Trial of Thrombectomy for Stroke with a Large Infarct of Unrestricted Size.

BACKGROUND: The use of thrombectomy in patients with acute stroke and a large infarct of unrestricted size has not been well studied. METHODS: We assigned, in a 1:1 ratio, patients with proximal cerebral vessel occlusion in the anterior circulation and a large infarct (as defined by an Alberta Stroke Program Early Computed Tomographic Score of ≤5; values range from 0 to 10) detected on magnetic resonance imaging or computed tomography within 6.5 hours after symptom onset to undergo endovascular thrombectomy and receive medical care (thrombectomy group) or to receive medical care alone (control group). The primary outcome was the score on the modified Rankin scale at 90 days (scores range from 0 to 6, with higher scores indicating greater disability). The primary safety outcome was death from any cause at 90 days, and an ancillary safety outcome was symptomatic intracerebral hemorrhage. RESULTS: A total of 333 patients were assigned to either the thrombectomy group (166 patients) or the control group (167 patients); 9 were excluded from the analysis because of consent withdrawal or legal reasons. The trial was stopped early because results of similar trials favored thrombectomy. Approximately 35% of the patients received thrombolysis therapy. The median modified Rankin scale score at 90 days was 4 in the thrombectomy group and 6 in the control group (generalized odds ratio, 1.63; 95% confidence interval [CI], 1.29 to 2.06; P<0.001). Death from any cause at 90 days occurred in 36.1% of the patients in the thrombectomy group and in 55.5% of those in the control group (adjusted relative risk, 0.65; 95% CI, 0.50 to 0.84), and the percentage of patients with symptomatic intracerebral hemorrhage was 9.6% and 5.7%, respectively (adjusted relative risk, 1.73; 95% CI, 0.78 to 4.68). Eleven procedure-related complications occurred in the thrombectomy group. CONCLUSIONS: In patients with acute stroke and a large infarct of unrestricted size, thrombectomy plus medical care resulted in better functional outcomes and lower mortality than medical care alone but led to a higher incidence of symptomatic intracerebral hemorrhage. (Funded by Montpellier University Hospital; LASTE ClinicalTrials.gov number, NCT03811769.).

Contour Neurovascular System for endovascular embolization of cerebral aneurysms: a multicenter cohort study of 10 European neurovascular centers.

BACKGROUND: Intrasaccular devices have become increasingly popular in the treatment of cerebral aneurysms, particularly at the bifurcation. Here we evaluate the Contour Neurovascular System, an intrasaccular device for the endovascular treatment of cerebral aneurysms, in a multicenter cohort study, the largest to the best of our knowledge. METHODS: Consecutive patients with intracranial aneurysms treated with the Contour Neurovascular System between February 2017 and October 2022 at 10 European neurovascular centers were prospectively collected and retrospectively reviewed. Patient and aneurysm characteristics, procedural details, and angiographic and clinical outcomes were evaluated. RESULTS: During the study period, 279 aneurysms (median age of patients 60 years, IQR 52-68) were treated with Contour. In 83.2% of patients the device was placed electively, whereas the remaining patients were treated in the setting of acute subarachnoid hemorrhage. The most common locations were the middle cerebral artery (26.5%) followed by the anterior communicating region (26.2%). Median aneurysm dome and neck size were 5.2 mm (IQR 4.2-7) and 3.9 mm (IQR 3-5). Contour size 7 (39%) and 9 (25%) were most used. Thromboembolic and hemorrhagic complications occurred in 6.8% and 0.4% of aneurysms, respectively. Raymond-Roy 1 and 2 occlusions at last follow-up were achieved in 63.2% and 28.3%, respectively, resulting in adequate occlusion of 91.5% of aneurysms. CONCLUSION: This is the largest multicenter study reporting the outcome on the Contour Neurovascular System. At 1 year, the self-evaluated data on safety and efficacy are comparable to data of existing intrasaccular devices. Contour is a promising technology in the treatment of cerebral aneurysms.

Prospective evaluation to characterize the real-world performance of the EMBOVAC aspiration catheter for neurothrombectomy: a post-market clinical follow-up trial.

BACKGROUND: A direct aspiration first pass technique (ADAPT) is an effective alternative to stent retriever thrombectomy for patients with large vessel occlusion (LVO). The PERFECT study evaluated direct aspiration with the EMBOVAC large bore aspiration catheter in patients with LVO strokes. METHODS: PERFECT was a prospective, post-market, single-arm, multicenter, observational study of patients enrolled across 11 European centers between October 2020 and July 2022. Three direct aspiration passes with EMBOVAC were mandated before switching strategy. The primary endpoint was core-lab assessed successful reperfusion (modified Thrombolysis In Cerebral Infarction (mTICI) ≥2b) post-procedure. Other outcomes included first pass mTICI ≥2c, independent 90-day modified Rankin Scale (mRS) evaluation, and symptomatic intracerebral hemorrhage (sICH) at 24 hours by a clinical events committee. RESULTS: EMBOVAC was used in 100 patients (mean age 70.4±14.0 years, 59.0% (59/100) female). Final mTICI ≥2b was achieved in 98.0% (97/99), final mTICI ≥2b with no change in frontline therapy or thrombolytics use during the procedure was achieved in 87.9% (87/99), final mTICI ≥2c in 86.9% (86/99), and first pass mTICI ≥2c in 53.5% (53/99). sICH at 24 hours was 0%. The 90-day mRS ≤2 rate was 56.6% (56/99) and all-cause mortality was 12.9%. One device-related serious adverse event occurred within 90 days (1.0%). CONCLUSIONS: PERFECT demonstrates that EMBOVAC achieves successful reperfusion rates and favorable clinical outcomes when used in the endovascular treatment of acute ischemic stroke (AIS) using a direct aspiration technique as first line therapy in a real-world setting in patients with AIS secondary to large vessel occlusion. TRIAL REGISTRATION: www. CLINICALTRIALS: gov Unique identifier: NCT04531904.

