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  • 1
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    Online Resource
    Investigation of Experimental Endovascular Air Embolisms Using a New Model for the Generation and Detection of Highly Calibrated Micro Air Bubbles
    SAGE Publications ; 2023
    In:  Journal of Endovascular Therapy Vol. 30, No. 3 ( 2023-06), p. 461-470
    Details
    In: Journal of Endovascular Therapy, SAGE Publications, Vol. 30, No. 3 ( 2023-06), p. 461-470
    Abstract: Air embolism (AE), especially when affecting the brain, is an underrated and potentially life-threatening complication in various endovascular interventions. This study aims to investigate experimental AEs using a new model to generate micro air bubbles (MAB), to assess the impact of a catheter on these MAB, and to demonstrate the applicability of this model in vivo. Materials and Methods: Micro air bubbles were created using a system based on microfluidic channels. The MAB were detected and analyzed automatically. Micro air bubbles, with a target size of 85 µm, were generated and injected through a microcatheter. The MAB diameters proximal and distal to the catheter were assessed and compared. In a subsequent in vivo application, 2000 MAB were injected into the aorta (at the aortic valve) and into the common carotid artery (CCA) of a rat, respectively, using a microcatheter, resembling AE occurring during cardiovascular interventions. Results: Micro air bubbles with a highly calibrated size could be successfully generated (median: 85.5 µm, SD 1.9 µm). After passage of the microcatheter, the MAB were similar in diameter (median: 86.6 µm) but at a lower number (60.1% of the injected MAB) and a substantially higher scattering of diameters (SD 29.6 µm). In vivo injection of MAB into the aorta resulted in cerebral microinfarctions in both hemispheres, whereas injection into the CCA caused exclusively ipsilateral microinfarctions. Conclusion: Using this new AE model, MAB can be generated precisely and reproducibly, resulting in cerebral microinfarctions. This model is feasible for further studies on the pathophysiology and prevention of AE in cardiovascular procedures.
    Type of Medium: Online Resource
    ISSN: 1526-6028 , 1545-1550
    URL: Article
    DOI: 10.1177/15266028221082010
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2023
    detail.hit.zdb_id: 2049858-5
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  • 2
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    Global impact of COVID-19 on stroke care
    SAGE Publications ; 2021
    In:  International Journal of Stroke Vol. 16, No. 5 ( 2021-07), p. 573-584
    Details
    In: International Journal of Stroke, SAGE Publications, Vol. 16, No. 5 ( 2021-07), p. 573-584
    Abstract: The COVID-19 pandemic led to profound changes in the organization of health care systems worldwide. Aims We sought to measure the global impact of the COVID-19 pandemic on the volumes for mechanical thrombectomy, stroke, and intracranial hemorrhage hospitalizations over a three-month period at the height of the pandemic (1 March–31 May 2020) compared with two control three-month periods (immediately preceding and one year prior). Methods Retrospective, observational, international study, across 6 continents, 40 countries, and 187 comprehensive stroke centers. The diagnoses were identified by their ICD-10 codes and/or classifications in stroke databases at participating centers. Results The hospitalization volumes for any stroke, intracranial hemorrhage, and mechanical thrombectomy were 26,699, 4002, and 5191 in the three months immediately before versus 21,576, 3540, and 4533 during the first three pandemic months, representing declines of 19.2% (95%CI, −19.7 to −18.7), 11.5% (95%CI, −12.6 to −10.6), and 12.7% (95%CI, −13.6 to −11.8), respectively. The decreases were noted across centers with high, mid, and low COVID-19 hospitalization burden, and also across high, mid, and low volume stroke/mechanical thrombectomy centers. High-volume COVID-19 centers (−20.5%) had greater declines in mechanical thrombectomy volumes than mid- (−10.1%) and low-volume (−8.7%) centers (p  〈  0.0001). There was a 1.5% stroke rate across 54,366 COVID-19 hospitalizations. SARS-CoV-2 infection was noted in 3.9% (784/20,250) of all stroke admissions. Conclusion The COVID-19 pandemic was associated with a global decline in the volume of overall stroke hospitalizations, mechanical thrombectomy procedures, and intracranial hemorrhage admission volumes. Despite geographic variations, these volume reductions were observed regardless of COVID-19 hospitalization burden and pre-pandemic stroke/mechanical thrombectomy volumes.
