Importance The benefits of endovascular revascularization using the contact aspiration technique vs the stent retriever technique in patients with acute ischemic stroke remain uncertain because of lack of evidence from randomized trials. Objective To compare efficacy and adverse events using the contact aspiration technique vs the standard stent retriever technique as a first-line endovascular treatment for successful revascularization among patients with acute ischemic stroke and large vessel occlusion. Design, Setting, and Participants The Contact Aspiration vs Stent Retriever for Successful Revascularization (ASTER) study was a randomized, open-label, blinded end-point clinical trial conducted in 8 comprehensive stroke centers in France (October 2015-October 2016). Patients who presented with acute ischemic stroke and a large vessel occlusion in the anterior circulation within 6 hours of symptom onset were included. Interventions Patients were randomly assigned to first-line contact aspiration (n = 192) or first-line stent retriever (n = 189) immediately prior to mechanical thrombectomy. Main Outcomes and Measures The primary outcome was the proportion of patients with successful revascularization defined as a modified Thrombolysis in Cerebral Infarction score of 2b or 3 at the end of all endovascular procedures. Secondary outcomes included degree of disability assessed by overall distribution of the modified Rankin Scale (mRS) score at 90 days, change in National Institutes of Health Stroke Scale (NIHSS) score at 24 hours, all-cause mortality at 90 days, and procedure-related serious adverse events. Results Among 381 patients randomized (mean age, 69.9 years; 174 women [45.7%]), 363 (95.3%) completed the trial. Median time from symptom onset to arterial puncture was 227 minutes (interquartile range, 180-280 minutes). For the primary outcome, the proportion of patients with successful revascularization was 85.4% (n = 164) in the contact aspiration group vs 83.1% (n = 157) in the stent retriever group (odds ratio, 1.20 [95% CI, 0.68-2.10]; P  = .53; difference, 2.4% [95% CI, −5.4% to 9.7%]). For the clinical efficacy outcomes (change in NIHSS score at 24 hours, mRS score at 90 days) and adverse events, there were no significant differences between groups. Conclusions and Relevance Among patients with ischemic stroke in the anterior circulation undergoing thrombectomy, first-line thrombectomy with contact aspiration compared with stent retriever did not result in an increased successful revascularization rate at the end of the procedure. Trial Registration clinicaltrials.gov Identifier:NCT02523261

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Effect of Endovascular Contact Aspiration vs Stent Retriever on Revascularization in Patients With Acute Ischemic Stroke and Large Vessel Occlusion: The ASTER Randomized Clinical Trial.

Background and Purpose—In acute ischemic stroke, fast and complete recanalization of the occluded vessel is associated with improved outcomes. We describe a novel measure for newer generation devic...

First Pass Effect: A New Measure for Stroke Thrombectomy Devices.

