Covalent Fragment Inhibits RhoA Activation by Guanine Exchange Factors

Ras homolog gene family member (RhoA) is a GTPase and a member of the RAS superfamily of GTPases. RhoA is a master regulator of the actin cytoskeleton. It inhibits axon growth preventing repair and recovery following spinal cord and traumatic brain injuries. Despite decades of research into the biological function of Rho GTPases, there exist no small-molecule Rho inhibitors. Here, we screen a library of cysteine electrophiles to explore whether covalent bond formation at Cys-107 leads to inhibition of RhoA activation by guanine exchange factor Trio. Two fragments, propiolamide 1 (ACR-895) and acrylamide 2 (ACR-917), inhibited RhoA nucleotide exchange by Trio in a time-dependent manner. The fragments formed a covalent bond with wild-type RhoA but not Cys107Ser RhoA mutant. Time- and concentration-dependent studies led to equilibrium constants K_Is and reaction rates that correspond to t_1/2 values in the single-digit hour range. One fragment was selective for RhoA over Rac1 GTPase and had no effect on KRAS nucleotide exchange by SOS1. The fragments did not inhibit RhoA binding to ROCK effector protein. This work establishes Cys-107 as a suitable site for Rho GTPase inhibition and provides fragment starting points for the future development of Rho GTPase covalent inhibitors that could have profound implications in the treatment of patients with injuries of the central nervous system.

Abstract WMP85: Mobile Stroke Unit: Direct To Angio Or Some Stops Along The Way?

Introduction: Reducing the time from last known well to recanalization are associated with better functional outcomes and lower mortality in ischemic stroke. Recent data suggests that a “direct to angio” approach might improve the outcome of stroke patients with suspected emergent large vessel occlusion (ELVO). In this study, we aim to describe our direct-to-angiography vs those taken for additional imaging-first experience in our mobile stroke unit (MSU).

Methods: Retrospective chart review from 2014 until 2022 was done. Patients with acute ischemic stroke due to ELVO arriving via MSU to our tertiary care comprehensive stroke center were included. We compared outcomes of those who went directly to the angiography suite versus those who underwent additional imaging studies first.

Results: 14 patients with ELVO went directly to angio (DTA group) compared to 52 patients who underwent additional imaging (CTA group). There were no differences in age, gender, pre-morbid vascular risk factors or presenting symptoms. The DTA group had a higher median initial NIHSS and a higher interquartile range when compared to the CTA group but not significant. The DTA group received more thrombolytic therapy compared to the CTA group (p = 0.03). The DTA group had better door-to-groin times (median 39 minutes) compared to the CTA group (median 51.5 minutes) (p = 0.02). TICI 0 - 2a was more frequently seen in the DTA group (35.7%) compared to the CTA group (9.6%) (p = 0.03). Mortality was significantly higher in the DTA group compared to the CTA group (35% vs. 9%; p = 0.028) but there was no difference in functional outcomes amongst groups (mRS 0 - 2 28% vs 17%; p = 0.45). There was a non-significantly higher incidence of tandem occlusions in the DTA group (28.5%) compared to the CTA group (28.5% vs. 15%; p = 0.43).

Conclusions: In our analysis, those going direct to angiography from the MSU had less successful recanalization and increased mortality. These findings could also be related to the higher rate of tandem occlusions in the DTA group. Due to head only scanning being available on MSU, additional information from in-hospital scanning may offer other information which may influence selection of patients for the procedure. Further analysis of these paradigms, particularly on MSUs, are warranted.

Comparison of Mobile Stroke Unit With Usual Care for Acute Ischemic Stroke Management: A Systematic Review and Meta-analysis

IMPORTANCE

So far, uncertainty remains as to whether there is sufficient cumulative evidence that mobile stroke unit (MSU; specialized ambulance equipped with computed tomography scanner, point-of-care laboratory, and neurological expertise) use leads to better functional outcomes compared with usual care.

OBJECTIVE

To determine with a systematic review and meta-analysis of the literature whether MSU use is associated with better functional outcomes in patients with acute ischemic stroke (AIS).

DATA SOURCES

MEDLINE, Cochrane Library, and Embase from 1960 to 2021.

STUDY SELECTION

Studies comparing MSU deployment and usual care for patients with suspected stroke were eligible for analysis, excluding case series and case-control studies.

DATA EXTRACTION AND SYNTHESIS

Independent data extraction by 2 observers, following the PRISMA and MOOSE reporting guidelines. The risk of bias in each study was determined using the ROBINS-I and RoB2 tools. In the case of articles with partially overlapping study populations, unpublished disentangled results were obtained. Data were pooled in random-effects meta-analyses.

MAIN OUTCOMES AND MEASURES

The primary outcome was excellent outcome as measured with the modified Rankin Scale (mRS; score of 0 to 1 at 90 days).

RESULTS

Compared with usual care, MSU use was associated with excellent outcome (adjusted odds ratio [OR], 1.64; 95% CI, 1.27-2.13; P < .001; 5 studies; n = 3228), reduced disability over the full range of the mRS (adjusted common OR, 1.39; 95% CI, 1.14-1.70; P = .001; 3 studies; n = 1563), good outcome (mRS score of 0 to 2: crude OR, 1.25; 95% CI, 1.09-1.44; P = .001; 6 studies; n = 3266), shorter onset-to-intravenous thrombolysis (IVT) times (median reduction, 31 minutes [95% CI, 23-39]; P < .001; 13 studies; n = 3322), delivery of IVT (crude OR, 1.83; 95% CI, 1.58-2.12; P < .001; 7 studies; n = 4790), and IVT within 60 minutes of symptom onset (crude OR, 7.71; 95% CI, 4.17-14.25; P < .001; 8 studies; n = 3351). MSU use was not associated with an increased risk of all-cause mortality at 7 days or at 90 days or with higher proportions of symptomatic intracranial hemorrhage after IVT.

CONCLUSIONS AND RELEVANCE

Compared with usual care, MSU use was associated with an approximately 65% increase in the odds of excellent outcome and a 30-minute reduction in onset-to-IVT times, without safety concerns. These results should help guideline writing committees and policy makers.

Click functionalized biocompatible gadolinium oxide core-shell nanocarriers for imaging of breast cancer cells

Site-specific delivery using functionalized nanocarriers is in high demand in imaging applications of modern clinical research. To improve the imaging capabilities of conventionally used contrast agents and expand the targeting accuracy, functional gadolinium oxide based nanocarriers originated from homogeneous core shells structures (Gd₂O₃@SiO₂@Fe₃O₄) were developed using a multilayer formation approach. The synthesis and chemical configuration for the covalent binding of macrocyclic chelating agents and estrogen targeting molecules on these nanocarriers were designed by a two-step chemical synthesis method. Initially, SiO₂@Fe₃O₄ structures were prepared and encapsulated with a homogenous thin Gd₂O₃ overlayer. The exterior surface of the as-prepared carriers offered chemical binding with a breast cancer specific estrogen molecule, covalently grafted through a Click-Chemistry protocol. In the next step, to enhance the diagnostic imaging capabilities of these carriers, thiocyanate-linked chelator molecule, DOTA, was attached to the surface of estrogen bound Gd₂O₃@SiO₂@Fe₃O₄ using basic reaction conditions. The active amino groups before and after conjugation of estrogen molecules on the surface were quantified using a fluorescamine based approach. Due to the covalent binding of the macrocyclic chelator to the Gd₂O₃@SiO₂@Fe₃O₄ surface, core shell carriers showed potential radiolabeling efficiency using positron emitter radionuclide, gallium-68 (⁶⁸Ga). Intracellular uptake of estrogen-conjugated carriers was evaluated with MCF7 breast cancer cell lines using confocal laser scanning microscopy and fluorescent flow cytometry. In addition, in vitro cytotoxicity studies of functional nanocarriers as compared to bare nanoparticles showed reduced toxicity to HEK-293 cells demonstrating the role of surface attached molecules in preventing direct exposure of the Gd₂O₃ surface to the cells. The as-developed gadolinium based nanocarriers presented excellent capabilities as biocompatible target-specific imaging probes which indicates great potential in the field of dual-mode contrast agents.

