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Pathological blood clotting, or thrombosis, limits vital blood flow to organs; such deprivation can lead to catastrophic events including myocardial infarction, pulmonary embolism, and ischemic stroke. Prompt restoration of blood flow greatly improves outcomes. We explored whether aptamers could serve as molecular imaging probes to rapidly detect thrombi. An aptamer targeting thrombin, Tog25t, was found to rapidly localize to and visualize pre-existing clots in the femoral and jugular veins of mice using fluorescence imaging and, when circulating, was able to image clots as they form. Since free aptamer is quickly cleared from circulation, contrast is rapidly developed, allowing clot visualization within minutes. Moreover, administration of an antidote oligonucleotide further enhanced contrast development, causing the unbound aptamer to clear within 5min while impacting the clot-bound aptamer more slowly. These findings suggest that aptamers can serve as imaging agents for rapid detection of thrombi in acute care and perioperative settings.

Background and purposePrevious studies suggest that mechanisms and outcomes in patients with COVID-19-associated stroke differ from those in patients with non-COVID-19-associated strokes, but there is limited comparative evidence focusing on these populations. The aim of this study, therefore, was to determine if a significant association exists between COVID-19 status with revascularization and functional outcomes following thrombectomy for large vessel occlusion (LVO), after adjustment for potential confounding factors.MethodsA cross-sectional, international multicenter retrospective study was conducted in consecutively admitted COVID-19 patients with concomitant acute LVO, compared to a control group without COVID-19. Data collected included age, gender, comorbidities, clinical characteristics, details of the involved vessels, procedural technique, and various outcomes. A multivariable-adjusted analysis was conducted.ResultsIn this cohort of 697 patients with acute LVO, 302 had COVID-19 while 395 patients did not. There was a significant difference (p

BackgroundThe mechanisms and outcomes in coronavirus disease (COVID-19)-associated stroke are unique from those of non-COVID-19 stroke.ObjectiveTo describe the efficacy and outcomes of acute revascularization of large vessel occlusion (LVO) in the setting of COVID-19 in an international cohort.MethodsWe conducted an international multicenter retrospective study of consecutively admitted patients with COVID-19 with concomitant acute LVO across 50 comprehensive stroke centers. Our control group constituted historical controls of patients presenting with LVO and receiving a mechanical thrombectomy between January 2018 and December 2020.ResultsThe total cohort was 575 patients with acute LVO; 194 patients had COVID-19 while 381 patients did not. Patients in the COVID-19 group were younger (62.5 vs 71.2; P < .001) and lacked vascular risk factors (49, 25.3% vs 54, 14.2%; P = .001). Modified thrombolysis in cerebral infarction 3 revascularization was less common in the COVID-19 group (74, 39.2% vs 252, 67.2%; P < .001). Poor functional outcome at discharge (defined as modified Ranklin Scale 3-6) was more common in the COVID-19 group (150, 79.8% vs 132, 66.7%; P = .004). COVID-19 was independently associated with a lower likelihood of achieving modified thrombolysis in cerebral infarction 3 (odds ratio [OR]: 0.4, 95% CI: 0.2-0.7; P < .001) and unfavorable outcomes (OR: 2.5, 95% CI: 1.4-4.5; P = .002).ConclusionCOVID-19 was an independent predictor of incomplete revascularization and poor outcomes in patients with stroke due to LVO. Patients with COVID-19 with LVO were younger, had fewer cerebrovascular risk factors, and suffered from higher morbidity/mortality rates.

Background: Cardiac implantable electronic device (CIED) generally excludes patients from undergoing fixed, high-field magnetic resonance imaging (MRI). Acute ischemic stroke patients undergo MRI as a standard part of an assessment of infarct burden. The use of a portable MRI scanner may be useful in patients who have contraindications to high-field MRI. We present the first case of a patient with a CIED who required an endovascular thrombectomy (EVT) for large vessel occlusion. She underwent a low-field MRI in the operating room with the Hyperfine portable system. Case: The patient is an 80-year-old female status post-CIED, on Eliquis who presented with an acute ischemic stroke. Her National Institutes of Health Stroke Scale (NIHSS) of 8. Imaging demonstrated a left M2 occlusion on computed tomography angiogram (CTA) of the head and neck. No lytics were used due to concomitant gastrointestinal bleed. While, admitted, her NIHSS increased to 15. A subsequent CTA demonstrated a left internal carotid artery terminus and M1 occlusion. She underwent EVT with thrombolysis in cerebral infarction (TICI) 3 revascularization. An MRI was performed intraoperatively using a Hyperfine system, which is a low-field, portable MRI, to assess infarct volume. Conclusion: Hyperfine Swoop brain MRI may be safe for use in patients with contraindications to high-field MRI scans. Continued technological refinement will improve the quality of diffusion-weighted imaging. Larger studies will be required to generalize Hyperfine MRI-based imaging for patients with devices that exclude them from high-field imaging. [ABSTRACT FROM AUTHOR]