Electrical impedance measurements can identify red blood cell-rich content in acute ischemic stroke clots ex vivo associated with first-pass successful recanalization.

Background: Electrochemical impedance spectroscopy can determine characteristics such as cell density, size, and shape. The development of an electrical impedance-based medical device to estimate acute ischemic stroke (AIS) clot characteristics could improve stroke patient outcomes by informing clinical decision making. Objectives: To assess how well electrical impedance combined with machine learning identified red blood cell (RBC)-rich composition of AIS clots ex vivo, which is associated with a successfully modified first-pass effect. Methods: A total of 253 clots from 231 patients who underwent thrombectomy in 5 hospitals in France, Japan, Serbia, and Spain between February 2021 and October 2023 were analyzed in the Clotbase International Registry. Electrical impedance measurements were taken following clot retrieval by thrombectomy, followed by Martius Scarlet Blue staining. The clot components were quantified via Orbit Image Analysis, and RBC percentages were correlated with the RBC estimations made by the electrical impedance machine learning model. Results: Quantification by Martius Scarlet Blue staining identified RBCs as the major component in clots (RBCs, 37.6%; white blood cells, 5.7%; fibrin, 25.5%; platelets/other, 30.3%; and collagen, 1%). The impedance-based RBC estimation correlated well with the RBC content determined by histology, with a slope of 0.9 and Spearman's correlation of r = 0.7. Clots removed in 1 pass were significantly richer in RBCs and clots with successful recanalization in 1 pass (modified first-pass effect) were richer in RBCs as assessed using histology and impedance signature. Conclusion: Electrical impedance estimations of RBC content in AIS clots are consistent with histologic findings and may have potential for clinically relevant parameters.

The reversed umbrella: displacement of a Contour device into an MCA aneurysm 18 months after treatment.

SummaryThe Contour is a promising new device designed to treat large-neck intra-cranial aneurysms. We describe a first case of Contour device displacement 18 months after initial treatment.A patient with a 10 mm unruptured right middle cerebral artery bifurcation aneurysm was treated with a 9 mm Contour. The device was correctly positioned at the neck during treatment and at the 6 month angiography follow-up. At 18 months follow-up we noticed a full displacement of the device into the aneurysm dome. The Contour had a reversed shape and the aneurysm was still fully opacified. No neurological event occurred during the whole follow-up. Contour may be a promising tool but needs to be assessed over a long-term period.

Evaluation of acute mechanical revascularization in large stroke (ASPECTS ⩽5) and large vessel occlusion within 7 h of last-seen-well: The LASTE multicenter, randomized, clinical trial protocol.

RATIONALE: Mechanical thrombectomy (MT), the standard of care for acute ischemic stroke (AIS) secondary to large vessel occlusion (LVO), is generally not offered to patients with large baseline infarct (core). Recent studies demonstrated MT benefit in patients with anterior circulation stroke and large core (i.e. Alberta Stroke Program Early Computed Tomography Score, ASPECTS 3-5). However, its benefit in patients with the largest core (ASPECTS 0-2) remains unproven. AIM: To compare the efficacy and safety of MT plus best medical treatment (BMT) and of BMT alone in patients with ASPECTS 0-5 (baseline computed tomography (CT) or magnetic resonance imaging (MRI)) and anterior circulation LVO within 7 h of last-seen-well. SAMPLE SIZE ESTIMATE: To detect with a two-sided test at 5% significance level (80% power) a common odds ratio of 1.65 for 1-point reduction in the 90-day modified Rankin Scale (mRS) score in the MT + BMT arm versus BMT arm and to anticipate 10% of patients with missing primary endpoint, 450 patients are planned to be included by 36 centers in France, Spain, and the United States. METHODS AND DESIGN: LArge Stroke Therapy Evaluation (LASTE) is an international, multicenter, Prospectively Randomized into two parallel (1:1) arms, Open-label, with Blinded Endpoint (PROBE design) trial. Eligibility criteria are diagnosis of AIS within 6.5 h of last-seen-well (or negative fluid-attenuated inversion recovery (FLAIR) if unknown stroke onset time), ASPECTS 0-5 (ASPECTS 4-5 for ⩾80-year-old patients), and LVO in the anterior circulation (intracranial internal carotid artery (ICA) and M1 or M1-M2 segment of the middle cerebral artery (MCA)). STUDY OUTCOMES: The primary endpoint is the day-90 mRS score distribution (shift analysis) with mRS categories 5 and 6 coalesced into one category. Secondary endpoints include day-180 mRS score, rates of 90-day and 180-day mRS score = 0-2 and 0-3, rate of decompressive craniectomy, the National Institutes of Health Stroke Scale (NIHSS) score change, revascularization and infarct volume growth at 24 h, and quality of life at day 90 and 180. Safety outcomes (90-day all-cause mortality, procedural complications, symptomatic intracerebral hemorrhage, and early NIHSS score worsening) are recorded. A dynamic balanced randomization (1:1) is used to distribute eligible patients into the experimental arm and control arm, by incorporating the center and these pre-specified factors: baseline ASPECTS (0-3 vs 4-5), age (⩽70 vs >70 years), baseline NIHSS (<20 vs ⩾20), intravenous thrombolysis (no vs yes), admission mode (Drip-and-Ship vs Mothership), occlusion site (intracranial ICA vs MCA-M1 or M1-M2), intravenous fibrinolysis (no vs yes), and last-seen-well to randomization time (0-4.5 vs >4.5-6.5 h). DISCUSSION: The LASTE trial will determine MT efficacy and safety in patients with ASPECTS 0-5 and LVO in the anterior circulation. TRIAL REGISTRATION: LASTE Trial NCT03811769.