Site-specific delivery using functionalized nanocarriers is in high demand in imaging applications of modern clinical research.

Correction: Click functionalized biocompatible gadolinium oxide core-shell nanocarriers for imaging of breast cancer cells

Correction for ‘Click functionalized biocompatible gadolinium oxide core-shell nanocarriers for imaging of breast cancer cells’ by Shifaa M. Siribbal et al., RSC Adv., 2022, 12, 31830–31845, https://doi.org/10.1039/D2RA00347C.

Up-regulation of GINS1 highlighted a good diagnostic and prognostic potential of survival in three different subtypes of human cancer

Cancer is a fatal malignancy and its increasing worldwide prevalence demands the discovery of more sensitive and reliable molecular biomarkers. To investigate the GINS1 expression level and its prognostic value in distinct human cancers using a series of multi-layered in silico approach may help to establish it as a potential shared diagnostic and prognostic biomarker of different cancer subtypes. The GINS1 mRNA, protein expression, and promoter methylation were analyzed using UALCAN and Human Protein Atlas (HPA), while mRNA expression was further validated via GENT2. The potential prognostic values of GINS1 were evaluated through KM plotter. Then, cBioPortal was utilized to examine the GINS1-related genetic mutations and copy number variations (CNVs), while pathway enrichment analysis was performed using DAVID. Moreover, a correlational analysis between GINS1 expression and CD8+ T immune cells and a the construction of gene-drug interaction network was performed using TIMER, CDT, and Cytoscape. The GINS1 was found down-regulated in a single subtypes of human cancer while commonly up-regulated in 23 different other subtypes. The up-regulation of GINS1 was significantly correlated with the poor overall survival (OS) of Liver Hepatocellular Carcinoma (LIHC), Lung Adenocarcinoma (LUAD), and Kidney renal clear cell carcinoma (KIRC). The GINS1 was also found up-regulated in LIHC, LUAD, and KIRC patients of different clinicopathological features. Pathways enrichment analysis revealed the involvement of GINS1 in two diverse pathways, while few interesting correlations were also documented between GINS1 expression and its promoter methylation level, CD8+ T immune cells level, and CNVs. Moreover, we also predicted few drugs that could be used in the treatment of LIHC, LUAD, and KIRC by regulating the GINS1 expression. The expression profiling of GINS1 in the current study has suggested it a novel shared diagnostic and prognostic biomarker of LIHC, LUAD, and KIRC.

Is the Management of Rectal Cancer Using a Watch and Wait Approach Feasible, Safe and Effective in a Publicly Funded General Hospital?

AIMS

Although there is emerging evidence to suggest equivalent oncological outcomes using a watch and wait approach compared with primary total mesorectal excision surgery, there is a paucity of evidence about the safety and efficacy of this approach in routine clinical practice. Here we report the long-term outcomes and quality of life from patients managed with watch and wait following a clinical complete response (cCR) to neoadjuvant therapy.

MATERIALS AND METHODS

Patients with adenocarcinoma of the rectum with cCR following neoadjuvant therapy managed using watch and wait were retrospectively identified. Demographic data, performance status, pretreatment staging information, oncological and surgical outcomes were obtained from routinely collected clinical data. Quality of life was measured by trained clinicians during telephone interviews.

RESULTS

Over a 7-year period, 506 patients were treated for rectal cancer, 276 had neoadjuvant therapy and 72 had a cCR (26.1%). Sixty-three were managed with watch and wait. Thirteen patients had mucosal regrowth. There was no significant difference in the incidence of metastatic disease between the surgical and watch and wait cohorts (P = 0.38). The 13 patients with mucosal regrowth underwent salvage surgery. Eleven of the patients who underwent surgical resection had R0 resections. There was also a statistically and clinically significant improvement in the Functional Assessment of Cancer Therapy - Colorectal (FACT-C) trial outcome index (P = 0.022).

CONCLUSION

This study shows that watch and wait is safe and effective outside of tertiary referral centres. It suggests that an opportunistic cCR is durable and when mucosal regrowth occurs it can be salvaged. Finally, we have shown that quality of life is probably improved if a watch and wait approach is adopted.

Mitogen and Stress-Activated Kinases 1 and 2 Mediate Endothelial Dysfunction

Inflammation promotes endothelial dysfunction, but the underlying mechanisms remain poorly defined in vivo. Using translational vascular function testing in myocardial infarction patients, a situation where inflammation is prevalent, and knock-out (KO) mouse models we demonstrate a role for mitogen-activated-protein-kinases (MAPKs) in endothelial dysfunction. Myocardial infarction significantly lowers mitogen and stress kinase 1/2 (MSK1/2) expression in peripheral blood mononuclear cells and diminished endothelial function. To further understand the role of MSK1/2 in vascular function we developed in vivo animal models to assess vascular responses to vasoactive drugs using laser Doppler imaging. Genetic deficiency of MSK1/2 in mice increased plasma levels of pro-inflammatory cytokines and promoted endothelial dysfunction, through attenuated production of nitric oxide (NO), which were further exacerbated by cholesterol feeding. MSK1/2 are activated by toll-like receptors through MyD88. MyD88 KO mice showed preserved endothelial function and reduced plasma cytokine expression, despite significant hypercholesterolemia. MSK1/2 kinases interact with MAPK-activated proteins 2/3 (MAPKAP2/3), which limit cytokine synthesis. Cholesterol-fed MAPKAP2/3 KO mice showed reduced plasma cytokine expression and preservation of endothelial function. MSK1/2 plays a significant role in the development of endothelial dysfunction and may provide a novel target for intervention to reduce vascular inflammation. Activation of MSK1/2 could reduce pro-inflammatory responses and preserve endothelial vasodilator function before development of significant vascular disease.

Infarct Growth despite Successful Endovascular Reperfusion in Acute Ischemic Stroke: A Meta-analysis

BACKGROUND

Infarct volume inversely correlates with good recovery in stroke. The magnitude and predictors of infarct growth despite successful reperfusion via endovascular treatment are not known.

PURPOSE

We aimed to summarize the extent of infarct growth in patients with acute stroke who achieved successful reperfusion (TICI 2b-3) after endovascular treatment.

DATA SOURCES

We performed a systematic review and meta-analysis by searching MEDLINE and Google Scholar for articles published up to October 31, 2020.

STUDY SELECTION

Studies of >10 patients reporting baseline and post-endovascular treatment infarct volumes on MR imaging were included. Only patients with TICI 2b-3 were included. We calculated infarct growth at a study level as the difference between baseline and follow-up MR imaging infarct volumes.

DATA ANALYSIS

Our search yielded 345 studies, and we included 10 studies reporting on 973 patients having undergone endovascular treatment who achieved successful reperfusion.

DATA SYNTHESIS

The mean baseline infarct volume was 19.5 mL, while the mean final infarct volume was 37.5 mL. A TICI 2b reperfusion grade was achieved in 24% of patients, and TICI 2c or 3 in 76%. The pooled mean infarct growth was 14.8 mL (95% CI, 7.9-21.7 mL). Meta-regression showed higher infarct growth in studies that reported higher baseline infarct volumes, higher rates of incomplete reperfusion (modified TICI 2b), and longer onset-to-reperfusion times.

LIMITATIONS

Significant heterogeneity among studies was noted and might be driven by the difference in infarct growth between early- and late-treatment studies.

CONCLUSIONS

These results suggest considerable infarct growth despite successful endovascular treatment reperfusion and call for a faster workflow and the need for specific therapies to limit infarct growth.

