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Background: Despite the well-established potent benefit of mechanical thrombectomy (MT) for large vessel occlusion (LVO) stroke, access to MT has not been studied globally. We conducted a worldwide survey of countries on 6 continents to define MT access (MTA), the disparities in MTA, and its determinants on a global scale. Methods: Our survey was conducted in 75 countries through the Mission Thrombectomy 2020+ global network between November 22, 2020, and February 28, 2021. The primary end points were the current annual MTA, MT operator availability, and MT center availability. MTA was defined as the estimated proportion of patients with LVO receiving MT in a given region annually. The availability metrics were defined as ([current MT operators×50/current annual number of estimated thrombectomy-eligible LVOs]×100 = MT operator availability) and ([current MT centers×150/current annual number of estimated thrombectomy-eligible LVOs]×100= MT center availability). The metrics used optimal MT volume per operator as 50 and an optimal MT volume per center as 150. Multivariable-adjusted generalized linear models were used to evaluate factors associated with MTA. Results: We received 887 responses from 67 countries. The median global MTA was 2.79% (interquartile range, 0.70–11.74). MTA was Conclusions: Access to MT on a global level is extremely low, with enormous disparities between countries by income level. The significant determinants of MT access are the country’s per capita gross national income, prehospital LVO triage policy, and MT operator and center availability.

Introduction: Mechanical thrombectomy (MT) is a highly safe and effective standard of care for acute ischemic strokes with large vessel occlusion. However, timely access to MT is extremely limited on a global scale, with vast disparities in access between countries. MT2020+, a global non-profit initiative of SVIN, aimed to create a semi-quantitative global MT access barrier score (MTABS) to objectively measure the barriers impeding the implementation of treatment worldwide. Methods: Four independent investigators performed an in-depth systematic literature review using the peer review of electronic search strategies. Barriers to access were identified and categorized into 3 groups: information and diagnostic, physical, and financial. An international expert panel was created and scored each attribute using a modified Delphi process with the assistance of consultants from the University of Calgary W21C. A 1-9-point scale was used, with 1 being not at all important and 9 being extremely important. A meeting was held for the attributes that require deliberation. After an agreement, a list of attributes for access was elaborated. Next, a ranking of importance and individual weighting was done. We assigned a presence of or lack of an attribute a numerical value (1 for yes, 0 for no) and multiply by its weight to determine a final score. Results: After an initial screening of 2864 abstracts, 121 studies were included in the final systematic review. A total of 34 possible attributes that are barriers to access were identified. After the modified Delphi process, 26 individual attributes were selected. The MTABS was made with possible results from 0-62 points, with higher scores meaning higher barriers to access to MT. Conclusions: The global MTABS represents the first tool to quantify barriers to MT access worldwide. Its implementation will objectively measure the magnitude and identify key barriers to guide regional public health interventions to improve MT workflow and access.

Introduction: Alteplase is the only FDA approved thrombolytic agent for acute ischemic stroke, tenecteplase is rapidly emerging as an alternative. While both agents are readily available worldwide, low to middle income countries have limited access to acute treatment. To our knowledge, there is no validated tool available to objectively measure access to thrombolytic agents or barriers to routine clinical use. Methods: We develop the 17-item tPA Spot Check tool to assess utilization of acute stroke thrombolysis in multiple languages. This tool was used to evaluate the current state of clinical practices in the MT2020+ Caribbean Region. Data was analyzed via SPSS. Results: The survey was validated by three international experts with an Average Content Validity Index of 1 and a Universal Agreement index of 1 across three domains: local experience, financial constraints, and barriers to utilization.Survey response rate was 64% (73/114 responses) 46 in English, 14 in Spanish and 13 in French. Fifteen out of 44 MT2020+ Caribbean countries (34%) participated: Haiti, Dominican Republic, Jamaica, Puerto Rico, St. Lucia, Bermuda, Bahamas, Cayman Islands, Trinidad and Tobago, Barbados, Dominica, Venezuela, Nicaragua, Honduras, and Guadalupe. There was limited or no access to thrombolytic agents in 40% of countries surveyed, with 13% resorting to the use of streptokinase. Among cases treated with thrombolytics, 43% of patients had to pay out of pocket before treatment provided, 36% of treatment was paid by insurance plus patients and less than 10% were covered by insurance or governmental support respectively. Among 51% of countries survey, no acute thrombolytic treatment was provided for acute stroke in 2021 calendar year. Only 1 center treated more than 100 cases per year. Majority of respondents (88%) agreed there were barriers to acute stroke thrombolysis in the region. Absence of Stroke protocol (p Conclusion: This this survey brings light to an enormous disparity in care of stroke patients around the world, specifically in the MT2020+ Caribbean region. We create a valid tool can be used to assess local access to thrombolytic.