BACKGROUND: CT perfusion (CTP) and diffusion or perfusion MRI might assist patient selection for endovascular thrombectomy. We aimed to establish whether imaging assessments of irreversibly injured ischaemic core and potentially salvageable penumbra volumes were associated with functional outcome and whether they interacted with the treatment effect of endovascular thrombectomy on functional outcome. METHODS: In this systematic review and meta-analysis, the HERMES collaboration pooled patient-level data from all randomised controlled trials that compared endovascular thrombectomy (predominantly using stent retrievers) with standard medical therapy in patients with anterior circulation ischaemic stroke, published in PubMed from Jan 1, 2010, to May 31, 2017. The primary endpoint was functional outcome, assessed by the modified Rankin Scale (mRS) at 90 days after stroke. Ischaemic core was estimated, before treatment with either endovascular thrombectomy or standard medical therapy, by CTP as relative cerebral blood flow less than 30% of normal brain blood flow or by MRI as an apparent diffusion coefficient less than 620 μm2/s. Critically hypoperfused tissue was estimated as the volume of tissue with a CTP time to maximum longer than 6 s. Mismatch volume (ie, the estimated penumbral volume) was calculated as critically hypoperfused tissue volume minus ischaemic core volume. The association of ischaemic core and penumbral volumes with 90-day mRS score was analysed with multivariable logistic regression (functional independence, defined as mRS score 0-2) and ordinal logistic regression (functional improvement by at least one mRS category) in all patients and in a subset of those with more than 50% endovascular reperfusion, adjusted for baseline prognostic variables. The meta-analysis was prospectively designed by the HERMES executive committee, but not registered. FINDINGS: We identified seven studies with 1764 patients, all of which were included in the meta-analysis. CTP was available and assessable for 591 (34%) patients and diffusion MRI for 309 (18%) patients. Functional independence was worse in patients who had CTP versus those who had diffusion MRI, after adjustment for ischaemic core volume (odds ratio [OR] 0·47 [95% CI 0·30-0·72], p=0·0007), so the imaging modalities were not pooled. Increasing ischaemic core volume was associated with reduced likelihood of functional independence (CTP OR 0·77 [0·69-0·86] per 10 mL, pinteraction=0·29; diffusion MRI OR 0·87 [0·81-0·94] per 10 mL, pinteraction=0·94). Mismatch volume, examined only in the CTP group because of the small numbers of patients who had perfusion MRI, was not associated with either functional independence or functional improvement. In patients with CTP with more than 50% endovascular reperfusion (n=186), age, ischaemic core volume, and imaging-to-reperfusion time were independently associated with functional improvement. Risk of bias between studies was generally low. INTERPRETATION: Estimated ischaemic core volume was independently associated with functional independence and functional improvement but did not modify the treatment benefit of endovascular thrombectomy over standard medical therapy for improved functional outcome. Combining ischaemic core volume with age and expected imaging-to-reperfusion time will improve assessment of prognosis and might inform endovascular thrombectomy treatment decisions. FUNDING: Medtronic.

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Penumbral imaging and functional outcome in patients with anterior circulation ischaemic stroke treated with endovascular thrombectomy versus medical therapy: a meta-analysis of individual patient-level data

Background: Revascularization after endovascular therapy for acute ischemic stroke is measured by the Thrombolysis In Cerebral Infarction (TICI) scale, yet variability exists in scale definitions We examined the degree of reperfusion with the expanded TICI (eTICI) scale and association with outcomes in the HERMES collaboration of recent endovascular trials Methods: The HERMES Imaging Core, blind to all other data, evaluated angiography after endovascular therapy in HERMES A battery of TICI scores (mTICI, TICI, TICI2C) was used to define reperfusion of the initial target occlusion defined by non-invasive imaging and conventional angiography Results: Angiography of 801 subjects was available, including 797 defined by non-invasive imaging (154 internal carotid artery (ICA), 583 M1, 60 M2) and 748 by conventional angiography (195 ICA, 459 M1, 94 M2) Among 729 subjects in whom the reperfusion grade could be established, using eTICI (3=100%, 2C=90-99%, 2b67=67-89%, 2b50=50-66%) of the conventional angiography target occlusion, there were 63 eTICI 3 (9%), 166 eTICI 2c (23%), 218 eTICI 2b67 (30%), 103 eTICI 2b50 (14%), 100 eTICI 2a (14%), 19 eTICI 1 (3%), and 60 eTICI 0 (8%) Modified Rankin Scale shift analyses from baseline to 90 days showed that increasing TICI grades were linked with better outcomes, with significant distinctions between TICI 0/1 versus 2a (p=0028), 2a versus 2b50 (p=0017), and 2b50 versus 2b67 (p=0014) Conclusions: The benefit of endovascular therapy in HERMES was strongly associated with increasing degrees of reperfusion defined by eTICI The eTICI metric identified meaningful distinctions in clinical outcomes and may be used in future studies and routine practice

