Impact of Balloon Guide Catheter Use on Clinical and Angiographic Outcomes in the STRATIS Stroke Thrombectomy Registry.

Background and Purpose- Mechanical thrombectomy has been shown to improve clinical outcomes in patients with acute ischemic stroke. However, the impact of balloon guide catheter (BGC) use is not well established. Methods- STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) was a prospective, multicenter study of patients with large vessel occlusion treated with the Solitaire stent retriever as first-line therapy. In this study, an independent core laboratory, blinded to the clinical outcomes, reviewed all procedures and angiographic data to classify procedural technique, target clot location, recanalization after each pass, and determine the number of stent retriever passes. The primary clinical end point was functional independence (modified Rankin Scale, 0-2) at 3 months as determined on-site, and the angiographic end point was first-pass effect (FPE) success rate from a single device attempt (modified Thrombolysis in Cerebral Infarction, ≥2c) as determined by a core laboratory. Achieving modified FPE (modified Thrombolysis in Cerebral Infarction, ≥2b) was also assessed. Comparisons of clinical outcomes were made between groups and adjusted for baseline and procedural characteristics. All participating centers received institutional review board approval from their respective institutions. Results- Adjunctive technique groups included BGC (n=445), distal access catheter (n=238), and conventional guide catheter (n=62). The BGC group had a higher rate of FPE following first pass (212/443 [48%]) versus conventional guide catheter (16/62 [26%]; P=0.001) and distal access catheter (83/235 [35%]; P=0.002). Similarly, the BGC group had a higher rate of modified FPE (294/443 [66%]) versus conventional guide catheter (26/62 [42%]; P<0.001) and distal access catheter (129/234 [55%]; P=0.003). The BGC group achieved the highest rate of functional independence (253/415 [61%]) versus conventional guide catheter (23/55 [42%]; P=0.007) and distal access catheter (113/218 [52%]; P=0.027). Final revascularization and mortality rates did not differ across the groups. Conclusions- BGC use was an independent predictor of FPE, modified FPE, and functional independence, suggesting that its routine use may improve the rates of early revascularization success and good clinical outcomes. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT02239640.

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 (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.

Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke: Primary Results of the STRATIS Registry.

BACKGROUND AND PURPOSE: Mechanical thrombectomy with stent retrievers has become standard of care for treatment of acute ischemic stroke patients because of large vessel occlusion. The STRATIS registry (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) aimed to assess whether similar process timelines, technical, and functional outcomes could be achieved in a large real world cohort as in the randomized trials. METHODS: STRATIS was designed to prospectively enroll patients treated in the United States with a Solitaire Revascularization Device and Mindframe Capture Low Profile Revascularization Device within 8 hours from symptom onset. The STRATIS cohort was compared with the interventional cohort of a previously published SEER patient-level meta-analysis. RESULTS: A total of 984 patients treated at 55 sites were analyzed. The mean National Institutes of Health Stroke Scale score was 17.3. Intravenous tissue-type plasminogen activator was administered in 64.0%. The median time from onset to arrival in the enrolling hospital, door to puncture, and puncture to reperfusion were 138, 72, and 36 minutes, respectively. The Core lab-adjudicated modified Thrombolysis in Cerebral Infarction ≥2b was achieved in 87.9% of patients. At 90 days, 56.5% achieved a modified Rankin Scale score of 0 to 2, all-cause mortality was 14.4%, and 1.4% suffered a symptomatic intracranial hemorrhage. The median time from emergency medical services scene arrival to puncture was 152 minutes, and each hour delay in this interval was associated with a 5.5% absolute decline in the likelihood of achieving modified Rankin Scale score 0 to 2. CONCLUSIONS: This largest-to-date Solitaire registry documents that the results of the randomized trials can be reproduced in the community. The decrease of clinical benefit over time warrants optimization of the system of care. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02239640.

Pivotal trial of the Neuroform Atlas stent for treatment of posterior circulation aneurysms: one-year outcomes.

