Brinjikji, Waleed

Background Although successful recanalization (modified Thrombolysis in Cerebral Infarction score 2b–3) can be achieved in >80% of patients experiencing stroke attributable to large‐vessel occlusion, up to 50% of patients may develop poor clinical outcomes (modified Rankin scale score at 90 days of 3–6), termed as futile recanalization (FR). The meta‐analysis aims to determine various risk factors associated with FR. Methods In February 2021, a comprehensive literature search on risk factors associated with FR was performed with keywords, including “stroke,” “thrombectomy,” “treatment outcome,” and “risk factors.” Their correlations with FR were evaluated using the random effect size meta‐analysis model. Results Twenty studies with 3037 patients were included with an FR rate of 51.0%. Our meta‐analyses showed that age (mean difference [MD], 5.6; 95% CI, 4.7–6.6), National Institutes of Health Stroke Scale score (MD, 4.2; 95% CI, 3.2–5.1), Alberta Stroke Program Early Computed Tomography (CT) Score (MD, −0.5; 95% CI, 0.8–0.3), hypertension (odds ratio [OR], 1.5; 95% CI, 1.3–1.9), systolic blood pressure (MD, 6.9; 95% CI, 3.6–8.7), atrial fibrillation (OR, 1.5; 95% CI, 1.2–1.8), IV tPA (tissue‐type plasminogen activator) (OR, 0.7; 95% CI, 0.5–0.8), puncture to recanalization time (MD, 9.6; 95% CI, 5.3–13.8), and time of onset to recanalization (MD, 32.1; 95% CI, 6.5–47.7) were significantly associated with FR ( P <0.001). Conclusions Age, admission National Institutes of Health Stroke Scale score, Alberta Stroke Program Early CT Score, comorbidities, including hypertension, systolic blood pressure, atrial fibrillation, and use of IV tPA, as well as time frames, including onset to recanalization and onset to arrival, were significant influencing factors for FR after mechanical thrombectomy. Future research on the mechanism underlying FR is warranted.

Angioinvasive fungal infections of the cerebral vasculature often lead to significant morbidity and mortality. High clinical suspicion and early antifungal therapy could improve outcomes. We describe the fatal case of a patient with a rapidly enlarging cavernous carotid aneurysm due to angioinvasive fungus. This case highlights the challenges in diagnosis and management of this condition.

Stenting of the intracranial venous sinuses has shown promising results in patients who are refractory to medical treatment of idiopathic intracranial hypertension (IIH). Among the reported complications associated with this procedure, in-stent thrombosis is an unreported one. We present a case of cerebral sinus thrombosis during endovascular treatment of IIH. A 33-year-old man with multiple comorbidities was presented with non-specific vision changes and headaches. Initial workup revealed a diagnosis of idiopathic intracranial hypertension which was treated medically but with no improvement. Therefore, cerebral sinus stenting was pursued. During the procedure, an in-stent thrombus was identified which was retrieved mechanically and was sent for histological and immunohistochemical evaluation. The retrieved thrombus was predominantly composed of RBCs (57.8%) followed by fibrin (30.78%), platelet (6.4%), and WBCs (5.95%), with high expression of CitH3 (neutrophil extra cellular traps specific marker) (10.9%), and CD66 (11.35%).

Background Extracellular DNA traps (ETs) have important implications in both thrombosis and thrombolysis. Thus, developing benchtop thrombus analogs that recapitulate clinical ETs is potentially of great value for preclinical development and testing of thrombolytic agents and thrombectomy devices. In this study, we aimed to develop ETs-rich thrombus analogs for preclinical testing. Methods Red blood cell (RBC)-rich, fibrin-rich, and platelet-rich thrombus analogs were created using human whole blood, platelet-poor plasma, and platelet-rich plasma obtained from the blood bank following institutional approval. Peripheral blood mononuclear cells (9.9×106 cells/mL) isolated from human whole blood and lipopolysaccharide (1 µg/mL) were added to induce ETs. Histochemical, immunohistochemistry and immunofluorescence were used to identify thrombus components and ETs. Scanning electronic microscopy was used to investigate the ultrastructure of the thrombus analogs. The thrombus compositions, morphologic features of ETs and citrullinated histone H3 (H3Cit) expression were compared with those of thrombi retrieved from patients by thrombectomy. Results ETs-rich thrombus analogs were more compacted th-an the ETs-poor thrombus analogs. ETs were identified in both ETs-rich thrombus analogs and patient thrombi showing morphologic features including nuclear lobulation, nuclear swelling, diffused chromatin within cytoplasm, DNA/chromatin extending intracellularly and extracellularly, and extracellular chromatin patches and bundles. In the ETs-poor thrombus analogs, ETs were not observed and H3Cit expression was absent to minimal. The compositions and H3Cit expression in the ETs-rich thrombus analogs fell in the range of patient thrombi. Conclusions ETs-rich thrombus analogs can be consistently created in vitro and may benefit the preclinical development and testing of new thrombolytic agents and thrombectomy devices.

