bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract TP373: Developing a Pre-Arrival Report Card
Authors: Bluma Dot , Girtler Bethany , Link Jessica , Elderbrook Megan
Published: June 2021

Background and Purpose:
Hospitals’ communication with EMS on pre-arrival evidence based measures is essential in ensuring the best care for stroke patients in their community. To assist in assessing EMS pre-hospital care, the Wisconsin Coverdell Stroke Program (Coverdell) developed a quarterly report card for each of our participating hospitals. Coverdell’s 66 participating hospitals represent 78% of annual stroke admissions to Wisconsin hospitals. Coverdell utilizes the data entered into Get With The Guidelines® (GWTGs) - Special Initiatives tab. The data in the report card can be used to identify gaps in quality stroke care, followed by identifying performance improvement opportunities which can be initiated to address these gaps in care.

Methods:
Coverdell hospitals participate in the quarterly Coverdell Learning Collaborative (CLC) where they review several aggregated data points. CLC recognized a report card would provide an opportunity for participating hospitals to discuss the pre-arrival quality measures with their EMS providers and assist in developing a trusting relationship. To develop the report card, Coverdell’s Epidemiologist and Stroke Project Specialist analyzed the data measures from the GWTGs- Special Initiatives tab. We determined the need to provide benchmark groups for comparison, and to have established goals for each measure to assist in motivating and gauging progress of quality improvement initiatives.

Findings:
Coverdell released the pilot quarterly report card in Q3 2018. We then met with Stroke Coordinators whose hospitals were entering into the GWTGs Special Initiatives tab to discuss the goals, measures, and the need for modifications. The Q4 2018 report card incorporated the identified edits.

Conclusion:
Providing quarterly report cards with EMS pre-arrival measures will assist hospitals and their EMS providers in jointly identifying, planning, and implementing performance improvement initiatives in efforts to ensure seamless transitions of care for stroke patients in their community.
Abstract TP380: Significant Factors of Early Independent Gait in Acute Ischemic Stroke Patients
Authors: Hosaka Yuna , Mori Takahisa , Sawada Yuki
Published: June 2021

Introduction:
Acute stroke patients have problems with gait disturbance. Independent gait in hospitalized patients is important for early discharge to home. Therefore, we must find factors of disturbing independent gait following acute stroke and intensively treat them.

Hypothesis:
Impaired trunk control and cognitive function are factors of disturbing early independent gait.

Methods:
We included acute ischemic stroke patients who were admitted in our hospital from June 2017 to May 2018 and excluded patients with disturbed level of consciousness. We defined a score of 6 (modified Independence) or 7 (complete independence) in the Functional Independence Measure (FIM) as gait independence. We evaluated association of stroke subtypes, Brunnstrom recovery stage (BRS) of upper limbs, fingers and lower limbs, trunk control test (TCT) score and Mini-Mental State Examination (MMSE) score with early gait independence on the 7th day of a stroke onset.

Results:
One hundred twenty- six patients met our inclusive criteria and we analyzed them. Stroke subtypes had no relation to early gait independence. In gait independent and dependent patients on the 7th day, median BRS score of upper limbs was 5 and 5 (ns), median BRS score of fingers was 5 and5 (ns), median BRS score of lower limbs was 6 and 5 (p<0.01), TCT score was 100and 75 (p<0.01) and MMSE score was 28.5 and 24.5 (p<0.01), respectively. Multiple logistic regression analysis that TCT (p<0.01) and BRS lower limbs (p<0.01) were independent factors for early independent gat. Receiver operating characteristic curve (ROC) for early gait independence demonstrated that cut-off values of TCT score and BRS of lower limbs and were 100 and 5.

Conclusions:
Impaired trunk control and muscle weakness of lower limbs were significant factors of disturbing early gait independence.
Abstract TP392: Life in the F.A.S.T. Lane: Improving Stroke Patient and Family Education by Using F.A.S.T
Authors: West Noella C
Published: June 2021

Background and Purpose:
Quality educational programs for stroke awareness promote early medical attention which lead to improved recovery and clinical outcomes. The implementation of an evidence-based education program using F.A.S.T. improved community awareness of both the signs and symptoms of stroke along with awareness of individual risk factors. The purpose of this quality enhancement initiative was to determine the efficacy of specific stroke education and the effects on the community for prompt medical treatment of suspected stroke when warning signs and symptoms are identified.

Methods:
A quality improvement pre-test/post-test design project was conducted to evaluate the implementation and impact of an evidenced-based patient/family centered education program regarding using F.A.S.T. and identifiable risk factors. Questions formulated using the Kirkpatrick Model. GetWell Rounds and Marabella application was used electronically at the beside to gather data. Outcomes were measured using a 10-point Likert scale in 311 patients and their caregivers at a busy level one trauma center over 5 months. As a result, creation of hospital wide education including videos, key discharge components and community outreach was newly implemented.

Results:
This evidenced-based initiative contributed to a significant increase in patients/families understanding of stroke signs and symptoms and recognition of individual risk factors that were modifiable. The highest level of improvement is comfort level explaining F.A.S.T. In addition, patient and caregiver survivors as well as non-stroke population participation in the community stroke programs have increased.

Conclusions:
Identifying stroke symptoms and acting rapidly can lower death and disability, but public awareness of stroke warning signs, symptoms and risk factors remains poor. Stroke educational programs are needed to improve community knowledge and behaviors to increase early treatment and potentially decreasing mortality. The community focused level is important to getting the message out and about stroke factors; therefore, developing cultural awareness is crucial.
Abstract TP396: Improving Documentation of Blood Pressure and Neurological Assessments in Post Alteplase Patients
Authors: BROADWAY Katie , Butler Winey Danielle , Garcia Jodie
Published: June 2021

Introduction:
Patients who receive alteplase for acute ischemic strokes are at a high risk for conversion to a hemorrhagic stroke and must be monitored closely through frequent vital signs and neurological checks. Documentation of these measures was found to have a low compliance due to various factors such as a new electronic medical record (EMR) and lack of knowledge related to required documentation.