https://jnis.bmj.com/content/neurintsurg/11/5/433.full.pdf

eTICI reperfusion: defining success in endovascular stroke therapy

Background and Purpose— Whether prior intravenous thrombolysis provides any additional benefits to the patients undergoing mechanical thrombectomy for large vessel, acute ischemic stroke remains unclear. Methods— We conducted a meta-analysis of 13 studies obtained through PubMed and EMBASE database searches to determine whether functional outcome (modified Rankin Scale) at 90 days, successful recanalization rate, and symptomatic intracerebral hemorrhage rate differed between patients who underwent mechanical thrombectomy with (MT+IVT) and without (MT−IVT) pre-treatment with intravenous thrombolysis. Results— MT+IVT patients compared with MT−IVT patients had better functional outcomes (modified Rankin Scale score, 0–2; summary odds ratio [OR], 1.27 [95% confidence interval (CI), 1.05–1.55]; P =0.02; n=1769/1174), lower mortality (OR, 0.71 [95% CI, 0.55–0.91]; P =0.006; n=1774/1202), and higher rate of successful recanalization (OR, 1.46 [95% CI, 1.09–1.96]; P =0.01; n=1652/1216) without having increased odds of symptomatic intracerebral hemorrhage (OR, 1.11 [95% CI, 0.69–1.77]; P =0.67; n=1471/1143). A greater number of MT+IVT patients required ≤2 passes with a neurothrombectomy device to achieve successful recanalization (OR, 2.06 [95% CI, 1.37–3.10]; P =0.0005; n=316/231). Conclusions— Our results demonstrated that MT+IVT patients had better functional outcomes, lower mortality, higher rate of successful recanalization, requiring lower number of device passes, and equal odds of symptomatic intracerebral hemorrhage compared with MT−IVT patients. The results support the current guidelines of offering intravenous thrombolysis to eligible patients even if they are being considered for mechanical thrombectomy. Because the data are compiled from studies where the 2 groups differed based on eligibility for intravenous thrombolysis, randomized trials are necessary to accurately evaluate the added value of intravenous thrombolysis in patients treated with mechanical thrombectomy.

Mechanical Thrombectomy Outcomes With and Without Intravenous Thrombolysis in Stroke Patients: A Meta-Analysis.

BACKGROUND AND PURPOSE: The TICI score is widely used to evaluate cerebral perfusion before and after the endovascular treatment of stroke. Recent studies showing the effectiveness and safety of mechanical thrombectomy combine modified TICI 2b and modified TICI 3 to assess the technical success of endovascular treatment. The purpose of this study was to determine how much clinical outcomes differ between patients achieving modified TICI 2b and modified TICI 3 reperfusion. MATERIALS AND METHODS: We analyzed 222 consecutive patients with acute large intracranial artery occlusion of the anterior circulation having achieved modified TICI 2b or modified TICI 3 reperfusion after thrombectomy. The primary end point was the rate of favorable outcome defined as the achievement of a modified Rankin Scale score of 0–2 at 3 months. RESULTS: Patients with modified TICI 3 more often had favorable collateral circulation and atherosclerosis etiology, with a shorter time from onset to reperfusion than patients with modified TICI 2b (all P CONCLUSIONS: Patients with modified TICI 3 reperfusion have better functional outcomes than those with modified TICI 2b. Given the improving reperfusion rates obtained with thrombectomy devices, future thrombectomy trials should consider modified TICI 2b and modified TICI 3 status separately.

http://www.ajnr.org/content/ajnr/38/1/90.full.pdf

Impact of Modified TICI 3 versus Modified TICI 2b Reperfusion Score to Predict Good Outcome following Endovascular Therapy.

Background and Purpose— In acute ischemic stroke patients, diffusion-weighted imaging (DWI)–Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is correlated with infarct volume and is an independent factor of functional outcome. Patients with pretreatment DWI-ASPECTS ≤6 were excluded or under-represented in the recent randomized mechanical thrombectomy trials. Our aim was to assess the impact of reperfusion in pretreatment DWI-ASPECTS ≤6 patients treated with mechanical thrombectomy.