Introduction: Mechanical thrombectomy (MT) is a highly safe and effective standard of care for acute ischemic strokes with large vessel occlusion. However, timely access to MT is extremely limited on a global scale, with vast disparities in access between countries. MT2020+, a global non-profit initiative of SVIN, aimed to create a semi-quantitative global MT access barrier score (MTABS) to objectively measure the barriers impeding the implementation of treatment worldwide. Methods: Four independent investigators performed an in-depth systematic literature review using the peer review of electronic search strategies. Barriers to access were identified and categorized into 3 groups: information and diagnostic, physical, and financial. An international expert panel was created and scored each attribute using a modified Delphi process with the assistance of consultants from the University of Calgary W21C. A 1-9-point scale was used, with 1 being not at all important and 9 being extremely important. A meeting was held for the attributes that require deliberation. After an agreement, a list of attributes for access was elaborated. Next, a ranking of importance and individual weighting was done. We assigned a presence of or lack of an attribute a numerical value (1 for yes, 0 for no) and multiply by its weight to determine a final score. Results: After an initial screening of 2864 abstracts, 121 studies were included in the final systematic review. A total of 34 possible attributes that are barriers to access were identified. After the modified Delphi process, 26 individual attributes were selected. The MTABS was made with possible results from 0-62 points, with higher scores meaning higher barriers to access to MT. Conclusions: The global MTABS represents the first tool to quantify barriers to MT access worldwide. Its implementation will objectively measure the magnitude and identify key barriers to guide regional public health interventions to improve MT workflow and access.

Introduction: EXCELLENT (NCT03685578) is a global prospective, multicenter, real-world registry of mechanical thrombectomy for stroke with the EmboTrap device as first line treatment which includes clot collection and analysis. Aim of the study: To report the rates of clinical outcomes and clot characteristics associated with first pass reperfusion in EXCELLENT. Methods: Per pass angiographic outcomes assessed by an independent core lab were available in 984 subjects Analysis of clot from 538 cases was performed by independent central labs blinded to clinical data. 90-day mRS assessment was blinded to subject data. Results: First pass reperfusion of mTICI 2b-3 (63.2%) and 2c-3 (38.3%) was significantly predictive of mRS 0-2 or ≤pre-stroke (p=0.011 and p=0.016) but not all-cause mortality at 90 days (p=0.080 and p=0.123, respectively). Further, mTICI 2c-3 in one pass was associated with a higher rate of mRS 0-2 or ≤pre-stroke vs. mTICI 2c-3 reperfusion in >1 pass, (55.5% and 45.1%, respectively, p=0.013) and a rate of all-cause mortality at 90 days of 14.6% vs. 19.8% (p=0.097). Full patient characteristics and clinical outcomes are shown in Table 1. Notable clot composition findings included: RBC (%, mean±SD): mTICI 2c-3, 1 pass 47.69±22.25, mTICI 2c-3, >1 pass 43.86±19.05, (p=0.088); fibrin: mTICI 2c-3, 1 pass 23.20±13.80, mTICI 2c-3 >1 pass 25.40 ± 13.52 (p=0.131); von Willebrand factor (VWF): mTICI2c-3, 1 pass 16.09±14.62, mTICI 2c-3, >1 pass 19.42±17.15 (p=0.038). Conclusions: First pass reperfusion in the EXCELLENT registry was associated with better clinical outcomes at 90 days. Clots retrieved with first pass reperfusion had higher RBC and lower fibrin and VWF content compared to those who achieved reperfusion at greater than one pass.

BackgroundEmergent large vessel occlusion (ELVO) acute ischemic stroke is a time-sensitive disease.ObjectiveTo describe our experience with artificial intelligence (AI) for automated ELVO detection and its impact on stroke workflow.MethodsWe conducted a retrospective chart review of code stroke cases in which VizAI was used for automated ELVO detection. Patients with ELVO identified by VizAI were compared with patients with ELVO identified by usual care. Details of treatment, CT angiography (CTA) interpretation by blinded neuroradiologists, and stroke workflow metrics were collected. Univariate statistical comparisons and linear regression analysis were performed to quantify time savings for stroke metrics.ResultsSix hundred and eighty consecutive code strokes were evaluated by AI; 104 patients were diagnosed with ELVO during the study period. Forty-five patients with ELVO were identified by AI and 59 by usual care. Sixty-nine mechanical thrombectomies were performed.Median time from CTA to team notification was shorter for AI ELVOs (7 vs 26 min; pConclusionsAI automated alerts can be incorporated into a comprehensive stroke center hub and spoke system of care. The use of AI to detect ELVO improves clinically meaningful stroke workflow metrics, resulting in faster treatment times for mechanical thrombectomy.

Wide-necked bifurcation aneurysms (WNBAs) are challenging lesions to treat via both open surgical and endovascular techniques. Presently, there are 3 intrasaccular devices available to address many of the limitations of prior techniques, all of which are at different phases of approval for human use around the world. These devices include the Woven EndoBridge (WEB®) made by MicroVention, the Artisse™ Embolization Device made by Medtronic, and the Contour Neurovascular System™ made by Cerus Endovascular. Although heterogenous in design, these devices rely on the principle of using fine mesh overlying the aneurysm neck to slow blood inflow, promoting stagnation and thrombosis that ultimately leads to healing across the neck and exclusion from the circulation. While our understanding improves as long-term occlusion rates from these devices continue to be studied, the safety profiles and short-term success rates demonstrated in recent studies provide optimism for these innovative intrasaccular devices for the treatment of WNBAs. In this paper, we review these 3 intra-saccular flow disruption devices for use in WNBAs and summarize recent literature and studies of their effectiveness and safety.

