Tenecteplase in acute ischemic stroke: Review of the literature and expert consensus from the French Neurovascular Society

BACKGROUND

Intravenous alteplase is the only thrombolytic treatment approved for patients with acute ischemic stroke (AIS). Although no randomized controlled trial (RCT) has shown the superiority of tenecteplase over alteplase in AIS, tenecteplase is increasingly used off-label in Stroke Units. The purpose of the present work was to provide an up-to-date set of expert consensus statements on the use of tenecteplase in AIS.

METHODS

Members of the working group were selected by the French Neurovascular Society. RCTs comparing tenecteplase and alteplase in the treatment of AIS were reviewed. Recent meta-analysis and real-life experience data on tenecteplase published until 30th October 2021 were also analyzed. After a description of the available data, we tried to answer the subsequent questions about the use of tenecteplase in AIS: What dosage of tenecteplase should be preferred? How effective is tenecteplase for cerebral artery recanalization? What is the clinical effectiveness of tenecteplase? What is the therapeutic safety of tenecteplase? What are the benefits associated with tenecteplase ease of use? Then expert consensus statements for tenecteplase use were submitted. In October 2021 the working group was asked to review and revise the manuscript. In November 2021, the current version of the manuscript was approved.

EXPERT CONSENSUS

A set of three expert consensus statements for the use of tenecteplase within 4.5hours of symptom onset in AIS patients were issued: (1) It is reasonable to use tenecteplase 0.25mg/kg when mechanical thrombectomy (MT) is planned. (2) Tenecteplase 0.25mg/kg can be used as an alternative to alteplase 0.9mg/kg in patients with medium- or small-vessel occlusion not retrievable with MT. (3) Tenecteplase 0.25mg/kg could be considered as an alternative to alteplase 0.9mg/kg in patients without vessel occlusion.

CONCLUSIONS

These expert consensus statements could provide a framework to guide the clinical decision-making process for the use of tenecteplase according to admission characteristics of AIS patients. However, existing data are limited, requiring inclusions in ongoing RCTs or real-life registries.

Comparative Study of Lipid Content in Leptoclinus maculatus Postlarvae from Kongsfjord and Rjipfjord, Svalbard Archipelago

A comparative study of lipid profile of the daubed shanny Leptoclinus maculatus postlarvae from fjords of different domains (arctic-boreal Kongsfjord and high-arctic Rjipfjord) of Svalbard Archipelago waters in summer was performed. A more efficient accumulation of lipids in the fishes from Kongsfjord compared to Rjipfjord due to triacylglycerols and wax esters was established. These differences may be related mainly to the trophic conditions of the habitat (species composition, abundance, and availability of food items). The higher level of cholesterol esters than wax esters at the L1 stage of development of the daubed shanny postlarvae compared to older fishes pointed to their active feeding mainly on phytoplankton. The differences in the content of certain classes of phospholipids may indicate adaptive changes at the level of biomembranes, contributing to the maintenance of cell homeostasis in response to abiotic environmental factors, and reflect their additional intake with food at the early stages of fish development.

Influence of operator experience on the technical and clinical results of Woven EndoBridge endovascular treatment for intracranial aneurysms

BACKGROUND & PURPOSE

The safety and efficacy of the Woven EndoBridge (WEB) device has been proven in recent multicenter trials. This study investigated whether operator experience influences WEB treatment-related outcomes.

MATERIAL AND METHODS

This was a retrospective analysis of a prospectively collected multicenter database. The data of all patients who underwent WEB treatment for an intracranial aneurysm from March 2014 to June 2020 in two high-volume centers were pooled. Operator experience was indexed by the number of WEB treatments performed previously. The primary endpoint was the overall complication rate. Secondary endpoints were long-term adequate (Raymond-Roy classification of 1-2.) angiographic occlusion, WEB-related complications, number of WEB not deployed, procedure duration, and radiation exposure (air kerma).

RESULTS

Among 237 patients (mean age 59.4 +/- 11.5 years) treated with WEB (median aneurysm diameter, 5.8 mm; interquartile range 4.5-7 mm), WEB-related complications occurred in 28 patients (11.8%) and adequate long-term occlusion was achieved for 154 aneurysms (86%). The median number of WEB treatment performed previously per operator was 20 (IQR, 9-41). The overall complication rate, WEB-related complication rate and aneurysm occlusion rate were not significantly correlated with WEB operator experience. There were also no significant correlations between the WEB operator experience and the number of WEB not deployed, procedure duration or radiation exposure.

CONCLUSION

There was no significant association between the number of WEB treatments previously performed per operator and any technical or clinical results after intracranial aneurysm treatment with WEB. These results imply a relatively short learning curve for this device in high-volume neurovascular centers.