Methods— We analyzed data collected between January 2012 and August 2015 in a bicentric prospective clinical registry of consecutive acute ischemic stroke patients treated with mechanical thrombectomy. Every patient with a documented internal carotid artery or middle cerebral artery occlusion with pretreatment DWI-ASPECTS ≤6 was eligible for this study. The primary end point was a favorable outcome defined by a modified Rankin Scale score ≤2 at 90 days.

Results— Two hundred and eighteen patients with a DWI-ASPECTS ≤6 were included. Among them, 145 (66%) patients had successful reperfusion at the end of mechanical thrombectomy. Reperfused patients had an increased rate of favorable outcome (38.7% versus 17.4%; P =0.002) and a decreased rate of mortality at 3 months (22.5% versus 39.1%; P =0.013) compared with nonreperfused patients. The symptomatic intracranial hemorrhage rate was not different between the 2 groups (13.0% versus 14.1%; P =0.83). However, in patients with DWI-ASPECTS <5, favorable outcome was low (13.0% versus 9.5%; P =0.68) with a high mortality rate (45.7% versus 57.1%; P =0.38) with or without successful reperfusion.

Conclusions— Successful reperfusion is associated with reduced mortality and disability in patients with a pretreatment DWI-ASPECTS ≤6. Further data from randomized studies are needed, particularly in patients with DWI-ASPECTS <5.

https://www.ahajournals.org/doi/pdf/10.1161/STROKEAHA.116.015202

Successful Reperfusion With Mechanical Thrombectomy Is Associated With Reduced Disability and Mortality in Patients With Pretreatment Diffusion-Weighted Imaging–Alberta Stroke Program Early Computed Tomography Score ≤6

Background In acute ischemic stroke (AIS), bridging therapy, including intravenous thrombolysis (IVT) and mechanical thrombectomy (MET), appears to be very promising. However, data on the impact of IVT before the endovascular procedure are limited. Methods To examine the impact of IVT on the MET procedure, we compared the duration of this procedure, number of passes, recanalization rate, safety issues, and outcome in consecutively recruited patients either eligible for MET alone (intravenous fibrinolysis contraindication) or receiving MET preceded by IVT for proximal middle cerebral artery (MCA) occlusion within 6 hours of stroke onset. Results From January 2011 to June 2013, 68 cases with proximal MCA occlusion were available for analysis (MET alone, 40; IVT + MET, 28). The 2 groups did not differ significantly in baseline characteristics. The median National Institutes of Health Stroke Scale score at admission was 15 (10-20) for MET and 18 (13-19) for IVT + MET groups, respectively ( P  = .39). The median duration of the endovascular procedure (from groin puncture to recanalization) was significantly shorter in the IVT + MET group compared with that in MET alone (35 minutes [21-60] versus 60 minutes [25-91]; P  = .043). The number of passes of the thrombectomy device per patient tended to be lower in the IVT + MET group than those in the MET group ( P  = .080). The IVT + MET group also had a higher rate of complete recanalization and a better outcome at 3 months. Conclusions Prior IVT may facilitate the MET procedure. Further studies on MET in AIS should assess the direct impact of IVT on the endovascular procedure.

Prior IV Thrombolysis Facilitates Mechanical Thrombectomy in Acute Ischemic Stroke.

Supplementary Material for: Is Reperfusion Useful in Ischaemic Stroke Patients Presenting with a Low National Institutes of Health Stroke Scale and a Proximal Large Vessel Occlusion of the Anterior Circulation?

G. Rodesch

Papers

Impact of Modified TICI 3 versus Modified TICI 2b Reperfusion Score to Predict Good Outcome following Endovascular Therapy.

Successful Reperfusion With Mechanical Thrombectomy Is Associated With Reduced Disability and Mortality in Patients With Pretreatment Diffusion-Weighted Imaging–Alberta Stroke Program Early Computed Tomography Score ≤6

Prior IV Thrombolysis Facilitates Mechanical Thrombectomy in Acute Ischemic Stroke.

Supplementary Material for: Is Reperfusion Useful in Ischaemic Stroke Patients Presenting with a Low National Institutes of Health Stroke Scale and a Proximal Large Vessel Occlusion of the Anterior Circulation?