Methods:
A team was created to address this issue which included the Emergency Department Nurse Manager, a Clinical Nurse Expert, and the Stroke Program Director. Inservices were provided to the ED and Critical Care nursing staff. Daily review of all alteplase patients and chart audits were performed and real-time feedback was given to the staff and leadership caring for the patients. This real-time feedback allowed for corrections to be made if necessary and served as both an educational and accountability opportunity. The feedback was not limited to just missed opportunities but was also used to praise staff for complete documentation.

Results:
Concurrent monitoring of blood pressure and neurological checks was completed from September 2018 to June 2019 on all alteplase patients. The overall compliance of documentation for blood pressure checks improved from 88% to 93.1% and the compliance for the neurological checks improved from 81.5% to 85.7%.

Conclusions:
Providing real time feedback is an effective way to notify staff of both missed opportunities and successes. Overall, when the staff has a better understanding of what is required, the patients are given more comprehensive care.
Abstract TP40: Time From Stroke Onset to Reperfusion is Associated With Worse Functional Outcomes in Patients With Rapidly Progressing Infarcts
Authors: Wang Anson , Strander Sumita , Kodali Sreeja , Silverman Andrew , Kimmel Alexandra , Nguyen Cindy Khanh , Peshwe Krithika , Sansing Lauren H , Schindler Joseph L , Matouk Charles C , Sheth Kevin N , Petersen Nils H
Published: June 2021

Introduction:
Recent trials have demonstrated the benefit of endovascular therapy (EVT) beyond 6 hours of symptom onset. However, the importance of time to reperfusion (TTR) in the extended time window has recently been questioned. Given the variability of infarct growth rate (IGR), the time delay until reperfusion may have greater consequences for those with rapidly progressing infarcts, and identifying such patients is essential for improving outcomes. We tested the hypothesis that TTR is more closely associated with functional outcome in patients with rapidly progressing infarcts compared to their slow-progressing counterparts.

Methods:
We retrospectively identified 106 patients at our center’s prospectively collected stroke database with anterior circulation large-vessel occlusion stroke and known time of symptom onset. Patients underwent initial CT perfusion imaging (CTP), EVT and and follow-up MRI at 24 hours. Core infarct volumes at presentation (CBF<30%) were estimated using RAPID software. The time between symptom onset and CTP was used to estimate IGR and to categorize patients as fast (≥5 mL/hour) or slow (<5 mL/hour) progressors. Alternatively, final infarct volume (FIV) was measured on MRI and used to calculate IGR in the absence of CTP. Functional outcome was assessed using the modified Rankin scale (mRS) at discharge and 90 days. Associations were computed using ordinal regression adjusting for age, ASPECTS, and TICI.

Results:
35 fast progressors (age 71±14, 17 F, TTR 288±91 minutes, mean IGR 21±24 mL/hour) and 71 slow progressors (age 71±17, 48 F, TTR 374±211 minutes, mean IGR 1.0±1.5 mL/hour) were identified. Fast progressors had higher admission NIHSS scores (18±6 vs 13±7, p<0.001) and significantly larger FIV (101±77 vs 47±65 mL, p<0.001). After adjusting for baseline factors, TTR was significantly associated with worse functional outcome at 90 days in fast progressors (p=0.026, aOR 1.13 per 10 minutes, 95% CI 1.02-1.28), but not for slow progressors (p=0.708).

Conclusions:
In patients with rapidly progressing infarcts (≥5 mL/hour), TTR was associated with worse functional outcomes at 90 days compared to slow progressors. Identifying such patients may be critical for appropriate triage and rapid delivery of acute stroke care.
Abstract TP407: Transvenous Pressure Monitoring Guides Endovascular Treatment of Vein of Galen Malformation
Authors: Chang Daniel , Quintero-Consuegra Miguel D , Toscano Juan F , Babadjouni Robin , Danielpour Kelly , Peyton Nisson , Gonzalez Nestor R
Published: June 2021

Background:
Vein of Galen Malformation (VGM) is a complex vascular disorder with high morbidity and mortality. Mainstay management involves staged endovascular embolizations. Determining when to stop an embolization during any single intervention is challenging. If embolization is excessive, it precipitates thrombosis on the VGM, increase in cardiac post-load, and worsening on heart failure, as well as hemorrhages. Conversely, insufficient embolization may be futile. We report the use of transvenous pressure monitoring as an adjuvant for guiding the extent of embolization.

Method:
Arterial and venous accesses were obtained through the common femoral artery and vein, respectively. After diagnostic angiography, the best working projection was selected in early and late venous phases. A microcatheter was placed at the VG, and an intermediate 5 Fr. catheter was located at the persistent falcine sinus. The microcatheter was used for coil embolization, while the intermediate catheter provided support and was connected for continuous venous pressure monitoring. Continuous arterial pressure monitoring was obtained via an A-line and transduction of a glide catheter located in the carotid artery. Arterial and venous SBP were recorded.

Result:
Serial angiograms during treatment showed reduction of flow within the VGM. Concomitantly, there was an increase in the A-V-gradient over time (Figure 1). The difference between the A-V SBP went from 36 mmHg at the start of the case to 51 mmHg after the final coil. The average pressure gradient went from 38.3 mmHg in the first quarter to 43.5 mmHg in the last.