Background and purpose: Posterior circulation strokes, accounting for 20% of acute ischemic strokes, significantly contribute to morbidity and mortality. Fibrinolysis by rtPA improves outcomes in stroke but the risk of intracranial hemorrhage limits benefit. Arterial recanalization of basilar artery occlusion by thrombolysis or endovascular thrombectomy improves outcomes in posterior circulation strokes. This study investigates a VWF-targeting RNA aptamer as a safer and more effective alternative to rtPA in a canine model. Materials and methods: Autologous clots were placed into the basilar artery to induce stroke in 24 beagles. To compare reperfusion, 0.9 mg/kg rtPA, 0.5 mg/kg BB-031, or vehicle were administered 60 min after the initiation of occlusion. Digital subtraction angiography, laser speckle imaging and magnetic resonance imaging were used to assess recanalization, reperfusion and infarct volume, respectively. Results: Treatment with BB-031 resulted in recanalization of the posterior circulation on digital subtraction angiography with no evidence of microembolism assessed at sacrifice. 66.5% of animals treated with BB-031 resulted in reperfusion with a TICI score of =1 whereas vehicle remained at TICI score 0 as did all but one rtPA animal at sacrifice. Improved perfusion was seen in the basilar artery and surrounding blood vessels visualized through the cranial window with laser speckle imaging to ~47% of its original baseline in BB-031 group compared to rtPA at 37% and vehicle at 22%. Finally, BB-031-treatment resulted in an approximate 32% mean infarct volume, significantly smaller on magnetic resonance imaging compared to 56% in vehicle treated and 48% with rtPA treatment. Conclusion: Targeted inhibition of VWF by BB-031 increased recanalization and reperfusion, and reduced infarct volume in a canine model of BAO stroke. It represents a promising target based on preliminary results for treating acute ischemic stroke. [ABSTRACT FROM AUTHOR]

Introduction: Venous sinus stenting is a well established alternative to cerebrospinal fluid diversion for the treatment of idiopathic intracranial hypertension (IIH) with associated venous sinus stenosis. During this procedure, distal guide catheter placement within the venous sinuses may be desirable to facilitate stent delivery. We report our initial experience using the TracStar LDP™ (Imperative Care, Campbell, USA, 0.088-inch inner diameter) as the guide catheter for intracranial access during venous sinus stenting. Methods: A multi-institutional retrospective chart review of a prospectively maintained IRB-approved database was performed. Consecutive patients who underwent venous sinus stenting from 1/1/2020-9/6/2021 for IIH were included. Patient characteristics, procedural details, TracStar distal reach, outcomes, and complications were collected and analyzed. Results: Fifty-eight patients were included. The mean age was 33.8 years and 93.1% of patients were female. Visual changes prompted evaluation in 86.2% of patients. Stent placement was successful in all patients. The TracStar LDP catheter was advanced to the location of stent placement in 97.9% of cases in which it was attempted. The large 0.088-inch inner diameter lumen enabled compatibility with all desired stent sizes ranging from six to 10 millimeters. Gradient pressure across transverse sinus stenosis dropped from an average of 19.5 mmHg pre-procedure to 1.7 mmHg post-stent placement (p < 0.001). Clinical improvement was achieved in 87.9% (51/58) of patients. There were no catheter-related complications. Conclusion: The TracStar LDP is a safe and effective access platform for reaching treatment locations in patients who present with idiopathic intracranial hypertension and who are candidates for venous sinus stent placement. [ABSTRACT FROM AUTHOR]

Background: A number of large bore guide catheters are currently available for use in neuroendovascular surgery. This study represents a multi-institutional retrospective series of patients undergoing mechanical thrombectomy with the use of a TracStar Large Distal Platform (LDP) guide catheter and assessed its performance in vivo in 107 patients. Objective: To review a multi-institutional initial experience with the TracStar LDP guide catheter during mechanical thrombectomy for emergent large vessel occlusion (ELVO). Methods: A retrospective review was performed at two level one stroke centres to include all patients who underwent mechanical thrombectomy and had the TracStar LDP guide catheter used during the intervention. Results: The TracStar LDP guide catheter was successfully used in 107 mechanical thrombectomies. In anterior circulation ELVO, the guide catheter advanced into the cavernous segment of the internal carotid artery in 62.6% (62/99) of cases. In posterior circulation cases, the guide catheter advanced to the basilar artery in 87.5% (7/8) of cases. A thrombolysis in cerebral infarction 2b or greater reperfusion was obtained in 90.7% (97/107). No complications occurred related to the TracStar LDP guide catheter. Three complications occurred with aspiration catheters including a small dissection that did not require further intervention and fracturing of the AXS Catalyst 6 catheter tip in two cases. No thromboembolic events occurred. Conclusions: The TracStar LDP large bore guide catheter is safe and effective at navigating the tortuous vascular anatomy often encountered during mechanical thrombectomy for stroke. The flexible distal and stiffer proximal components provide a good combination of navigability and support for use in neuroendovascular interventions. [ABSTRACT FROM AUTHOR]