Thrombectomy within 8 hours after symptom onset in ischemic stroke

Mechanical thrombectomy versus systemic thrombolysis in MCA stroke: a distance to thrombus-based outcome analysis

BACKGROUND

Acute ischemic stroke due to occlusion of the middle cerebral artery (MCA) has a poor outcome. The distance to thrombus (DT) from the carotid T can predict the outcome after intravenous thrombolysis (IVT). With a DT <16 mm, fewer than 50% of patients treated with IVT have a favorable outcome.

OBJECTIVE

To compare stent retriever-based endovascular mechanical thrombectomy (MT) plus additional IVT (IVT-MT) with IVT alone.

MATERIALS AND METHODS

Patients with MCA occlusion proved by CT angiography with a DT <16 mm, treated with either IVT alone or with stent retriever-based endovascular IVT-MT, were included in this study. Changes in National Institutes of Health Stroke Scale (NIHSS), the 7-day NIHSS, and the 90-day modified Rankin Scale (mRS) scores were analyzed by treatment modality.

RESULTS

Of 621 patients, 87 fulfilled all inclusion criteria. Fifty-nine patients were treated with IVT and 28 with IVT-MT. Although patients treated with IVT-MT had had significantly more severe strokes than those treated with IVT alone (initial NIHSS 16 (7-18) vs 14 (5-22); p=0.032), both the short- and long-term outcomes were significantly better in this patient group (NIHSS improvement on day 7: 10.9±6.3 vs 6.7±6.7; p=0.008/90-day mRS: 2 (0.75-2.5) vs 4 (2-6); p=0.003).

CONCLUSIONS

In patients with an acute MCA occlusion and a DT <16 mm, IVT-MT leads to a significantly better outcome than in patients treated with IVT alone.

Stent Retriever Thrombectomy in Patients Who Are Ineligible for Intravenous Thrombolysis: A Multicenter Retrospective Observational Study

BACKGROUND AND PURPOSE

Intravenous thrombolysis with rtPA is the standard of care for patients with acute ischemic stroke within 4.5 hours after symptom onset. However, a considerable number of patients are ineligible for IV thrombolysis due to various contraindications. Recent studies have proved the superiority of mechanical thrombectomy for patients with large-vessel occlusions in combination with IV rtPA compared with IV rtPA alone. We aimed to demonstrate the efficacy of mechanical thrombectomy for patients who are ineligible for IV rtPA.

MATERIALS AND METHODS

Patients from the stroke registries of 4 dedicated centers who were treated with mechanical thrombectomy from January 2010 to October 2014 were retrospectively evaluated. Inclusion criteria were the following: acute stroke due to proved large-artery occlusion, ineligibility for IV thrombolysis, and a timeframe of ≤4.5 hours between stroke and the start of mechanical thrombectomy. Recanalization success, periprocedural complications, clinical outcome, and hemorrhages were evaluated.

RESULTS

One hundred thirty endovascular recanalization procedures were identified. The locations were the following: proximal ICA in 17 (13.1%), terminus ICA in 25 (19.2%), M1 segment in 77 (59.2%), and M2 segment in 11 (8.5%). TICI 2b/3 results were achieved in 101 (77.7%), and an mRS score of 0-2 in 47 patients (37.9%). There was a significant correlation between TICI 2b/3 results and good clinical outcomes (87.2% versus 6.8%; P = .048). A good clinical result was most frequent when recanalization was achieved within 4.5 hours (37/74 = 50% versus 10/50 = 20.0%; P = .001). Symptomatic hemorrhage occurred in 13.1% of patients; mortality was 24.2%. Periprocedural complications were recorded in 10 patients (7.7%).

CONCLUSIONS

Mechanical thrombectomy can achieve good clinical outcomes in patients with acute large-artery occlusion ineligible for IV thrombolysis, in particular when recanalization is reached early.

Previous and Recent Evidence of Endovascular Therapy in Acute Ischemic Stroke

The ideal therapy of acute ischemic stroke is achieved by early recanalization that finally leads to good clinical outcome. The recombinant intravenous tissue plasminogen activator (rtPA) within 4.5 hours was approved as an important thrombolytic treatment. However, the recanalization rate was low in patients with a large artery occlusion. The efficacy of intravenous rtPA regarding recanalization of a large artery occlusion was limited. In several clinical trials, pharmacological and mechanical intra-arterial thrombolytic therapy showed improved recanalization rates, but the favorable outcome had not been achieved. Through those trials and errors, researchers have learned that speed of treatment initiation, patient selection by documentation of large artery occlusion and the use of effective devices could be crucial for good clinical outcomes. Finally, five recent randomized controlled trials of endovascular therapy compared to standard medical care have been published. The superiority of endovascular thrombolysis to standard medical care was proved. In this article, we reviewed previous and recent clinical evidence about endovascular thrombolytic therapy of acute ischemic stroke.

