Computational fluid dynamic characterization of carotid bifurcation stenosis in patient-based geometries

Hemodynamic forces play a role in determining endothelial cell (EC) phenotype and influence vascular remodeling. We present a lesion-based computational fluid dynamic (CFD) pilot analysis to understand the complex spatial and temporal hemodynamic changes that prevail in patients with high-grade carotid artery stenosis (CS). High-resolution three-dimensional (3D) rotational angiography datasets were acquired in eight patients, and used to generate computational meshes. CFD analysis was carried out implementing realistic shear-dependent viscosity for blood. The mean wall shear stress (WSS) within the stenosis region was 107 ± 73 dyn/cm2 rapidly followed by direction reversal and lower oscillating values in the recirculation zone at a mean of 19 ± 14 dyn/cm2. WSS vectors exhibited complex dynamic directional and amplitude oscillations not seen in healthy segments, along with time-dependent convergence and divergence strips during the cardiac cycle. The spatial gradient of WSS revealed an elevated average magnitude at the throat of the stenosis of 1425 ± 1012 dyn/cm3. In conclusion, patient-based CFD analysis of CS predicts a complex hemodynamic environment with large spatial WSS variations that occur very rapidly over short distances. Our results improve estimates of the flow changes and forces at the vessel wall in CS and the link between hemodynamic changes and stenosis pathophysiology

Cessation and Resumption of Elective Neurointerventional Procedures during the Coronavirus Disease 2019 Pandemic and Future Pandemics

At the time of this writing, the coronavirus disease 2019 pandemic continues to be a global threat, disrupting usual processes, and protocols for delivering health care around the globe. There have been significant regional and national differences in the scope and timing of these disruptions. Many hospitals were forced to temporarily halt elective neurointerventional procedures with the first wave of the pandemic in the spring of 2020, in order to prioritize allocation of resources for acutely ill patients and also to minimize coronavirus disease 2019 transmission risks to non-acute patients, their families, and health care workers. This temporary moratorium on elective neurointerventional procedures is generally credited with helping to flatten the curve and direct scarce resources to more acutely ill patients; however, there have been reports of some delaying seeking medical care when it was in fact urgent, and other reports of patients having elective treatment delayed with the result of morbidity and mortality. Many regions have resumed elective neurointerventional procedures, only to now watch coronavirus disease 2019 positivity rates again climbing as winter of 2020 approaches. A new wave is now forecast which may have larger volumes of hospitalized coronavirus disease 2019 patients than the earlier wave(s) and may also coincide with a wave of patients hospitalized with seasonal influenza. This paper discusses relevant and practical elements of cessation and safe resumption of nonemergent neurointerventional services in the setting of a pandemic

Delayed presentation of acute ischemic strokes during the COVID-19 crisis

This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Background: The COVID-19 pandemic has disrupted established care paths worldwide. Patient awareness of the pandemic and executive limitations imposed on public life have changed the perception of when to seek care for acute conditions in some cases. We sought to study whether there is a delay in presentation for acute ischemic stroke patients in the first month of the pandemic in the US. Methods: The interval between last-known-well (LKW) time and presentation of 710 consecutive patients presenting with acute ischemic strokes to 12 stroke centers across the US were extracted from a prospectively maintained quality database. We analyzed the timing and severity of the presentation in the baseline period from February to March 2019 and compared results with the timeframe of February and March 2020. Results: There were 320 patients in the 2-month baseline period in 2019, there was a marked decrease in patients from February to March of 2020 (227 patients in February, and 163 patients in March). There was no difference in the severity of the presentation between groups and no difference in age between the baseline and the COVID period. The mean interval from LKW to the presentation was significantly longer in the COVID period (603±1035 min) compared with the baseline period (442±435 min, P<0.02). Conclusion: We present data supporting an association between public awareness and limitations imposed on public life during the COVID-19 pandemic in the US and a delay in presentation for acute ischemic stroke patients to a stroke center

Periprocedural safety of saccular aneurysm embolization with the Penumbra SMART Coil System: a SMART registry subset analysis

Background Using data from the SMART registry, we report on periprocedural safety of the Penumbra SMART Coil System for endovascular coil embolization of saccular intracranial aneurysms. Methods The SMART registry was a prospective, multi-center registry of site standard of care endovascular coiling procedures performed using at least 75% Penumbra SMART Coil, PC400, and/or POD coils. This subset analysis reports on the periprocedural safety outcomes of the saccular intracranial aneurysm cohort. Predictors of rupture/re-rupture or perforation (RRP), thromboembolic complications, and device- or procedure-related adverse events (AEs) were determined in univariate and multivariate analysis. Results Between June 2016 and August 2018, 851 saccular aneurysm patients (31.0%, 264/851 ruptured) were enrolled across 66 North American centers. Clinically significant (ie, a serious adverse event) RRP occurred in 2.0% (17/851) of cases – 1.9% (5/264) for the ruptured cohort and 2.0% (12/587) for the un-ruptured cohort. Clinically significant thromboembolic events occurred in 3.1% (26/851) of cases – 5.3% (14/264) for the ruptured cohort and 2.0% (12/587) for the un-ruptured cohort. Multivariate predictors of periprocedural RRP were increased packing density and adjunctive treatment with a balloon. For periprocedural thromboembolic events, multivariate predictors were bifurcation location and ruptured status. For device- or procedure-related AEs, multivariate predictors were bifurcation location and adjunctive treatment with stent or balloon. Conclusion The low rates of thromboembolic complications and RRP events demonstrate the adequate safety profile of the SMART Coil System to treat cerebral aneurysms in routine clinical practice