Brain MRI Findings in Severe COVID-19: A Retrospective Observational Study

Background Brain MRI parenchymal signal abnormalities have been associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Purpose To describe the neuroimaging findings (excluding ischemic infarcts) in patients with severe coronavirus disease 2019 (COVID-19) infection. Materials and Methods This was a retrospective study of patients evaluated from March 23, 2020, to April 27, 2020, at 16 hospitals. Inclusion criteria were (a) positive nasopharyngeal or lower respiratory tract reverse transcriptase polymerase chain reaction assays, (b) severe COVID-19 infection defined as a requirement for hospitalization and oxygen therapy, (c) neurologic manifestations, and (d) abnormal brain MRI findings. Exclusion criteria were patients with missing or noncontributory data regarding brain MRI or brain MRI showing ischemic infarcts, cerebral venous thrombosis, or chronic lesions unrelated to the current event. Categorical data were compared using the Fisher exact test. Quantitative data were compared using the Student t test or Wilcoxon test. P < .05 represented a significant difference. Results Thirty men (81%) and seven women (19%) met the inclusion criteria, with a mean age of 61 years ± 12 (standard deviation) (age range, 8-78 years). The most common neurologic manifestations were alteration of consciousness (27 of 37, 73%), abnormal wakefulness when sedation was stopped (15 of 37, 41%), confusion (12 of 37, 32%), and agitation (seven of 37, 19%). The most frequent MRI findings were signal abnormalities located in the medial temporal lobe in 16 of 37 patients (43%; 95% confidence interval [CI]: 27%, 59%), nonconfluent multifocal white matter hyperintense lesions seen with fluid-attenuated inversion recovery and diffusion-weighted sequences with variable enhancement, with associated hemorrhagic lesions in 11 of 37 patients (30%; 95% CI: 15%, 45%), and extensive and isolated white matter microhemorrhages in nine of 37 patients (24%; 95% CI: 10%, 38%). A majority of patients (20 of 37, 54%) had intracerebral hemorrhagic lesions with a more severe clinical presentation and a higher admission rate in intensive care units (20 of 20 patients [100%] vs 12 of 17 patients without hemorrhage [71%], P = .01) and development of the acute respiratory distress syndrome (20 of 20 patients [100%] vs 11 of 17 patients [65%], P = .005). Only one patient had SARS-CoV-2 RNA in the cerebrospinal fluid. Conclusion Patients with severe coronavirus disease 2019 and without ischemic infarcts had a wide range of neurologic manifestations that were associated with abnormal brain MRI scans. Eight distinctive neuroradiologic patterns were described. © RSNA, 2020.

Development of a bio-optical model for the Barents Sea to quantitatively link glider and satellite observations

A bio-optical model for the Barents Sea is determined from a set of in situ observations of inherent optical properties (IOPs) and associated biogeochemical analyses. The bio-optical model provides a pathway to convert commonly measured parameters from glider-borne sensors (CTD, optical triplet sensor-chlorophyll and CDOM fluorescence, backscattering coefficients) to bulk spectral IOPs (absorption, attenuation and backscattering). IOPs derived from glider observations are subsequently used to estimate remote sensing reflectance spectra that compare well with coincident satellite observations, providing independent validation of the general applicability of the bio-optical model. Various challenges in the generation of a robust bio-optical model involving dealing with partial and limited quantity datasets and the interpretation of data from the optical triplet sensor are discussed. Establishing this quantitative link between glider-borne and satellite-borne data sources is an important step in integrating these data streams and has wide applicability for current and future integrated autonomous observation systems. This article is part of the theme issue 'The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning'.

Neurologic and neuroimaging findings in patients with COVID-19: A retrospective multicenter study

OBJECTIVE

To describe neuroimaging findings and to report the epidemiologic and clinical characteristics of patients with coronavirus disease 2019 (COVID-19) with neurologic manifestations.

METHODS

In this retrospective multicenter study (11 hospitals), we included 64 patients with confirmed COVID-19 with neurologic manifestations who underwent a brain MRI.

RESULTS

The cohort included 43 men (67%) and 21 women (33%); their median age was 66 (range 20-92) years. Thirty-six (56%) brain MRIs were considered abnormal, possibly related to severe acute respiratory syndrome coronavirus. Ischemic strokes (27%), leptomeningeal enhancement (17%), and encephalitis (13%) were the most frequent neuroimaging findings. Confusion (53%) was the most common neurologic manifestation, followed by impaired consciousness (39%), presence of clinical signs of corticospinal tract involvement (31%), agitation (31%), and headache (16%). The profile of patients experiencing ischemic stroke was different from that of other patients with abnormal brain imaging: the former less frequently had acute respiratory distress syndrome (p = 0.006) and more frequently had corticospinal tract signs (p = 0.02). Patients with encephalitis were younger (p = 0.007), whereas agitation was more frequent for patients with leptomeningeal enhancement (p = 0.009).

CONCLUSIONS

Patients with COVID-19 may develop a wide range of neurologic symptoms, which can be associated with severe and fatal complications such as ischemic stroke or encephalitis. In terms of meningoencephalitis involvement, even if a direct effect of the virus cannot be excluded, the pathophysiology seems to involve an immune or inflammatory process given the presence of signs of inflammation in both CSF and neuroimaging but the lack of virus in CSF.

CLINICALTRIALSGOV IDENTIFIER

NCT04368390.

Consensus Guidelines of the French Society of Neuroradiology (SFNR) on the use of Gadolinium-Based Contrast agents (GBCAs) and related MRI protocols in Neuroradiology

Gadolinium-based contrast agents (GBCAs) are used in up to 35% of magnetic resonance imaging (MRI) examinations and are associated with an excellent safety profile. Nevertheless, two main issues have arisen in the last two decades: the risk of nephrogenic systemic fibrosis and the risk of gadolinium deposition and retention. As a first step, this article reviews the different categories of GBCAs available in neuroradiology, their issues, and provides updates regarding the use of these agents in routine daily practice. Recent advances in MRI technology, as well as the development of new MRI sequences, have made GBCA injection avoidable in many indications, especially in patients with chronic diseases when iterative MRIs are required and when essential diagnostic information can be obtained without contrast enhancement. These recent advances also lead to changes in recommended MRI protocols. Thus, in a second step, this review focuses on consensus concerning brain MRI protocols in 10 common situations (acute ischemic stroke, intracerebral hemorrhage, cerebral venous thrombosis, multiple sclerosis, chronic headache, intracranial infection, intra- and extra-axial brain tumors, vestibular schwannoma and pituitary adenoma). The latter allowing the standardization of practices in neuroradiology. Recommendations were also made concerning the use of GBCAs in neuroradiology, based on evidence in the literature and/or by consensus between the different coauthors.