Updated European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist anticoagulants in patients with non-valvular atrial fibrillation

The current manuscript is an update of the original Practical Guide, published in June 2013[Heidbuchel H, Verhamme P, Alings M, Antz M, Hacke W, Oldgren J, et al. European Heart Rhythm Association Practical Guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation. Europace 2013;15:625-51; Heidbuchel H, Verhamme P, Alings M, Antz M, Hacke W, Oldgren J, et al. EHRA practical guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation: executive summary. Eur Heart J 2013;34:2094-106]. Non-vitamin K antagonist oral anticoagulants (NOACs) are an alternative for vitamin K antagonists (VKAs) to prevent stroke in patients with non-valvular atrial fibrillation (AF). Both physicians and patients have to learn how to use these drugs effectively and safely in clinical practice. Many unresolved questions on how to optimally use these drugs in specific clinical situations remain. The European Heart Rhythm Association set out to coordinate a unified way of informing physicians on the use of the different NOACs. A writing group defined what needs to be considered as 'non-valvular AF' and listed 15 topics of concrete clinical scenarios for which practical answers were formulated, based on available evidence. The 15 topics are (i) practical start-up and follow-up scheme for patients on NOACs; (ii) how to measure the anticoagulant effect of NOACs; (iii) drug-drug interactions and pharmacokinetics of NOACs; (iv) switching between anticoagulant regimens; (v) ensuring adherence of NOAC intake; (vi) how to deal with dosing errors; (vii) patients with chronic kidney disease; (viii) what to do if there is a (suspected) overdose without bleeding, or a clotting test is indicating a risk of bleeding?; (xi) management of bleeding complications; (x) patients undergoing a planned surgical intervention or ablation; (xi) patients undergoing an urgent surgical intervention; (xii) patients with AF and coronary artery disease; (xiii) cardioversion in a NOAC-treated patient; (xiv) patients presenting with acute stroke while on NOACs; and (xv) NOACs vs. VKAs in AF patients with a malignancy. Additional information and downloads of the text and anticoagulation cards in >16 languages can be found on an European Heart Rhythm Association web site (www.NOACforAF.eu).

Protected stent retriever thrombectomy prevents iatrogenic emboli in new vascular territories

Introduction

Diagnostic tools to show emboli reliably and protection techniques against embolization when employing stent retrievers are necessary to improve endovascular stroke therapy. The aim of the present study was to investigate iatrogenic emboli using susceptibility-weighted imaging (SWI) in an open series of patients who had been treated with stent retriever thrombectomy using emboli protection techniques.

Methods

Patients with anterior circulation stroke examined with MRI before and after stent retriever thrombectomy were assessed for iatrogenic embolic events. Thrombectomy was performed in flow arrest and under aspiration using a balloon-mounted guiding catheter, a distal access catheter, or both.

Results

In 13 of 57 patients (22.8 %) post-interventional SWI sequences detected 16 microemboli. Three of them were associated with small ischemic lesions on diffusion-weighted imaging (DWI). None of the microemboli were located in a new vascular territory, none showed clinical signs, and all 13 patients have been rated as Thrombolysis in Cerebral Infarction (TICI) 2b (n = 3) or 3 (n = 10). Retrospective reevaluation of the digital subtraction angiography (DSA) detected discrete flow stagnation nearby the iatrogenic microemboli in four patients with a positive persistent collateral sign in one.

Conclusion

Our study demonstrates two things: First, SWI seems to be more sensitive to detect emboli than DWI and DSA and, second, proximal or distal protected stent retriever thrombectomy seems to prevent iatrogenic embolization into new vascular territories during retraction of the thrombus, but not downstream during mobilization of the thrombus. Both techniques should be investigated and refined further.

In vitro experiments of cerebral blood flow during aspiration thrombectomy: potential effects on cerebral perfusion pressure and collateral flow

Background

Mechanical thrombectomy with stent retriever devices is associated with significantly better outcomes than thrombolysis alone in the treatment of acute ischemic stroke. Thrombus aspiration achieves high patency rates, but clinical outcomes are variable. The aim of this study was to examine the effect of different suction conditions on perfusate flow during aspiration thrombectomy.

Methods

A computational fluid dynamics model of an aspiration device within a patent and occluded blood vessel was used to simulate flow characteristics using fluid flow solver software. A physical particulate flow model of a patent vessel and a vessel occluded by thrombus was then used to visualize flow direction and measure flow rates with the aspiration catheter placed 1–10 mm proximal of the thrombus, and recorded on video.

Results

The mathematical model predicted that, in a patent vessel, perfusate is drawn from upstream of the catheter tip while, in an occluded system, perfusate is drawn from the vessel proximal to the device tip with no traction on the occlusion distal of the tip. The in vitro experiments confirmed the predictions of this model. In the occluded vessel aspiration had no effect on the thrombus unless the tip of the catheter was in direct contact with the thrombus.

Conclusions

These experiments suggest that aspiration is only effective if the catheter tip is in direct contact with the thrombus. If the catheter tip is not in contact with the thrombus, aspirate is drawn from the vessels proximal of the occlusion. This could affect collateral flow in vivo.