    Type of Medium: Online Resource
    ISSN: 1747-4930 , 1747-4949
    URL: Article
    DOI: 10.1177/1747493021991652
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2021
    detail.hit.zdb_id: 2211666-7
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  • 3
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    Effect of treatment technique on radiation exposure in mechanical thrombectomy for acute ischaemic stroke: A matched-pair analysis
    SAGE Publications ; 2020
    In:  The Neuroradiology Journal Vol. 33, No. 4 ( 2020-08), p. 286-291
    Details
    In: The Neuroradiology Journal, SAGE Publications, Vol. 33, No. 4 ( 2020-08), p. 286-291
    Abstract: This study aimed to compare radiation exposure (RE) in patients receiving mechanical thrombectomy (MT) for large-vessel occlusions in the anterior circulation using direct thrombo-aspiration (DT) versus stent-retriever thrombectomy under continuous distal aspiration (STA). Methods This was a retrospective single-centre analysis of an Institutional Review Board−approved stroke database of a comprehensive stroke centre focusing on RE per dose area product, procedure time (PT) and fluoroscopy time (FT) in patients receiving MT. Patients who received MT with DT were matched with patients treated using STA according to occlusion location, mode of anaesthesia, manoeuvre count and sex. Results Apart from patient age (DT: M = 74 years (standard deviation ( SD)=13 years); STA: M = 79 years ( SD = 11 years); p = 0.023), there was no difference in baseline patient characteristics ( n = 68 per group). PT (DT: median = 26 minutes (interquartile range (IQR) = 21–38 minutes); STA: median = 49 minutes (IQR 37–77 minutes); p  〈  0.0001) and FT (DT: median = 12 minutes (IQR 7–18 minutes); STA: median = 26 minutes (IQR 14–43 minutes); p  〈  0.0001) were shorter in patients who received MT using DT. RE (DT: median = 62.6 Gy·cm 2 (IQR 41.7–89.4 Gy·cm 2 ); STA: median = 89.8 Gy·cm 2 (IQR 53.7–131.7 Gy·cm 2 ); p = 0.034) was significantly lower in patients who received MT using DT. This represents a relative increase of RE, FT and PT by 43.6%, 116.6% and 88.5%, respectively, in patients who received MT using STA. Conclusion MT using DT is associated with shorter FT and PT and lower RE compared to matched patients treated with STA.
    Type of Medium: Online Resource
    ISSN: 1971-4009 , 2385-1996
    URL: Article
    DOI: 10.1177/1971400920925433
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2020
    detail.hit.zdb_id: 2622347-8
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  • 4
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    Accuracy and reliability of PBV ASPECTS, CBV ASPECTS and NCCT ASPECTS in acute ischaemic stroke: a matched-pair analysis
    SAGE Publications ; 2021
    In:  The Neuroradiology Journal Vol. 34, No. 6 ( 2021-12), p. 585-592
    Details
    In: The Neuroradiology Journal, SAGE Publications, Vol. 34, No. 6 ( 2021-12), p. 585-592
    Abstract: To investigate the reliability and accuracy of Alberta Stroke Program Early Computed Tomography Scores (ASPECTS) derived from flatpanel detector computed tomography pooled blood volume maps compared to non-contrast computed tomography and multidetector computed tomography perfusion cerebral blood volume maps. Methods ASPECTS from pooled blood volume maps were evaluated retrospectively by two experienced readers for 37 consecutive patients with acute middle cerebral artery (MCA) M1 occlusion who underwent flatpanel detector computed tomography perfusion imaging before mechanical thrombectomy between November 2016 and February 2019. For comparison with ASPECTS from non-contrast computed tomography and cerebral blood volume maps, a matched-pair analysis according to pre-stroke modified Rankin scale, age, stroke severity, site of occlusion, time from stroke onset to imaging and final modified thrombolysis in cerebral infarction (mTICI) was performed in a separate group of patients who underwent multimodal computed tomography prior to mechanical thrombectomy between June 2015 and February 2019. Follow-up ASPECTS were derived from either non-contrast computed tomography or from magnetic resonance imaging (in seven patients) one day after mechanical thrombectomy. Results Interrater agreement was best for non-contrast computed tomography ASPECTS (w-kappa = 0.74, vs. w-kappa = 0.63 for cerebral blood volume ASPECTS and w-kappa = 0.53 for pooled blood volume ASPECTS). Also, accuracy, defined as correlation between acute and follow-up ASPECTS, was best for non-contrast computed tomography ASPECTS (Spearman ρ = 0.86 (0.65–0.97), P  〈  0.001), while it was lower and comparable for pooled blood volume ASPECTS (ρ = 0.58 (0.32–0.79), P  〈  0.001) and cerebral blood volume ASPECTS (ρ = 0.52 (0.17–0.80), P = 0.001). It was noteworthy that cases of relevant infarct overestimation by two or more ASPECTS regions (compared to follow-up imaging) were observed for both acute pooled blood volume and cerebral blood volume ASPECTS but occurred more often for acute pooled blood volume ASPECTS (25% vs. 5%, P = 0.02). Conclusion Non-contrast computed tomography ASPECTS outperformed both pooled blood volume ASPECTS and cerebral blood volume ASPECTS in accuracy and reliability. Importantly, relevant infarct overestimation was observed more often in pooled blood volume ASPECTS than cerebral blood volume ASPECTS, limiting its present clinical applicability for acute stroke imaging.