Intravenous thrombolysis with tenecteplase versus alteplase combined with endovascular treatment of anterior circulation tandem occlusions: A pooled analysis of ETIS and TETRIS.

BACKGROUND: Tandem occlusions are a singular large vessel occlusion entity involving specific endovascular and perioperative antithrombotic management. In this context, data on safety and efficacy of prior intravenous thrombolysis (IVT) with tenecteplase is scarce. We aimed to compare IVT with tenecteplase or alteplase in patients with acute tandem occlusions intended for endovascular treatment. PATIENTS AND METHODS: A retrospective pooled analysis of two large observational registries (ETIS (Endovascular Treatment of Ischemic Stroke) and TETRIS (Tenecteplase Treatment in Ischemic Stroke)) was performed on consecutive patients presenting with anterior circulation tandem occlusion treated with IVT using either alteplase (ETIS) or tenecteplase (TETRIS) followed by endovascular treatment between January 2015 and June 2022. Sensitivity analyses on atherosclerosis related tandem occlusions and on patient treated with emergent carotid stenting were conducted. Propensity score overlap weighting analyses were performed. RESULTS: We analyzed 753 patients: 124 in the tenecteplase and 629 in the alteplase group. The overall odds of favorable outcome (3-month modified Rankin score 0-2) were comparable between both groups (49.4% vs 47.1%; OR = 1.10, 95%CI 0.85-1.41). Early recanalization, final successful recanalization and mortality favored the use of tenecteplase. The occurrence of any intracranial hemorrhage (ICH) was more frequent after tenecteplase use (OR = 2.24; 95%CI 1.75-2.86). However, risks of symptomatic ICH and parenchymal hematoma remained similar. In atherosclerotic tandems, favorable outcome, mortality, parenchymal hematoma, early recanalization, and final successful recanalization favored the tenecteplase group. In the carotid stenting subgroup, PH were less frequent in the tenecteplase group (OR = 0.18; 95%CI 0.05-0.69). CONCLUSION: In patients with tandem occlusions, IVT with tenecteplase seemed reasonably safe in particular with increased early recanalization rates. These findings remain preliminary and should be further confirmed in randomized trials.

Intravenous Thrombolysis before Complete Angiographic Reperfusion: Beyond Angiographic Assessment to Target Microvascular Obstruction?

OBJECTIVE: Recent data have suggested that ineffective tissue reperfusion despite successful angiographic reperfusion was partly responsible for unfavorable outcomes after endovascular therapy (EVT) and might be modulated by intravenous thrombolysis (IVT) use before EVT. To specifically decipher the effect played by IVT before EVT, we compared the clinical and safety outcomes of patients who experienced a complete reperfusion at the end of EVT according to IVT use before EVT. METHODS: The Endovascular Treatment in Ischemic Stroke (ETIS) registry is an ongoing, prospective, observational study at 21 centers that perform EVT in France. Patients were included if they had an anterior large vessel occlusion of the intracranial internal carotid artery or middle cerebral artery (M1/M2 segments) and complete reperfusion (expanded Thrombolysis in Cerebral Infarction score = 3) with EVT within 6 hours, between January 2015 and December 2021. The cohort was divided into two groups according to IVT use before EVT, and propensity score matching (PSM) was used to balance the two groups. Primary outcome was the shift in the degree of disability as measured by the modified Rankin Scale (mRS) at 90 days. Secondary outcomes included favorable outcome (mRS 0-2) at 90 days. Safety outcomes included symptomatic intracranial hemorrhage and 90-day mortality. Outcomes were estimated with multivariate logistic models adjusted for age, National Institutes of Health Stroke Scale, Alberta Stroke Program Early CT Score, and time from symptom onset to puncture. RESULTS: Among 5,429 patients included in the ETIS registry, 1,093 were included in the study, including 651 patients with complete recanalization treated with IVT before EVT. After PSM, 488 patients treated with IVT before EVT were compared to 337 patients without IVT. In the matched cohort analysis, the IVT+EVT group had a favorable shift in the overall mRS score distribution (adjusted odds ratio [aOR] = 1.41, 95% confidence interval [CI] = 1.04-1.91, p = 0.023) and higher rates of favorable outcome (61.1% vs 48.7%, aOR = 1.49, 95% CI = 1.02-2.20, p = 0.041) at 90 days compared with the EVT alone group. Rates of symptomatic intracerebral hemorrhage were comparable between both groups (6.0% vs 4.3%, aOR = 1.16, 95% CI = 0.53-2.54, p = 0.709). INTERPRETATION: In clinical practice, even after complete angiographic reperfusion by EVT, prior IVT use improves clinical outcomes of patients without increasing bleeding risk. ANN NEUROL 2024;95:762-773.