Mechanical Thrombectomy Using the New ERIC Retrieval Device Is Feasible, Efficient, and Safe in Acute Ischemic Stroke: A Swiss Stroke Center Experience

BACKGROUND AND PURPOSE

Intravenous thrombolysis and mechanical thrombectomy predominantly using stent retrievers have been shown to effectively restore cerebral blood flow and improve functional outcome in patients with acute ischemic stroke. We sought to determine the safety and feasibility of mechanical thrombectomy using the new ERIC retrieval device.

MATERIALS AND METHODS

We identified 36 consecutive patients from our Stroke Center registry with acute ischemic stroke who were treated with the new ERIC retriever from September 2013 to December 2014. Patients with ischemic stroke meeting the following criteria were eligible: onset-to-treatment time of ≤4.5 hours or wake-up stroke (n = 10) with relevant CT perfusion mismatch, NIHSS score of ≥4, and proof of large-vessel occlusion in the anterior circulation on CT angiography. We assessed the baseline characteristics including age, sex, comorbidities, stroke severity, site of vessel occlusion, presence of tissue at risk, and treatment-related parameters such as onset-to-treatment time, recanalization grade, and outcome.

RESULTS

The mean age was 70 ± 13 years, and the median NIHSS score on admission was 18 (interquartile range, 10-20). Seventeen of 36 patients were on platelet inhibitors or anticoagulants before endovascular treatment (47.2%); 20 patients received intravenous thrombolysis (55.5%). The ERIC was used as the sole retriever in 28 patients (77.8%) and as a rescue device in 8. Excellent recanalization was achieved in 30/36 patients (83.3%) with TICI 3 in 19/36 and 2b in 11/36, respectively. Median procedural time in these patients was 90 minutes (interquartile range, 58-133 minutes). No intraprocedural complications occurred.

CONCLUSIONS

In this observational study, the new ERIC retrieval device was technically feasible, safe, and effective in acute ischemic stroke with large-vessel occlusion.

Intra-arterial thrombectomy: does invasive treatment lead to better outcomes than intravenous thrombolysis alone?

Intravenous thrombolysis is considered to be standard of care for acute ischemic stroke patients arriving within 3-4.5 h of stroke symptom onset. Recently, endovascular therapies have been proposed to extend and enhance stroke outcomes by targeting large vessel occlusions. Different radiologic methods, time windows, and treatment tools have delineated differences between trials. Overall, intravenous thrombolysis remains the treatment of choice for all acute ischemic stroke patients, with a small subset benefiting from additional endovascular therapy. Endovascular therapy remains a viable singular option for patients with large vessel occlusion unable to receive thrombolysis.

Posterior circulation CT angiography collaterals predict outcome of endovascular acute ischemic stroke therapy for basilar artery occlusion

Introduction

The natural history of acute ischemic stroke (AIS) due to basilar artery occlusion (BAO) is poor. Endovascular reperfusion therapy (EVT) improves recanalization rates in patients with emergent large vessel intracranial occlusion.

Objective

To examine the hypothesis that good collateral patterns identified by pretreatment CT angiography (CTA) might be associated with favorable outcomes after EVT.

Methods

We conducted a retrospective chart review of patients presenting with AIS due to BAO in a tertiary care stroke center during a 4-year period. BAO was diagnosed by CTA in all cases. Admission stroke severity was documented using the National Institute of Health Stroke Scale (NIHSS) score. Pretreatment collateral score for posterior circulation was defined as follows: 0, no posterior communicating artery (PCOM); 1, unilateral PCOM; 2, bilateral PCOM. Favorable outcome was defined as modified Rankin Scale score of 0–2 at 3 months.

Results

A total of 21 patients with AIS due to BAO (age range 31–84 years, median admission NIHSS score: 18 points, range 2–38) underwent EVT. Eleven of 21 patients (52.4%) had bilateral PCOMs, while unilateral PCOM was seen in 3 patients (14.3%). Patients with bilateral PCOMs tended (p=0.261) to have less severe stroke at admission than those with absent/unilateral PCOM (median NIHSS score 18 vs 27 points). Neurological improvement during hospitalization (quantified by the median decrease in NIHSS score) and the rate of 3-month functional independence were greater in patients with good collaterals (16 vs 0 points (p=0.016) and 72.7% vs 0% (p=0.001)).

Conclusions

The presence of bilateral PCOMs on pretreatment CTA appears to be associated with more favorable outcomes in BAO treated with EVT.

Mechanical thrombectomy with the Trevo ProVue device in ischemic stroke patients: does improved visibility translate into a clinical benefit?

PURPOSE

To investigate the efficacy and safety of the Trevo ProVue (TPV) stent retriever in stroke patients with large artery occlusions, with particular attention to the full structural radiopacity of the TPV.

MATERIALS AND METHODS

Case files and images of TPV treatments were reviewed for clinical and technical outcome data, including revascularization rates, device and procedure related complications, and outcome at discharge and after 90 days.