Engineering of a critical membrane-anchored enzyme for high solubility and catalytic activity

Membrane-associated proteins carry out a wide range of essential cellular functions but the structural characterization needed to understand these functions is dramatically underrepresented in the Protein Data Bank. Producing a soluble, stable and active form of a membrane-associated protein presents formidable challenges, as evidenced by the variety of approaches that have been attempted with a multitude of different membrane proteins to achieve this goal. Aspartate N-acetyltransferase (ANAT) is a membrane-anchored enzyme that performs a critical function, the synthesis of N-acetyl-l-aspartate (NAA), the second most abundant amino acid in the brain. This amino acid is a precursor for a neurotransmitter, and alterations in brain NAA levels have been implicated as a causative effect in Canavan disease and has been suggested to be involved in other neurological disorders. Numerous prior attempts have failed to produce a soluble form of ANAT that is amenable for functional and structural investigations. Through the application of a range of different approaches, including fusion partner constructs, linker modifications, membrane-anchor modifications, and domain truncations, a highly soluble, stable and fully active form of ANAT has now been obtained. Producing this modified enzyme form will accelerate studies aimed at structural characterization and structure-guided inhibitor development.

Abstract P83: Acute Stroke Presentations During the Course of the COVID-19 Pandemic

Background: Decline in presentations of acute stroke during the early period of COVID-19 pandemic have been reported. We aimed to investigate the stroke presentations during the subsequent months as the pandemic evolved into a second wave.

Methods: Data was obtained from a health system with 19 emergency departments (EDs) in northeast Ohio in the United States. Baseline period from January 1 to February 29, 2020, was compared with the individual months during COVID-19 period from March through July. Variables included were numbers of daily stroke alerts across the EDs, thrombolysis, thrombectomy, time to presentation, stroke severity, time from door-to-needle in thrombolysis, and door-to puncture in thrombectomy. The time periods were compared using nonparametric statistics and Poisson regression with month, weekend, and daily COVID cases as independent variables.

Results: A total of 2264 stroke alerts from EDs were analyzed between January 1 to July 31, 2020. Total daily stroke alerts decreased from a median of 10 (interquartile range [IQR]:10-13) in January and February to 9 (IQR:6-11, p=0.001) in March, 8(IQR:7-10, p=0.0001) in April, 10 (IQR:8-11, p=0.04) in May, and returned similar to baseline in June (12, IQR:10-13, p=0.5) and July (13, IQR:11-14,p=0.1). In Poisson regression, stroke alert numbers showed no significant association with daily COVID-19 counts, but significant association with months, with rate ratios of 0.74 (95%CI 0.64-0.85) for March, 0.71 (95%CI 0.61-0.82) for April, and 0.86 (95%CI 0.75-0.98) for May, but not with June and July. Time to presentation and stroke severity were unchanged throughout the study period. Thrombolysis volume decreased in March and May but thrombectomy volume was unchanged.

Conclusion: We observed a decrease in stroke presentations across emergency departments by about 30% during the early period of COVID-19 pandemic, followed by return to baseline frequency despite a second wave of COVID-19 cases.

RRP7A links primary microcephaly to dysfunction of ribosome biogenesis, resorption of primary cilia, and neurogenesis

Primary microcephaly (MCPH) is characterized by reduced brain size and intellectual disability. The exact pathophysiological mechanism underlying MCPH remains to be elucidated, but dysfunction of neuronal progenitors in the developing neocortex plays a major role. We identified a homozygous missense mutation (p.W155C) in Ribosomal RNA Processing 7 Homolog A, RRP7A, segregating with MCPH in a consanguineous family with 10 affected individuals. RRP7A is highly expressed in neural stem cells in developing human forebrain, and targeted mutation of Rrp7a leads to defects in neurogenesis and proliferation in a mouse stem cell model. RRP7A localizes to centrosomes, cilia and nucleoli, and patient-derived fibroblasts display defects in ribosomal RNA processing, primary cilia resorption, and cell cycle progression. Analysis of zebrafish embryos supported that the patient mutation in RRP7A causes reduced brain size, impaired neurogenesis and cell proliferation, and defective ribosomal RNA processing. These findings provide novel insight into human brain development and MCPH.

The RRP7A a gene is involved in ribosome biogenesis. Here the authors report a homozygous missense mutation segregating with primary microcephaly, and show that this occurs via functional defects in both nucleoli and primary cilia disrupting cell proliferation and neurogenesis.

A randomized controlled trial of metformin on left ventricular hypertrophy in patients with coronary artery disease without diabetes: the MET-REMODEL trial

Aim

We tested the hypothesis that metformin may regress left ventricular hypertrophy (LVH) in patients who have coronary artery disease (CAD), with insulin resistance (IR) and/or pre-diabetes.

Methods and results

We randomly assigned 68 patients (mean age 65 ± 8 years) without diabetes who have CAD with IR and/or pre-diabetes to receive either metformin XL (2000 mg daily dose) or placebo for 12 months. Primary endpoint was change in left ventricular mass indexed to height^1.7 (LVMI), assessed by magnetic resonance imaging. In the modified intention-to-treat analysis (n = 63), metformin treatment significantly reduced LVMI compared with placebo group (absolute mean difference −1.37 (95% confidence interval: −2.63 to −0.12, P = 0.033). Metformin also significantly reduced other secondary study endpoints such as: LVM (P = 0.032), body weight (P = 0.001), subcutaneous adipose tissue (P = 0.024), office systolic blood pressure (BP, P = 0.022) and concentration of thiobarbituric acid reactive substances, a biomarker for oxidative stress (P = 0.04). The glycated haemoglobin A1C concentration and fasting IR index did not differ between study groups at the end of the study.

Conclusion

Metformin treatment significantly reduced LVMI, LVM, office systolic BP, body weight, and oxidative stress. Although LVH is a good surrogate marker of cardiovascular (CV) outcome, conclusive evidence for the cardio-protective role of metformin is required from large CV outcomes trials.

Cost-Consequence Analysis of Mobile Stroke Units vs. Standard Prehospital Care and Transport

Background: Mobile stroke units (MSUs) are the latest approach to improving time-sensitive stroke care delivery. Currently, there are no published studies looking at the expanded value of the MSU to diagnose and transport patients to the closest most appropriate facility. The purpose of this paper is to perform a cost consequence analysis of standard transport (ST) vs. MSU.

Methods and Results: A cost consequence analysis was undertaken within a decision framework to compare the incremental cost of care for patients with confirmed stroke that were served by the MSU vs. their simulated care had they been served by standard emergency medical services between July 2014 and October 2015. At baseline values, the incremental cost between MSU and ST was $70,613 ($856,482 vs. $785,869) for 355 patient transports. The MSU avoided 76 secondary interhospital transfers and 76 emergency department (ED) encounters. Sensitivity analysis identified six variables that had measurable impact on the model's variability and a threshold value at which MSU becomes the optimal strategy: number of stroke patients (>391), probability of requiring transfer to a comprehensive stroke center (CSC, >0.52), annual cost of MSU operations (<$696,053), cost of air transfer (>$8,841), probability initial receiving hospital is a CSC (<0.32), and probability of ischemic stroke with ST (<0.76).

Conclusions: MSUs can avert significant costs in the administration of stroke care once optimal thresholds are achieved. A comprehensive cost-effectiveness analysis is required to determine not just the operational value of an MSU but also its clinical value to patients and the society.

Abstract 34: Outcomes of Thrombolysis on Mobile Stroke Unit

Introduction: Mobile stroke Units (MSU) can shorten the time to intravenous thrombolytic therapy (IVT) in patients with acute ischemic stroke. We aimed to demonstrate the effects of pre-hospital IVT on clinical outcomes.

Methods: We reviewed patients received IVT from July 2014 to December 2017, and compared patients with pre-hospital IVT on MSU with patients brought to the ED via a conventional ambulance. The primary outcome was the modified Rankin scale score (mRS) of 1 or better at 90 days. Binary logistic regression model of 90-day mRS for 0-1 vs 2-6 was adjusted for age, initial National Institutes of Health Stroke Scale (NIHSS) score, and pre-morbid mRS.