Mechanical Thrombectomy for Acute Ischemic Stroke Amid the COVID-19 Outbreak: Decreased Activity, and Increased Care Delays

BACKGROUND AND PURPOSE

The efficiency of prehospital care chain response and the adequacy of hospital resources are challenged amid the coronavirus disease 2019 (COVID-19) outbreak, with suspected consequences for patients with ischemic stroke eligible for mechanical thrombectomy (MT).

METHODS

We conducted a prospective national-level data collection of patients treated with MT, ranging 45 days across epidemic containment measures instatement, and of patients treated during the same calendar period in 2019. The primary end point was the variation of patients receiving MT during the epidemic period. Secondary end points included care delays between onset, imaging, and groin puncture. To analyze the primary end point, we used a Poisson regression model. We then analyzed the correlation between the number of MTs and the number of COVID-19 cases hospitalizations, using the Pearson correlation coefficient (compared with the null value).

RESULTS

A total of 1513 patients were included at 32 centers, in all French administrative regions. There was a 21% significant decrease (0.79; [95%CI, 0.76-0.82]; P<0.001) in MT case volumes during the epidemic period, and a significant increase in delays between imaging and groin puncture, overall (mean 144.9±SD 86.8 minutes versus 126.2±70.9; P<0.001 in 2019) and in transferred patients (mean 182.6±SD 82.0 minutes versus 153.25±67; P<0.001). After the instatement of strict epidemic mitigation measures, there was a significant negative correlation between the number of hospitalizations for COVID and the number of MT cases (R² -0.51; P=0.04). Patients treated during the COVID outbreak were less likely to receive intravenous thrombolysis and to have unwitnessed strokes (both P<0.05).

CONCLUSIONS

Our study showed a significant decrease in patients treated with MTs during the first stages of the COVID epidemic in France and alarming indicators of lengthened care delays. These findings prompt immediate consideration of local and regional stroke networks preparedness in the varying contexts of COVID-19 pandemic evolution.

Mechanical thrombectomy practices in France: Exhaustive survey of centers and individual operators

BACKGROUND AND PURPOSE

Mechanical thrombectomy (MT) has dramatically changed the landscape of stroke care as well as stroke care organization. Public health institutions are faced with the challenge of swiftly providing equal access to this high technical level procedure with rapidly broadening indications, and constantly developing techniques. The aim of this study was to present a current nationwide overview of technical MT practices in France as well as local organizations.

MATERIALS AND METHODS

Thrombectomy capable French stroke centers, and physicians performing MT were invited to participate to a nationwide survey, disseminated through an existing trainee-led research network (the JENI-RC) under the aegis of the French Society of Neuroradiology. The survey was composed of 64 questions to collect both individual practices and general center-based information.

RESULTS

All French centers (100%) answered the survey, and 74% (110/148) of active interventional neuroradiologists (INR) performing MT completed individual questionnaires. The mean number of INR per center performing MT was 3.7±1.85, and 85% of the centers were organized for 24/7 continuity of care. MRI was the most commonly used imaging modality for stroke diagnosis and patients' selection, and perfusion imaging was routinely available in 85% of the centers. Half of centers performed yearly between 100 and 200 MT. Anesthesiologic, and technical considerations are also developed in the manuscript.

CONCLUSIONS

This nationwide survey highlights the impressive response to the challenge of reorganization of stroke care with regards to mechanical thrombectomy in France. Technical and management disparities remain. Most centers remain understaffed to properly function in the long term, but the inflow of INT trainees is substantial.

P09.08 Increased incidence of intracranial meningiomas in patients with acromegaly

BACKGROUND

An increased incidence of various neoplasms has been described in patients with acromegaly and there is evidence to suggest that growth factors are risk factors for the development of meningiomas. We aimed to study if patients with acromegaly are more at risk for developing intracranial meningiomas

MATERIAL AND METHODS

We conducted an observational study on 221 consecutive acromegalic patients recruited between January 1, 2000 and December 31, 2015, and 357 consecutive patients with a non-somatotropic pituitary adenoma recruited between March 1, 2015 and December 31, 2016 in our institution. Patients underwent a gadolinium-enhanced 3D T1 brain MRI to look for meningiomas. The proportion of meningiomas was compared between the two groups and the standardized incidence ratio (SIR) was computed from the incidence rates of meningiomas observed in the population of acromegalic patients and compared to that of the general population given by the local registry of central nervous system tumors.

RESULTS

Patients with acromegaly had a significant risk for developing intracranial meningiomas as compared to patients without acromegaly (7.7% vs. 2.2%, p = .005, OR = 3.45 [1.46; 8.15]). There was a significant increased incidence of intracranial meningiomas in patients with acromegaly (SIR = 126 [25; 367]) as compared to the general population.

CONCLUSION

Our study provides the first evidence that patients with acromegaly are more at risk for developing intracranial meningiomas.

First-Line Sofia Aspiration Thrombectomy Approach within the Endovascular Treatment of Ischemic Stroke Multicentric Registry: Efficacy, Safety, and Predictive Factors of Success

BACKGROUND AND PURPOSE

After publications on the effectiveness of mechanical thrombectomy by stent retrievers in acute ischemic stroke with large-vessel occlusion, alternative endovascular approaches have been proposed using first-line aspiration catheters. Several devices are currently available to perform A Direct Aspiration First Pass Technique. The Sofia catheter aspiration has been widely used by interventionalists, but data are scarce about its efficacy and safety. Our aim was to report our multicenter thrombectomy experience with first-line Sofia catheter aspiration and to identify independent prognostic factors of clinical and procedural outcomes.

