Increasingly, experimental research in subarachnoid hemorrhage (SAH) has investigated early brain injury and the microcirculation. A number of pathophysiological changes occur in the cerebral microvessels after SAH including altered vasoreactivity, vasoconstriction, inflammation, blood-brain barrier impairment, increased microthrombi, and inversion of neurovascular coupling. This focused review looks at the current state of knowledge regarding the changes that occur in the microcirculation and the neurovascular unit after SAH.

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BackgroundMiddle meningeal artery (MMA) embolization is an emerging therapy for the resolution of subacute or chronic subdural hematoma (CSDH). CSDH patients are often elderly and have several comorbidities. We evaluated our experience with transradial access (TRA) for MMA embolization using predominantly Onyx under conscious sedation.MethodsData for consecutive patients who underwent transradial MMA embolization for CSDH during a 2-year period (2018–2019) were analyzed from a single-center, prospectively-maintained database. Patient demographics, comorbidities, ambulatory times, subdural hematoma resorption status, and guide catheter type were recorded. Conversion to femoral access and complication rates were also recorded. Univariate and multivariate analyses were performed.ResultsForty-six patients (mean age, 71.7±14.4 years) were included in this study. Mean CSDH size was 14±5.5 mm. Most (91.3%) TRA embolizations were performed with 6-French 0.071-inch Benchmark guide catheters (Penumbra). MMA embolization was successful in 44 patients (95.7%) (including two cases of TRA conversion). Twenty-one (48%) patients had a severe Charlson Comorbidity Index (>5). Symptomatic improvement was noted in 39 of 44 patients (88.6%). Mean length of stay was 4±3 days. Patients were ambulated immediately postprocedure. At mean follow-up (8±4 weeks), 86.4% of patients had complete or partial CSDH resolution. Persistent use of antiplatelet agents after the procedure was associated with failed or minimal CSDH resorption (5 of 6, 83.3% vs 9 of 38 23.7% with complete or near-complete resolution; P=0.009).ConclusionTransradial Onyx MMA embolization under conscious sedation is safe and effective for CSDH treatment. TRA may be especially useful in elderly patients with numerous comorbidities.

230Ischemic stroke is the leading cause of permanent disability in the developed world.1 Up to 20% of ischemic strokes result from atherosclerotic stenosis of the internal carotid artery. 2 Carotid endarterectomy (CEA) has been shown to be of benefit in the treatment of symptomatic and asymptomatic carotid artery stenosis by several large randomized controlled trials (RCTs). [3][4][5][6][7] Over the past decade, however, a growing interest has arisen in carotid artery stenting (CAS) as a less invasive means of carotid revascularization.Disparate results have been reported by RCTs investigating the relative efficacy of CAS and CEA. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Three trials were stopped prematurely after their interim analyses revealed an increased risk of stroke following CAS. 13,14,16,23 In contrast, six ABSTRACT: Background: A meta-analysis of randomized controlled trials (RCTs) was conducted to update the available evidence on the safety and efficacy of carotid endarterectomy (CEA) versus carotid artery stenting (CAS) in the treatment of carotid artery stenosis. Methods: A comprehensive search was performed of MEDLINE, EMBASE, CENTRAL, bibliographies of included articles and past systematic reviews, and abstract lists of recent scientific conferences. For each reported outcome, a Mantel-Haenszel random-effects model was used to calculate odds ratios (ORs) and 95% confidence intervals (CI). The I 2 statistic was used as a measure of heterogeneity. Results: Twelve RCTs enrolling 6,973 patients were included in the meta-analysis. Carotid artery stenting was associated with a significantly greater odds of periprocedural stroke (OR 1.72, 95% CI 1.20 to 2.47) and a significantly lower odds of periprocedural myocardial infarction (OR 0.47, 95% CI 0.29 to 0.78) and cranial neuropathy (OR 0.08, 95% CI, 0.04 to 0.16). The odds of periprocedural death (OR 1.11, 95% CI 0.56 to 2.18), target vessel restenosis (OR 1.95, 95% CI 0.63 to 6.06), and access-related hematoma were similar following either intervention (OR 0.60, 95% CI 0.30 to 1.21). Conclusions: In comparison with CEA, CAS is associated with a greater odds of stroke and a lower odds of myocardial infarction. While the results our meta-analysis support the continued use of CEA as the standard of care in the treatment of carotid artery stenosis, CAS is a viable alternative in patients at elevated risk of cardiac complications. Bien que les résultats de notre méta-analyse soient en faveur de continuer à utiliser l'EC comme norme de soins dans le traitement de la sténose carotidienne, la PEV est une alternative valable chez les patients à risque élevé de complications cardiaques.