Results: Seventy eight patients were treated in the MSU and 153 patients were received IVT in the ED. There were no significant differences in gender, age, pre-morbid mRS, initial NIHSS score, and risk factors between the MSU group and the ED group. The MSU patients received thrombolysis 38 minutes earlier from onset than the ED patients (median 79 minutes compared to117 minutes, p<0.001). In an unadjusted analysis, the difference in primary outcome between MSU group and ED group was not significant (41% with MSU vs 29% with ED, p=0.061, Figure). After adjustment for age, initial NIHSS score, and pre-morbid mRS, the odds ratio for mRS of 0-1 at 90 days with IVT on MSU compared to ED for was 2.09 (95% confidence interval (CI), 1.02-4.28, p = 0.044). Further adjustment for the time from onset to thrombolytic treatment, the effect of MSU on 90-day mRS was attenuated and no longer significant (odds ratio 1.65, 95% CI, 0.77-3.55, p=0.196).

Conclusion: Pre-hospital IVT on MSU compared to conventional care shortened the time to thrombolytic treatment and was associated with improved functional outcomes in patients with acute ischemic stroke.

Abstract TMP19: Mobile Stroke Units have Higher Rates of Recanalization of Emergent Large Vessel Occlusion

Introduction: Emergent Large Vessel Occlusion (ELVO) has low recanalization rates with intravenous tissue plasminogen activator (IV tPA). Ultra-early treatment with IV tPA, however, may lead to higher recanalization rates. Mobile stroke units (MSUs) have been shown to reduce treatment times. We compared the recanalization rates of ELVO patients treated on our MSUs against those treated in the traditional emergency department (ED) setting.

Methods: We reviewed patients from two MSU programs who were identified to have ELVO treated either in the ED or on the MSU from August 2014 to July 2017. Demographics, imaging characteristics, times to treatment, and recanalization rates were collected and analyzed. Statistical comparison was performed utilizing chi-squared and t-tests.

Results: One hundred ninety (34 treated on MSU, 156 treated in the ED) ELVO patients were included in the analysis. Baseline characteristics including age (70 years MSU vs. 66 years in ED); sex (MSU 50% female vs. ED 46.8% female) and vessel occlusion location (ICA: MSU 23.5% vs. ED 25.2%; MCA: MSU 67.6% vs. ED 66.9%) were similar between the two groups. However, the MSU group had a higher initial median National Institutes of Health Stroke Scale (NIHSS) score (15.5 vs. 11.6; p = 0.01). The MSU group also had a shorter time from stroke onset to treatment (70 minutes vs. 126 minutes; p = 0.001). Recanalization of ELVO was seen more frequently on the MSU as compared to in the ED (29.4% vs. 22%; p=0.04).

Conclusion: Higher recanalization rate of ELVO was observed with thrombolysis on mobile stroke units as compared to the emergency department.

Cerebrospinal fluid drainage and blood pressure elevation to treat acute spinal cord infarct

BACKGROUND

Current management of acute spinal cord infarction (SCI) is limited. Lumbar cerebrospinal fluid drainage (CSFD) with blood pressure augmentation is utilized in the thoracic/thoracoabdominal aortic repair and thoracic endovascular aortic repair (TEVAR) populations to increase spinal perfusion pressure.

CASE DESCRIPTION

We identified 3 patients who sustained acute SCI and underwent CSFD and maintenance of elevated mean arterial pressure (MAP) within 24 hours of injury. The first patient exhibited delayed-onset ischemia after a TEVAR. The second patient presented with an acute type B aortic intramural hematoma. The third patient developed spinal cord ischemia following bronchial artery embolization. There was significant improvement in the motor examination (e.g., ASIA impairment scale grade B or C) to grade D utilizing both blood pressure augmentation and CSFD.

CONCLUSIONS

Lumbar CSFD with MAP elevation benefited 3 patients with acute SCI of varying etiologies.

Abstract WP226: Bypassing Interhospital Transfers for Large Vessel Occlusions in the Era of Mobile Stroke Units

Introduction: Mobile stroke units (MSU) provide prehospital intravenous thrombolysis (IVT) for patients with acute ischemic strokes and transport to thrombectomy-capable stroke centers. Door-in-door-out (DIDO) time is recognized as a measure of efficient workflow for interhospital transfer of patients for thrombectomy. We applied this measure to the MSU and compared with our Primary Stroke Center (PSC) transfer process in patients presenting with large vessel occlusions.

Methods: We identified 50 patients who underwent thrombectomy for large vessel occlusion in a retrospective review. Mode of transport included MSU (n=18), conventional ambulance from PSC to Comprehensive Stroke Center (CSC) (n=19), or directly presenting to a CSC (n=13) in 2016-2017. Measured outcomes included times for PSC DIDO, MSU DIDO (MSU door to scene departure), door-to-CT, door-to-needle (DTN), and door-to-groin.

Results: Among thrombectomy patients, IVT was more likely to be administered in a MSU (55.6%, n=10), than either a PSC (36.8%, n=7) or CSC (38.5%, n=5). Door-to-CT completed times were significantly lower in the MSU versus PSC (27 vs. 44 minutes, p<0.01). DTN times in MSU were significantly shorter than PSC DTN times (27 vs. 56 minutes, p<0.01), as were the median DTN times between CSC vs. PSC (27 vs. 56 minutes, p=0.09). Median DTN times comparing CSC vs. MSU were the same (27 minutes, p=0.33). DIDO time was reduced for MSU patients compared to PSC patients (27 vs. 87 minutes, p<0.01). Door-to-groin times for MSU patients compared to PSC patients was significantly reduced (97 minutes vs. 171 minutes, p<0.01). Door-to-groin times for CSC patients were comparable to MSU patients (100 minutes vs. 97 minutes, p=0.97).

Conclusion: Advanced stroke systems of care which include a MSU are highly efficient in both IVT and transport for potential thrombectomy among patients presenting with large vessel occlusion. We introduce a concept of a MSU functioning as a mobile PSC, thus bypassing interhospital transfers.

Abstract TP223: Then and Now: Temporal Evolution of a Mobile Stroke Unit

Introduction: Mobile stroke units (MSU) deliver pre-hospital intravenous thrombolysis (IVT) to patients with acute ischemic stroke. We hypothesize that time efficiencies with the MSU have improved over time with a dedicated team and experience.

Methods: We reviewed 100 consecutive patients evaluated on the MSU from July-October 2014 (Group 1), compared to the most recent 100 patients April-July 2017 (Group 2). Collected data including initial NIHSS, patient age, door to CT performance time, door to CT read time, door to needle (DTN) time, alarm to IVT time, MSU scene arrival to departure time, and MSU alarm to back-in-service time were analyzed with rank sum test. Reported times are in medians with interquartile ranges (IQR).

Results: Initial median NIHSS (6, IQR 3-12, p=0.78) and ages (65 years old, IQR 55-80, p=0.06) were comparable between the groups. Thrombolysis rate was 16% (n=16) in each cohort. Group 1’s DTN time declined from 31 to 23 minutes (p=0.01). Door to CT completion and read times were faster, at 17 versus 25 minutes (p<0.01), and 10 versus 13 minutes (p<0.01) for Group 2 and Group 1 respectively. MSU arrival to departure time also reduced from 43 to 30 minutes (p<0.01), with total MSU utilization time significantly improved from 88 minutes to 74 minutes (p<0.01) in Group 1 compared to Group 2. While alarm to door times extended from 20 minutes to 22 minutes in Group 2 (p=0.03), the alarm to IVT time was reduced from 55 minutes to 41 minutes (p<0.01).

Conclusion: While the MSU geographical range has extended, the alarm to IVT time has shortened, reflecting a learned experience by a specialized team.

Interhospital Transfer Before Thrombectomy Is Associated With Delayed Treatment and Worse Outcome in the STRATIS Registry (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke)

Supplemental Digital Content is available in the text.

Background:

Endovascular treatment with mechanical thrombectomy (MT) is beneficial for patients with acute stroke suffering a large-vessel occlusion, although treatment efficacy is highly time-dependent. We hypothesized that interhospital transfer to endovascular-capable centers would result in treatment delays and worse clinical outcomes compared with direct presentation.