RESULTS

76 patients were treated with TPV. Mean National Institutes of Health Stroke Scale (NIHSS) score was 18 and 68% had additional intravenous thrombolysis. 63 occlusions were in the anterior circulation: 44 M1 (58%), 8 M2 (11%), 8 internal carotid artery-terminus (11%), 2 internal carotid artery- left (3%), 1 A2 (1%), and 13 vertebrobasilar (17%). 58 of 76 (76%) were solely treated with TPV; the remainder were treated with additional stent retrievers. Mean number of passes in TPV only cases was 2.2 (SD 1.2). In rescue cases, 3.2 (SD 2.2) passes were attempted with the TPV followed by 2.6 rescue device passes (SD 2). TPV related adverse events occurred in 4/76 cases (5%) and procedural events in 6/76 cases (8%). Mean procedural duration was 64 min (SD 42). Thrombolysis in Cerebral Infarction (TICI) 2b/3 recanalization was achieved in 69/76 patients (91%), including 50% TICI 3. Of 56 survivors (74%), 37 (49%) showed a favorable outcome at 90 days (Solitaire With the Intention for Thrombectomy trial criteria), statistically associated with age, baseline NIHSS, onset to revascularization time, and TICI 2b-3 reperfusion. TPV radiopacity allowed for visual feedback, changing the methodology of stent retriever use in 44/76 cases (58%).

CONCLUSIONS

Neurothrombectomy with TPV is feasible, effective, and safe. The recanalization rate compares favorably with reported data in the literature. Improved structural radiopacity may facilitate neurothrombectomy or influence the course of action during retrieval.

Severe hemiparesis as a prehospital tool to triage stroke severity: a pilot study to assess diagnostic accuracy and treatment times

INTRODUCTION

With the publication of the recent trials showing the tremendous benefits of mechanical thrombectomy, opportunities exist to refine prehospital processes to identify patients with larger stroke syndromes.

MATERIALS AND METHODS

We retrospectively reviewed consecutive patients who were brought via scene flight from rural parts of the region to our institution, from December 1, 2014 to June 5, 2015, with severe hemiparesis or hemiplegia. We assessed the accuracy of the diagnosis of stroke and the number of patients requiring endovascular therapy. Moreover, we reviewed the times along the pathway of patients who were treated with endovascular therapy.

RESULTS

45 patients were brought via helicopter from the field to our institution. 27 (60%) patients were diagnosed with an ischemic stroke. Of these, 12 (26.7%) were treated with mechanical thrombectomy and 6 (13.3%) with intravenous tissue plasminogen activator alone. An additional three patients required embolization procedures for either a dural arteriovenous fistula or cerebral aneurysm. Thus a total of 15 (33%) patients received an endovascular procedure and 21/45 (46.7%) received an acute treatment. For patients treated with thrombectomy, the median time from first medical contact to groin puncture was 101 min, with 8 of the 12 patients (66.7%) being discharged to home.

CONCLUSIONS

We have presented a pilot study showing that severe hemiparesis or hemiplegia may be a reasonable prehospital tool in recognizing patients requiring endovascular treatment. Patients being identified earlier may be treated faster and potentially improve outcomes. Further prospective controlled studies are required to assess the impact on outcomes and cost effectiveness using this methodology.

[Imaging-based indications for interventional treatment of stroke]

The indications for mechanical thrombectomy are based on a proximal vessel occlusion in the absence of extensive ischemic damage in the corresponding dependent vascular territory. The maximum extent of early ischemic edema for which endovascular treatment is still useful is not clear from the studies. A benefit of mechanical thrombectomy can be safely assumed with an ASPECT score of 6-10, possibly also with lower scores. A more complex imaging with assessment of the status of collateral vessels or perfusion abnormality is scientifically interesting but usually not necessary for clinical decision-making for endovascular stroke treatment within the first 6 h after symptom onset.

Younger Stroke Patients With Large Pretreatment Diffusion-Weighted Imaging Lesions May Benefit From Endovascular Treatment

BACKGROUND AND PURPOSE

Lesion volume on diffusion-weighted magnetic resonance imaging (DWI) before acute stroke therapy is a predictor of outcome. Therefore, patients with large volumes are often excluded from therapy. The aim of this study was to analyze the impact of endovascular treatment in patients with large DWI lesion volumes (>70 mL).

METHODS

Three hundred seventy-two patients with middle cerebral or internal carotid artery occlusions examined with magnetic resonance imaging before treatment since 2004 were included. Baseline data and 3 months outcome were recorded prospectively. DWI lesion volumes were measured semiautomatically.

RESULTS

One hundred five patients had lesions >70 mL. Overall, the volume of DWI lesions was an independent predictor of unfavorable outcome, survival, and symptomatic intracerebral hemorrhage (P<0.001 each). In patients with DWI lesions >70 mL, 11 of 31 (35.5%) reached favorable outcome (modified Rankin scale score, 0-2) after thrombolysis in cerebral infarction 2b-3 reperfusion in contrast to 3 of 35 (8.6%) after thrombolysis in cerebral infarction 0-2a reperfusion (P=0.014). Reperfusion success, patient age, and DWI lesion volume were independent predictors of outcome in patients with DWI lesions >70 mL. Thirteen of 66 (19.7%) patients with lesions >70 mL had symptomatic intracerebral hemorrhage with a trend for reduced risk with avoidance of thrombolytic agents.