CLinical EValuation of WEB 17 device in intracranial aneuRysms (CLEVER): procedural, 30-day and 1-year safety results for ruptured and unruptured aneurysms.

BACKGROUND: Intrasaccular flow disruption is an endovascular approach for the treatment of wide-neck aneurysms and, more specifically, wide-neck bifurcation aneurysms, which are challenging to treat with previously developed technologies. The Woven EndoBridge (WEB) device has demonstrated its efficacy and safety, for both unruptured and ruptured aneurysms. METHODS: The CLEVER study was an observational, multicenter, prospective study conducted in 17 European investigational sites using the WEB 17 device, for the treatment of ruptured and unruptured aneurysms. The study objective was to provide safety and efficacy data on the WEB 17 device in the treatment of wide-neck bifurcation aneurysms. Imaging results were assessed independently by a Corelab and adverse events adjudicated by a Clinical Event Adjudicator. This analysis reports procedural results and safety at 30 days and 12 months. RESULTS: A total of 163 patients (mean age 58.1 years; 68.1% women) with 103 unruptured aneurysms and 60 ruptured aneurysms were enrolled. Most aneurysms were located on the anterior communicating artery (ACom) (37.4%) or the middle cerebral artery (MCA) bifurcation (30.1%). Aneurysm widths ranged from 2.0-9.2 mm, and the mean sac width was 5.0 mm. The WEB procedure was successfully completed in 163 patients (100%). At the 12-month follow-up, major stroke events occurred in 3 of 163 patients (1.8%), and no device-related mortality was observed. CONCLUSION: Endovascular treatment of ruptured and unruptured wide-neck bifurcation aneurysms using WEB 17 is safe, with a low complication rate and no device-related mortality. In particular, none of the ruptured aneurysms bled again up to 1 year of follow-up. TRIAL REGISTRATION NUMBER: NCT03844334.

Large vessel occlusion prediction scale thresholds that are sensitive for DAWN Trial patients.

BACKGROUND: Large vessel occlusion (LVO) prediction scales are used to triage prehospital suspected stroke patients with a high probability of LVO stroke to endovascular therapy centers. The sensitivities of these scales in the 6-to-24-h time window are unknown. Higher scale score thresholds are typically less sensitive and more specific. Knowing the highest scale score thresholds that remain sensitive could inform threshold selection for clinical use. Sensitivities may also vary between left and right-sided LVOs. METHODS: LVO prediction scale scores were retrospectively calculated using the National Institutes of Health Stroke Scale (NIHSS) scores of patients enrolled in the DAWN Trial. All patients had last known well times between 6 and 24 h, NIHSS scores ≥ 10, intracranial internal carotid artery or proximal middle cerebral artery occlusions, and mismatches between their clinical severities and infarct core volumes. Scale thresholds with sensitivities ≥ 85% were identified, along with scores ≥ 5% more sensitive for left or right-sided LVOs. Specificities could not be calculated because all patients had LVOs. RESULTS: A total of 201 out of 206 patients had the required NIHSS subitem scores. CPSS = 3, C-STAT ≥ 2, FAST-ED ≥ 4, G-FAST ≥ 3, RACE ≥ 5, and SAVE ≥ 3 were the highest thresholds that were still 85% sensitive for DAWN Trial LVO stroke patients. RACE ≥ 5 was the only typically used score threshold more sensitive for right-sided LVOs, though similar small differences were seen for other scales at higher thresholds. CONCLUSIONS: Our findings likely represent the maximum sensitivities of the LVO prediction scales tested for ideal thrombectomy candidates in the 6-to-24-h time window because NIHSS scores were documented in hospitals during a clinical trial rather than in the prehospital setting. Patients with NIHSS scores < 10 or more distal LVOs would lower sensitivities further. Selecting even higher scale thresholds for LVO triage would lead to many missed LVO strokes.

Factors Associated With Fast Early Infarct Growth in Patients With Acute Ischemic Stroke With a Large Vessel Occlusion.