MATERIALS AND METHODS

We performed a retrospective analysis of the prospectively maintained Endovascular Treatment of Ischemic Stroke multicentric registry. Data from consecutive patients who benefited from thrombectomy with a first-line Sofia approach between January 2013 and April 2018 were studied. We excluded other first-line approaches (stent retriever or combined aspiration and stent retriever) and extracranial occlusions. Baseline characteristics, procedural data, and angiographic and clinical outcomes were analyzed.

RESULTS

During the study period, 296 patients were treated. Mean age and initial NIHSS score were, respectively, 69.5 years and 16. Successful reperfusion, defined by the modified TICI 2b/3, was obtained in 86.1% (n = 255; 95% CI, 81.7%-89.9%). Complete reperfusion (modified TICI 3) was obtained in 41.2% (n = 122; 95% CI, 35.5%-47.1%). A first-pass effect was achieved in 24.2% (n = 71; 95% CI, 19.4%-29.6%). A rescue stent retriever approach was required in 29.7% (n = 88; 95% CI, 24.6%-35.3%). The complication rate was 9.5% (n = 28; 95% CI, 6.4%-13.5%). Forty-three percent (n = 122; 95% CI, 37.1%-48.9%) of patients presented with a favorable 3-month outcome (mRS ≤ 2). Older age, M1-occlusion topography, and intravenous thrombolysis use prior to thrombectomy were independent predictors of the first-pass effect.

CONCLUSIONS

The first-line contact aspiration approach appeared safe and efficient with Sofia catheters. These devices achieved very high reperfusion rates with a low requirement for stent retriever rescue therapy, especially for M1 occlusions.

Cost-effectiveness analysis of mechanical thrombectomy plus tissue-type plasminogen activator compared with tissue-type plasminogen activator alone for acute ischemic stroke in France

BACKGROUND AND PURPOSE

Recent studies demonstrated the benefit of mechanical thrombectomy (MT) plus intravenous tissue-type plasminogen activator (IV-tPA) (MT-IV-tPA) in acute ischemic stroke. This study aimed to estimate the cost-utility of MT-IV-tPA compared with IV-tPA alone from the perspective of the French National Health Insurance.

METHODS

We developed a decision tree for the first 3 months after stroke onset and a Markov model until 10 years post-stroke. The health states of the Markov model were according to the modified Rankin Scale (mRS): independent (mRS=0-2), dependent (mRS=3-5), dead (mRS=6). Recurrent stroke was the fourth health stage of our model. We conducted systematic literature reviews and meta-analyses to estimate the cost and utility of each health state, and the transition probabilities between health states. A microcosting study was conducted to estimate the cost of MT. We estimated the incremental cost-effectiveness ratio of MT-IV-tPA and conducted a probabilistic analysis in order to estimate the probability that MT-IV-tPA is cost-effective compared to IV-tPA, the expected value of perfect information (EVPI), and the expected value of partial perfect information (EVPPI), given the uncertainty surrounding the value of our model's parameters.

RESULTS

The total mean (standard deviation (SD) cost of MT was €6708.9 (2357.0). The incremental cost-effectiveness ratio (ICER) of the strategy using IV-tPA combined to MT costs was €14,715 per QALY gained as compared to a strategy using IV-tPA alone. The probabilistic analysis showed that the probability of MT-IV-TPA being cost-effective was 85.4% at threshold willingness-to-pay of €30,000 per QALY gained, reaching 98% at €50,000 per QALY gained.

CONCLUSION

Although there is no universally accepted willingness-to-pay threshold in France, our analysis suggest that MT combined to IV-tPA can be considered a cost-effective treatment compared with IV-tPA alone.

Modified Thrombolysis in Cerebral Infarction 2C/Thrombolysis in Cerebral Infarction 3 Reperfusion Should Be the Aim of Mechanical Thrombectomy

Background and Purpose—

Although successful reperfusion is usually defined as a modified Thrombolysis in Cerebral Infarction (mTICI) 2B or 3 at the end of the procedure, studies have shown that mTICI 2B patients had poorer functional outcomes than TICI 3 patients. An mTICI 2C category has been recently introduced for patients with near-complete perfusion except for slow flow in a few distal cortical vessels or presence of small distal cortical emboli after mechanical thrombectomy. The purpose of this study was to evaluate the difference in functional outcome between patients achieving successful reperfusion (ie, mTICI 2B, mTICI 2C, and TICI 3 scores).

Methods—

Ancillary study from the ASTER (Contact Aspiration Versus Stent Retriever for Successful Revascularization) prospective multicenter blinded end point trial. Reperfusion results are reported as the mTICI score, including the mTICI 2C grade. Primary outcome was the percentage of patients with favorable outcome defined as a 90-day modified Rankin Scale score of 0 to 2.

Results—

Two hundred ninety patients with successful reperfusion (mTICI ≥2B), harboring ischemic stroke secondary to occlusion of the anterior circulation within 6 hours of onset of symptoms, undergoing mechanical thrombectomy by contact aspiration or stent retriever were included. Favorable outcome (pre-specified as primary outcome of this ancillary study) did not differ significantly between the 3 reperfusion grades, with a similar positive effect of 2C (odds ratio, 1.71; 95% confidence interval, 0.98–3.00) and 3 (odds ratio, 1.73; 95% confidence interval, 0.88–3.41) grades compared with 2B grade. After combining grades 2C and 3, patients had a significantly higher rate of favorable outcome than patients with 2B (odds ratio, 1.72; 95% confidence interval, 1.01–2.90; P =0.043). Favorable outcome rate decreased with increasing onset-to-reperfusion time, with no significant interaction between mTICI 2C/3 grade and onset-to-reperfusion time on favorable outcome.

Conclusions—

Combining mTICI 2C and TICI 3 grades helps to determine a subgroup of patients achieving better functional outcomes than mTICI 2B patients. Achieving mTICI 2C/3 reperfusion should be the new aim of mechanical thrombectomy for anterior circulation LVO.