    Type of Medium: Online Resource
    ISSN: 1971-4009 , 2385-1996
    URL: Article
    DOI: 10.1177/19714009211015771
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2021
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  • 5
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    The impact of the DWI-FLAIR-mismatch in the ECASS-4 trial – A post hoc analysis
    SAGE Publications ; 2020
    In:  European Stroke Journal Vol. 5, No. 4 ( 2020-12), p. 370-373
    Details
    In: European Stroke Journal, SAGE Publications, Vol. 5, No. 4 ( 2020-12), p. 370-373
    Abstract: To investigate the impact of a mismatch between diffusion-weighted imaging (DWI) and fluid attenuated inversion recovery (FLAIR) on functional outcome in patients with acute stroke in a prolonged time window or unknown time of symptom onset randomized to intravenous thrombolysis or placebo. Patients and Methods We performed a post-hoc analysis of the European Cooperative Acute Stroke Study-4 (ECASS-4) trial. ECASS-4 was an investigator driven, phase 3, multi-center, double-blind, placebo-controlled study which randomized ischemic stroke patients presenting within 4.5 and 9h of stroke onset or unknown time-window to either rt-PA or placebo after MR-imaging. Two subgroups “no mismatch” (nMM) and “any mismatch” (aMM) were created by applying a DWI-FLAIR-mismatch criterion. We calculated frequency of nMM and aMM and performed a univariate analysis (Fisher's Test) for excellent clinical outcome (mRS 0-1) and mortality (mRS=6). Results MR-Imaging of n=111/119 (93.2%) patients was suitable for this analysis. DWI-FLAIR mismatch was found in 49 patients (44.1%). Proportions of mismatch nMM and aMM were comparable in treatment-groups (aMM: Placebo 46.3%, Alteplase 42.1%; p=0.70). Patients with nMM showed no benefit of rt-PA-treatment (OR (95%CI) mRS 0-1: 0.95 (0.29-3.17)). Patients with aMM showed a point estimate of the odds ratio in favour of a treatment benefit of rt-PA (mRS 0-1: OR (95%CI) 2.62 (0.68-11.1)). Mortality within 90 days was not different in patients treated with rt-PA if nMM (15.2%) or aMM (12.5%) was present. Discussion In this analysis no significant evidence, but subtle indication towards patients treated with rt-PA in a prolonged time window reaching an excellent clinical outcome if a DWI-FLAIR-mismatch is present on initial stroke MR-imaging. Conclusion A DWI-FLAIR mismatch in the region of ischemia as imaging based surrogate parameter for patient selection for i.v. rt-PA should be strongly pursued.
    Type of Medium: Online Resource
    ISSN: 2396-9873 , 2396-9881
    URL: Article
    DOI: 10.1177/2396987320920114
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2020
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  • 6
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    Sedation vs. Intubation for Endovascular Stroke TreAtment (SIESTA) – A Randomized Monocentric Trial
    SAGE Publications ; 2015
    In:  International Journal of Stroke Vol. 10, No. 6 ( 2015-08), p. 969-978
    Details
    In: International Journal of Stroke, SAGE Publications, Vol. 10, No. 6 ( 2015-08), p. 969-978
    Abstract: The optimal peri-interventional management of sedation and airway for endovascular stroke treatment (EST) appears to be a crucial factor for treatment success. According to retrospective studies, the widely favored general anesthesia with intubation seems to be associated with poor functional outcome compared to a slightly sedated non-intubated condition (conscious sedation). Method SIESTA is a monocentric, prospective, randomized parallel-group, open-label treatment trial with blinded endpoint evaluation (PROBE design). The study compares the non-intubated with the intubated state in patients receiving endovascular treatment of acute ischemic anterior circulation stroke. The primary endpoint is early neurological improvement as by National Institutes of Health Stroke Scale (NIHSS) after 24 h (difference between NIHSS on admission and NIHSS after 24 h). Secondary endpoints include: functional outcome after three-months as by modified Rankin Scale (mRS), mortality, parameters of ventilation and critical care, feasibility, and safety, i.e. complications related to endovascular stroke treatment. Conclusion The aims of this study are to prospectively clarify whether the non-intubated state of conscious sedation is feasible, safe, and superior with regard to early neurological improvement compared to the intubated state of general anesthesia in patients receiving acute endovascular stroke treatment.