BACKGROUND AND OBJECTIVES: The optimal methods for predicting early infarct growth rate (EIGR) in acute ischemic stroke with a large vessel occlusion (LVO) have not been established. We aimed to study the factors associated with EIGR, with a focus on the collateral circulation as assessed by the hypoperfusion intensity ratio (HIR) on perfusion imaging, and determine whether the associations found are consistent across imaging modalities. METHODS: Retrospective multicenter international study including patients with anterior circulation LVO-related acute stroke with witnessed stroke onset and baseline perfusion imaging (MRI or CT) performed within 24 hours from symptom onset. To avoid selection bias, patients were selected from (1) the prospective registries of 4 comprehensive stroke centers with systematic use of perfusion imaging and including both thrombectomy-treated and untreated patients and (2) 1 prospective thrombectomy study where perfusion imaging was acquired per protocol, but treatment decisions were made blinded to the results. EIGR was defined as infarct volume on baseline imaging divided by onset-to-imaging time and fast progressors as EIGR ≥10 mL/h. The HIR, defined as the proportion of time-to-maximum (Tmax) >6 second with Tmax >10 second volume, was measured on perfusion imaging using RAPID software. The factors independently associated with fast progression were studied using multivariable logistic regression models, with separate analyses for CT- and MRI-assessed patients. RESULTS: Overall, 1,127 patients were included (CT, n = 471; MRI, n = 656). Median age was 74 years (interquartile range [IQR] 62-83), 52% were male, median NIH Stroke Scale was 16 (IQR 9-21), median HIR was 0.42 (IQR 0.26-0.58), and 415 (37%) were fast progressors. The HIR was the primary factor associated with fast progression, with very similar results across imaging modalities: The proportion of fast progressors was 4% in the first HIR quartile (i.e., excellent collaterals), ∼15% in the second, ∼50% in the third, and ∼77% in the fourth (p < 0.001 for each imaging modality). Fast progression was independently associated with poor 3-month functional outcome in both the CT and MRI cohorts (p < 0.001 and p = 0.030, respectively). DISCUSSION: The HIR is the primary factor associated with fast infarct progression, regardless of imaging modality. These results have implication for neuroprotection trial design, as well as informing triage decisions at primary stroke centers.

Value of intravenous thrombolysis in endovascular treatment for large-vessel anterior circulation stroke: individual participant data meta-analysis of six randomised trials.

BACKGROUND: Intravenous thrombolysis is recommended before endovascular treatment, but its value has been questioned in patients who are admitted directly to centres capable of endovascular treatment. Existing randomised controlled trials have indicated non-inferiority of endovascular treatment alone or have been statistically inconclusive. We formed the Improving Reperfusion Strategies in Acute Ischaemic Stroke collaboration to assess non-inferiority of endovascular treatment alone versus intravenous thrombolysis plus endovascular treatment. METHODS: We conducted a systematic review and individual participant data meta-analysis to establish non-inferiority of endovascular treatment alone versus intravenous thrombolysis plus endovascular treatment. We searched PubMed and MEDLINE with the terms "stroke", "endovascular treatment", "intravenous thrombolysis", and synonyms for articles published from database inception to March 9, 2023. We included randomised controlled trials on the topic of interest, without language restrictions. Authors of the identified trials agreed to take part, and individual participant data were provided by the principal investigators of the respective trials and collated centrally by the collaborators. Our primary outcome was the 90-day modified Rankin Scale (mRS) score. Non-inferiority of endovascular treatment alone was assessed using a lower boundary of 0·82 for the 95% CI around the adjusted common odds ratio (acOR) for shift towards improved outcome (analogous to 5% absolute difference in functional independence) with ordinal regression. We used mixed-effects models for all analyses. This study is registered with PROSPERO, CRD42023411986. FINDINGS: We identified 1081 studies, and six studies (n=2313; 1153 participants randomly assigned to receive endovascular treatment alone and 1160 randomly assigned to receive intravenous thrombolysis and endovascular treatment) were eligible for analysis. The risk of bias of the included studies was low to moderate. Variability between studies was small, and mainly related to the choice and dose of the thrombolytic drug and country of execution. The median mRS score at 90 days was 3 (IQR 1-5) for participants who received endovascular treatment alone and 2 (1-4) for participants who received intravenous thrombolysis plus endovascular treatment (acOR 0·89, 95% CI 0·76-1·04). Any intracranial haemorrhage (0·82, 0·68-0·99) occurred less frequently with endovascular treatment alone than with intravenous thrombolysis plus endovascular treatment. Symptomatic intracranial haemorrhage and mortality rates did not differ significantly. INTERPRETATION: We did not establish non-inferiority of endovascular treatment alone compared with intravenous thrombolysis plus endovascular treatment in patients presenting directly at endovascular treatment centres. Further research could focus on cost-effectiveness analysis and on individualised decisions when patient characteristics, medication shortages, or delays are expected to offset a potential benefit of administering intravenous thrombolysis before endovascular treatment. FUNDING: Stryker and Amsterdam University Medical Centers, University of Amsterdam.

Successful Thrombectomy Improves Functional Outcome in Tandem Occlusions with a Large Ischemic Core.