BackgroundTo evaluate anatomical and clinical factors that make trans-radial cerebral angiography more difficult.MethodsA total of 52 trans-radial diagnostic angiograms were evaluated in a tertiary care stroke center from December 2019 until March 2020. We analyzed a number of anatomical variables to evaluate for correlation to outcome measures of angiography difficulty.ResultsThe presence of a proximal radial loop had a higher conversion to femoral access (pConclusionThe presence of a proximal radial loop, large diameter aortic arch, double subclavian innominate curve, proximal left CCA loop, acute subclavian vertebral angle, and absence of bovine aortic arch anatomy were associated with more difficult trans-radial cerebral angiography. We also introduce a novel grading scale for diagnostic trans-radial angiography.

BACKGROUND AND PURPOSE We investigated the effectiveness of intravenous thrombolysis (IVT) in acute ischaemic stroke (AIS) patients with large vessel or distal occlusions and mild neurological deficits, defined as National Institutes of Health Stroke Scale scores

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Mechanical thrombectomy (MT) is the most effective treatment for selected patients with an acute ischemic stroke due to emergent large vessel occlusions (LVOs). There is an urgent need to identify and address challenges in access to MT to maximize the numbers of patients who can benefit from this treatment. Barriers in access to MT include delays in evaluation and accurate diagnosis of LVO leading to inappropriate triage, logistical delays related to availability of facilities and trained interventionalists, and financial hurdles that affect treatment reimbursement. Collection of regional data related to these barriers is critical to better understand current access gaps and a measurable access score to thrombectomy could be useful to plan local public health intervention.

Background and Purpose: Epidemiological studies have shown racial and ethnic minorities to have higher stroke risk and worse outcomes than non-Hispanic Whites. In this cohort study, we analyzed the STAR (Stroke Thrombectomy and Aneurysm Registry) database, a multi-institutional database of patients who underwent mechanical thrombectomy for acute large vessel occlusion stroke to determine the relationship between mechanical thrombectomy outcomes and race. Methods: Patients who underwent mechanical thrombectomy between January 2017 and May 2020 were analyzed. Data included baseline characteristics, vascular risk factors, complications, and long-term outcomes. Functional outcomes were assessed with respect to Hispanic status delineated as non-Hispanic White (NHW), non-Hispanic Black (NHB), or Hispanic patients. Multivariate analysis was performed to identify variables associated with unfavorable outcome or modified Rankin Scale ≥3 at 90 days. Results: Records of 2115 patients from the registry were analyzed. Median age of Hispanic patients undergoing mechanical thrombectomy was 60 years (72–84), compared with 63 years (54–74) for NHB, and 71 years (60–80) for NHW patients ( P P P P Conclusions: Hispanic patients are less likely to have favorable outcome at 90 days following mechanical thrombectomy compared to NHW or NHB patients. Further prospective studies are required to validate our findings.

The indication for mechanical thrombectomy for acute ischemic stroke (AIS) secondary to large vessel occlusion has substantially increased in the past few years, but predictors of symptomatic intracranial hemorrhage (sICH) remain largely unstudied. A recent study assessing these predictors, led to the development of the TICI-ASPECTS-glucose (TAG) score, an internally validated model to predict sICH following thrombectomy.To externally validate this scoring system and identify other potential risk factors for hemorrhagic conversion following endovascular therapy for AIS, 420 consecutive patients treated with mechanical thrombectomy from 2014-2017 were retrospectively reviewed. Data were collected pertaining to admission factors, procedural metrics, and functional outcomes. The components comprising the TAG score consist of modified thrombolysis in cerebral infarction (mTICI) score (mTICI 0-2a=2 points; 2b-3=0 points), Alberta stroke program early CT (ASPECTS) score (6=4 points, 6-7=2 points, ≥8=0 points), and glucose (≥150 mg/dL=1 point,150 mg/dL=0 points). Statistical analyses including univariate analysis, logistic regression analysis, and area under the receiver-operating curve (AUROC) were performed to validate the predictive capability of the model.The patients with sICH presented with lower ASPECTS (8.13±1.55 v 9.16±1.24, p 0.001), but no significant correlation with mTICI scores and admission glucose was observed. Decreasing ASPECTS correlated with increased risk of sICH (OR 1.57, 95% CI 1.25-1.96, p 0.001), and increasing TAG score was associated with increased sICH (OR 1.46, 95% CI 1.11-1.94, p 0.01). AUROC of the model was 0.633. Stratifying patients into low (TAG 0-2), intermediate,The TICI-ASPECTS-glucose (TAG) score adequately predicts sICH following mechanical thrombectomy, and appropriately stratifies individual patient risk. Further inclusion of additional predictors of sICH would likely yield a more robust model.