    Type of Medium: Online Resource
    ISSN: 1747-4930 , 1747-4949
    URL: Article
    DOI: 10.1111/ijs.12488
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2015
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  • 7
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    ERic Acute StrokE Recanalization: A study using predictive analytics to assess a new device for mechanical thrombectomy
    SAGE Publications ; 2017
    In:  International Journal of Stroke Vol. 12, No. 6 ( 2017-08), p. 659-666
    Details
    In: International Journal of Stroke, SAGE Publications, Vol. 12, No. 6 ( 2017-08), p. 659-666
    Abstract: Using a new study design, we investigate whether next-generation mechanical thrombectomy devices improve clinical outcomes in ischemic stroke patients. We hypothesize that this new methodology is superior to intravenous tissue plasminogen activator therapy alone. Methods and design ERic Acute StrokE Recanalization is an investigator-initiated prospective single-arm, multicenter, controlled, open label study to compare the safety and effectiveness of a new recanalization device and distal access catheter in acute ischemic stroke patients with symptoms attributable to acute ischemic stroke and vessel occlusion of the internal cerebral artery or middle cerebral artery. Study outcome The primary effectiveness endpoint is the volume of saved tissue. Volume of saved tissue is defined as difference of the actual infarct volume and the brain volume that is predicted to develop infarction by using an optimized high-level machine learning model that is trained on data from a historical cohort treated with IV tissue plasminogen activator. Sample size estimates Based on own preliminary data, 45 patients fulfilling all inclusion criteria need to complete the study to show an efficacy 〉 38% with a power of 80% and a one-sided alpha error risk of 0.05 (based on a one sample t-test). Discussion ERic Acute StrokE Recanalization is the first prospective study in interventional stroke therapy to use predictive analytics as primary and secondary endpoint. Such trial design cannot replace randomized controlled trials with clinical endpoints. However, ERic Acute StrokE Recanalization could serve as an exemplary trial design for evaluating nonpivotal neurovascular interventions.
    Type of Medium: Online Resource
    ISSN: 1747-4930 , 1747-4949
    URL: Article
    DOI: 10.1177/1747493017700661
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2017
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  • 8
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    Recanalization after cerebral venous thrombosis. A randomized controlled trial of the safety and efficacy of dabigatran etexilate versus dose-adjusted warfarin in patients with cerebral venous and dural sinus thrombosis
    SAGE Publications ; 2022
    In:  International Journal of Stroke Vol. 17, No. 2 ( 2022-02), p. 189-197
    Details
    In: International Journal of Stroke, SAGE Publications, Vol. 17, No. 2 ( 2022-02), p. 189-197
    Abstract: The effect of different anticoagulants on recanalization after cerebral venous thrombosis has not been studied in a randomized controlled trial. Methods RE-SPECT CVT (ClinicalTrials.gov number: NCT02913326) was a Phase III, prospective, randomized, parallel-group, open-label, multicenter, exploratory trial with blinded endpoint adjudication. Acute cerebral venous thrombosis patients were allocated to dabigatran 150 mg twice daily, or dose-adjusted warfarin, for 24 weeks, after 5–15 days’ treatment with unfractionated or low-molecular-weight heparin. A standardized magnetic resonance protocol including arterial spin labeling, three-dimensional time-of-flight venography, and three-dimensional contrast-enhanced magnetic resonance angiography was obtained at the end of the treatment period. Cerebral venous recanalization at six months was assessed by two blinded adjudicators, using the difference in a score of occluded sinuses and veins (predefined secondary efficacy endpoint) and in the modified Qureshi scale (additional endpoint), between baseline and the end of the treatment. Results Of 120 cerebral venous thrombosis patients randomized, venous recanalization could be evaluated in 108 (55 allocated to dabigatran and 53 to warfarin, 1 patient had a missing occlusion score at baseline). No patient worsened in the score of occluded cerebral veins and sinuses, while 33 (60%) on dabigatran and 35 (67%) on warfarin improved. The mean score change from baseline in the occlusion score was similar in the two treatment groups (dabigatran −0.8, SD 0.78; warfarin −1.0, SD 0.92). In the modified Qureshi score, full recanalization was adjudicated in 24 (44%) and 19 (36%), and partial recanalization in 23 (42%) and 26 (49%) patients in the dabigatran and warfarin arms, respectively. No statistically significant treatment difference in the modified Qureshi score could be detected ( p = 0.44). Conclusion The majority of patients with cerebral venous thrombosis, anticoagulated with either dabigatran or warfarin for six months, showed partial or complete recanalization of occluded sinuses and veins at the end of the treatment. Clinical trial registration: Trial registry name: ClinicalTrials.gov URL: https://clinicaltrials.gov Registration number: NCT02913326