BACKGROUND: Emergent stenting in tandem occlusions and mechanical thrombectomy (MT) of acute ischemic stroke related to large vessel occlusion (LVO-AIS) with a large core are tested independently. We aim to assess the impact of reperfusion with MT in patients with LVO-AIS with a large core and a tandem occlusion and to compare the safety of reperfusion between large core with tandem and nontandem occlusions in current practice. METHODS: We analyzed data of all consecutive patients included in the prospective Endovascular Treatment in Ischemic Stroke Registry in France between January 2015 and March 2023 who presented with a pretreatment ASPECTS (Alberta Stroke Program Early CT Score) of 0-5 and angiographically proven tandem occlusion. The primary end point was a favorable outcome defined by a modified Rankin Scale (mRS) score of 0-3 at 90 days. RESULTS: Among 262 included patients with a tandem occlusion and ASPECTS 0-5, 203 patients (77.5%) had a successful reperfusion (modified Thrombolysis in Cerebral Infarction grade 2b-3). Reperfused patients had a favorable shift in the overall mRS score distribution (adjusted odds ratio [aOR], 1.57 [1.22-2.03]; P < 0.001), higher rates of mRS score 0-3 (aOR, 7.03 [2.60-19.01]; P < 0.001) and mRS score 0-2 at 90 days (aOR, 3.85 [1.39-10.68]; P = 0.009) compared with nonreperfused. There was a trend between the occurrence of successful reperfusion and a decreased rate of symptomatic intracranial hemorrhage (aOR, 0.5 [0.22-1.13]; P = 0.096). Similar safety outcomes were observed after large core reperfusion in tandem and nontandem occlusions. CONCLUSIONS: Successful reperfusion was associated with a higher rate of favorable outcome in large core LVO-AIS with a tandem occlusion, with a safety profile similar to nontandem occlusion.

What is a Challenging Clot? : A DELPHI Consensus Statement from the CLOTS 7.0 Summit.

BACKGROUND: Predicting a challenging clot when performing mechanical thrombectomy in acute stroke can be difficult. One reason for this difficulty is a lack of agreement on how to precisely define these clots. We explored the opinions of stroke thrombectomy and clot research experts regarding challenging clots, defined as difficult to recanalize clots by endovascular approaches, and clot/patient features that may be indicative of such clots. METHODS: A modified DELPHI technique was used before and during the CLOTS 7.0 Summit, which included experts in thrombectomy and clot research from different specialties. The first round included open-ended questions and the second and final rounds each consisted of 30 closed-ended questions, 29 on various clinical and clot features, and 1 on number of passes before switching techniques. Consensus was defined as agreement ≥ 50%. Features with consensus and rated ≥ 3 out of 4 on the certainty scale were included in the definition of a challenging clot. RESULTS: Three DELPHI rounds were performed. Panelists achieved consensus on 16/30 questions, of which 8 were rated 3 or 4 on the certainty scale, namely white-colored clots (mean certainty score 3.1), calcified clots under histology (3.7) and imaging (3.7), stiff clots (3.0), sticky/adherent clots (3.1), hard clots (3.1), difficult to pass clots (3.1) and clots that are resistant to pulling (3.0). Most panelists considered switching endovascular treatment (EVT) techniques after 2-3 unsuccessful attempts. CONCLUSION: This DELPHI consensus identified 8 distinct features of a challenging clot. The varying degree of certainty amongst the panelists emphasizes the need for more pragmatic studies to enable accurate a priori identification of such occlusions prior to EVT.

Thrombectomy with or without Intravenous Thrombolytics in Basilar Artery Occlusion.

OBJECTIVE: Two randomized trials demonstrated the benefit of endovascular therapy (EVT) in patients suffering from a stroke due to a basilar artery occlusion (BAO). However, intravenous thrombolytic (IVT) use before EVT was low in these trials, questioning the added value of this treatment in this setting. We sought to investigate the efficacy and safety of EVT alone compared to IVT + EVT in stroke patients with a BAO. METHODS: We analyzed data from the Endovascular Treatment in Ischemic Stroke registry, a prospective, observational, multicenter study of acute ischemic stroke patients treated with EVT in 21 centers in France between 1 January 2015 and 31 December 2021. We included patients with BAO and/or intracranial vertebral artery occlusion and compared patients treated with EVT alone versus IVT + EVT after propensity score (PS) matching. Variables selected for the PS were pre-stroke mRS, dyslipidemia, diabetes, anticoagulation, admission mode, baseline NIHSS and ASPECTS, type of anesthesia, and time from symptom onset to puncture. Efficacy outcomes were good functional outcome (modified Rankin Scale [mRS] 0-3) and functional independence (mRS 0-2) at 90 days. Safety outcomes were symptomatic intracranial hemorrhages and all-cause mortality at 90 days. RESULTS: Among 385 patients, 243 (134 EVT alone and 109 IVT + EVT) were included after PS matching. There was no difference between EVT alone and IVT + EVT regarding good functional outcome (adjusted odd ratio [aOR] labeling = 1.27, 95% confidence interval [CI], 0.68-2.37, p = 0.45) and functional independence (aOR = 1.50, 95% CI, 0.79-2.85, p = 0.21). Symptomatic intracranial hemorrhage and all-cause mortality were also similar between the two groups (aOR = 0.42, 95% CI, 0.10-1.79, p = 0.24 and aOR = 0.56, 95% CI, 0.29-1.10, p = 0.09, respectively). INTERPRETATION: In this PS matching analysis, EVT alone seemed to lead to similar neurological recovery than IVT + EVT, with comparable safety profile. However, given our sample size and the observational nature of this study, further studies are needed to confirm these findings. ANN NEUROL 2023;94:596-604.

Role of Brain Imaging in the Prediction of Intracerebral Hemorrhage Following Endovascular Therapy for Acute Stroke.