Introduction EXCELLENT (NCT03685578) is a prospective, single-arm, multicenter, real-world international registry of mechanical thrombectomy (MT) for stroke with the EmboTrap device as first line treatment. The study entails thrombus analysis of specimens collected with each MT pass. Aim of the Study To compare rates of mRS 0–2 at 90 days and clot characteristics in subjects with and without first pass effect (FPE). Methods FPE was defined as mTICI 2c/3 after one pass and non-FPE as mTICI 2c/3 after >1 pass as adjudicated by an independent core lab. Clot analysis was performed by independent central labs blinded to clinical data. mRS at 90 days was scored by investigators blinded to procedural data. Results Overall mTICI2c/3 rates were 63.7% (326/512). FPE was achieved in 37.1% (190/512) and non-FPE in 26.6% (136/512) subjects. 90 day mRS 0–2 or equal to pre-stroke was achieved in 47.2% (75/159) with FPE and in 42.1% (51/121) non-FPE patients. All-cause 90-day mortality was 19.1% (34/178) in subjects with FPE and 26.4% (34/129) in subjects with non-FPE. Major thrombus components (mean% ±SD) were as follows: RBC: FPE 45.88±20.54, non-FPE 39.08±18.23, and first pass mTICI Conclusions The high rate of ‘real-world’ FPE observed in EXCELLENT was associated with improved clinical outcomes. Clots retrieved with FPE had higher RBC and lower fibrin content compared to non FPE and to first pass mTICI Disclosure EXCELLENT is sponsored by Cerenovus. Dr. Jovin is a consultant for Neuravi, Codman Neurovascular, Stryker (PI DAWN; unpaid), Fundacio Ictus (PI REVASCAT; unpaid), and holds stock in Anaconda, Silk Road, and Blockade Medical.

Background Some emergent large vessel occlusions (ELVOs) are refractory to reperfusion because of underlying intracranial atherosclerosis (ICAS), often requiring rescue therapy (RT) with balloon angioplasty, stenting, or both. In this study, we investigate the safety, efficacy, and long‐term outcomes of RT in the setting of mechanical thrombectomy for ICAS‐related ELVO. Methods and Results We queried the databases of 10 thrombectomy‐capable centers in North America and Europe included in STAR (Stroke Thrombectomy and Aneurysm Registry). Patients with ELVO who underwent ICAS‐related RT were included. A matched sample was produced for variables of age, admission National Institute of Health Stroke Scale, Alberta Stroke Program Early CT Score, onset to groin puncture time, occlusion site, and final recanalization. Out of 3025 patients with MT, 182 (6%) patients required RT because of underlying ICAS. Balloon angioplasty was performed on 122 patients, and 117 patients had intracranial stenting. In the matched analysis, 141 patients who received RT matched to a similar number of controls. The number of thrombectomy passes was higher (3 versus 1, P P =0.004). There was a higher rate of symptomatic hemorrhagic transformation in the RT group (7.8% versus 4.3%, P =0.211), however, the difference was not significant. There was no difference in 90‐day modified Rankin scale of 0 to 2 (44% versus 47.5%, P =0.543) between patients in the RT and control groups. Conclusions In patients with ELVO with underlying ICAS requiring RT, despite longer procedure time and a more thrombectomy passes, the 90 days favorable outcomes were comparable with patients with embolic ELVO.

Introduction Flat panel imaging for emergent large vessel occlusion can be acquired prior to mechanical thrombectomy (MT). In this study, we examined patients undergoing MT with computed tomography angiography (CTA) to determine agreement on the site of occlusion and CTA collateral score (CS). Methods Flat Panel CTA (FP-CTA) was acquired before MT. Time between CTA and FP-CTA acquisition, site of occlusion, and CS were reported. Significant CS change was defined as >2-point change, or any change to/from a malignant profile (CS = 0 to CS > 0, or vice versa). Results Eleven patients (mean age, 60.8 years; NIHSS, 17; 55.0% female) were included; IV tPA was administered to 7. Intra-reader occlusion site, dichotomous CS, and continuous CS correlation between CTA and FP-CTA were 96.6%, 90.0%, and 86.6%, respectively. Inter-reader correlation for occlusion site was 93% for CTA and 100% for FP-CTA; dichotomous CS correlation was 87% for both CTA and FP-CTA; correlation of continuous CS was 77% for CTA and 87% for FP-CTA. Conclusion Standard CTA and FP-CTA have high intra and inter-reader correlation determining site of occlusion and CS in ELVO setting. This angiographic tool may have potential applications for both triage and patient selection.

IntroductionWe sought to evaluate the impact of pretreatment with intravenous thrombolysis (IVT) on the rate and speed of successful reperfusion (SR) in patients with emergent large vessel occlusion (ELVO) treated with mechanical thrombectomy (MT) in a high-volume tertiary care stroke center.MethodsConsecutive patients with ELVO treated with MT were evaluated. Outcomes were compared between patients who underwent combined IVT and MT (IVT+MT) and those treated with direct MT (dMT). The elapsed time between groin puncture to beginning of reperfusion (GPTBRT) and the numbers of device passes required to achieve SR were also documented.ResultsA total of 287 and 132 patients were treated with IVT+MT and dMT, respectively. The IVT+MT group had higher SR (73.8% vs 62.9%; p=0.023) and 3-month functional independence (modified Rankin Scale score 0–2;51.6% vs 38.2%; p=0.008) rates. The median GPTBRT was shorter in the IVT+MT group (48 (IQR 33–70) vs 70 (IQR 44–98) min; pConclusionsIVT pretreatment appears to increase the rates of SR and shortens the duration of the endovascular procedure by requiring fewer device passes in patients with ELVO treated with MT.