Conclusion:
The continuous assessment of transvenous pressure monitoring during embolization of VGM provides measurable changes that correlate with degree of flow. This quantifiable metric may be used as an adjunct to guide adequate reduction of flow during endovascular treatment of VGM.
Abstract TP437: Statin Treatment and Accrual of Covert Cerebral Ischemia on Neuroimaging: A Systematic Review and Meta-Analysis of Randomized Trials
Authors: Katsanos Aristeidis H , Lioutas Vasileios-Arsenios , Charidimou Andreas , Catanese Luciana , Ng Kelvin K , Perera Kanjana , de Sa Boasquevisque Danielle , Tsivgoulis Georgios , Smith Eric E , Sharma Mukul , Selim Magdy H , Shoamanesh Ashkan
Published: June 2021

Introduction:
Stroke prevention is an established benefit of statin therapy, but the effects of statin treatment on the accrual of MRI markers of ischemic cerebral injury remain unknown.

Methods:
We performed a systematic review of MEDLINE and SCOPUS databases from inception to July 29
th
, 2019 to identify all studies that randomized patients to statin treatment and assessed the effect of statin treatment on incident infarcts (asymptomatic and symptomatic), covert infarcts (asymptomatic evident only in neuroimaging) and white matter hyperintensity (WMH) accrual on magnetic resonance imaging. We included only studies reporting WMH change following normal distribution. We used random effects model to calculate the pooled estimates of the crude risk ratios (RRs) and standardized mean differences (SMDs).

Results:
We included data from 3 randomized controlled trials with a total of 1399 participants evaluating the effect of rosuvastatin (10mg/d) in 637 hypertensive patients older than 60 years of age over 5 years, pravastatin (40mg/d) in 554 elderly people more than 70 years of age over 3 years and simvastatin (20mg/d) in 208 patients with asymptomatic middle cerebral artery stenosis over 2 years. Patients randomized to statin treatment had decreased accrual of new infarcts (RR=0.59; 95%CI: 0.36, 0.95), new covert infarcts (RR=0.64, 95%CI: 0.46-0.89). Only one study reported WMH decreased volume change in patients randomized to statin treatment compared to patients randomized to non-statin treatment (SMD= -1.16; -1.33, -1.00).

Conclusion:
Our findings suggest that statin treatment can reduce the accrual of covert MRI markers of ischemic cerebral injury. Dose-response effect and population disparities need to be investigated in future studies.
Abstract TP44: Evaluating Mechanical Properties of Human Blood Clot Analogues Using Ultrasound-mediated Optical Coherence Elastography
Authors: Liu Hsiao-Chuan , Fitzgerald Seán , Rizvi Asim , Caracena Thomas , Doyle Karen M , Kadirvel Ramanathan , Kallmes David F , Brinjikji Waleed , Urban Matthew W
Published: June 2021

Ischemic stroke results from thrombus becoming lodged in a vessel in the cerebrovascular circulation. The constituents of the thrombus can vary widely and have direct effects on the mechanical properties of the thrombus. Thrombectomy procedures could potentially be improved if the mechanical properties of the thrombus could be determined prior to treatment. In the study, we developed a new non-contact method associated with Rayleigh wave propagations for evaluating mechanical properties of human clotted blood, referred to as ultrasound-mediated optical coherence elastography (UOCE). Due to clot mechanical properties being associated with fibrin and platelet content, eight different clot analogues with varying fibrin/platelets concentrations, from 0.6% (control group) to 19.0%, were produced, and the clot analog in each concentration was repeatedly measured five times. A highly focused transducer with a center frequency of 7.5 MHz was used to generate acoustic radiation forces exerted on the surface of clotted blood to induce Rayleigh wave propagations. The transducer was driven by a 50 dB radio frequency amplifier a 4 ms pulse which was repeated at a rate of 19 Hz. The optical coherence tomography (OCT) acquisition was set to 50 lateral positions and 4000 A-scans for each lateral position at a 76 kHz scan rate for total acquisition time of 52.6 ms. The results demonstrated that the Rayleigh wave group velocities positively correlated with the concentrations of fibrin/platelets. The group velocities ranged from 0.78 ± 0.02 m/s for 0.6% fibrin/platelets and increased to 2.42 ± 0.06 m/s at a fibrin/platelets concentration of 19.0%. There are statistically significant difference (
p
<0.05) between control group and all clot analogues with a fibrin/platelets concentration of greater than 2.3%. In conclusion, we propose UOCE as a novel approach capable of evaluating mechanical properties of human blood clots based on Rayleigh wave propagation. This sensitive method can be used for the evaluation of the mechanical properties of human blood clot analogues and thrombectomy samples.
Abstract TP443: Silent Ischemia and Clinical Manifestations in a Cohort of Asymptomatic Carotid Stenosis Patients According to Stenosis Degree
Authors: Zurru Maria C , Colla Machado Pedro , Balian Natalia , Luzzi Ariel , Brescacin Laura , Alonzo Claudia , Milei José
Published: June 2021

Background:
Asymptomatic carotid plaques (ACP) generating less than 70% stenosis still have risk of complications.Our objective was to compare the incidence of silent lesions (SL) in patients with moderate stenosis (50-70%), severe stenosis (70-99%) or carotid occlusion, as well as the incidence of ipsilateral ischemic stroke or transient ischemic attack (TIA) during follow-up

Material and method:
cohort study of patients with carotid stenosis >50% by Doppler. LS were evaluated by MRI at admission and the end-points were ischemic stroke or TIA during follow-up. The study was approved by the Ethics Committee.