Contact Aspiration Versus Stent Retriever in Patients With Acute Ischemic Stroke With M2 Occlusion in the ASTER Randomized Trial (Contact Aspiration Versus Stent Retriever for Successful Revascularization)

Background and Purpose—

Middle cerebral artery M2-segment occlusions represent an important subgroup of patients with acute stroke with large-vessel occlusion. The safety of mechanical thrombectomy, especially contact aspiration (CA), in such distal intracranial occlusions is still under debate. We compared reperfusion, adverse events, neurological recovery, and functional outcome of patients with isolated M2 occlusions according to the first-line strategy mechanical thrombectomy devices (CA versus stent retriever [SR]).

Methods—

This is a post hoc analysis of the ASTER trial (Contact Aspiration Versus Stent Retriever for Successful Revascularization). The primary outcome was successful reperfusion at the end of all endovascular procedures, defined as modified Thrombolysis in Cerebral Infarction (mTICI) scores 2b/3. Secondary outcomes were mTICI 2c/3 and mTICI 3, 90-day functional outcome, assessed with the modified Rankin Scale score. Safety outcomes included 90-day mortality and any symptomatic intracerebral hemorrhage.

Results—

Seventy-nine patients were included: 48 were allocated to the CA group and 31 to the SR group. There were no significant differences between CA and SR groups in reperfusion after all endovascular procedures regarding mTICI 2b/3 (89.6% versus 83.9%; P =0.36), mTICI 2c/3 (54.2% versus 54.8%; P =0.90), and mTICI 3 (35.4% versus 41.9%; P =0.36) rates. There were no significant differences between CA and SR groups in 90-day modified Rankin Scale ≤2 rate (54.4% versus 50.0%; P =0.84), 24-hour change in National Institutes of Health Stroke Scale (mean difference, −3.9; 95% confidence interval, −7.9 to 0.01), and Alberta Stroke Program Early Computed Tomography score (mean difference, 0.9; 95% confidence interval, −0.1 to 2.0) scores. Safety parameters were well balanced between the 2 groups except for a higher 90-day mortality rate in the CA group (19.6% versus 3.3%; P =0.078).

Conclusions—

First-line mechanical thrombectomy with CA compared with SR did not result in an increased successful revascularization rate in patients with acute stroke with isolated M2 occlusion.

First-line use of contact aspiration for thrombectomy versus a stent retriever for recanalization in acute cerebral infarction: The randomized ASTER study protocol

Rationale Mechanical thrombectomy with a stent retriever is now the standard of care in anterior circulation ischemic stroke caused by large vessel occlusion. New techniques for mechanical thrombectomy, such as contact aspiration, appear promising to increase reperfusion status and improve clinical outcome. Aim We aim at ascertaining whether contact aspiration is more efficient than the stent retriever as a first-line endovascular procedure. Sample size estimates With a two-sided test (alpha = 5%, power = 90%) and an anticipated rate of spontaneous recanalization and catheterization failures of 15%, we estimate that a sample size of 380 patients will be necessary to detect an absolute difference of 15% in primary outcome (superiority design). Methods and design The ASTER trial is a prospective, randomized, multicenter, controlled, open-label, blinded end-point clinical trial. Patients admitted with suspected ischemic anterior circulation stroke secondary to large vessel occlusion, with onset of symptoms <6 h, will be randomly assigned to contact aspiration or stent retriever in a 1:1 ratio; stratified by center and prior IV thrombolysis. If the assigned treatment technique is not successful after three attempts, another technique will be applied, at the operator's discretion. Study outcomes The primary outcome will be successful recanalization (modified Thrombolysis in Cerebral Infarction score 2b-3) at the end of the endovascular procedures. Secondary outcome will include successful recanalization after the assigned first-line treatment technique alone, procedural times, the need for a rescue technique, complications and modified Rankin Scale at three months. Discussion No previous head to head randomized trials have directly compared contact aspiration versus stent retriever reperfusion techniques. This prospective trial aims to provide further evidence of benefit of contact aspiration versus stent retriever techniques among patients with ischemic stroke.

Myelin Detection Using Rapid Quantitative MR Imaging Correlated to Macroscopically Registered Luxol Fast Blue-Stained Brain Specimens

BACKGROUND AND PURPOSE

Myelin detection is of great value in monitoring diseases such as multiple sclerosis and dementia. However, most MR imaging methods to measure myelin are challenging for routine clinical use. Recently, a novel method was published, in which the presence of myelin is inferred by using its effect on the intra- and extracellular water relaxation rates and proton density, observable by rapid quantitative MR imaging. The purpose of this work was to validate this method further on the brains of 12 fresh, intact cadavers.

MATERIALS AND METHODS

The 12 brains were scanned with a quantification sequence to determine the longitudinal and transverse relaxation rates and proton density as input for the myelin estimations. Subsequently, the brains were excised at postmortem examination, and brain slices were stained with Luxol fast blue to verify the presence of myelin. The optical density values of photographs of the stained brain slices were registered with the MR images and correlated with the myelin estimation performed by quantitative MR imaging.

RESULTS

A correlation was found between the 2 methods with a mean Spearman ρ for all subjects of 0.74 ± 0.11. Linear regression showed a mean intercept of 1.50% ± 2.84% and a mean slope of 4.37% ± 1.73%/%. A lower correlation was found for the separate longitudinal relaxation rates and proton density (ρ = 0.63 ± 0.12 and -0.73 ± 0.09, respectively). For transverse relaxation rates, the ρ was very low (0.11 ± 0.28).

CONCLUSIONS

The observed correlation supports the validity of myelin measurement by using the MR imaging quantification method.