Currently most acute ischemic stroke patients presenting with a large vessel occlusion are treated with endovascular therapy (EVT), which results in high rates of successful recanalization. Despite this success, more than half of EVT-treated patients are significantly disabled 3 months later partly due to the occurrence of post-EVT intracerebral hemorrhage. Predicting post-EVT intracerebral hemorrhage is important for individualizing treatment strategies in clinical practice (eg, safe initiation of early antithrombotic therapies), as well as in selecting the optimal candidates for clinical trials that aim to reduce this deleterious outcome. Emerging data suggest that brain and vascular imaging biomarkers may be particularly relevant since they provide insights into the ongoing acute stroke pathophysiology. In this review/perspective, we summarize the accumulating literature on the role of cerebrovascular imaging biomarkers in predicting post-EVT-associated intracerebral hemorrhage. We focus on imaging acquired before EVT, during the EVT procedure, and in the early post-EVT time frames when new therapeutic therapies could be tested. Accounting for the complex pathophysiology of post-EVT-associated intracerebral hemorrhage, this review may provide some guidance for future prospective observational or therapeutic studies.

Evaluation of acute mechanical revascularization in minor stroke (NIHSS score ⩽ 5) and large vessel occlusion: The MOSTE multicenter, randomized, clinical trial protocol.

RATIONALE: Mechanical thrombectomy (MT) has become the standard of care for patients with acute ischemic stroke secondary to large vessel occlusion (LVO) of the anterior circulation. Conversely, its benefit in patients with National Institutes of Health Stroke Scale (NIHSS) score ⩽ 5 is unproven. AIM: To demonstrate the superiority of immediate MT plus best medical treatment (BMT) compared to BMT (with secondary MT in case of deterioration) for increasing the rate of modified Rankin Scale (mRS) score ⩽ 1 at 90 days after minor stroke (NIHSS score ⩽ 5) and anterior circulation LVO. SAMPLE SIZE ESTIMATES: To detect an absolute increase of 10% (80% power) in the 90-day mRS score = 0-1 rate in the MT + BMT group, by assuming an mRS score = 0-1 rate of 60% in the BMT group and by considering two interim efficacy/futility analyses (after study completion by 274 and 548 patients), 824 patients must be included by 36 centers in France, Spain, and the USA. METHODS AND DESIGN: MOSTE is an international, multicenter, prospectively randomized into two parallel (1:1) arms, open-label, with blinded endpoint trial. Eligibility criteria are diagnosis of acute ischemic stroke within 23 h of last-seen-well, NIHSS score ⩽ 5, and LVO in the anterior circulation (intracranial internal carotid artery, M1 or M1-M2 segment of the middle cerebral artery). STUDY OUTCOMES: The primary endpoint is the rate of excellent outcome at day 90 (mRS score = 0-1). Secondary endpoints include the rates of 90-day mRS score = 0-2 and score = 0, NIHSS score change, secondary MT, revascularization and infarct volume growth at 24 h, and quality of life and cognitive function at day 90. Safety outcomes (90-day all-cause mortality, procedural complications, symptomatic intracerebral hemorrhage, and rapid NIHSS score worsening) are recorded. DISCUSSION: The MOSTE trial will determine MT efficacy and safety in patients with minor stroke and LVO in the anterior circulation. TRIAL REGISTRATION: MOSTE Trial. NCT03796468.

Identifying ex vivo acute ischemic stroke thrombus composition using electrochemical impedance spectroscopy.

BACKGROUND: Intra-procedural characterization of stroke thromboemboli might guide mechanical thrombectomy (MT) device choice to improve recanalization rates. Electrochemical impedance spectroscopy (EIS) has been used to characterize various biological tissues in real time but has not been used in thrombus. OBJECTIVE: To perform a feasibility study of EIS analysis of thrombi retrieved by MT to evaluate: (1) the ability of EIS and machine learning to predict red blood cell (RBC) percentage content of thrombi and (2) to classify the thrombi as "RBC-rich" or "RBC-poor" based on a range of cutoff values of RBC. METHODS: ClotbasePilot was a multicentric, international, prospective feasibility study. Retrieved thrombi underwent histological analysis to identify proportions of RBC and other components. EIS results were analyzed with machine learning. Linear regression was used to evaluate the correlation between the histology and EIS. Sensitivity and specificity of the model to classify the thrombus as RBC-rich or RBC-poor were also evaluated. RESULTS: Among 514 MT,179 thrombi were included for EIS and histological analysis. The mean composition in RBC of the thrombi was 36% ± 24. Good correlation between the impedance-based prediction and histology was achieved (slope of 0.9, R2 = 0.53, Pearson coefficient = 0.72). Depending on the chosen cutoff, ranging from 20 to 60% of RBC, the calculated sensitivity for classification of thrombi ranged from 77 to 85% and the specificity from 72 to 88%. CONCLUSION: Combination of EIS and machine learning can reliably predict the RBC composition of retrieved ex vivo AIS thrombi and then classify them into groups according to their RBC composition with good sensitivity and specificity.

Endovascular treatment of brain arteriovenous malformations: clinical outcomes of patients included in the registry of a pragmatic randomized trial.