Results:
646 patients were included from June 2010 to June 2018, 25% with bilateral stenosis >50%. Mean age 75 (ICR 53-79), 54% female. Sixty-three percent (n 507) had stenosis 70-99%, 31% (n 250) stenosis 50-70% and 6% (n 50) had carotid occlusion. SL were present in 15% (n 119) of the 807 plaques evaluated. Only limitrofe lesions were more prevalent in patients occlusion when comparing with severe and moderate stenosis:(20% vs 2% vs 1%, respectively; p 0.02 (table). Four patients had minor ipsilateral stroke (NIHSS < 5) during follow-up and 8 TIA; endarterectomy was performed in all of them. Clinical events did not occur in carotid occlusion, 3% (n 8) in moderate stenosis and 1% (n 4) in severe stenosis.

Conclusion:
SL incidence was not different in different stenosis degree, except for limitrofe infarcts in carotid occlusion (probably due to hemodynamic effect). Incidence of cerebrovascular complications was similar in patients with moderate and severe stenosis.
Abstract TP449: Hypertonic Saline Solution After Aneurysmal Subarachnoid Hemorrhage Does Not Affect Sodium Balance
Authors: Herpich Franziska , Rincon Fred , Habib Sara , Mukhar Umer , McAdams Maxwell , Jallo Jack
Published: June 2021

Background:
Euvolemic hyponatremia is prevalent in patients with aneurysmal subarachnoid hemorrhages (aSAH) and is associated with poor outcome, gait imbalance, cognitive impairment, and prolonged length of stay. We sought to determine the effect of 3% hypertonic saline (HTS3%) on sodium (Na) trends in an interim analysis of the HS3 clinical trial.

Methods:
The “Safety and Feasibility of HTS3% after aSAH Hemorrhage (HS3)” Clinical Trial (ClinicalTrials.gov NCT02432157) is a randomized, safety and efficacy, single center, single blinded clinical trial designed to evaluate if a protocol of volume expansion with HTS3% is safe and effective in patients with aSAH for the prevention of hyponatremia. Within 72 hours of index hemorrhage, aSAH patients were randomized to receive prophylactic intravenous HTS3% bolus injections at a dose of 250ml via central line every 6 hours for 7 days vs. routine fluid management with isotonic fluids as pre-specified by our local management protocol, which is based on multi-professional guidelines for the management of aSAH. We followed serum Na levels from day of admission (D0) to hospital day 10 (D10) and compared them using the Mann-U-Whitney test for non-parametric data.

Results:
In total, 22 patients participated in the study. Half of the patients (11) were randomized to the treatment group and 11 were part of the control arm. Mean age was 53±12years, 68.2% (n=15) were female, 54.5% (n=12) were white, and median (Md) Hunt and Hess was 3 (IQR=1), Md-modified-Fisher was 3 (IQR=1). Mean GCS on admission was 10 (SD 4) and mean ICP was 13 (SD 5). There was no significant difference in the demographics between the groups. Md-Na levels from D0-D10 did not differ between the groups and hyponatremia did not occur in either group.

Conclusion:
Data from an interim analysis of HS3 clinical trial indicate that both fluid strategies were associated with similar profile in Na balance and no incidence of hyponatremia. Further data is needed to investigate association between HTS3% and mortality, clinical outcome, delayed cerebral ischemia and vasospasms.
Abstract TP45: Impact of Carotid Tortuosity on Outcome After Endovascular Thrombectomy
Authors: Leker Ronen R , Cohen Jose E , Hurst Robert W , Abu El Hasan Hosni , Sacagio Tzvika , Honig Asaf , Gomori John M , Guan Kevin , Kasner Scott E
Published: June 2021

Background:
Endovascular thrombectomy (EVT) is effective in patients with large vessel occlusion (LVO) stroke. We hypothesized that a tortuous internal carotid (ICA) may increase the technical difficulty of EVT and prevent optimal positioning of aspiration catheters thereby lowering the chances of successful recanalization and likelihood of favorable outcome.

Patients and Methods:
Consecutive patients with LVO and patent cervical ICAs who underwent EVT at 2 academic centers were included. Demographics, clinical and radiological factors, time metrics, occurrence of symptomatic intracranial hemorrhage (sICH), functional outcome and survival data were collected. ICA tortuosity was determined on pre-EVT sagittal maximal intensity projection images and classified into three categories: type 1 - straight ICA trunk, type 2 - moderate degree of tortuosity not judged to impair distal catheter placement and type 3 - severe tortuosity preventing optimal aspiration catheter placement. Thrombolysis in cerebral infarction (TICI) 2b-3 was considered successful recanalization and modified Rankin Scale (mRS)≤2 90days post stroke was considered favorable outcome.

Results:
The study included 313 patients (mean age 69±15, median NIHSS 17), and 53% had type 1, 33% type 2 and 14% type 3 ICA tortuosity. Severe tortuosity was significantly less common in patients with atrial fibrillation (p=0.032) but no other factors were associated with the degree of tortuosity. Overall, 85% had successful recanalization and 47% had favorable outcomes. The chances of favorable outcome at 90days were independent of the degree of observed tortuosity (53% type1, 32% type2 and 49% type3 respectively, p=0.94). Similarly, mortality rates, chances of succesful recanalization and sICH rates did not differ between the tortuosity groups. Clustering patients with moderate and severe tortuosity into one group showed that those with marked tortuosity were significantly older (74±12 vs. 65±16; p<0.0001) and less frequently achieved successful recanalization (79% vs. 89%; p=0.018) but had similar functional outcomes and survival rates compared to those with mild tortuosity.