The Woven EndoBridge (WEB) device (MicroVention, Aliso Viejo, California) is an intrasaccular flow disruptor used for the treatment of both unruptured and ruptured intracranial aneurysms. WEB has been shown to have 54% complete and 85% adequate aneurysm occlusion rates at 1-yr follow-up.1 Residual and recurrent ruptured aneurysms have been shown to have a higher risk of re-rupture than completely occluded aneurysms.2 With increased utilization of WEB in the United States, optimizing treatment strategies of residual aneurysms previously treated with the WEB device is essential, including surgical clipping.3,4 Here, we present an operative video demonstrating the surgical clip occlusion of previously ruptured middle cerebral artery and anterior communicating artery aneurysms that had been treated with the WEB device and had sizable recurrence on follow-up angiography. Informed consent was obtained from both patients. Lessons learned include the following: (1) the WEB device is highly compressible, unlike coils; (2) proximal WEB marker may interfere with clip closure; (3) no evidence of WEB extrusion into the subarachnoid space; (4) no more scarring than expected in ruptured cases; and (5) clipping is a feasible option for treating WEB recurrent or residual aneurysms.

Introduction: The COVID-19 pandemic has strained the healthcare systems across the world but its impact on acute stroke care is just being elucidated. We hypothesized a major global impact of COVID-19 not only on stroke volumes but also on thrombectomy practice. Methods: A 19-item questionnaire survey aimed to identify the changes in stroke volumes and treatment practices seen during COVID-19 pandemic was designed using Qualtrics software. It was sent to stroke and neuro-interventional physicians around the world who are part of the executive committee of a global coalition, Mission Thrombectomy 2020 (MT2020) between April 5 th to May 15 th , 2020. Results: There were 113 responses across 25 countries. Globally there was a median 33% decrease in stroke admissions and a 25% decrease in mechanical thrombectomy (MT) procedures during COVID-19 pandemic compared to immediately preceding months (Figure 1A-B). This overall median decrease was despite a median increase in stroke volume in 4 European countries which diverted all stroke patients to only a few selected centers during the pandemic. The intubation policy during the pandemic for patients undergoing MT was highly variable across participating centers: 44% preferred intubating all patients, including 25% centers that changed their policy to preferred-intubation (PI) vs 27% centers that switched to preferred-conscious-sedation (PCS). There was no significant difference in rate of COVID-19 infection between PI vs PCS (p=0.6) or if intubation policy was changed in either direction (p=1). Low-volume (20 strokes/month) are less likely to have neurointerventional suite specific written personal protective equipment protocols (74% vs 88%) and if present, these centers are more likely to report them to be inadequate (58% vs 92%). Conclusion: Our data provides a comprehensive snapshot of the impact on acute stroke care observed worldwide during the pandemic.

Background: Stroke Coordinators (SC) are commonly utilized in US Stroke Centers, ensuring provision of evidence-based service, overseeing quality improvement, and supporting interdisciplinary and community education. Mission Thrombectomy 2020 (MT2020) partnered with the Association of Neurovascular Clinicians (ANVC) to understand how SCs are utilized outside the US and to compare developmental needs for this role across the world. Methods: A brief survey was constructed to capture information about the use of SCs and their duties, including personnel utilized to execute the role and areas deemed important for role development. The survey was disseminated through the MT2020 and ANVC membership rosters; returned data were assembled in SPSS (version 25) and analyzed using descriptive and X 2 statistics. Results: A total of 70 surveys were returned from 16 countries (63% USA). Survey responders were SCs (41%), physicians (39%), program managers (19%) and APPs(1%), and 49% were from CSCs/TSCs with 40% PSC and 11% ASR/other hospital; 92% had someone completing SC duties with MDs more commonly in the SC role outside the USA (63%) versus RNs in the USA (95%; X 2 =25.2, p Conclusions: Non-USA Stroke Centers have significant SC development needs that differ markedly from those within the USA. MT2020 provides an important platform to engage international programs and the MT2020-ANVC partnership is well positioned to further stroke nursing care and SC development globally.