CONCLUSIONS

There was a growing risk for poor outcome and symptomatic intracerebral hemorrhage with increasing pretreatment DWI lesion volumes. Nevertheless, favorable outcome was achieved in every third patient with DWI lesions >70 mL after successful endovascular reperfusion, whereas after poor or failed reperfusion, outcome was favorable in only every 12th patient. Therefore, endovascular treatment might be considered in patients with large DWI lesions, especially in younger patients.

Cost-Utility Analysis of Mechanical Thrombectomy Using Stent Retrievers in Acute Ischemic Stroke

Supplemental Digital Content is available in the text.

Recently, 5 randomized controlled trials demonstrated the benefit of endovascular therapy compared with intravenous tissue-type plasminogen activator in acute stroke. Economic evidence evaluating stent retrievers is limited. We compared the cost-effectiveness of intravenous tissue-type plasminogen activator alone versus mechanical thrombectomy and intravenous tissue-type plasminogen activator as a bridging therapy in eligible patients in the UK National Health Service.

Imaging of prehospital stroke therapeutics

Despite significant quality improvement efforts to streamline in-hospital acute stroke care in the conventional model, there remain inherent layers of treatment delays, which could be eliminated with prehospital diagnostics and therapeutics administered in a mobile stroke unit. Early diagnosis using telestroke and neuroimaging while in the ambulance may enable targeted routing to hospitals with specialized care, which will likely improve patient outcomes. Key clinical trials in telestroke, mobile stroke units with prehospital neuroimaging capability, prehospital ultrasound and co-administration of various classes of neuroprotectives, antiplatelets and antithrombin agents with intravenous thrombolysis are discussed in this article.

Combined Approach to Lysis Utilizing Eptifibatide and Recombinant Tissue-Type Plasminogen Activator in Acute Ischemic Stroke-Full Dose Regimen Stroke Trial

BACKGROUND AND PURPOSE

The Combined Approach to Lysis Utilizing Eptifibatide and Recombinant Tissue-Type Plasminogen Activator (r-tPA; CLEAR) in Acute Ischemic Stroke (AIS) and CLEAR-Enhanced Regimen (CLEAR-ER) trials demonstrated safety of reduced dose r-tPA plus the glycoprotein 2b/3a inhibitor, eptifibatide, in AIS compared with r-tPA alone. The objective of the CLEAR-Full Dose Regimen (CLEAR-FDR) trial was to estimate the rate of symptomatic intracerebral hemorrhage (sICH) in AIS patients treated with the combination of full-dose r-tPA plus eptifibatide.

METHODS

CLEAR-FDR was a single-arm, prospective, open-label, multisite study. Patients aged 18 to 85 years treated with 0.9 mg/kg IV r-tPA within 3 hours of symptom onset were enrolled. After obtaining consent, eptifibatide (135 μg/kg bolus and 2-hour infusion at 0.75 μg/kg per minute) was administered. The primary end point was the proportion of patients who experienced sICH within 36 hours. An independent clinical monitor adjudicated if an sICH had occurred and an independent neuroradiologist reviewed all images. The stopping rule was 3 sICHs within the first 19 patients or 4 sICHs within 29 patients.

RESULTS

From October 2013 to December 2014, 27 patients with AIS were enrolled. Median age was 73 years (range, 34-85; interquartile range, 65-80) and median National Institute of Health stroke scale score was 12 (range, 6-26; interquartile range, 9-16). One sICH (3.7%; 95% confidence interval, 0.7%-18%) was observed.

CONCLUSIONS

These results demonstrate comparable safety of full-dose r-tPA plus eptifibatide with historical rates of sICH with r-tPA alone and support proceeding with a phase 3 trial evaluating full-dose r-tPA combined with eptifibatide to improve outcomes after AIS.

Futile Interhospital Transfer for Endovascular Treatment in Acute Ischemic Stroke

Background and Purpose—

The complexity of endovascular revascularization treatment (ERT) in acute ischemic stroke and the small number of patients eligible for treatment justify the development of stroke center networks with interhospital patient transfers. However, this approach might result in futile transfers (ie, the transfer of patients who ultimately do not undergo ERT). Our aim was to analyze the frequency of these futile transfers and the reasons for discarding ERT and to identify the possible associated factors.

Methods—

We analyzed an observational prospective ERT registry from a stroke collaboration ERT network consisting of 3 hospitals. There were interhospital transfers from the first attending hospital to the on-call ERT center for the patients for whom this therapy was indicated, either primarily or after intravenous thrombolysis (drip and shift).

Results—

The ERT protocol was activated for 199 patients, 129 of whom underwent ERT (64.8%). A total of 120 (60.3%) patients required a hospital transfer, 50 of whom (41%) ultimately did not undergo ERT. There were no differences in their baseline characteristics, the times from stroke onset, or in the delays in interhospital transfers between the transferred patients who were treated and those who were not treated. The main reasons for rejecting ERT after the interhospital transfer were clinical improvement/arterial recanalization (48%) and neuroimaging criteria (32%).

Conclusions—

Forty-one percent of the ERT transfers were futile, but none of the baseline patient characteristics predicted this result. Futility could be reduced if repetition of unnecessary diagnostic tests was avoided.