Conclusions:
Carotid tortuosity does not impact functional outcome but may influence recanalization rates.
Abstract TP455: Race-Ethnic Disparities in Subarachnoid Hemorrhage Outcomes
Authors: Bustillo Antonio , Wang Kefeng , Gardener Hannah , Gutierrez Carolina M , Sur Nicole , Asdaghi Negar , Romano Jose G , Rundek Tatjana , Sacco Ralph L , Koch Sebastian
Published: June 2021

Introduction:
Identification of race/ethnic disparities in stroke outcomes is essential in achieving equity of patient care across demographic subgroups. We sought to identify disparities by race/ethnicity in patient outcomes following subarachnoid hemorrhage (SAH).

Methods:
Records obtained from the Florida Stroke Registry (FSR), a multi-hospital Get With the Guidelines (GWTG)-Stroke data collaborative, were used to compare descriptive statistics and outcomes by race/ethnicity. Pearson chi-squared and Kruskall-Wallis tests were used to compare descriptive statistics by race/ethnicity. Outcomes included in-hospital mortality, discharge location, ambulation at discharge, modified Rankin Scale (mRS) score at discharge, and receiving comfort measures only. Logistic regression models with generalized estimating equations accounted for age, insurance, smoking, hypertension, diabetes, dyslipidemia, atrial fibrillation/flutter, coronary artery disease, peripheral vascular disease, prior stroke/TIA, carotid stenosis, prior anticoagulation or antiplatelet use, prior ambulatory status, arrival mode, admission NIHSS, Florida region, number of beds, years in GWTG, and teaching hospital status.

Results:
The sample consisted of 10, 559 records with SAH discharged between 2010-2018; 63% were non-Hispanic White (NHW), 19.4% non-Hispanic Black (NHB), and 17.6% Hispanic. NHB were younger at onset (median age=54, IQR=45-65; NHW: 62, 53-73; Hispanic: 58, 48-71; p < 0.0001) and had the highest rate of hypertension (62%; NHW: 50%, Hispanic: 51%; p < 0.001), while NHW had the highest rate of smoking (24%; NHB: 20%; Hispanic: 17%; p < 0.0001). NHB had lower odds of in-hospital mortality compared to NHW (adjusted OR 0.8, 95% CI 0.68-0.94), but were less likely to have been discharged home/rehab (0.83, 0.73-0.94), to ambulate independently at discharge (0.71, 0.60-0.84), and to have a discharge mRS score of 0-2 (0.67, 0.49-0.92).

Conclusions:
While NHB have lowered odds of dying in-hospital from SAH, survivors have worse functional outcomes. These race/ethnic disparities highlight the need for further research into the causes of these differences and to refine approaches to improve acute care of SAH.
Abstract TP484: Superficial Femoral Artery Atrophy and Reduced Lower Limb Blood Flow in Subacute Stroke Survivors
Authors: Durand Matthew J , Nguyen Jennifer N , Minkin Rachel R , Schmit Brian D , Gutterman David D , Hyngstrom Allison S
Published: June 2021

Introduction:
Femoral artery atrophy and reduced endothelial function in the peripheral arteries of the affected lower limb contribute to reduced hyperemic blood flow in response to muscle contractions in chronic stroke survivors. These impairments could contribute to increased muscle weakness and exacerbate neuromuscular fatigue in stroke survivors. The time-course of these changes to the peripheral vasculature post-stroke have not been examined.

Hypothesis:
Superficial femoral artery atrophy and reduced blood flow to the affected limb occur in the subacute stroke period.

Methods:
This was a prospective, observational study which enrolled subacute stroke survivors admitted to inpatient rehabilitation at a single site. Maximum voluntary contractions (MVCs) of the paretic and non-paretic knee extensor muscles were assessed using a Biodex dynamometer. The superficial femoral artery was imaged in both legs using ultrasonography and arterial diameter was measured off-line with Brachial Analyzer software. Superficial femoral artery resting and hyperemic blood flow following MVCs was also quantified using ultrasonography.

Results:
Twelve subacute stroke survivors were enrolled in this study (7 men, 5 women). The mean age of all study participants was 65±10 years and the mean time since stroke was 12±6 days. Superficial femoral artery diameter was smaller in the affected leg compared to the non-affected leg (5.9±0.9 mm vs. 6.3±0.9 mm, respectively; p=0.006 paired t-test). Resting blood flow to the affected leg was also lower compared to the non-affected leg (164±68 ml/min vs. 205±105 ml/min, respectively; p=0.031 paired t-test). The MVC of the knee extensor muscles of the affected leg was less than the non-affected leg (103±63 Nm vs. 152±58 Nm, respectively; p=0.027, Wilcoxon signed rank test) and hyperemic blood flow was also reduced in the affected limb (248±94 ml/min vs. 428±203 ml/min, respectively; p<0.001, Wilcoxon signed rank test). There was a positive correlation between hyperemic blood flow (fold change from rest) and MVC in the affected leg (r
2
=0.47, p=0.014).

Conclusions:
Superficial femoral artery atrophy and reduced limb blood flow occur in stroke survivors in the first weeks post-stroke and may contribute to limb weakness.
Abstract TP489: Microglia Involved in Soluble Endoglin-Induced Brain Vascular Malformation
Authors: Park Eun S. , Chen P. Roc , Kim Eunhee
Published: June 2021

Introduction:
Microglia are closely communicating with endothelial cells and involved in cerebrovascular disease. In brain arteriovenous malformation (bAVM), microglia are highly detected in the vascular walls and brain parenchyma, however, the role of microglia in bAVM are not clear. Meanwhile, soluble endoglin (sENG) has been involved in inflammation and endothelial dysfunction in bAVM. Therefore, we hypothesized that microglia mediate sENG-induced endothelial dysfunction in bAVM.

