlusion and INT-DWI in novel territories, occur in about 2 in every 5 cases. Predictors of EDT-SVS are pretreatment intravenous fibrinolysis, potentially disrupting thrombus structural integrity; atrial fibrillation, possibly reflecting larger target thrombus burden; lower diastolic blood pressure, suggestive of impaired embolic washout; and pretreatment target occlusion SVS sign, indicating erythrocyte-rich, friable target thrombus.