Treatment of acute stroke: an update

Stroke is the second leading cause of global mortality after coronary heart disease, and a major cause of neurological disability. About 17 million strokes occur worldwide each year. Patients with stroke often require long-term rehabilitation following the acute phase, with ongoing support from the community and nursing home care. Thus, stroke is a devastating disease and a major economic burden on society. In this overview, we discuss current strategies for specific treatment of stroke in the acute phase, focusing on intravenous thrombolysis and mechanical thrombectomy. We will consider two important issues related to intravenous thrombolysis treatments: (i) how to shorten the delay between stroke onset and treatment and (ii) how to reduce the risk of symptomatic intracerebral haemorrhage. Intravenous thrombolysis has been approved treatment for acute ischaemic stroke in most countries for more than 10 years, with rapid development towards new treatment strategies during that time. Mechanical thrombectomy using a new generation of endovascular tools, stent retrievers, is found to improve functional outcome in combination with pharmacological thrombolysis when indicated. There is an urgent need to increase public awareness of how to recognize a stroke and seek immediate attention from the healthcare system, as well as shorten delays in prehospital and within-hospital settings.

Endovascular stroke therapy with the Aperio thrombectomy device

BACKGROUND

The pharmaceutical therapy for acute ischemic stroke has shortcomings in reopening large vessels and dissolving long thrombi, and endovascular treatment has been found to provide added value. The Aperio thrombectomy device showed promising results in an experimental study. The purpose of this study was to evaluate the device clinically.

METHODS

119 patients with acute stroke were treated in nine centers using the Aperio thrombectomy device. Target vessel, diameter, thrombus length, procedure time, recanalization, number of deployments, additional use of anticoagulants, complications, and the use of additional devices were assessed.

RESULTS

The median thrombus length was 15 mm (range 1.5-20 mm) and the average time from device insertion to recanalization was 30 min (range 5-120 min). Blood flow restoration (Thrombolysis In Cerebral Infarction (TICI) 2-3) was achieved in 85%. In the majority of cases complete clot removal was achieved (TICI 0, 12%; TICI 1, 2%; TICI 2a, 14%; TICI 2b, 18%; TICI 3, 53%). The median number of deployments was 2 (range 1-6). Twelve procedural complications (10%) occurred.

CONCLUSIONS

The Aperio thrombectomy device seems to be an effective and adequately safe tool for reopening occluded cerebral arteries in the setting of acute stroke.

Initial experience using the 3MAX cerebral reperfusion catheter in the endovascular treatment of acute ischemic stroke of distal arteries

Introduction

The advancement of technology has allowed the development of new catheters that may provide safe intracranial navigation.

Objective

To report our first experience with the direct aspiration first pass technique in small arteries as the primary method for recanalization with the Penumbra 3MAX cerebral reperfusion catheter.

Methods

A retrospective case series analysis study of patients with acute ischemic stroke endovascularly treated with the direct aspiration technique using the 3MAX reperfusion catheter in our hospital in the past year.

Results

We treated six patients in our hospital for acute ischemic stroke using the 3MAX aspiration catheter as first choice. The patients had a median National Institutes of Health Strokes Scale (NIHSS) score of 12 (range 10–17) at admission, with occlusions of an M2 segment of a middle cerebral artery (MCA) treated through an anterior communicating artery, pericallosal artery, P2 artery, and M2-MCA and M3-MCA arteries. Recanalization (TICI 2b–3) was achieved in all cases and no complications occurred. It was not necessary to combine treatment with a stent retriever in any of the patients. All the patients showed early neurological improvement. The median NIHSS score at discharge was 1 (0–3) and 5/6 (83%) patients had a modified Rankin Scale score 0–2 at discharge.

Conclusions

Our initial experience suggests that treatment of distal cerebrovascular occlusions with the 3MAX catheter is feasible. We achieved complete recanalization in all cases without unexpected complications while obtaining good clinical results. However, larger studies are necessary to establish its benefits and its safety.

A Mobile Stroke Treatment Unit for Field Triage of Patients for Intraarterial Revascularization Therapy

INTRODUCTION

Favorable outcomes in intraarterial therapy (IAT) for acute ischemic stroke (AIS) are related to early vessel recanalization. The mobile stroke treatment unit (MSTU) is an on-site, prehospital, treatment team, laboratory, and CT scanner that reduces time to treatment for intravenous thrombolysis and may also shorten time to IAT.

METHODS

Using our MSTU database, we identified patients that underwent IAT for AIS. We compared the key time metrics to historical controls, which included patients that underwent IAT at our institution six months prior to implementation of the MSTU. We further divided the controls into two groups: (1) transferred to our institution for IAT and (2) directly presented to our emergency room and underwent IAT.

RESULTS

After 164 days of service, the MSTU transported 155 patients of which 5 underwent IAT. We identified 5 historical controls that were transferred to our center for IAT. Substantial reduction in times including median door to initial CT (12 minute vs. 32 minute), CT to IAT (82 minute vs. 165 minute), and door to MSTU/primary stroke center departure (37 minute vs. 106 minute) were noted among the two groups. Compared to the 6 patients who presented to our institution directly, the MSTU process times were also shorter.