BACKGROUND: Stent-assisted coiling of wide-necked intracranial aneurysms (IAs) using the Neuroform Atlas Stent System (Atlas) has shown promising results. OBJECTIVE: To present the primary efficacy and safety results of the ATLAS Investigational Device Exemption (IDE) trial in a cohort of patients with posterior circulation IAs. METHODS: The ATLAS trial is a prospective, multicenter, single-arm, open-label study of unruptured, wide-necked, IAs treated with the Atlas stent and adjunctive coiling. This study reports the results of patients with posterior circulation IAs. The primary efficacy endpoint was complete aneurysm occlusion (Raymond-Roy (RR) class I) on 12-month angiography, in the absence of re-treatment or parent artery stenosis >50%. The primary safety endpoint was any major ipsilateral stroke or neurological death within 12 months. Adjudication of the primary endpoints was performed by an imaging core laboratory and a Clinical Events Committee. RESULTS: The ATLAS trial enrolled and treated 116 patients at 25 medical centers with unruptured, wide-necked, posterior circulation IAs (mean age 60.2±10.5 years, 81.0% (94/116) female). Stents were placed in all patients with 100% technical success rate. A total of 95/116 (81.9%) patients had complete angiographic follow-up at 12 months, of whom 81 (85.3%) had complete aneurysm occlusion (RR class I). The primary effectiveness outcome was achieved in 76.7% (95% CI 67.0% to 86.5%) of patients. Overall, major ipsilateral stroke and secondary persistent neurological deficit occurred in 4.3% (5/116) and 1.7% (2/116) of patients, respectively. CONCLUSIONS: In the ATLAS IDE posterior circulation cohort, the Neuroform Atlas Stent System with adjunctive coiling demonstrated high rates of technical and safety performance. Trial registration number https://clinicaltrials.gov/ct2/show/NCT02340585.

Republished: A lumbar arteriovenous fistula presenting with intraventricular hemorrhage and hydrocephalus.

Pediatric spinal vascular malformations are rare entities that typically present with symptoms from their effect on surrounding structures. Here we report a unique case of lumbar spinal dural/perimedullary arteriovenous fistula (AVF) that presented with intraventricular hemorrhage and hydrocephalus. The previously healthy child presented with lethargy and headache, and initial imaging revealed only ventriculomegaly with trace intraventricular blood. His mental status improved with CSF diversion via an external ventricular drain. Further workup revealed a spinal AVF that was treated via endovascular embolization. His course was complicated by vasospasm requiring endovascular treatment and he eventually required ventriculoperitoneal shunt placement. He made a full recovery and has returned to his normal activities. This is a unique case of spinal AVF presentation and highlights the importance of considering imaging of the entire neuroaxis during workup for hydrocephalus.

A lumbar arteriovenous fistula presenting with intraventricular hemorrhage and hydrocephalus.

Pediatric spinal vascular malformations are rare entities that typically present with symptoms from their effect on surrounding structures. Here we report a unique case of lumbar spinal dural/perimedullary arteriovenous fistula (AVF) that presented with intraventricular hemorrhage and hydrocephalus. The previously healthy child presented with lethargy and headache, and initial imaging revealed only ventriculomegaly with trace intraventricular blood. His mental status improved with CSF diversion via an external ventricular drain. Further workup revealed a spinal AVF that was treated via endovascular embolization. His course was complicated by vasospasm requiring endovascular treatment and he eventually required ventriculoperitoneal shunt placement. He made a full recovery and has returned to his normal activities. This is a unique case of spinal AVF presentation and highlights the importance of considering imaging of the entire neuroaxis during workup for hydrocephalus.

Predictive value of platelet reactivity unit (PRU) value for thrombotic and hemorrhagic events during flow diversion procedures: a meta-analysis.