Background: EXCELLENT (NCT03685578) is a large, prospective, single-arm, multicenter, international registry of mechanical thrombectomy (MT) with EmboTrap as the first attempted device in routine clinical practice. The study collects per pass data on procedural and technical details that are based on interventionalists’ preference, providing an opportunity to assess current practices in MT across multiple international high-volume stroke centers. Methods: Subjects treated according to standard of care were eligible for inclusion in the study if EmboTrap was used in the first MT pass. Interim analysis focusing on procedural details and per pass clot retrieval technique was performed based on 689 subjects enrolled by 79 physicians across 26 international sites (US, Belgium, Germany, France) between Sept 2018 and Jul 2020. Results: Mean #passes was 2.1 (median=1, max=10), 50.3% subjects had only 1 pass and 84.8% had 3 or fewer. Per pass use of stent retriever, aspiration, balloon guide, intermediate catheter and long sheath catheter, along with technique details (e.g. incubation time, device positioning, co-aspiration) are summarized in Table 1. Rates and reasons for device changes are also given. Conclusion: Interim analysis of the ongoing EXCELLENT registry informs on current practice patterns in MT. This is the first report of detailed per pass clot retrieval strategies in a large international multicenter cohort.

Background The COVID-19 pandemic has strained the healthcare systems across the world but its impact on acute stroke care is just being elucidated. We hypothesized a major global impact of COVID-19 not only on stroke volumes but also on various aspects of thrombectomy systems. Aims We conducted a convenience electronic survey with a 21-item questionnaire aimed to identify the changes in stroke admission volumes and thrombectomy treatment practices seen during a specified time period of the COVID-19 pandemic. Methods The survey was designed using Qualtrics software and sent to stroke and neuro-interventional physicians around the world who are part of the Global Executive Committee (GEC) of Mission Thrombectomy 2020, a global coalition under the aegis of Society of Vascular and Interventional Neurology, between April 5th to May 15th, 2020. Results There were 113 responses to the survey across 25 countries with a response rate of 31% among the GEC members. Globally there was a median 33% decrease in stroke admissions and a 25% decrease in mechanical thrombectomy (MT) procedures during the COVID-19 pandemic period until May 15th, 2020 compared to pre-pandemic months. The intubation policy for MT procedures during the pandemic was highly variable across participating centers: 44% preferred intubating all patients, including 25% of centers that changed their policy to preferred-intubation (PI) from preferred non-intubation (PNI). On the other hand, 56% centers preferred not intubating patients undergoing MT, which included 27% centers that changed their policy from PI to PNI. There was no significant difference in rate of COVID-19 infection between PI versus PNI centers (p=0.60) or if intubation policy was changed in either direction (p=1.00). Low-volume (20 strokes/month) were less likely to have neurointerventional suite specific written personal protective equipment protocols (74% vs 88%) and if present, these centers were more likely to report them to be inadequate (58% vs 92%). Conclusion Our data provides a comprehensive snapshot of the impact on acute stroke care observed worldwide during the pandemic. Overall, respondents reported decreased stroke admissions as well as decreased cases of MT with no clear preponderance in intubation policy during MT. Data access statement The corresponding author will consider requests for sharing survey data. The study was exempt from institutional review board approval as it did not involve patient level data.

Larger microcatheters are being used with increasing frequency in routine neurovascular procedures. Navigating catheters safely and effectively to the target intracranial vessels can be a challenge when using conventional 0.014″ microwires. A new family of 0.024″ Aristotle 24 microwires (Scientia Vascular, West Valley City, UT) specifically designed for intracranial navigation were recently introduced. These microwires offer significant technical advantages over the standard 0.014″ microwires, including a reduced ledge gap, improved torquability and support, and overall safety. This video case series contains several illustrative cases to demonstrate the features of the novel Aristotle 24 microwire for use in endovascular neurointervention.