Methods:

STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) was a prospective, multicenter, observational, single-arm study of real-world MT for acute stroke because of anterior-circulation large-vessel occlusion performed at 55 sites over 2 years, including 1000 patients with severe stroke and treated within 8 hours. Patients underwent MT with or without intravenous tissue plasminogen activator and were admitted to endovascular-capable centers via either interhospital transfer or direct presentation. The primary clinical outcome was functional independence (modified Rankin Score 0–2) at 90 days. We assessed (1) real-world time metrics of stroke care delivery, (2) outcome differences between direct and transfer patients undergoing MT, and (3) the potential impact of local hospital bypass.

Results:

A total of 984 patients were analyzed. Median onset-to-revascularization time was 202.0 minutes for direct versus 311.5 minutes for transfer patients (P<0.001). Clinical outcomes were better in the direct group, with 60.0% (299/498) achieving functional independence compared with 52.2% (213/408) in the transfer group (odds ratio, 1.38; 95% confidence interval, 1.06–1.79; P=0.02). Likewise, excellent outcome (modified Rankin Score 0–1) was achieved in 47.4% (236/498) of direct patients versus 38.0% (155/408) of transfer patients (odds ratio, 1.47; 95% confidence interval, 1.13–1.92; P=0.005). Mortality did not differ between the 2 groups (15.1% for direct, 13.7% for transfer; P=0.55). Intravenous tissue plasminogen activator did not impact outcomes. Hypothetical bypass modeling for all transferred patients suggested that intravenous tissue plasminogen activator would be delayed by 12 minutes, but MT would be performed 91 minutes sooner if patients were routed directly to endovascular-capable centers. If bypass is limited to a 20-mile radius from onset, then intravenous tissue plasminogen activator would be delayed by 7 minutes and MT performed 94 minutes earlier.

Conclusions:

In this large, real-world study, interhospital transfer was associated with significant treatment delays and lower chance of good outcome. Strategies to facilitate more rapid identification of large-vessel occlusion and direct routing to endovascular-capable centers for patients with severe stroke may improve outcomes.

Clinical Trial Registration:

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02239640.

Flow Diverter Treatment of Tandem Intracranial Aneurysms

OBJECTIVE

To assess technical success and clinical and imaging outcomes of flow diversion (FD) treatment of multiple, tandem intracranial aneurysms.

METHODS

Retrospective analysis was performed of patients treated with FD for tandem intracranial aneurysms.

RESULTS

Twenty female patients with a mean (±SD) age of 60 (±12) years were included. One patient was treated after subarachnoid hemorrhage. In 22 separate procedures, 47 aneurysms, all located in the intracranial internal carotid artery, were treated. In 3 cases, treatment was performed for aneurysm recurrence after previous endovascular treatment. All aneurysms were successfully treated in 1 session. A single stent was used in most (82%) cases, with no adjunctive coiling. There were no intraprocedural complications. Three patients experienced mild, transient neurologic symptoms after the procedure with no long-term neurologic deficits. Follow-up imaging with digital subtraction angiography and/or contrast-enhanced magnetic resonance angiography was available in 18/20 (90%) patients at an average (±SD) of 18.8 (±11.2) months. Of 40 aneurysms with follow-up imaging, 34 (85%) were completely occluded. Clinical follow-up, available in 20/20 (100%) patients, showed that 19/20 (95%) achieved a modified Rankin Scale score of 0-2. There were no cases of aneurysm rupture after treatment, and no patients required retreatment at last available follow-up.

CONCLUSIONS

FD appears technically feasible, safe, and effective for treatment of tandem intracranial aneurysms, with potential advantages over traditional endovascular or surgical treatment modalities. Larger studies are needed to confirm these findings.

Reduction in time to treatment in prehospital telemedicine evaluation and thrombolysis

OBJECTIVE

To compare the times to evaluation and thrombolytic treatment of patients treated with a telemedicine-enabled mobile stroke treatment unit (MSTU) vs those among patients brought to the emergency department (ED) via a traditional ambulance.

METHODS

We implemented a MSTU with telemedicine at our institution starting July 18, 2014. A vascular neurologist evaluated each patient via telemedicine and a neuroradiologist and vascular neurologist remotely assessed images obtained by the MSTU CT. Data were entered in a prospective registry. The evaluation and treatment of the first 100 MSTU patients (July 18, 2014-November 1, 2014) was compared to a control group of 53 patients brought to the ED via a traditional ambulance in 2014. Times were expressed as medians with their interquartile ranges.

RESULTS

Patient and stroke severity characteristics were similar between 100 MSTU and 53 ED control patients (initial NIH Stroke Scale score 6 vs 7, p = 0.679). There was a significant reduction of median alarm-to-CT scan completion times (33 minutes MSTU vs 56 minutes controls, p < 0.0001), median alarm-to-thrombolysis times (55.5 minutes MSTU vs 94 minutes controls, p < 0.0001), median door-to-thrombolysis times (31.5 minutes MSTU vs 58 minutes controls, p = 0.0012), and symptom-onset-to-thrombolysis times (97 minutes MSTU vs 122.5 minutes controls, p = 0.0485). Sixteen patients evaluated on MSTU received thrombolysis, 25% of whom received it within 60 minutes of symptom onset.

CONCLUSION

Compared with the traditional ambulance model, telemedicine-enabled ambulance-based thrombolysis resulted in significantly decreased time to imaging and treatment.

Genetic heterogeneity in Pakistani microcephaly families revisited

Autosomal recessive primary microcephaly (MCPH) is a rare and heterogeneous genetic disorder characterized by reduced head circumference, low cognitive prowess and, in general, architecturally normal brains. As many as 14 different loci have already been mapped. We recruited 35 MCPH families in Pakistan and could identify the genetic cause of the disease in 31 of them. Using homozygosity mapping complemented with whole-exome, gene panel or Sanger sequencing, we identified 12 novel mutations in 3 known MCPH-associated genes - 9 in ASPM, 2 in MCPH1 and 1 in CDK5RAP2. The 2 MCPH1 mutations were homozygous microdeletions of 164,250 and 577,594 bp, respectively, for which we were able to map the exact breakpoints. We also identified four known mutations - three in ASPM and one in WDR62. The latter was initially deemed to be a missense mutation but we demonstrate here that it affects splicing. As to ASPM, as many as 17 out of 27 MCPH5 families that we ascertained in our sample were found to carry the previously reported founder mutation p.Trp1326*. This study adds to the mutational spectra of four known MCPH-associated genes and updates our knowledge about the genetic heterogeneity of MCPH in the Pakistani population considering its ethnic diversity.

Abstract WP72: Early Experience on Intravenous Tissue Plasminogen Activator Delivery in Mobile Stroke Unit Patients with Stroke Mimics

Background: A mobile stroke unit (MSU) allows for early delivery for intravenous tissue plasminogen activator (IV-tPA). A proportion of IV-tPA treated patients may turn out to be stroke mimics. We evaluated the rate and complications seen in stroke mimics treated with tPA from our early experience on MSU.

Methods: Retrospective review of patients treated with IV-tPA on the MSU from 2014 to 2016. Charts were reviewed for confirmed strokes by imaging (MRI or CT) and hemorrhagic transformation. Stroke mimics were defined as those without imaging evidence of infarction and a final diagnosis which was not suspected to be stroke.

Results: Among 62 patients treated with IV-tPA, 14 (28.6%) had a final diagnosis consistent with a stroke mimics. The majority of these occurred in the first year of the MSU program. Most common mimics included conversion disorder (n=5) and seizures (n=5). While the last known well to IV-tPA times were similar, the MSU door-to-needle time was significantly longer in stroke mimics (38 vs 31 minutes, p = 0.03). No intracerebral hemorrhages or other IV-tPA related complications were identified in the stroke mimics group.