A comparison of acute vascular damage caused by ADAPT versus a stent retriever device after thrombectomy in acute ischemic stroke: a histological and ultrastructural study in an animal model

Background

It has been amply demonstrated that endovascular procedures can be successful treatment for stroke, both in terms of revascularization and clinical outcome. There is not, however, a published comparison of any histological or ultrastructural damage to the vessels that may be caused by a direct aspiration first pass technique (ADAPT) or stent retrievers (SR) used in these procedures. This study analyses and compares acute damage to the arterial wall caused by ADAPT or SR.

Material and methods

Damage to the walls of swine extracranial arteries was evaluated after ADAPT with the Penumbra system or thrombectomy with an SR (Solitaire 6×30). The procedures were performed after injecting thrombi into the selected arteries (arteries with diameters similar to those of the human internal carotid artery and first segment of the middle cerebral artery). After the procedures, the animal was euthanized and 12 arterial samples were obtained for analysis by optical and electronic microscopy.

Results

Tissue samples from the vessels treated with SR showed almost complete loss of endothelium, thickening of the internal elastic lamina, and degeneration of the elastic fibers of the bordering lamina media and adventitia. In contrast, tissue samples of the vessels treated with ADAPT had a clear integral internal elastic lamina and uninterrupted endothelial lining, although cell alignment was altered and there were surface lacerations due to manipulation of the samples.

Conclusions

Both techniques caused acute damage to the vessel walls, however, thrombectomy with SR appeared to be more harmful to all layers of the arterial wall, particularly the endothelium.

Role of parenting styles in adolescent substance use: results from a Swedish longitudinal cohort study

OBJECTIVE

Adolescent substance use is an area of concern because early substance use is associated with a higher risk of adverse outcomes. Parenting style, defined as the general style of parenting, as well as substance-specific parenting practices may influence children's substance use behaviour. The present study aims to probe the impact of parenting style on adolescent substance use.

METHOD

A cohort of 1268 adolescents (48% girls), aged 12-13 years at baseline, from 21 junior high schools was assessed in the first semester of junior high school, and then again in the last semester of the 9th grade, 32 months later. Parenting style, operationalised as a fourfold classification of parenting styles, including established risk factors for adolescent substance use, were measured at baseline.

RESULTS

Neglectful parenting style was associated with worse substance use outcomes across all substances. After adjusting for other proximal risk factors in multivariate analyses, parenting style was found to be unrelated to substance use outcomes with one exception: authoritative parenting style was associated with less frequent drinking. Association with deviant peers, delinquent behaviour, provision of alcohol by parents, and previous use of other substances were associated with substance use outcomes at follow-up.

CONCLUSIONS

The results of the present study indicate that parenting style may be less important for adolescent substance use outcomes than what has previously been assumed, and that association with deviant peers and delinquent behaviour may be more important for adolescent substance use outcomes than general parenting style.

Osteoblastoma of the ethmoid sinus

Osteoblastoma is a rare benign bone tumor that occurs unusually in the nasal sinuses. We report one case of sinonasal osteoblastoma in a 12-year-old girl who presented with nasal obstruction and telecanthus on the right side. Computed tomography revealed a lesion of the right ethmoid sinus with heterogenous bony density, which was displacing the orbital contents and the skull base. Biopsy caused significant bleeding. Magnetic resonance imaging showed intense homogeneous enhancement with typical flow-void areas due to large pathological vessels. This MRI feature must alert the clinician on the diagnosis before biopsy and surgical resection after embolization is performed. This case report describes the diagnostic and therapeutic difficulties of this rare tumor.

Retention of ice-associated amphipods: possible consequences for an ice-free Arctic Ocean

Recent studies predict that the Arctic Ocean will have ice-free summers within the next 30 years. This poses a significant challenge for the marine organisms associated with the Arctic sea ice, such as marine mammals and, not least, the ice-associated crustaceans generally considered to spend their entire life on the underside of the Arctic sea ice. Based upon unique samples collected within the Arctic Ocean during the polar night, we provide a new conceptual understanding of an intimate connection between these under-ice crustaceans and the deep Arctic Ocean currents. We suggest that downwards vertical migrations, followed by polewards transport in deep ocean currents, are an adaptive trait of ice fauna that both increases survival during ice-free periods of the year and enables re-colonization of sea ice when they ascend within the Arctic Ocean. From an evolutionary perspective, this may have been an adaptation allowing success in a seasonally ice-covered Arctic. Our findings may ultimately change the perception of ice fauna as a biota imminently threatened by the predicted disappearance of perennial sea ice.

Flow-diverter silk stent for the treatment of intracranial aneurysms: 1-year follow-up in a multicenter study

BACKGROUND AND PURPOSE

FD stent placement is a promising therapy for challenging intracranial aneurysms. Long-term evaluations about angiographic and morphologic results are still missing. This is the aim of this multicenter series.

MATERIALS AND METHODS

We report our experience and 1-year FU in a retrospective chart review of 65 consecutive subjects with 77 unruptured or recanalized aneurysms that were treated with Silk FD stents at 6 centers in France. Both angiographic and clinical results were recorded before treatment and at 6 and 12 months after treatment. At the 12-month FU, relationships between angiographic aneurysm occlusion and shrinkage of the thrombosed aneurysm sac were evaluated.

RESULTS

Stent deployment was achieved in 64 cases (98.5%) and failed in 1 case (1.5%). Seven misdeployments of the Silk stent caused the occlusion of 6 parent arteries. Overall acute/subacute procedural morbidity was 7.7%, and mortality was zero. Delayed complications were observed in 10.9% of subjects. At the 6-month FU, permanent morbidity was 7.8% and mortality was 3%. Complete occlusion occurred within 6 months in 68% of aneurysms and within 12 months after treatment in 84.5% of aneurysms. At the 12-month FU, in angiographically complete occluded aneurysms, MR imaging/CT analysis showed the complete disappearance of the thrombosed aneurysm in 30% of cases and partial shrinkage in 52%; furthermore, thrombosed aneurysms were stable in 11% of cases and enlarged in 7%.