CONCLUSION

Our initial experience shows that MSTU may help in early triage and shorten the time to IAT for AIS.

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Recent successful endovascular stroke trials have provided unequivocal support for these therapies in selected patients with large-vessel occlusive acute ischemic stroke. In this piece, we briefly review these trials and their utilization of advanced neuroimaging techniques that played a pivotal role in their success through targeted patient selection. In this context, the unique challenges and opportunity for advancement in current stroke networks' routine delivery of care created by these trials are discussed and recommendations to change current national stroke system guidelines are proposed.

Canadian Stroke Best Practice Recommendations: Hyperacute Stroke Care Guidelines, Update 2015

The 2015 update of the Canadian Stroke Best Practice Recommendations Hyperacute Stroke Care guideline highlights key elements involved in the initial assessment, stabilization, and treatment of patients with transient ischemic attack (TIA), ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage, and acute venous sinus thrombosis. The most notable change in this 5th edition is the addition of new recommendations for the use of endovascular therapy for patients with acute ischemic stroke and proximal intracranial arterial occlusion. This includes an overview of the infrastructure and resources required for stroke centers that will provide endovascular therapy as well as regional structures needed to ensure that all patients with acute ischemic stroke that are eligible for endovascular therapy will be able to access this newly approved therapy; recommendations for hyperacute brain and enhanced vascular imaging using computed tomography angiography and computed tomography perfusion; patient selection criteria based on the five trials of endovascular therapy published in early 2015, and performance metric targets for important time-points involved in endovascular therapy, including computed tomography-to-groin puncture and computed tomography-to-reperfusion times. Other updates in this guideline include recommendations for improved time efficiencies for all aspects of hyperacute stroke care with a movement toward a new median target door-to-needle time of 30 min, with the 90th percentile being 60 min. A stronger emphasis is placed on increasing public awareness of stroke with the recent launch of the Heart and Stroke Foundation of Canada FAST signs of stroke campaign; reinforcing the public need to seek immediate medical attention by calling 911; further engagement of paramedics in the prehospital phase with prehospital notification to the receiving emergency department, as well as the stroke team, including neuroradiology; updates to the triage and same-day assessment of patients with transient ischemic attack; updates to blood pressure recommendations for the hyperacute phase of care for ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage. The goal of these recommendations and supporting materials is to improve efficiencies and minimize the absolute time lapse between stroke symptom onset and reperfusion therapy, which in turn leads to better outcomes and potentially shorter recovery times.

Improved clinical outcome 3 months after endovascular treatment, including thrombectomy, in patients with acute ischemic stroke: a meta-analysis

Background and purpose

Intravenous thrombolysis with tissue plasminogen activator is standard treatment in acute stroke today. The benefit of endovascular treatment has been questioned. Recently, studies evaluating endovascular treatment and intravenous thrombolysis compared with intravenous thrombolysis alone, have reported improved outcome for the intervention group. The aim of this study was to perform a meta-analysis of randomized controlled trials comparing endovascular treatment in addition to intravenous thrombolysis with intravenous thrombolysis alone.

Methods

Databases were searched for eligible randomized controlled trials. The primary outcome was a functional neurological outcome after 90 days. A secondary outcome was severe disability and death. Data were pooled in the control and intervention groups, and OR was calculated on an intention to treat basis with 95% CIs. Outcome heterogeneity was evaluated with Cochrane's Q test (significance level cut-off value at <0.10) and I² (significance cut-off value >50%) with the Mantel–Haenszel method for dichotomous outcomes. A p value <0.05 was regarded as statistically significant.

Results

Six studies met the eligibility criteria, and data from 1569 patients were analyzed. A higher probability of a functional neurological outcome after 90 days was found for the intervention group (OR 2, 95% CI 2 to 3). There was a significantly higher probability of death and severe disability in the control group compared with the intervention group.

Conclusions

Endovascular treatment in addition to intravenous thrombolysis for acute ischemic stroke leads to an improved clinical outcome after 3 months, compared with patients receiving intravenous thrombolysis alone.

2015 American Heart Association/American Stroke Association Focused Update of the 2013 Guidelines for the Early Management of Patients With Acute Ischemic Stroke Regarding Endovascular Treatment: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

PURPOSE

The aim of this guideline is to provide a focused update of the current recommendations for the endovascular treatment of acute ischemic stroke. When there is overlap, the recommendations made here supersede those of previous guidelines.

METHODS

This focused update analyzes results from 8 randomized, clinical trials of endovascular treatment and other relevant data published since 2013. It is not intended to be a complete literature review from the date of the previous guideline publication but rather to include pivotal new evidence that justifies changes in current recommendations. Members of the writing committee were appointed by the American Heart Association/American Stroke Association Stroke Council's Scientific Statement Oversight Committee and the American Heart Association/American Stroke Association Manuscript Oversight Committee. Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process. Recommendations follow the American Heart Association/American Stroke Association methods of classifying the level of certainty of the treatment effect and the class of evidence. Prerelease review of the draft guideline was performed by 6 expert peer reviewers and by the members of the Stroke Council Scientific Statement Oversight Committee and Stroke Council Leadership Committee.