OBJECTIVE: The role of endovascular treatment in the management of patients with brain arteriovenous malformations (AVMs) remains uncertain. AVM embolization can be offered as stand-alone curative therapy or prior to surgery or stereotactic radiosurgery (SRS) (pre-embolization). The Treatment of Brain AVMs Study (TOBAS) is an all-inclusive pragmatic study that comprises two randomized trials and multiple registries. METHODS: Results from the TOBAS curative and pre-embolization registries are reported. The primary outcome for this report is death or dependency (modified Rankin Scale [mRS] score > 2) at last follow-up. Secondary outcomes include angiographic results, perioperative serious adverse events (SAEs), and permanent treatment-related complications leading to an mRS score > 2. RESULTS: From June 2014 to May 2021, 1010 patients were recruited in TOBAS. Embolization was chosen as the primary curative treatment for 116 patients and pre-embolization prior to surgery or SRS for 92 patients. Clinical and angiographic outcomes were available in 106 (91%) of 116 and 77 (84%) of 92 patients, respectively. In the curative embolization registry, 70% of AVMs were ruptured, and 62% were low-grade AVMs (Spetzler-Martin grade I or II), while the pre-embolization registry had 70% ruptured AVMs and 58% low-grade AVMs. The primary outcome of death or disability (mRS score > 2) occurred in 15 (14%, 95% CI 8%-22%) of the 106 patients in the curative embolization registry (4 [12%, 95% CI 5%-28%] of 32 unruptured AVMs and 11 [15%, 95% CI 8%-25%] of 74 ruptured AVMs) and 9 (12%, 95% CI 6%-21%) of the 77 patients in the pre-embolization registry (4 [17%, 95% CI 7%-37%] of 23 unruptured AVMs and 5 [9%, 95% CI 4%-20%] of 54 ruptured AVMs) at 2 years. Embolization alone was confirmed to occlude the AVM in 32 (30%, 95% CI 21%-40%) of the 106 curative attempts and in 9 (12%, 95% CI 6%-21%) of 77 patients in the pre-embolization registry. SAEs occurred in 28 of the 106 attempted curative patients (26%, 95% CI 18%-35%, including 21 new symptomatic hemorrhages [20%, 95% CI 13%-29%]). Five of the new hemorrhages were in previously unruptured AVMs (n = 32; 16%, 95% CI 5%-33%). Of the 77 pre-embolization patients, 18 had SAEs (23%, 95% CI 15%-34%), including 12 new symptomatic hemorrhages [16%, 95% CI 9%-26%]). Three of the hemorrhages were in previously unruptured AVMs (3/23; 13%, 95% CI 3%-34%). CONCLUSIONS: Embolization as a curative treatment for brain AVMs was often incomplete. Hemorrhagic complications were frequent, even when the specified intent was pre-embolization before surgery or SRS. Because the role of endovascular treatment remains uncertain, it should preferably, when possible, be offered in the context of a randomized trial.

Outcomes After Endovascular Therapy With Procedural Sedation vs General Anesthesia in Patients With Acute Ischemic Stroke: The AMETIS Randomized Clinical Trial.

Importance: General anesthesia and procedural sedation are common practice for mechanical thrombectomy in acute ischemic stroke. However, risks and benefits of each strategy are unclear. Objective: To determine whether general anesthesia or procedural sedation for anterior circulation large-vessel occlusion acute ischemic stroke thrombectomy are associated with a difference in periprocedural complications and 3-month functional outcome. Design, Setting, and Participants: This open-label, blinded end point randomized clinical trial was conducted between August 2017 and February 2020, with final follow-up in May 2020, at 10 centers in France. Adults with occlusion of the intracranial internal carotid artery and/or the proximal middle cerebral artery treated with thrombectomy were enrolled. Interventions: Patients were assigned to receive general anesthesia with tracheal intubation (n = 135) or procedural sedation (n = 138). Main Outcomes and Measures: The prespecified primary composite outcome was functional independence (a score of 0 to 2 on the modified Rankin Scale, which ranges from 0 [no neurologic disability] to 6 [death]) at 90 days and absence of major periprocedural complications (procedure-related serious adverse events, pneumonia, myocardial infarction, cardiogenic acute pulmonary edema, or malignant stroke) at 7 days. Results: Among 273 patients evaluable for the primary outcome in the modified intention-to-treat population, 142 (52.0%) were women, and the mean (SD) age was 71.6 (13.8) years. The primary outcome occurred in 38 of 135 patients (28.2%) assigned to general anesthesia and in 50 of 138 patients (36.2%) assigned to procedural sedation (absolute difference, 8.1 percentage points; 95% CI, -2.3 to 19.1; P = .15). At 90 days, the rate of patients achieving functional independence was 33.3% (45 of 135) with general anesthesia and 39.1% (54 of 138) with procedural sedation (relative risk, 1.18; 95% CI, 0.86-1.61; P = .32). The rate of patients without major periprocedural complications at 7 days was 65.9% (89 of 135) with general anesthesia and 67.4% (93 of 138) with procedural sedation (relative risk, 1.02; 95% CI, 0.86-1.21; P = .80). Conclusions and Relevance: In patients treated with mechanical thrombectomy for anterior circulation acute ischemic stroke, general anesthesia and procedural sedation were associated with similar rates of functional independence and major periprocedural complications. Trial Registration: ClinicalTrials.gov Identifier: NCT03229148.