Acute ischaemic stroke associated with SARS-CoV-2 infection in North America

BACKGROUND: To analyse the clinical characteristics of COVID-19 with acute ischaemic stroke (AIS) and identify factors predicting functional outcome. METHODS: Multicentre retrospective cohort study of COVID-19 patients with AIS who presented to 30 stroke centres in the USA and Canada between 14 March and 30 August 2020. The primary endpoint was poor functional outcome, defined as a modified Rankin Scale (mRS) of 5 or 6 at discharge. Secondary endpoints include favourable outcome (mRS ≤2) and mortality at discharge, ordinal mRS (shift analysis), symptomatic intracranial haemorrhage (sICH) and occurrence of in-hospital complications. RESULTS: A total of 216 COVID-19 patients with AIS were included. 68.1% (147/216) were older than 60 years, while 31.9% (69/216) were younger. Median [IQR] National Institutes of Health Stroke Scale (NIHSS) at presentation was 12.5 (15.8), and 44.2% (87/197) presented with large vessel occlusion (LVO). Approximately 51.3% (98/191) of the patients had poor outcomes with an observed mortality rate of 39.1% (81/207). Age \u3e60 years (aOR: 5.11, 95% CI 2.08 to 12.56, p\u3c0.001), diabetes mellitus (aOR: 2.66, 95% CI 1.16 to 6.09, p=0.021), higher NIHSS at admission (aOR: 1.08, 95% CI 1.02 to 1.14, p=0.006), LVO (aOR: 2.45, 95% CI 1.04 to 5.78, p=0.042), and higher NLR level (aOR: 1.06, 95% CI 1.01 to 1.11, p=0.028) were significantly associated with poor functional outcome. CONCLUSION: There is relationship between COVID-19-associated AIS and severe disability or death. We identified several factors which predict worse outcomes, and these outcomes were more frequent compared to global averages. We found that elevated neutrophil-to-lymphocyte ratio, rather than D-Dimer, predicted both morbidity and mortality

Analysis of chemokine and chemokine receptor expression in squamous cell carcinoma of the head and neck (SCCHN) cell lines

The purpose of this work was to analyze chemokine and chemokine receptor expression in untreated and in irradiated squamous cell carcinoma of the head and neck (SCCHN) tumor cell lines, aiming at the establishment of assays to test for the relevance of chemokine and chemokine receptor expression in the response of SCCHN to radiotherapy and radiochemotherapy. Five low passage and 10 established SCCHN lines, as well as two normal cell lines, were irradiated at 2 Gy or sham-irradiated, and harvested between 1 and 48 h after treatment. For chemokines with CC and CXC structural motifs and their receptors, transcript levels of target and reference genes were quantified relatively by real-time PCR. In addition, CXCL1 and CXCL12 protein expression was analyzed by ELISA. A substantial variation in chemokine and chemokine receptor expression between SCCHN was detected. Practically, all cell lines expressed CCL5 and CCL20, while CCL2 was expressed in normal cells and in some of the tumor cell lines. CXCL1, CXCL2, CXCL3, CXCL10, and CXCL11 were expressed in the vast majority of the cell lines, while the expression of CXCL9 and CXCL12 was restricted to fibroblasts and few tumor cell lines. None of the analyzed cell lines expressed the chemokines CCL3, CCL4, or CCL19. Of the receptors, transcript expression of CCR1, CCR2, CCR3, CCR5, CCR7, CCXR2, and CCXR3 was not detected, and CCR6, CXCR1, and CXCR4 expression was restricted to few tumor cells. Radiation caused up- and down-regulation with respect to chemokine expressions, while for chemokine receptor expressions down-regulations were prevailing. CXCL1 and CXCL12 protein expression corresponded well with the mRNA expression. We conclude that the substantial variation in chemokine and chemokine receptor expression between SCCHN offer opportunities for the establishment of assays to test for the relevance of chemokine and chemokine receptor expression in the response of SCCHN to radiotherapy and radiochemotherapy

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).

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 ( 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

Image-guided, Minimally Invasive Evacuation of Intracerebral Hematoma: A Matched Cohort Study Comparing the Endoscopic and Tubular Exoscopic Systems

Introduction Novel image-guided, minimally invasive techniques to evacuate intracerebral hematomas represent a promising new avenue in the management of this disease entity. To our knowledge, a direct comparison of the Penumbra Apollo (Penumbra Inc, Alameda, California, US) and Nico BrainPath (Indianapolis, Indiana, US) system has not yet been performed. Methods A retrospective review of image-guided, minimally invasive evacuation of intracerebral hematomas performed at one academic institution in the United States between July 2015 and July 2017 was performed. Cases performed with the Apollo and BrainPath system were matched based on age, gender, hematoma location and laterality, and volume. Results Twenty-four patients underwent surgery using either of the two minimally invasive surgical systems and five cases in each group were matched for age, gender, hematoma location and laterality, and volume. Median time from symptom onset to evacuation was two days with a mean distance from the brain surface to the clot of approximately 40 millimeters in both groups. Both techniques achieved comparable clot evacuation. The functional outcome was poor with either technique with the majority of patients dependent or dead at last follow-up. Conclusions In the present, small, matched cohort study, both the Apollo and BrainPath techniques achieved satisfactory clot evacuation. Nevertheless, the functional outcome in this patient population remains poor in the majority of cases