Methods:
sENG was subcutaneously injected to mice with VEGF overexpression in the brain. After latex casting to visualize brain vasculature, dysplastic capillaries were measured by Zen software. Microglia was detected by iba-1 staining. In
in vitro
, sENG or vehicle was treated in BV2 microglial cell line and the cultured media from BV2 (BV2-CM) were transferred to primary mouse brain endothelial cell (EC). We determined the expression of inflammatory/angiogenic factors in the BV2 and EC, and tested the tube formation in the EC.

Results:
The sENG with VEGF induced dysplastic/enlarged capillaries in the mouse brain (8567 μm
2
± 2797 vs 2584 μm
2
± 763,
p
<0.01) and activated microglia were accumulated around the abnormal vessels. In
in vitro
study, sENG increased inflammatory cytokines (TNF-α and IL-6) and angiogenic mediators (MMP-9 and VEGF-A) in BV2 cells. The sENG-treated BV2-CM significantly increased angiogenic factors (Notch-1 and TGF-β) but decreased an anti-angiogenic factor (IL-17RD), and it was accompanied with increased pERK1/2 in EC. In addition, we observed that tube formation is significantly increased in EC treated with sENG-treated BV2-CM.

Conclusion:
The study shows that sENG-stimulated microglia released inflammatory and angiogenic factors and it regulates endothelial functions. It suggests that microglia may contribute to sENG-induced dysplastic capillary
via
regulating inflammatory and angiogenic factors.
Abstract TP491: Hypofractionated Stereotactic Radiosurgery for Brain AVM Post Aruba: Obliteration, Complication, and Hemorrhage Rates
Authors: Satti Sudhakar R , Shah Sunjay , Eden Tim , Rashid Arif , Shah Sohan
Published: June 2021

Introduction:
Patients harboring brain AVMs associated with moderate-high surgical morbidity (large lesions, deep location and eloquent cortex) are increasingly undergoing hypofractionated stereotactic radiosurgery (SRS) at our institution. Most published literature is based on a single fraction SRS technique. In this review we sought to evaluate/present our hypofractionated SRS experience using the Accuray Cyberknife device.

Hypothesis:
Cyberknife Stereotactic Radiosurgery (C-SRS) can be used for a high risk brain arteriovenous malformations (AVMs) with high rates of successful complete obliteration and low rates of hemorrhagic, death and major disability.

Methods:
We performed a retrospective analysis of all patients having undergone Cyberknife SRS for brain AVMs between 2013-2019 at a large community based tertiary care health system and identified 33 patients. Of these patients 12 had a minimum of 2 year follow-up. We divided the patients into hemorrhagic and non-hemorrhagic presentations, prior endovascular treatment with embolization and based on Spetzler Martin grades.

Results:
58% males with median age of 44 and 9% presenting with hemorrhage. Median planning target volume (PTV) was 7.2 cc (range 1.25-15.56 cc) and median HFSRT dose was three fractions (range 3-5) of 10.25 Gy (range 8.5-11 Gy) each. Complete obliteration was achieved in 100% of patients after salvage SRS 21 Gy x1 fraction to a residual AVM volume in 2 patients. The median time to obliteration was 747 days. 3 of 12 patients suffered radiation necrosis1 patient with a large AVM (maximum diameter of 4 cm and PTV of 12.6 cc) suffered re-hemorrhage and radiation necrosis, but ultimately completely obliterated after 402 days and was left with mRS ≤2).

Conclusion:
Although we have a small sample size, fractionated SRS with Cyberknife resulted in 100% obliteration, low rates recurrent hemorrhage and low morbidity (no mortality). These outcomes are superior to published single fraction radiosurgery results in high risk patients. Further study with a prospective multicenter registry or as part of a larger RCT is warranted.
Abstract TP492: Novel in vitro Model of Arteriovenous Malformation for Endovascular Embolization and Flow Analysis
Authors: Kaneko Naoki , Ullman Henrik , Ali Fadil , Berg Philipp , Ooi Yinn Cher , Tateshima Satoshi , Colby Geoffrey , Szeder Viktor , Nour May , Guo Lea , Hu Peng , Nemoto Shigeru , Komuro Yutaro , Hinman Jason , Duckwiler Gary , Jahan Reza
Published: June 2021

Introduction:
3D printed human vascular in vitro models of aneurysms and acute stroke have been utilized for training, simulation and device development. However, there are no realistic in vitro arteriovenous malformation (AVM) models. Current experimental models analyzing the efficacy of embolic materials or flow conditions are limited by their simplistic design, lacking complex AVM nidus anatomic features. The purpose of this study is to develop a new in vitro AVM model for embolic material testing and flow analysis.

Methods:
3D images of the AVM nidus were extracted from 3D rotational angiography from a patient. Artificial feeders and drainers were added to the nidus and an inner vascular mold was printed using a 3D printer. The inner mold was coated with polydimethylsiloxanes. The inner plastic mold was removed by acetone, leaving a hollow AVM model. ONYX injection and 4DFlow MRI (Phase Contrast MRA) were performed using the AVM models. In addition, computational fluid dynamics (CFD) analysis was performed to compare flow rate with 4DFlow MRI.

Results:
An in vitro AVM model with realistic representation of nidus vasculature and complexity was successfully created. Liquid onyx injection performed in the in vitro model successfully replicated real-life treatment conditions. The model effectively simulated plug and push technique before penetration of the ONYX into the AVM nidus. 4DFlow MRI flow rates were similar to the CFD analysis.