CONCLUSIONS

The Silk stent is an effective tool for the treatment of challenging aneurysms because it allows complete occlusion in most cases 1 year after treatment. Permanent morbidity was 7.8%, and mortality was 3%.

Perianeurysmal brain inflammation after flow-diversion treatment

BACKGROUND AND PURPOSE

Flow-diverter stents are an alternative treatment for challenging and recurrent aneurysms. Thrombosis of the sac is thought to induce perianeurysmal brain inflammation, but such phenomena have never been studied in flow-diverter devices. We developed imaging data to explain the clinical exacerbation of symptoms after flow-diversion treatment.

MATERIALS AND METHODS

Seventeen patients with unruptured aneurysms were treated by using a flow-diverter device. Clinical symptoms and angiographic and MR imaging features were recorded before and after treatment, during both the acute and chronic phases, to look for inflammatory reaction.

RESULTS

Seven of the 17 patients (41%) showed a delayed clinical aggravation of symptoms posttreatment consisting of a headache (n = 7) with aggravation of pre-existing compressive symptoms (n = 4) and the appearance of compressive symptoms (n = 1). This clinical deterioration was transient; it was observed between 3 and 15 days posttreatment and resolved by day 30. MR imaging revealed signs highly suggestive of perianeurysmal inflammation with vasogenic edema and blood-brain barrier breakdown. The association between MR imaging inflammatory features and clinical aggravation was statistically significant. Large aneurysmal size and its proximity to surrounding brain tissue were predictive of this inflammatory reaction after flow diversion.

CONCLUSIONS

The main finding of the series is that MR imaging-defined perianeurysmal inflammation is observed with a high frequency after treatment of unruptured aneurysms with flow diverters and is, in most cases, associated with a transient clinical deterioration.

Bioluminescence in the high Arctic during the polar night

This study examines the composition and activity of the planktonic community during the polar night in the high Arctic Kongsfjord, Svalbard. Our results are the first published evidence of bioluminescence among zooplankton during the Arctic polar night. The observations were collected by a bathyphotometer detecting bioluminescence, integrated into an autonomous underwater vehicle, to determine the concentration and intensity of bioluminescent flashes as a function of time of day and depth. To further understand community dynamics and composition, plankton nets were used to collect organisms passing through the bathyphotometer along with traditional vertical net tows. Additionally, using a moored bathyphotometer closed to the sampling site, the bioluminescence potential itself was shown not to have a diurnal or circadian rhythm. Rather, our results provide evidence for a diel vertical migration of bioluminescent zooplankton that does not correspond to any externally detectable changes in illumination.

Overestimation of moderate carotid stenosis assessed by both Doppler US and contrast enhanced 3D-MR angiography in the CARMEDAS study

PURPOSE

To evaluate the agreement and diagnostic accuracy of Contrast enhanced magnetic resonance angiography (CE-MRA), Doppler ultrasound (DUS) and Digital subtraction angiography (DSA) in the assessment of carotid stenosis.

METHODS

DUS, CE-MRA and DSA were performed in 56 patients included in the Carotide-angiographie par résonance magnétique-échographie-doppler-angioscanner (CARMEDAS) multicenter study with a carotid stenosis ≥ 50%. Three readers evaluated stenoses on CE-MRA and DSA (NASCET criteria). Velocities criteria were used for stenosis estimation on DUS.

RESULTS

CE-MRA had a sensitivity and specificity of 96-98% and 66-83% respectively for carotid stenoses ≥ 50% and a sensitivity and specificity of 94% and 76-84% respectively for carotid stenoses ≥ 70%. The interobserver agreement of CE-MRA was excellent, except for moderate stenoses (50-69%). DUS had a sensitivity and specificity of 88 and 75% respectively for carotid stenoses ≥ 50% and a sensitivity and specificity of 83 and 86% respectively for carotid stenoses ≥ 70%. Combined concordant CE-MRA and DUS had a sensitivity and specificity of 100 and 85-90% respectively for carotid stenoses ≥ 50% and a sensitivity and specificity of 96-100% and 80-87% respectively for carotid stenoses ≥ 70%. The positive predictive value of the association CE-MRA and DUS for carotid stenoses ≥ 70% is calculated between 77 and 82% while the negative predictive value is calculated between 97 and 100%. CE-MRA and DUS have concordant findings in 63-72%, and the overestimations cases were recorded only for carotid stenosis ≤ 69%.

CONCLUSION

Combined DUS-CE-MRA is excellent for evaluation of severe stenosis but remains debatable in moderate stenosis (50-69%) due to the risk of overestimations.

[Diffusion-weighted MR imaging of the spine and cord]

Due to its excellent sensitivity, MR imaging is invaluable for the evaluation of lesions of the cord and spine. Several studies dedicated to diffusion-weighted MR evaluation of the cord and spine have been published. While diffusion-weighted MR imaging of the brain is routinely performed, it is seldom performed when imaging the spine due to serious limitations. While anatomical limitations may not be changed, the voxel size, phase-encoding direction, mode of k-space filling, and acceleration factor are all parameters that can be optimized in order to routinely obtain diffusion-weighted imaging of the spine on 1.5T and 3T scanners.

Endovascular treatment of brain arteriovenous malformations using onyx: results of a prospective, multicenter study

BACKGROUND AND PURPOSE

To evaluate the safety and efficacy of onyx for embolization of brain arteriovenous malformations (BAVM).