Conclusions: In our early experience with MSU, treatment of stroke mimics occurred without IV-tPA related complications. This does not appear to be due to rushed decision making.

Abstract TP230: Prehospital Timeline of Mobile Stroke Treatment Unit and Traditional Ambulance

Introduction: Prehospital evaluation and response is vital to effective and early delivery of acute stroke treatment. We aimed to compare the times across various prehospital times among stroke patients arriving by municipal EMS and MSTU.

Methods: We performed a retrospective study of 107 patients with a final diagnosis of ischemic stroke within our hospital system from June 2014 to July 2015. We compared on scene arrival, hospital arrival, and time of physician assessment of patients evaluated on MSTU to traditional municipal EMS. Times are reported as medians and groups were compared by Rank-Sum Test.

Results: Of 107 patients, 49 patients were evaluated by traditional EMS and 58 evaluated by MSTU. Time from dispatch to scene arrival was median 9 min (IQR 5.5 - 12min) in EMS group and median 12 min (IQR 8-16 min) n MSTU (p&lt0.01). Time on scene was 17 min (IQR 14 - 24min) in EMS group and median 42 min (IQR 36-48 min) in MSTU. There was no difference within the MSTU group in time on-scene among those treated with IV tpA (43 min) and those without (41 min, p=.08 ). After dispatch, patients arrived in hospital by EMS earlier (median 40 min, IQR 33-49min) than by MSTU (median 72 min, IQR 58-81min, p&lt.01), but patients on MSTU were evaluated by a physician at median 28 (IQR 21.5-34.5) min after dispatch.

Conclusion: Early evaluation of ischemic stroke patients with MSTU, doubles the time on scene compared to municipal EMS.

Abstract WP85: Flow-diverter Embolization for Tandem Intracranial Aneurysms: A Single Center Experience

Introduction: Flow diverter embolization is a novel method to treat intracranial aneurysms. The device has been shown to reduce procedure time and radiation exposure along with excellent long-term occlusion rates for single lesions. However, the effect of flow diversion on multiple adjacent aneurysms has not been well studied. We present our single center experience with flow diverter treatment of tandem aneurysms.

Methods: We retrospectively collected clinical, imaging, procedural and follow up data on patients in whom flow diverters were used to treat intracranial anterior circulation aneurysms between 2011 and 2016. We included patients who had 2 or more tandem aneurysms of the internal carotid artery segment and where flow diverter was intended to treat all the aneurysms either as primary or secondary method.

Results: We identified 21 patients with 52 aneurysms that met inclusion criteria. All were females with median age of 57 (Interquartile range [IQR] 51 - 69). Seventeen patients had 2 adjacent aneurysms, while 4 patients had 3 contiguous aneurysms. Of these, only one patient was treated acutely for ruptured aneurysm. The median largest aneurysm diameter was 3.1mm (IQR 2.5 - 4.8) with most common locations being cavernous and ophthalmic aneurysms. In 19 patients (90.5%) only a single flow diverter stent was used; only one patient required concurrent coiling. One patient (4.8%) suffered a post procedural mild stroke but improved rapidly. There were no other procedural complications. Follow up data in 13 patients (61.9%) with a median follow up of 8 months (IQR 6 - 13) demonstrated that 20 out of 28 aneurysms showed complete occlusion (71.4%). None of the patients at follow up required re-treatment, and there were no delayed/late aneurysm ruptures.

Conclusion: Flow diverter is a feasible, efficacious and safe treatment option in patients with multiple tandem aneurysms, in a single session with good early outcomes. Long term follow up data and large cohort studies are required.

Safety and outcomes of simultaneous vasospasm and endovascular aneurysm treatment (SVAT) in subarachnoid hemorrhage

Background

Simultaneous vasospasm and endovascular aneurysm treatment (SVAT) has been shown to be effective with good clinical outcomes in small series, but these studies have not examined predictive factors for clinical outcome after treatment.

Objective

To identify the safety and efficacy of SVAT in a large multicenter patient cohort and evaluate prognostic markers of clinical outcome following SVAT.

Methods

This study retrospectively enrolled 50 consecutive patients undergoing SVAT at 11 different centers. We analyzed Hunt and Hess and Fisher grades, aneurysm location, angiographic vasospasm grade, Glasgow Outcome Scale (GOS) at discharge, and 90-day modified Rankin Scale (mRS) scores.

Results

A total of 50 patients undergoing SVAT between the years 2003 and 2009 were identified. Patients presented, on average, 6.48±4.45 days after subarachnoid hemorrhage. Hunt and Hess and Fisher grades were 1 (n=7), 2 (n=12), 3 (n=14), 4 (n=15), 5 (n=2), and 3 and 4 (n=33), respectively. Aneurysm location was distributed as follows: anterior (n=32), posterior (n=16), anterior and posterior (n=2). Patients with good clinical condition (Hunt and Hess score 1–3) had significantly higher odds of surviving (OR=17.5, 95% CI 1.9 to 161.5), favorable GOS (OR=4.2, 95% CI 1.2 to 14.8), and favorable 90-day mRS (OR=4.2, 95% CI 1.2 to 14.8).

Conclusions

SVAT is safe, with the majority of patients achieving good clinical outcome. Patients with lower Hunt and Hess grades have higher odds of surviving and favorable clinical prognosis.

Telemedicine in Prehospital Stroke Evaluation and Thrombolysis: Taking Stroke Treatment to the Doorstep

IMPORTANCE

Mobile stroke treatment units (MSTUs) with on-site treatment teams that include a vascular neurologist can provide thrombolysis in the prehospital setting faster than treatment in the hospital. These units can be made more resource efficient if the need for an on-site neurologist can be eliminated by relying solely on telemedicine for physician presence.

OBJECTIVE

To test whether telemedicine is reliable and remote physician presence is adequate for acute stroke treatment using an MSTU.

DESIGN, SETTING, AND PARTICIPANTS

Prospective observational study conducted between July 18 and November 1, 2014. The dates of the study analysis were November 1, 2014, to March 30, 2015. The setting was a community-based study assessing telemedicine success of the MSTU in Cleveland, Ohio. Participants were the first 100 residents of Cleveland who had an acute onset of stroke-like symptoms between 8 am and 8 pm and were evaluated by the MSTU after the implementation of the MSTU program at the Cleveland Clinic. A vascular neurologist evaluated the first 100 patients via telemedicine, and a neuroradiologist remotely assessed images obtained by mobile computed tomography (CT). Data were entered into the medical record and a prospective registry.

MAIN OUTCOMES AND MEASURES

The study compared the evaluation and treatment of patients on the MSTU with a control group of patients brought to the emergency department via ambulance during the same year. Process times were measured from the time the patient entered the door of the MSTU or emergency department, and any problems encountered during his or her evaluation were recorded.

RESULTS

Ninety-nine of 100 patients were evaluated successfully. The median duration of telemedicine evaluation was 20 minutes (interquartile range [IQR], 14-27 minutes). One connection failure was due to crew error, and the patient was transported to the nearest emergency department. There were 6 telemedicine disconnections, none of which lasted longer than 60 seconds or affected clinical care. Times from the door to CT completion (13 minutes [IQR, 9-21 minutes]) and from the door to intravenous thrombolysis (32 minutes [IQR, 24-47 minutes]) were significantly shorter in the MSTU group compared with the control group (18 minutes [IQR, 12-26 minutes] and 58 minutes [IQR, 53-68 minutes], respectively). Times to CT interpretation did not differ significantly between the groups.

CONCLUSIONS AND RELEVANCE

An MSTU using telemedicine is feasible, with a low rate of technical failure, and may provide an avenue for reducing the high cost of such systems.

Timeline of blood pressure changes after intra-arterial therapy for acute ischemic stroke based on recanalization status

BACKGROUND

There is sparse literature on the natural history of blood pressure (BP) after intra-arterial therapy (IAT) for acute ischemic stroke (AIS).