BACKGROUND AND PURPOSE: Clot perviousness in acute ischemic stroke is a potential CT imaging biomarker for mechanical thrombectomy efficacy. We investigated the association among perviousness, clot cellular composition, and first-pass effect. MATERIALS AND METHODS: In 40 mechanical thrombectomy-treated cases of acute ischemic stroke, we calculated perviousness as the difference in clot density on CT angiography and noncontrast CT. We assessed the proportion of fibrin/platelet aggregates, red blood cells, and white blood cells on clot histopathology. We tested for linear correlation between histologic components and perviousness, differences in components between "high" and "low" pervious clots defined by median perviousness, and differences in perviousness/composition between cases that did and did not achieve a first-pass effect. RESULTS: Perviousness significantly positively and negatively correlated with the percentage of fibrin/platelet aggregates (P ¼ .001) and the percentage of red blood cells (P ¼ .001), respectively. Higher pervious clots had significantly greater fibrin/platelet aggregate content (P ¼ .042). Cases that achieved a first-pass effect (n ¼ 14) had lower perviousness, though not significantly (P ¼ .055). The percentage of red blood cells was significantly higher (P ¼ .028) and the percentage of fibrin/platelet aggregates was significantly lower (P ¼ .016) in cases with a first-pass effect. There was no association between clot density on NCCT and clot composition or first-pass effect. Receiver operating characteristic analysis indicated that clot composition was the best predictor of firstpass effect (area under receiver operating characteristic curve: percentage of fibrin/platelet aggregates ¼ 0.731, percentage of red blood cells ¼ 0.706, perviousness ¼ 0.668). CONCLUSIONS: Clot perviousness on CT is associated with a higher percentage of fibrin/platelet aggregate content. Histologic data and, to a lesser degree, perviousness may have value in predicting first-pass outcome. Imaging metrics that more strongly reflect clot biology than perviousness may be needed to predict a first-pass effect with high accuracy. ABBREVIATIONS: AIS ¼ acute ischemic stroke; AUC ¼ area under the curve; CV ¼ coefficient of variation; FP ¼ fibrin/platelet aggregates; FPE ¼ first-pass effect; MMI ¼ Mattes mutual information; MT ¼ mechanical thrombectomy; mTICI ¼ modified TICI; RBC ¼ red blood cells; ROC ¼ receiver operating characteristic; WBC ¼ white blood cells C T is the most common imaging technique used to evaluate patients with acute ischemic stroke (AIS). Together, NCCT and CTA can provide valuable information about the occlusive clot, such as its location, length, and density. 1-3 One parameter derived from these images is clot permeability, or perviousness, which indicates the amount of contrast that diffuses through the clot tissue. 1,4 Several clinical studies have claimed that perviousness may be an important indicator of how easily occlusive clots can be treated by tPA or mechanical thrombectomy (MT). 1...

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OBJECTIVE Blunt cerebrovascular injury (BCVI) occurs in approximately 1% of the blunt trauma population and may lead to stroke and death. Early vascular imaging in asymptomatic patients at high risk of having BCVI may lead to earlier diagnosis and possible stroke prevention. The objective of this study was to determine if the implementation of a formalized asymptomatic BCVI screening protocol with CT angiography (CTA) would lead to improved BCVI detection and stroke prevention. METHODS Patients with vascular imaging studies were identified from a prospective trauma registry at a single Level 1 trauma center between 2002 and 2008. Detection of BCVI and stroke rates were compared during the 3-year periods before and after implementation of a consensus-based asymptomatic BCVI screening protocol using CTA in 2005. RESULTS A total of 5480 patients with trauma were identified. The overall BCVI detection rate remained unchanged postprotocol compared with preprotocol (0.8% [24 of 3049 patients] vs 0.9% [23 of 2431 patients]; p = 0.53). However, postprotocol there was a trend toward a decreased risk of stroke secondary to BCVI on a trauma population basis (0.23% [7 of 3049 patients] vs 0.53% [13 of 2431 patients]; p = 0.06). Overall, 75% (35 of 47) of patients with BCVI were treated with antiplatelet agents, but no patient developed new or progressive intracranial hemorrhage despite 70% of these patients having concomitant traumatic brain injury. CONCLUSIONS The results of this study suggest that a CTA screening protocol for BCVI may be of clinical benefit with possible reduction in ischemic complications. The treatment of BCVI with antiplatelet agents appears to be safe.

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