METHODS

A prospective, multicenter study was conducted in France to evaluate embolization of BAVM with onyx. From May 2003 to March 2005, 50 patients (26 females, 24 males; mean age: 34.8 years, range: 16-64years) were included. Clinical presentation was haemorrhage in 22 patients (44.0%), seizures in 16 patients (32.0%), headaches in six patients (12.0%) and progressive neurological deficit in two cases (4.0%). Four patients were asymptomatic (8.0%).

RESULTS

One hundred and forty-ninesessions of embolization were performed: one to eight sessions/patient with a mean of 3.0sessions. One hundred and sixteen sessions (77.9%) were performed with onyx, 20 sessions (13.4%) with glue and 13 sessions (8.7%) with onyx and glue. Symptomatic acute postembolization haemorrhage (APEH) was observed in four cases (8.0% per patient). At 1 month, morbidity and mortality related to the treatment were of 8% and 2%, respectively. Complete BAVM occlusion was obtained in 8.3% of cases. In the remaining cases, occlusion rate was between 99 and 80% in 56.3% of patients, 79 and 60% in 16.7%, and less than 60 in 18.7%. In case of incomplete occlusion, complementary treatment was performed by radiosurgery.

CONCLUSION

Onyx is suitable for BAVM embolization with acceptable morbidity and mortality.

An evaluation of immediate sheath removal and use of the Angio-Seal vascular closure device in neuroradiological interventions

We set out to assess the effect of using an arteriotomy closure device in patients at high risk of access site complications. One-hundred nineteen patients with femoral artery access were prospectively included in five centers in France (56 males, 63 females, age range 20-84 years). The neurointerventional procedures were embolization of intracranial aneurysm (71.4%), carotid angioplasty (11.8%), cerebral angioplasty (1.7%), thrombolysis (0.8%), and other procedures (14.3%). Sheaths were removed and the closure device deployed immediately postprocedure. One patient developed a false aneurysm, and one developed a small hematoma. Neither required treatment. Postdevice deployment bleeding was experienced in three patients (2.5%), requiring minimal management. There were no major complications. Three patients died of causes unrelated to the vessel closure. Patient comfort was 2.2 on a scale of 1 (none) to 10 (severe). The results showed that immediate sheath removal followed by use of the closure device is safe in patients undergoing neurointerventional procedures and offers a low level of patient discomfort. In selected patients, early hospital discharge was possible.

Endovascular treatment of brain arteriovenous malformations using onyx: preliminary results of a prospective multicenter study

SUMMARY

The main final goal of the treatment of brain AVMs is to prevent bleeding and to obtain a complete occlusion of the nidus. The strategy of treatment of brain arteriovenous malformations (AVM) has to be defined by a multidisciplinary team and will usually combine several modalities (surgery, radiosurgery, embolization). Embolization is generally the first step of treatment. Occasionally embolization is able to completely occlude a small AVM. Otherwise embolization is the first step before surgery or radiosurgery. Several embolic agents have been proposed for embolization of brain AVMs like particles or cyanoacrylates. The main disadvantage of particles is the high frequency of recanalization. The cyanoacrylates are probably more appropriate, providing a permanent occlusion. However, due to the polymerizing characteristics of the glue, the time of injection is relatively short (few seconds or minutes) and a complete or substantial occlusion of the nidus is difficult to obtain, especially in the case of medium or largesized AVMs. Onyx is a nonadhesive liquid polymer made of a mixture of ethylene-vinyl-alcohol copolymer and dimethylsulfoxide. The theoretical advantage of a nonadhesive liquid is to eliminate the risk of gluing the microcatheter and subsequently to perform a more durable injection with a larger amounts of agent delivered in a single injection. Several French centers have undertaken a prospective, multicentric study to evaluate the clinical value of Onyx in embolization of brain AVMs. As required, 50 patients were included. Preliminary results are presented regarding the first 48 patients, the last 2 patients being included after writing of this paper. The treatment is now completed in 15 patients. As expected, it was possible with Onyx to perform long duration injections (5 to 70 minutes with a mean of 34 minutes). Volumes injected per session were also important (0.25 to 6 ml with a mean of 1.6 ml). According to the clinical experience of the centers, duration and volume injected were most important with Onyx than with cyanoacrylates. Out of the 15 patients for whom embolization is now completed, 14 had a percentage of occlusion of the nidus greater than 60% (with 2 complete occlusion). With regard to procedural complications, four acute postembolization hemorrhages (APEH) were observed (8% per patient, 4% per procedure). This rate of APEH is in the same range as with cyanoacrylates.

Triple total cervical vertebrectomy for a giant cell tumor: case report

STUDY DESIGN

Case report of a triple total cervical vertebrectomy.

OBJECTIVE

To describe a new management for cervical tumor. Preoperative planning using arteriography, successive occlusion of both vertebral arteries, and the cervical vertebrectomy are reported.

SUMMARY OF BACKGROUND DATA

Thoracic or lumbar complete vertebrectomy for primary malignant tumor or metastasis is a well established surgical technique. The presence of the vertebral arteries appears to have prevented the previous use of complete vertebrectomy in the cervical spine.

METHODS

A 25-year-old male patient who had a giant cell tumor in C6 underwent hemi-vertebrectomy. Before this surgical procedure, the ipsilateral vertebral artery was embolized. The tumor recurred locally 18 months later. Using temporary balloon occlusion of the remaining vertebral artery, an abundant collateral circulation from the cervical arteries to the vertebrobasilar territory was shown. Triple total cervical vertebrectomy from C5-C7 was then performed with double stage surgery.

RESULTS

At 2-year follow-up, the patient is tumor-free.

CONCLUSIONS

Complete resection of malignant cervical vertebrae is possible if both vertebral arteries can be successively occluded, permitting complete removal of the transverse processes.