In the evaluation of embolic strokes of undetermined source, great emphasis is often placed on cardiovascular disease, namely on atrial fibrillation. Other pathophysiologic mechanisms, however, may also be involved. Carotid artery intraplaque hemorrhage (IPH)—the presence of blood components within an atheromatous plaque—has become increasingly recognized as a possible etiologic mechanism in some cryptogenic strokes. IPH is a marker of plaque instability and is associated with ipsilateral neurologic ischemic events, even in nonstenotic carotid plaques. As recognition of carotid IPH as an etiology of embolic strokes has grown, so too has the complexity with which such patients are evaluated and treated, particularly because overlaps exist in the risk factors for atrial fibrillation and IPH. In this article, we review what is currently known about carotid IPH and how this clinical entity should be approached in the context of the evaluation of embolic strokes of undetermined source.

Background: Cranial dural arteriovenous fistulas with cortical venous drainage are rare lesions that can present with hemorrhage. A high rate of rebleeding in the early period following hemorrhage has been reported, but published long-term rates are much lower. No study has examined how risk of rebleeding changes over time. Our objective was to quantify the relative incidence of rebleeding in the early and later periods following hemorrhage. Methods: Patients with dural arteriovenous fistula and cortical venous drainage presenting with hemorrhage were identified from the multinational CONDOR (Consortium for Dural Fistula Outcomes Research) database. Natural history follow-up was defined as time from hemorrhage to first treatment, rebleed, or last follow-up. Rebleeding in the first 2 weeks and first year were compared using incidence rate ratio and difference. Results: Of 1077 patients, 250 met the inclusion criteria and had 95 cumulative person-years natural history follow-up. The overall annualized rebleed rate was 7.3% (95% CI, 3.2–14.5). The incidence rate of rebleeding in the first 2 weeks was 0.0011 per person-day; an early rebleed risk of 1.6% in the first 14 days (95% CI, 0.3–5.1). For the remainder of the first year, the incidence rate was 0.00015 per person-day; a rebleed rate of 5.3% (CI, 1.7–12.4) over 1 year. The incidence rate ratio was 7.3 (95% CI, 1.4–37.7; P , 0.026). Conclusions: The risk of rebleeding of a dural arteriovenous fistula with cortical venous drainage presenting with hemorrhage is increased in the first 2 weeks justifying early treatment. However, the magnitude of this increase may be considerably lower than previously thought. Treatment within 5 days was associated with a low rate of rebleeding and appears an appropriate timeframe.

Telesurgery is not a foreign concept and dates to as early as the 1920s. The use of robots in medicine has had a very positive effect and improved outcomes with little to no adverse effects. Having global access to telemedicine and telesurgery during the COVID-19 pandemic and being able to provide top medical care to gravely ill and contagious patients without compromising the safety of the medical team would be a very big achievement. We explore the hurdles needed to make it a realistic goal and give recommendations to achieve it utilizing the major advancements that have occurred over the past few years in the fields of engineering, communication etc. The biggest issues needed to be addressed are of financial investment, legal concerns, and availability of high-speed uninterrupted data connections.

Introduction: The selection of acute ischemic stroke patients relies on the interpretation of radiological studies, commonly including noncontrast CT (ASPECTS score), CTA, and in some circumstances, CT perfusion (CTP) scans. Hypothesis: The interrater reliability between readers of noncontrast head CT will be moderate and not as good as that between readers of CT perfusion scans. Methods: Retrospective study of consecutive ischemic stroke patients who were considered for endovascular stroke therapy at an academic medical center from April 2010 - November 2014. All patients underwent CT, CTA, and CTP. Images were independently reviewed by four readers (A, B, C, D) in total (2 experienced neuroradiologists, one experienced neurointensivist, and one neuroradiology fellow). Each rated half of the cohort. All readers performed online training in ASPECTS. Moderate-to-good collateral circulation was defined as filling of 50% or more of the middle cerebral artery pial arterial territory on CTA, as in ESCAPE trial. An “acceptable core” on CTP was defined as in EXTEND-IA trial with core volume < 70 mL, mismatch ratio >1.2, and absolute mismatch volume >10 mL but was qualitatively estimated. Interrater agreement was assessed for total ASPECTS, dichotomized ASPECTS (≥6 vs <6), evaluation of collaterals, and evaluation of core. Agreement was assessed using kappa statistic, which was weighted for the total ASPECTS analysis. Results: Our cohort included 119 patients with acute stroke and large vessel occlusion. Interrater agreement for total ASPECTS was very good between readers C and D (' 0.70) and good between A and B (' 0.55). For dichotomized ASPECTS, agreement was fair-to-good (' 0.30 for C/D; ' 0.41 for A/B). Agreement for grading collaterals on CTA was good to very good (' 0.64 for C /D; ' 0.54 for A/B). Agreement for rating core on CTP was very good (' 0.78 for C/D; ' 0.62 for A/D). Conclusions: Interrater reliability is good to very good for total ASPECTS score, dichotomous grading of collaterals on CTA, and subjective estimation of core size on CTP. Agreement is only fair to good for dichotomized ASPECTS.