METHODS

A retrospective analysis was performed of patients with AIS who underwent IAT without endotracheal intubation for internal carotid artery terminus (ICA-T) or M1 middle cerebral artery occlusion from January 2008 to February 2012. Systolic BP (SBP) values at the beginning (First) and end (End) of IAT and for 36 h after the procedure were collected. Successful recanalization was defined as Thrombolysis In Cerebral Infarction (TICI) 2b-3.

RESULTS

Sixty-two patients (14 (22.5%) ICA-T, 46 (74.2%) M1, 2 (3.2%) ICA-T+M1) met the study criteria and 37 (59.7%) achieved successful recanalization. The First and End SBP values were similar in the successful (Group R) and unsuccessful (Group NR) recanalization groups. Taking the whole cohort, End SBP was significantly lower than First SBP, but this decline was significant only in Group R. Subsequently, absolute SBP values in Group R were not significantly different from Group NR. However, when comparing the hourly decline of SBP with First SBP, Group R demonstrated a greater fall than Group NR and the decline was significantly different from hours 8 to 12 post-procedure. The SBP in Group NR then decreased further, and its difference from baseline was similar to Group R from hour 14 onwards. Mean SBP and SBP variability over 36 h were similar between the two groups.

CONCLUSIONS

SBP falls significantly in patients with AIS with large vessel occlusion who recanalize with IAT. While SBP in non-recanalized patients also drops from baseline, it occurs to a lesser degree and stays higher only for a short period of time before falling to similar levels as in recanalized patients.

Lower Intraprocedural Systolic Blood Pressure Predicts Good Outcome in Patients Undergoing Endovascular Therapy for Acute Ischemic Stroke

BACKGROUND

It is unknown if intraprocedural blood pressure (BP) influences clinical outcomes and what BP parameter best predicts outcomes in acute ischemic stroke (AIS) patients who undergo intra-arterial therapy (IAT) for emergent large vessel occlusion.

METHODS

We retrospectively reviewed 147 patients who underwent IAT for anterior circulation AIS from January 2008 to December 2012 at our institution. Baseline demographics, stroke treatment variables, and detailed intraprocedural hemodynamic variables were collected.

RESULTS

The entire cohort consisted of 81 (55%) females with a mean age of 66.9 ± 15.6 years and a median National Institutes of Health Stroke Scale (NIHSS) score of 16 (IQR 11-21). Thirty-six (24.5%) patients died during hospitalization, 25 (17%) achieved a 30-day modified Rankin Scale score of 0-2, and 24 (16.3%) suffered symptomatic parenchymal hematoma type 1/2 hemorrhage. Patients who achieved a good outcome had a significantly lower admission NIHSS score, a higher baseline CT ASPECTS score, and a lower rate of ICA terminus occlusions. Successful recanalization was more frequent in the good-outcome group, while symptomatic hemorrhages occurred only in poor-outcome patients. The first systolic BP (SBP; 146.5 ± 0.2 vs. 157.7 ± 25.6 mm Hg, p = 0.042), first mean arterial pressure (MAP; 98.1 ± 20.8 vs. 109.7 ± 20.3 mm Hg, p = 0.024), maximum SBP (164.6 ± 27.6 vs. 180.9 ± 18.3 mm Hg, p = 0.0003), and maximum MAP (125.5 ± 18.6 vs. 138.5 ± 24.6 mm Hg, p = 0.0309) were all significantly lower in patients who achieved good outcomes. A lower maximum intraprocedural SBP was an independent predictor of good outcome (adjusted OR 0.929, 95% CI 0.886-0.963, p = 0.0005). Initial NIHSS score was the only other independent predictor of a good outcome.

CONCLUSION

Lower intraprocedural SBP was associated with good outcome in patients undergoing IAT for AIS, and maximum SBP was an independent predictor of good outcome. SBP may be the optimal hemodynamic variable to monitor intraprocedurally during IAT and may predict outcome.

Abstract TP94: Effect of Flow Diversion on Large and Giant Aneurysms: an MRI-DSA Correlation Follow-up Study

Background: There is sparse literature on the effect of flow diversion (FD) on large or giant intracranial aneurysms. We assessed the effects of FD with Pipeline stent on aneurysm sac size using MRI follow-up

Methods: All patients at our institution who underwent FD for treatment of intracranial aneurysms were retrospectively identified. Aneurysms with maximum dimension > 20mm, with pre and post treatment MRI were selected. These aneurysms were not previously treated, and did not receive adjunctive devices for current treatment. The largest diameter in 2-dimensions was measured on the MRI sequence that best demonstrated the aneurysm sac, and compared on serial scans. MRI changes were compared to DSA where aneurysm occlusion was graded by the O'Kelly-Marotta (OKM) scale.

Results: Between 6/2011-4/2015, 87 patients with 96 aneurysms were treated with FD. Eighteen patients had aneurysm >20mm. Pre and post treatment MRI were available in 12/18 (67%) patients. This included 9 (75%) females, with mean age 65.5 years. All aneurysms were unruptured and symptomatic. Nine (75%) patients had cavernous/ophthalmic aneurysms, and 3 had basilar aneurysms. Average largest aneurysm diameter was 26.7 (range 21-37) mm. Pipeline was used in all patients (mean 1.9, range 1-5 stents), with 8 (67%) requiring > 1 stent. At the first MRI follow-up (median 4, range 1-18 months), 4 (33%) aneurysms decreased in size, 6 (50%) remained stable, 1 (8%) increased in size. The stent thrombosed in the last patient. At the last MRI follow-up (median 10.5, range 1-48 months), 9 (75%) aneurysms decreased in size and 2 (16%) remained stable from baseline. No aneurysm completely resolved. DSA follow-up was available in 10 (83%) patients (median 9, range 1-25 months). Patients with decreased size on MRI had OKM grade C2, C3 or D, while aneurysms with stable size had OKM grade B3. The one patient with initial increased size on MR had corresponding OKM grade D (no filling).

Conclusion: Majority (75%) of large aneurysms decrease in size on serial MRIs after FD treatment. This corresponds with no filling or early remnant on DSA. Rare aneurysms increase in size despite no filling on DSA, which suggests caution when using only DSA follow-up post treatment. These findings require further study.

Abstract 18: Defining Clinical Presentation, Imaging Findings, and Management of Intracranial Fibromuscular Dysplasia: a Single Center Experience

Introduction: Intracranial (IC) artery involvement in fibromuscular dysplasia (FMD) may manifest as stenosis, dissection, or cerebral aneurysm. We sought to identify clinical, imaging, and treatment characteristics of FMD patients with IC manifestations.

Methods: Analysis of prospectively collected data from a single center of the US FMD patient registry with additional medical record and imaging review. Patients were consented for enrollment if FMD was confirmed by imaging in at least one vascular territory.

Results: From 2/2/2009-7/10/2015, 474 FMD patients were enrolled in the registry. Of the 421 patients with IC arterial imaging, 52 (12.4%) had IC FMD, with catheter angiography available in 29 (55.8%) patients. Median age of initial FMD symptoms was 47 years (IQR 38 - 55) and 51 patients were female. Concomitant extracranial (EC) carotid FMD was present in 92.3%, vertebral FMD in 48.9%, and renal FMD in 50.0%. Among 52 patients with IC FMD, 41 (78.8%) had IC aneurysm (9.7% of entire cohort with IC imaging), 7 (13.5%) had IC dissection, 6 (11.5%) had focal IC stenosis, and 2 (3.8%) had multifocal IC FMD. Fifteen patients with IC FMD (28.8%) were symptomatic (9 TIA/ischemic stroke, 2 hemorrhagic stroke, 4 isolated cranial neuropathy). Among patients with IC FMD, 22 (42.3%) required intervention. Treatment included EC-IC carotid artery bypass in 2 patients, aneurysm coiling in 13, aneurysm clipping in 9, and IC stenosis stenting in 1 patient. At the time of last follow-up, 47 patients (90.4%) were treated with an anti- platelet agent.