Background Novel devices are being developed to maximize the efficacy of mechanical thrombectomy (MT). The MIVI R4Q series of distal access catheters has a unique design with an 0.20-inch wire (117 cm length) that replaces the proximal three quarters of the catheter and is attached to a distal catheter (25 cm length). The proximal end is flared with an outside diameter of 0.088 inch so that the outside is sealed with the inside of an 8F guide catheter allowing direct aspiration from the guide catheter thus providing greater aspiration force than smaller diameter catheters. This is the first report of patients in the United States using this technology to perform contact aspiration (CA). Methods We retrospectively reviewed all patients who underwent MT with the R4Q system at three high volume stroke centers. Baseline demographic and clinical data, as well as technical and clinical outcomes were recorded. Statistical comparison of rates of successful revascularization (SR) mTICI score 2b-3 and first pass effect (FPE) with MIVI technology were compared to the CA arms of ASTER and COMPASS using the Fischer’s Exact Test. Results 32 consecutive patients were identified. Median presenting NIHSS score at admission was 18. The site of occlusion was the middle cerebral artery M1 segment in 11 (34.4%), M2 segment in 6 (19%), M3 segment in 1 (3.1%), internal carotid artery in 8 (25%), tandem cervical ICA and intracranial occlusion in 2 (6.2%), ACA in 2 (6.3%), and basilar artery in 2 (6.3%). The R4Q was successfully delivered to the point of occlusion in 28 (87%) patients. SR to mTICI score 2b-3 on FPE was achieved in 21/32 (65%) patients and 16/26 (62%) patients where the R4Q was successfully delivered without a stent retriever. Final mTICI 2b-3 was achieved in 29/32 (91%) patients and 26/28 (93%) patients where the R4Q was successfully delivered. Three (9%) patients had intracranial hemorrhage – all HI1 (ECASS 2), 2 (6%) patients had vasospasm, and 1 (3%) patient had an embolus to a new territory. Fourteen patients (44%) had a 90-day modified Rankin scale (mRS) 0–2. SR with MIVI was similar to results from ASTER (91% vs. 85%, p=0.58) and COMPASS (91% vs 83%, p=0.41). FPE with MIVI was more frequent than in ASTER (62% vs. 26%, p=0.0009) and equivalent to COMPASS (62% vs 57%, p=0.83) and more frequent in comparison to the combined ASTER and COMPASS cohort (62% vs. 40%, p=0.04). Conclusion The R4Q family of catheters incorporates novel technology for CA. This series demonstrates a high FPE and similar rates of SR compared with published data using other aspiration catheters. Further prospective studies of this technology are planned to evaluate its clinical efficacy. Disclosures R. Torabi: None. M. Mokin: 1; C; NIH R21NS109575. 2; C; Medtronic, Canon Medical, Cerenovus. 4; C; Serenity Medical, Synchron, Endostream, VICIS. Z. Ren: None. A. Siddiqui: 1; C; NIH/NINDS, Cerenovus, Medtronic, Microvention, MUSC, Penumbra. 2; C; Amnis Therapeutics, Boston Scientific, Canon Medical Systems USA, Cerebrotech Medical Systems, Cerenovus, Corindus, Endostream Medical, Guidepoint Global Consulting, Imperative Care, Integra, Medtronic, Microvention, Minnetronix Neuro, Northwest University, Penumbra, Q’Apel Medical, Rapid Medical, Rebound Therapeutics, Serenity Medical, Silk Road Medical, StimMed, Stryker, Three Rivers Medical, VasSol, W.L. Gore & Associates. 4; C; Adona Medical, Amnis Therapeutics, BlinkTBI, Buffalo Technology Partners, Cardinal Consultants, Cerebrotech Medical Systems, Cognition Medical, Endostream Medical, Imperative Care, International Medical Distribution Partners, Neurovascular Diagnostics, Q’Apel Medical, Rebound Therapeutics, Rist Neurovascular, Sense Diagnostics, Serenity Medical, Silk Road Medical, Spinnaker Medical, StimMed Synchron, Three Rivers Medical, VasSol, W.L Gore & Associates. E. Levy: 2; C; Claret Medical, GLG Consulting, Guidepoint Global, Imperative Care, Medtronic, Rebound Therapeutics, StimMed. 4; C; NeXtGen Biologics, RAPID Medical, Claret Medical, Cognition Medical, Imperative Care, Rebound Therapeutics, StimMed, Three Rivers Medical. 6; C; National PI: Medtronic, Steering committees for SWIFT Prime and SWIFT Direct trials, Honorarium for Training and Lectures: Medtronic, Advisory Board: Styker (AIS clinical advisory board), NeXtGen Biologics, MEDX, Cognition Medical, Endostream Medical, Site PI: Microvention (Confidence Study). M. Waqas: None. A. Arthur: 1; C; Balt, Cerenovus, Medtronic, Microvention, Penumbra, Siemens, Stryker. 2; C; Johnson & Johnson, Microvention, Medtronic, Penumbra, Scientia, Siemens, Stryker. 4; C; Bendit, Cerebrotech, Endostream, Magneto, Marblehead, Neurogami, Serenity, Synchron, Triad Medical, Vascular Simulations. D. Hoit: 2; C; Medtronic, Microvention. 4; C; Silver Bullet, Cerebrotech, Marblehead Medical. C. Nickele: 1; C; Microvention. 2; C; Leica. V. Inoa: None. B. Jankowitz: 2; C; Stryker, Medtronic.

Background and Purpose Mechanical thrombectomy (MT) is demonstrated to improve functional outcome of patients with anterior circulation strokes with emergency large vessel occlusion (ELVO). Despite successful recanalization (SR), a proportion of these patients require decompressive hemicraniectomy (DHC). We aimed to study the predictors of DHC in successfully recanalized anterior circulation ELVO patients. Methods Consecutive anterior circulation ELVO patients treated with MT during a 6-year period in a tertiary stroke center were evaluated. Only patients with SR (mTICI 2b, 2c or 3) after MT were included in the analysis. Baseline demographic, clinical and procedural variables were compared between the patients who required DHC after successful recanalization vs. who did not. Collaterals for anterior circulation ELVO (ie, poor (collateral score=0) vs. good (collateral score=1, 2 and 3) were reported using a methodology that has been shown to predict clinical outcome. Good functional outcome was defined as mRS score of 0–2 at 3 months. Univariable and multivariable logistic regression analyses were used to determine the predictors of DHC. Results Of 453 successfully recanalized anterior circulation ELVO patients, 47 underwent DHC (mean age 58±13 years, 53% male, median admission NIHSS-score: 17 points, IQR 13–21). The patients in DHC group were younger in age (mean age in years±SD; 58±13 vs. 65±15, p=0.004), had higher admission systolic blood pressure (mmHg: 167±33 vs. 155±30, p=0.010), higher admission diastolic blood pressure (mmHg: 95±28 vs. 87±19, p=0.019), higher admission blood glucose levels (mg/dl: 170±88 vs. 142±66, p=0.008), similar median admission NIHSS (17 (IQR: 13–21) vs. 15 (IQR: 11–20), p=0.087), lower median ASPECTS (9 (IQR: 8–10) vs. 10 (IQR: 9–10), p=0.002), and poor collaterals on pre-treatment CT angiogram (% with poor collaterals: 75% vs. 26%, p Conclusion Higher blood glucose levels on admission, poor collateral pattern on CT angiography and higher number of passes during MT were independently associated with DHC in anterior circulation EVLO patients achieving SR at the end of MT. Of these, admission glucose levels and number of passes during MT are potentially modifiable factors. Disclosures N. Goyal: None. G. Tsivgoulis: None. A. Pandhi: None. M. Ishfaq: None. J. Goyanes: None. A. Deep: None. D. Alsbrook: None. S. Singh: None. G. Zaid: None. D. Hoit: None. C. Nickele: None. V. Inoa: None. D. Dornbos: None. A. Alexandrov: None. A. Arthur: None. L. Elijovich: None.