    Type of Medium: Online Resource
    ISSN: 1747-4930 , 1747-4949
    URL: Article
    DOI: 10.1177/17474930211006303
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2022
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  • 9
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    A collaborative sequential meta-analysis of individual patient data from randomized trials of endovascular therapy and tPA vs. tPA alone for acute ischemic stroke: T h R omb E ctomy A nd t PA (TREAT) analysis: statistical analysis plan for a sequential meta-analysis performed within the VISTA-Endovascular collaboration
    SAGE Publications ; 2015
    In:  International Journal of Stroke Vol. 10, No. SA100 ( 2015-10), p. 136-144
    Details
    In: International Journal of Stroke, SAGE Publications, Vol. 10, No. SA100 ( 2015-10), p. 136-144
    Abstract: Endovascular treatment has been shown to restore blood flow effectively. Second-generation medical devices such as stent retrievers are now showing overwhelming efficacy in clinical trials, particularly in conjunction with intravenous recombinant tissue plasminogen activator. Aims and Design This statistical analysis plan utilizing a novel, sequential approach describes a prospective, individual patient data analysis of endovascular therapy in conjunction with intravenous recombinant tissue plasminogen activator agreed upon by the Thrombectomy and Tissue Plasminogen Activator Collaborative Group. Study outcomes This protocol will specify the primary outcome for efficacy, as ‘favorable’ outcome defined by the ordinal distribution of the modified Rankin Scale measured at three-months poststroke, but with modified Rankin Scales 5 and 6 collapsed into a single category. The primary analysis will aim to answer the questions: ‘what is the treatment effect of endovascular therapy with intravenous recombinant tissue plasminogen activator compared to intravenous tissue plasmi-nogen activator alone on full scale modified Rankin Scale at 3 months?’ and ‘to what extent do key patient characteristics influence the treatment effect of endovascular therapy?’. Key secondary outcomes include effect of endovascular therapy on death within 90 days; analyses of modified Rankin Scale using dichotomized methods; and effects of endovascular therapy on symptomatic intracranial hemorrhage. Several secondary analyses will be considered as well as expanding patient cohorts to intravenous recombinant tissue plasminogen activator-ineligible patients, should data allow. Discussion This collaborative meta-analysis of individual participant data from randomized trials of endovascular therapy vs. control in conjunction with intravenous thrombolysis will demonstrate the efficacy and generalizability of endovascular therapy with intravenous thrombolysis as a concomitant medication.
    Type of Medium: Online Resource
    ISSN: 1747-4930 , 1747-4949
    URL: Article
    DOI: 10.1111/ijs.12622
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2015
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  • 10
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    Analyses of thrombi in acute ischemic stroke: A consensus statement on current knowledge and future directions
    SAGE Publications ; 2017
    In:  International Journal of Stroke Vol. 12, No. 6 ( 2017-08), p. 606-614
    Details
    In: International Journal of Stroke, SAGE Publications, Vol. 12, No. 6 ( 2017-08), p. 606-614
    Abstract: Limited data exist on clot composition and detailed characteristics of arterial thrombi associated with large vessel occlusion in acute ischemic stroke. Advances in endovascular thrombectomy and related imaging modalities have created a unique opportunity to analyze thrombi removed from cerebral arteries. Insights into thrombus composition, etiology, physical properties and neurovascular interactions may lead to future advancements in acute ischemic stroke treatment and improved clinical outcomes. Advances in imaging techniques may enhance clot characterization and inform therapeutic decision-making prior to treatment and reveal stroke etiology to guide secondary prevention. Current imaging techniques can provide some information about thrombi, but there remains much to evaluate about relationships that may exist among thrombus composition, occlusion characteristics and treatment outcomes. Improved pathophysiological characterization of clot types, their properties and how these properties change over time, together with clinical correlates from ongoing studies, may facilitate revascularization with thrombolysis and thrombectomy. Interdisciplinary approaches covering clinical, engineering and scientific aspects of thrombus research will be key to advancing the understanding of thrombi and improving acute ischemic stroke therapy. This consensus statement integrates recent research on clots and thrombi retrieved from cerebral arteries and provides a rationale for further analyses, including current opportunities and limitations.
    Type of Medium: Online Resource
    ISSN: 1747-4930 , 1747-4949
    URL: Article
    DOI: 10.1177/1747493017709671
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2017
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