Conclusion: In a single center cohort, 12.4% patients with FMD had IC involvement. Arterial aneurysm was the most common manifestation followed by dissection and stenosis. Aneurysm was present in 9.7% of patients who underwent IC imaging, highlighting the importance of comprehensive vascular assessment of patients with FMD.

Brain Imaging Using Mobile CT: Current Status and Future Prospects

Computed tomography (CT) is an invaluable tool in the diagnosis of many clinical conditions. Several advancements in biomedical engineering have achieved increase in speed, improvements in low-contrast detectability and image quality, and lower radiation. Portable or mobile CT constituted one such important advancement. It is especially useful in evaluating critically ill, intensive care unit patients by scanning them at bedside. A paradigm shift in utilization of mobile CT was its installation in ambulances for the management of acute stroke. Given the time sensitive nature of acute ischemic stroke, Mobile stroke units (MSU) were developed in Germany consisting of an ambulance equipped with a CT scanner, point of care laboratory system, along with teleradiological support. In a radical reconfiguration of stroke care, the MSU would bring the CT scanner to the stroke patient, without waiting for the patient at the emergency room. Two separate MSU projects in Saarland and Berlin demonstrated the safety and feasibility of this concept for prehospital stroke care, showing increased rate of intravenous thrombolysis and significant reduction in time to treatment compared to conventional care. MSU also improved the triage of patients to appropriate and specialized hospitals. Although multiple issues remain yet unanswered with the MSU concept including clinical outcome and cost-effectiveness, the MSU venture is visionary and enables delivery of life-saving and enhancing treatment for ischemic and hemorrhagic stroke. In this review, we discuss the development of mobile CT and its applications, with specific focus on its use in MSUs along with our institution's MSU experience.

Emergent mechanical thrombectomy for acute stroke using the Mindframe Capture LP system: initial single-center experience

Background

Mechanical thrombectomy using stentrievers is the standard of care for emergent large vessel occlusion stroke. Data on the use of stentrievers in smaller caliber vessels are sparse.

Objective

To present our initial experience with the Mindframe Capture LP device, which was designed for mechanical thrombectomy in small cerebral arteries.

Methods

A retrospective chart review was conducted of patients who underwent Mindframe device assisted emergent thrombectomy. Clinical, imaging, procedural and early follow-up data were obtained.

Results

Nine patients met inclusion criteria (5 men, median age 62 years). Median National Institute of Health Stroke Scale (NIHSS) score was 18 (IQR 9–22), and 6 patients received intravenous tissue plasminogen activator. Six patients had M2 segment occlusions, and 2 patients had distal M1 segment occlusions of the middle cerebral artery. One had distal basilar artery occlusion. Median vessel diameter at the thrombus was 1.7 mm (IQR 1.5–2.5). In all 9 patients the Mindframe device was used together with manual aspiration, with median groin puncture to recanalization time of 35 min (IQR 27–54), and median procedural time of 67 min (IQR 51–91). Final Thrombolysis in Cerebral Infarction score was 3 and 2b in 4 patients each (89% total), and 2a in 1 patient. No patient had any postprocedural complications or symptomatic intracerebral hemorrhage. Median postprocedure and discharge NIHSS were 4 and 1, respectively.

Conclusions

Our data suggest that the Mindframe device is safe and effective for rapid treatment of acute strokes involving small caliber intracranial vessels. Further study in a larger cohort is warranted.

A Mobile Stroke Treatment Unit for Field Triage of Patients for Intraarterial Revascularization Therapy

INTRODUCTION

Favorable outcomes in intraarterial therapy (IAT) for acute ischemic stroke (AIS) are related to early vessel recanalization. The mobile stroke treatment unit (MSTU) is an on-site, prehospital, treatment team, laboratory, and CT scanner that reduces time to treatment for intravenous thrombolysis and may also shorten time to IAT.

METHODS

Using our MSTU database, we identified patients that underwent IAT for AIS. We compared the key time metrics to historical controls, which included patients that underwent IAT at our institution six months prior to implementation of the MSTU. We further divided the controls into two groups: (1) transferred to our institution for IAT and (2) directly presented to our emergency room and underwent IAT.

RESULTS

After 164 days of service, the MSTU transported 155 patients of which 5 underwent IAT. We identified 5 historical controls that were transferred to our center for IAT. Substantial reduction in times including median door to initial CT (12 minute vs. 32 minute), CT to IAT (82 minute vs. 165 minute), and door to MSTU/primary stroke center departure (37 minute vs. 106 minute) were noted among the two groups. Compared to the 6 patients who presented to our institution directly, the MSTU process times were also shorter.

CONCLUSION

Our initial experience shows that MSTU may help in early triage and shorten the time to IAT for AIS.

Large deep white matter lesions may predict futile recanalization in endovascular therapy for acute ischemic stroke

OBJECTIVE

This study investigated whether large ischemic lesions in the deep white matter (DWM) on pretreatment diffusion-weighted MRI (DWI) predict futile recanalization.

METHODS

Consecutive acute stroke patients with anterior circulation ischemia who underwent successful arterial recanalization with thrombolysis in cerebral infarction grade 2b or 3 were enrolled. A large DWI-DWM lesion was defined as a hyperintense lesion in the DWM on initial DWI, located mainly between the anterior and posterior horns of the lateral ventricle. The Alberta Stroke Program Early CT score on CT and DWI and stroke volume on initial DWI were recorded. Stroke severity was assessed using the National Institutes of Health Stroke Scale (NIHSS) score. Futile recanalization was defined as a 30-day modified Rankin scale score of 3-6 despite successful recanalization. Univariate and multivariate regression analyses were performed to identify predictors of futile recanalization.

RESULTS

In 35 of 46 patients (76%) with successful recanalization, futile recanalization was observed in 20 patients (57%). Patients with futile recanalization were older (median age 74 vs. 58 years; p = 0.053), had higher initial NIHSS scores (median 17 vs. 9; p = 0.042), and a higher prevalence of large DWI-DWM lesions (45 vs. 9%; p = 0.022). Logistic regression analysis showed that a large DWI-DWM lesion was an independent predictor of futile recanalization (OR 13.97; 95% CI 1.32-147.73; p = 0.028).

CONCLUSION

Patients with large preintervention DWI-DWM lesions may be poor candidates for endovascular therapy.

Degree of Collaterals and Not Time Is the Determining Factor of Core Infarct Volume within 6 Hours of Stroke Onset

BACKGROUND AND PURPOSE

Growth of the core infarct during the first hours of ischemia onset is not well-understood. We hypothesized that factors other than time from onset of ischemia contribute to core infarct volume as measured by MR imaging.

MATERIALS AND METHODS

Prospectively collected clinical and imaging data of consecutive patients with stroke presenting between March 2008 and April 2013 with anterior circulation large-vessel occlusion and MR imaging performed within 6 hours from the time of onset were reviewed. The association of time from onset, clinical, and radiographic features with DWI volume was assessed by using χ(2) and Mann-Whitney U tests.

RESULTS

Of 91 patients, 21 (23%) underwent MR imaging within 0-3 hours from onset, and 70 (76%), within 3-6 hours. Median MR imaging infarct volume was similar in both timeframes, (24.7 versus 29.4 mL, P = .906), and there was no difference in the proportion of patients with large infarct volumes (≥70 mL, 23.8% versus 22.8%, P = .928). Using receiver operating characteristic analysis, we detected no association between the time from onset and MR imaging infarct volume (area under the curve = 0.509). In multivariate analysis, CTA collaterals (>50% of the territory) (adjusted OR, 0.192; 95% CI, 0.04-0.9; P = .046), CTA ASPECTS (adjusted OR, 0.464; 95% CI, 0.3-0.8; P = .003), and a history of hyperlipidemia (adjusted OR, 11.0; 95% CI, 1.4-88.0; P = .023) (but not time from stroke onset to imaging) were independent predictors of MR imaging infarct volume.

CONCLUSIONS

Collateral status but not time from stroke onset to imaging was a predictor of the size of core infarct in patients with anterior circulation large-vessel occlusion presenting within 6 hours from onset.