Conclusions:
An in vitro AVM model using 3D printing technology was successfully created. The model demonstrated realistic pliability during ONYX injection. This in vitro AVM model may represent a useful tool for training and development of new materials, and have potential of highly-resolved flow quantifications.
Abstract TP51: Comparison of Recanalization Rate Between Intravenous Actilyse and Intravenous Actilyse With Mechanical Thrombectomy in Larger Artery Occlusion Ischemic Stroke Patients
Authors: Im Sanghyuk , Yoo Do-Sung , Lee MinHyung , Cho Byung-Rae , Eun Jin , Ahn JaeKun , Park Haekwan
Published: June 2021

Background and Purpose:
According to the guidelines for acute ischemic stroke treatment, intravenous tissue plasminogen activator (IV-tPA) administration is the first line treatment and intraarterial thrombolysis (IA-Tx) with retrieval stent is regarded as additional treatment. But recanalization rate of large artery intracranial occlusion disease (LAICOD) after IV-tPA is very low and inconsistent according to the reports. Authors tried to find out the early recanalization rate of IV-tPA in patients with LAICOD.

Methods:
278 with anterior circulation occlusion patients were included in this analysis. Brain CT-angiography (CTA) was an initial imaging study and acute stroke MRI was following after the IV-tPA. Recanalization rate was studied with initial CTA and followed MRA image. And other clinical outcomes were compared with IV-tPA, IA-Tx or perfusion/diffusion-mismatching (P/D-mismatching) or not.

Results:
The overall recanalization rate of LAICOD after IV-tPA was 15.5% (43/278), 86.0% (86/100) in patients treated with IA-Tx after IV-tPA, and 78.7% (48/61) in IA-Tx without IV-tPA. In patients who underwent IA-Tx after IV-tPA, P/D-mismatching patients showed higher recanalization rate (88.2% = 67/76 vs. 66.7% = 16/27,
p
= 0.020), and higher incidence of favorable outcomes (63.2% = 48/76 vs. 12.5% = 3/27,
p
= 0.000) compared to P/D-matching patients.

Conclusion:
This study suggests that recanalization rate after IV-tPA for the patients with acute ischemic stroke due to LAICOD is very low and IV-tPA before IA-Tx does not significantly influence on the neurologic outcomes and complication rates. Bridging treatment is effective, for stroke patient management, but authors would like to propose that IA-Tx might be applied as the first therapy option, just like in the management of acute myocardial infarction patients.
Abstract TP52: Endovascular Therapy in Patients Over 80 Years of Age With Acute Ischemic Stroke
Authors: Modak Janhavi M , Asad Syed Daniyal , Lima Jussie , Nouh Amre , Staff Ilene , Ollenschleger Martin
Published: June 2021

Introduction:
Acute ischemic stroke treatment has undergone a paradigm shift, with patients being treated in the extended time window (6-24 hours post symptom onset). The purpose of this study is to assess outcomes in stroke patients above 80 years of age undergoing endovascular treatment (EVT) in the extended time window.

Methods:
Acute ischemic stroke patients presenting to Hartford Hospital between January 2017 to June 2019 were considered for the study. Stroke outcomes in patients above 80 years of age with anterior circulation ischemic strokes presenting in the extended time window (Group A, n=30) were compared to a younger cohort of patients below 80 years (Group B, n=31). Patients over 80 years treated in the traditional time window (within 6 hours of symptom onset) served as a second set of controls (Group C, n=40). Statistical analysis was performed with a significance level of 0.05

Results:
For angiographic results, there were no statistically significant differences in terms of good outcomes (TICI 2b-3) among patients of Group A, when compared to Groups B or C (p>0.05). For the endovascular procedures, no significant differences were noted in the total fluoroscopy time (Median Group A 44.05, Group B 38.1, Group C 35.25 min), total intra-procedure time (Median Group A 144, Group B 143, Group C 126 min) or total radiation exposure (Median Group A 8308, Group B 8960, Group C 8318 uGy-m
2
). For stroke outcomes, a good clinical outcome was defined as modified Rankin score of 0-2 at discharge. Significantly better outcomes were noted in the younger patients in Group B - 35.4%, when compared to 13.3% in Group A (p=0.03). Comparative outcomes differed in the elderly patients above 80 years, Group A -13.3% vs Group C - 25%, although not statistically significant (p=0.23). There was a significant difference in mortality in patients of Group A - 40% as compared to 12% in the younger cohort, Group B (p= 0.01).

Conclusions:
In the extended time window, patients above 80 years of age were noted to have a higher mortality, morbidity compared to the younger cohort of patients. No significant differences were noted in the stroke outcomes in patients above 80 years of age when comparing the traditional and the extended time window for stroke treatment.
Abstract TP53: How Do Physicians Approach Intravenous Alteplase Treatment in Acute Ischemic Stroke Patients? Insights From Unmask Evt, an International Multidisciplinary Study
Authors: Ospel Johanna M , Kashani Nima , Almekhlafi Mohammed , Menon Bijoy , Singh Ravinder , Fischer Urs , Saposnik Gustavo , Goyal Mayank , Hill Michael D
Published: June 2021

Background and Purpose:
With increasing use of endovascular therapy (EVT), physician attitudes towards intravenous alteplase in EVT-eligible patients may be changing. We explored current intravenous alteplase treatment practices of physicians and compared how their current treatment practice differs to an assumed ideal environment.

Methods:
In an international multidisciplinary survey, 607 physicians involved in acute stroke care were randomly assigned 10 of 22 case-scenarios, among them 14 with guideline-based recommendation for intravenous alteplase treatment, and asked how they would treat the patient: A) under their current local resources and B) under assumed ideal conditions, i.e. with no external restraints. Answer options were 1) anticoagulation/antiplatelet therapy, 2) EVT, 3) EVT plus intravenous alteplase and 4) intravenous alteplase . Decision rates were calculated and clustered multivariable regression analysis was performed to determine adjusted measures of effect size.