BACKGROUND AND PURPOSE: Platelet function testing prior to flow diversion procedures, although initially heavily debated, has seen a substantial increase in its adoption to assess the risk of operative and perioperative thrombotic and hemorrhagic events. This meta-analysis was conducted to assess platelet function testing, particularly the VerifyNow Platelet Reactivity Unit (PRU) assay, for a relationship between the reported assay PRU value and thrombotic and hemorrhagic events. MATERIALS AND METHODS: The currently available literature (2013-2018) was surveyed with PubMed and Google Scholar searches. Included studies were those for which there were at least 30 cases during the study period, for which VerifyNow platelet reactivity unit values were obtained prior to the procedures and for which intraoperative and perioperative adverse events were noted. PRU value cut-offs ranging from >200 to >240 comprised the hyporesponse group while values ranging from <60 to <70 comprised the hyper-response group. The data were subject to statistical analysis to assess the relationship between PRU values and thrombotic and hemorrhagic events. The collected data were subsequently statistically analyzed to assess for publication bias. RESULTS: The searches yielded 27 studies, of which 12 met the inclusion criteria for the meta-analysis. The meta-analysis included data from 1464 reported Pipeline cases. The study included 273 men and 1177 women with a mean age across the analyzed procedures of 58 years (range 25-85). After loading with antiplatelet medications, preprocedural platelet hyper-responsiveness was associated with a greater incidence of hemorrhagic events with an increased absolute risk of 12%, but showed no relationship with thrombotic events. Preprocedural platelet hyporesponsiveness was associated with a greater incidence of thrombotic events with an absolute risk of 15%, but showed no relationship with hemorrhagic events. CONCLUSIONS: VerifyNow PRU values that correspond to platelet hyporesponse or hyper-response to dual antiplatelet therapy are associated with a higher risk of thrombotic and hemorrhagic events, respectively. Thus, the PRU value may offer some predictive value for these events.

Immune System Activation in Perioperative Thrombectomy Patients: Preliminary Retrospective Study.

BACKGROUND: Ischemic stroke is a devastating condition resulting in significant morbidity. Mechanical thrombectomy is now standard for large vessel occlusive stroke. Neuroinflammation is known to play important roles in ischemic stroke. Our aims were to examine our thrombectomy procedures and preliminarily examine systemic immune response in relation to thrombectomy changes. METHODS: A retrospective review was conducted on mechanical thrombectomy cases from July 2011 through December 2015. Primary outcomes were time to recanalization, final Thrombolysis in Cerebral Infarction score, procedural complications, National Institutes of Health Stroke Scale improvement, and changes in white blood cell (WBC) count. RESULTS: One-hundred and twenty-nine procedures were performed. We found a significant difference between WBC count on admission and WBC count post thrombectomy day 1 for patients with >90 minutes to recanalization (P = 0.006107). There was a positive association between WBC change and absolute National Institutes of Health Stroke Scale change among females (P = 0.0273) but not among males. CONCLUSIONS: Overall, we found that systemic immune response has close relationships with speed of recanalization and preliminarily may shift differently on the basis of sex.

Expression of Cytokines and Chemokines as Predictors of Stroke Outcomes in Acute Ischemic Stroke.

Introduction: Ischemic stroke remains one of the most debilitating diseases and is the fifth leading cause of death in the US. The ability to predict stroke outcomes within the acute period of stroke would be essential for care planning and rehabilitation. The Blood and Clot Thrombectomy Registry and Collaboration (BACTRAC; clinicaltrials.gov NCT03153683) study collects arterial blood immediately distal and proximal to the intracranial thrombus at the time of mechanical thrombectomy. These blood samples are an innovative resource in evaluating acute gene expression changes at the time of ischemic stroke. The purpose of this study was to identify inflammatory genes and important immune factors during mechanical thrombectomy for emergent large vessel occlusion (ELVO) and which patient demographics were predictors for stroke outcomes (infarct and/or edema volume) in acute ischemic stroke patients. Methods: The BACTRAC study is a non-probability sampling of male and female subjects (≥18 year old) treated with mechanical thrombectomy for ELVO. We evaluated 28 subjects (66 ± 15.48 years) relative concentrations of mRNA for gene expression in 84 inflammatory molecules in arterial blood distal and proximal to the intracranial thrombus who underwent thrombectomy. We used the machine learning method, Random Forest to predict which inflammatory genes and patient demographics were important features for infarct and edema volumes. To validate the overlapping genes with outcomes, we perform ordinary least squares regression analysis. Results: Machine learning analyses demonstrated that the genes and subject factors CCR4, IFNA2, IL-9, CXCL3, Age, T2DM, IL-7, CCL4, BMI, IL-5, CCR3, TNFα, and IL-27 predicted infarct volume. The genes and subject factor IFNA2, IL-5, CCL11, IL-17C, CCR4, IL-9, IL-7, CCR3, IL-27, T2DM, and CSF2 predicted edema volume. The overlap of genes CCR4, IFNA2, IL-9, IL-7, IL-5, CCR3, and IL-27 with T2DM predicted both infarct and edema volumes. These genes relate to a microenvironment for chemoattraction and proliferation of autoimmune cells, particularly Th2 cells and neutrophils. Conclusions: Machine learning algorithms can be employed to develop prognostic predictive biomarkers for stroke outcomes in ischemic stroke patients, particularly in regard to identifying acute gene expression changes that occur during stroke.