Introduction Time resolved three-dimensional angiography (4D DSA) was developed initially to investigate parameters related to the flow in arterio-venous malformations (AVMs). We have extended this protocol to evaluate flow before and after placement of a flow diverter for treatment of an intracranial aneurysm. Here we evaluate a prototype for 3D iFlow using 4D DSA imaging. Methods In this study, 4D DSA angiographic imaging (6 s syngo Dyna4D, Siemens Healthineers AG, Forchheim, Germany) was performed on 13 patients before and after receiving a pipeline (Medtronic, USA) across a known intracranial aneurysm. 4D DSA imaging was acquired before a pipeline was placed and after deployment of a pipeline on the same day using a constant flow rate of 3 ml/sec and 21 cc of contrast. 3D iFlow information was extracted using prototype software from the imaging and 3 bolus arrival time definitions were evaluated. Results Using three separate reconstruction protocols for 3D iFlow the flow proximal to the aneurysm and distal to the aneurysm showed similar average bolus arrival times (table 1). The bolus arrival time was then measured at a point just distal to the aneurysm being treated and within the aneurysm itself (table 2). The RECON 1 protocol appeared to most reliably demonstrate slowed contrast inflow into the aneurysm post deployment of the Pipeline device. Conclusion The 3D iFlow information obtained using 4D DSA imaging can provide clinicians information on the amount of flow pre and post deployment of a pipeline device for treatment of an intracranial aneurysm. This information could be useful to model aneurysm treatment and time to obliteration when utilizing pipeline flow diversion for the treatment of intracranial aneurysms. Continued work to refine protocols and software are needed to implement into clinical care. Disclaimer This product is under development and not commercially available. Its future availability cannot be ensured. Disclosures N. Khan: None. J. DiNitto: 5; C; Siemens. A. Birkhold: 5; C; Siemens. A. Arthur: None. C. Nickele: None. D. Hoit: None. V. Inoa: None. L. Elijovich: None.

Introduction: We investigated the effectiveness of intravenous thrombolysis (IVT) in acute ischemic stroke (AIS) patients with large vessel occlusion (LVO) and mild neurological deficits defined as National Institutes of Health Stroke Scale scores Methods: The primary efficacy outcome was three-month functional independence (FI; mRS-scores of 0-2) that was compared between patients with and without IVT treatment. Other efficacy outcomes of interest included three-month favorable functional outcome (FFO; mRS-scores of 0-1) and mRS-scores distribution at discharge and at 3 months. The safety outcomes comprised all-cause 3-month mortality, symptomatic intracranial hemorrhage (ICH), asymptomatic ICH and severe systemic bleeding. Results: We evaluated 336 AIS patients with mELVO (mean age: 63±15 years, 45% women). Patients treated with IVT (n=162) had higher FI (85.6% vs. 74.8%, p=0.027) with lower mRS scores at hospital discharge (p=0.034) compared to the rest. Three-month mRS-scores tended to be lower in the IVT group (p=0.069). No differences were detected in any of the safety outcomes including symptomatic ICH, asymptomatic ICH, severe systemic bleeding and 3-month mortality (p>0.1). IVT was associated with higher likelihood of 3-month FI (OR=2.19, 95%CI: 1.09-4.42), 3-month FFO (OR=1.99, 95%CI: 1.10-3.57) and functional improvement at discharge [cOR (per 1-point decrease in mRS-score)=2.94, 95%CI: 1.67-5.26] and at 3 months (cOR=1.72, 95%CI: 1.06-2.86) on multivariable logistic regression models adjusting for potential confounders including mechanical thrombectomy. Conclusion: IVT is independently associated with higher odds of improved discharge and three-month functional outcomes in AIS patients with mELVO. IVT does not increase the risk of systemic or intracranial bleeding.

IMPORTANCE: The benefit of mechanical thrombectomy (MT) in patients with stroke presenting with mild deficits (National Institutes of Health Stroke Scale [NIHSS] score