Results:
Physicians favored intravenous alteplase in 82.0% (85.0% in level 1A scenarios and 76.5% in level 2B scenarios) under current local resources and in 79.3% (82.4% in level 1A scenarios and 73.7% in level 2B scenarios) under assumed ideal conditions (difference between current and ideal rates: p<0.001 respectively). This discrepancy was driven by physicians who favored EVT alone rather than EVT in combination with intravenous alteplase . Interventional neuroradiologists favored dropping intravenous alteplase most often (6.28%), and this specialty was associated with greater odds of dropping intravenous alteplase (OR 1.97, p=.041).

Conclusion:
Participants of this survey currently favoured treating slightly more patients with intravenous alteplase than they would like to treat in an ideal environment.
Abstract TP55: The Use of Alternative Routes for the Delivery of Intra-Arterial Chemotherapy for Retinoblastoma
Authors: Sweid Ahmad , Hammoud Batoul , Texakalidis Pavlos , Xu Vivian , Shivashankar Kavya , Baldassari Michael , Das Somnath , Tjoumakaris Stavropoula. , Shields Carol L , Lezama David A , Lim Li-Anne S , Dalvin Lauren , Jabbour Pascal M
Published: June 2021

Background:
The introduction of intra-arterial chemotherapy (IAC) for treatment of retinoblastoma considerably changed the paradigm by which this disease is managed, with event-free survival rates being above 70%.

Objective:
Our aim is to analyze efficacy of IAC treatment using alternative approaches to OAC such as external carotid artery (ECA) approach or balloon-assisted drug delivery.

Methods:
This is a retrospective chart review for subjects receiving IAC for retinoblastoma. The primary approach was OAC. In cases where selective OAC was not feasible, alternative routes including catheterization of the ECA or use of a balloon-assisted drug infusion where used.

Results:
This study included 197 consecutive patients with 207 retinoblastomas who underwent 658 IAC procedures overall. The mean age at diagnosis was 24 months, and 54.5% of the study population was male. Success rate with IAC was 97% (639. Alternative approaches to OAC were in total 42 cases (6.4%) - external carotid artery catheterization and use of ICA balloon were performed in 22 (3.3%) and 20 (3%) cases respectively. A mean of 3.1 IAC cycles were performed for each patient. In total, 23 technical failures of the primary OAC technique (3.4%). Periprocedural adverse events occurred in 4 procedures (0.6%). Use of an alternative technique for chemotherapy delivery other than selective OAC in at least one IAC cycle was not a predictor of enucleation.

Conclusions:
IAC is a safe and effective treatment option for retinoblastoma. Chemotherapy delivery using alternative techniques is as effective as selective OAC.
Abstract TP58: Initial Non-Contrast Computed Tomography Predicts Atherosclerotic M1 Occlusions and Poor Functional Outcomes After Mechanical Thrombectomy
Authors: Weber Matthew , Ume Kiddy L , Dandapat Sudeepta , Zevallos Cynthia , Levy Abigail , Siddiqui Fazeel M , Ortega-Gutierrez Santiago
Published: June 2021

Introduction:
Intracranial atherosclerosis related occlusions (ICAS-O), occurring in 5-15% of all middle cerebral artery (MCA) infarcts, carry a poor functional outcome and high mortality despite mechanical thrombectomy (MT). We aimed to identify early non-contrast computed tomography (NCCT) predictors for ICAS-O and unfavorable outcomes in patients with M1 occlusions.

Methods:
We conducted a retrospective analysis of 104 consecutive patients presenting with acute M1 occlusions undergoing MT. Based on our previous observational experience, NCCT patterns that had been associated with atherosclerosis included the absence of visible hyperdense MCA sign, the presence of anterior temporal/insular hypodensity and the presence M1/M2 caliber asymmetry (diminutive vessels). These were used as predictors and were scored (1 for each) to build a 0-3 CT atherosclerosis score (CTAS) which was correlated with findings on cerebral angiogram, reperfusion status (TICI), 3-month Modified Rankin Scale (mRS), mortality, and other clinical variables.

Results:
CTAS was 3 in 16, 2 in 15, 1 in 41, and 0 in 30 patients. Two patients were excluded for poor quality NCCT. Age (69.1 ± 16.1), presenting NIHSS (15.7 ± 5.1), and time to groin (347.2 ± 281.4 min) were similar across all CTAS scores. Mortality and 3-month mRS both showed significant correlation with increasing CTAS (p=0.0198 and p=0.0111, respectively). CTAS 3 patients did poorly, carrying a mortality of 62.5%, and having a mean 3-month mRS of 5.1. The probability of unfavorable reperfusion (TICI 0, 1, and 2A) also increased with CTAS (p=0.0207). There was a significant correlation between CTAS and the presence of ICAS-O (p<0.00001), with 75%, 20%, 4.9%, and 0% of cases being ICAS-O on angiogram for CTAS 3, 2, 1, and 0, respectively. A CTAS of 3 was 70.6% sensitive and 95.3% specific for ICAS-O.

Conclusion:
Initial non-contrast CT can be used to predict atherosclerotic M1 occlusions, failed reperfusions, and poor functional outcomes after mechanical thrombectomy. Co-existence of the above 3 predictors (CTAS 3) is more than 95% specific for atherosclerotic M1 occlusions and may identify an at-risk population that may be considered for alternative treatment approaches in the future.