The Blood And Clot Thrombectomy Registry And Collaboration (BACTRAC) protocol: novel method for evaluating human stroke.

BACKGROUND: Ischemic stroke research faces difficulties in translating pathology between animal models and human patients to develop treatments. Mechanical thrombectomy, for the first time, offers a momentary window into the changes occurring in ischemia. We developed a tissue banking protocol to capture intracranial thrombi and the blood immediately proximal and distal to it. OBJECTIVE: To develop and share a reproducible protocol to bank these specimens for future analysis. METHODS: We established a protocol approved by the institutional review board for tissue processing during thrombectomy (www.clinicaltrials.gov NCT03153683). The protocol was a joint clinical/basic science effort among multiple laboratories and the NeuroInterventional Radiology service line. We constructed a workspace in the angiography suite, and developed a step-by-step process for specimen retrieval and processing. RESULTS: Our protocol successfully yielded samples for analysis in all but one case. In our preliminary dataset, the process produced adequate amounts of tissue from distal blood, proximal blood, and thrombi for gene expression and proteomics analyses. We describe the tissue banking protocol, and highlight training protocols and mechanics of on-call research staffing. In addition, preliminary integrity analyses demonstrated high-quality yields for RNA and protein. CONCLUSIONS: We have developed a novel tissue banking protocol using mechanical thrombectomy to capture thrombus along with arterial blood proximal and distal to it. The protocol provides high-quality specimens, facilitating analysis of the initial molecular response to ischemic stroke in the human condition for the first time. This approach will permit reverse translation to animal models for treatment development.

Acute pancreatitis: value and impact of CT severity index.

Acute pancreatitis is a disease with a broad spectrum of findings that varies in severity from mild interstitial or edematous pancreas to severe forms with significant local and systemic complications that are associated with a substantial degree of morbidity and mortality. Several scoring systems are used to assess the severity and predict the outcome and prognosis of acute pancreatitis. These include the Ranson, Acute Physiology And Chronic Health Evaluation II (APACHE II) and Glasgow scales. The CT severity index (CTSI) derived by Balthazar et al. has become widely used for description of CT findings in acute pancreatitis. The purpose of this project was to examine the current best evidence about regarding the effect of using a CTSI on patient outcome and its value in comparison with other widely used scoring systems.

Intra-arterial verapamil post-thrombectomy is feasible, safe, and neuroprotective in stroke.

Large vessel ischemic stroke represents the most disabling subtype. While t-PA and endovascular thrombectomy can recanalize the occluded vessel, good clinical outcomes are not uniformly achieved. We propose that supplementing endovascular thrombectomy with superselective intra-arterial (IA) verapamil immediately following recanalization could be safe and effective. Verapamil, a calcium channel blocker, has been shown to be an effective IA adjunct in a pre-clinical mouse focal ischemia model. To demonstrate translational efficacy, mechanism, feasibility, and safety, we conducted a group of translational experiments. We performed in vivo IA dose-response evaluation in our animal stroke model with C57/Bl6 mice. We evaluated neuroprotective mechanism through in vitro primary cortical neuron (PCN) cultures. Finally, we performed a Phase I trial, SAVER-I, to evaluate feasibility and safety of administration in the human condition. IA verapamil has a likely plateau or inverted-U dose-response with a defined toxicity level in mice (LD50 16-17.5 mg/kg). Verapamil significantly prevented PCN death and deleterious ischemic effects. Finally, the SAVER-I clinical trial showed no evidence that IA verapamil increased the risk of intracranial hemorrhage or other adverse effect/procedural complication in human subjects. We conclude that superselective IA verapamil administration immediately following thrombectomy is safe and feasible, and has direct, dose-response-related benefits in ischemia.

Neurologic emergencies: case studies.

During the past 2 decades, the world has witnessed a significant improvement in the understanding of the pathogenesis and treatment of neurologic diseases, which presents emergencies. Every day neurologists are consulted for patients who present with neurologic emergencies to the emergency departments. In this article, we present a series of case reports about patients with acute neurologic and psychiatric problems and discuss their management briefly.