RESULTS

Evidence-based guidelines are presented for the selection of patients with acute ischemic stroke for endovascular treatment, for the endovascular procedure, and for systems of care to facilitate endovascular treatment.

CONCLUSIONS

Certain endovascular procedures have been demonstrated to provide clinical benefit in selected patients with acute ischemic stroke. Systems of care should be organized to facilitate the delivery of this care.

Endovascular stent thrombectomy: the new standard of care for large vessel ischaemic stroke

BACKGROUND

Results of initial randomised trials of endovascular treatment for ischaemic stroke, published in 2013, were neutral but limited by the selection criteria used, early-generation devices with modest efficacy, non-consecutive enrollment, and treatment delays.

RECENT DEVELOPMENTS

In the past year, six positive trials of endovascular thrombectomy for ischaemic stroke have provided level 1 evidence for improved patient outcome compared with standard care. In most patients, thrombectomy was performed in addition to thrombolysis with intravenous alteplase, but benefits were also reported in patients ineligible for alteplase treatment. Despite differences in the details of eligibility requirements, all these trials required proof of major vessel occlusion on non-invasive imaging and most used some imaging technique to exclude patients with a large area of irreversibly injured brain tissue. The results indicate that modern thrombectomy devices achieve faster and more complete reperfusion than do older devices, leading to improved clinical outcomes compared with intravenous alteplase alone. The number needed to treat to achieve one additional patient with independent functional outcome was in the range of 3·2-7·1 and, in most patients, was in addition to the substantial efficacy of intravenous alteplase. No major safety concerns were noted, with low rates of procedural complications and no increase in symptomatic intracerebral haemorrhage. WHERE NEXT?: Thrombectomy benefits patients across a range of ages and levels of clinical severity. A planned meta-analysis of individual patient data might clarify effects in under-represented subgroups, such as those with mild initial stroke severity or elderly patients. Imaging-based selection, used in some of the recent trials to exclude patients with large areas of irreversible brain injury, probably contributed to the proportion of patients with favourable outcomes. The challenge is how best to implement imaging in clinical practice to maximise benefit for the entire population and to avoid exclusion of patients with smaller yet clinically important potential to benefit. Although favourable imaging identifies patients who might benefit despite long delays from symptom onset to treatment, the proportion of patients with favourable imaging decreases with time. Health systems therefore need to be reorganised to deliver treatment as quickly as possible to maximise benefits. On the basis of available trial data, intravenous alteplase remains the initial treatment for all eligible patients within 4·5 h of stroke symptom onset. Those patients with major vessel occlusion should, in parallel, proceed to endovascular thrombectomy immediately rather than waiting for an assessment of response to alteplase, because minimising time to reperfusion is the ultimate aim of treatment.

Endovascular Clot Retrieval Therapy

Endovascular acute ischemic stroke therapy is now proven by randomized controlled trials to produce large, clinically meaningful benefits. In response, stroke systems of care must change to increase timely and equitable access to this therapy. In this review, we provide a North American perspective on implications for stroke systems, focusing on the United States and Canada, accompanied by initial recommendations for changes. Most urgently, every community must create access to a hospital that can safely and quickly provide intravenous tissue-type plasminogen activator and immediately transfer appropriate patients onward to a more capable center as required. Safe and effective therapy in the community setting will be ensured by certification programs, performance measurement, and data entry into registries.

Evolution of Endovascular Therapy in Acute Stroke: Implications of Device Development

Intravenous thrombolysis is an effective treatment for acute ischaemic stroke. However, vascular recanalization rates remain poor especially in the setting of large artery occlusion. On the other hand, endovascular intra-arterial therapy addresses this issue with superior recanalization rates compared with intravenous thrombolysis. Although previous randomized controlled studies of intra-arterial therapy failed to demonstrate superiority, the failings may be attributed to a combination of inferior intra-arterial devices and suboptimal selection criteria. The recent results of several randomized controlled trials have demonstrated significantly improved outcomes, underpinning the advantage of newer intra-arterial devices and superior recanalization rates, leading to renewed interest in establishing intra-arterial therapy as the gold standard for acute ischaemic stroke. The aim of this review is to outline the history and development of different intra-arterial devices and future directions in research.

Endovascular Mechanical Thrombectomy for Acute Ischemic Stroke: A New Standard of Care

The treatment of acute ischemic stroke (AIS) in the setting of intracranial large artery occlusion (LAO) with intravenous tissue plasminogen activator (IV-tPA) is associated with low rates of recanalization and high rates of neurological morbidity and functional dependence. Endovascular intervention, particularly mechanical thrombectomy, is a promising therapeutic adjunct to IV-tPA for the treatment of acute LAO. However, until recently, its efficacy has been controversial. In this brief review, we analyze the criticisms of three negative randomized controlled trials (RCT) of endovascular stroke treatment and evaluate the results from seven positive endovascular stroke RCTs that have recently been presented or published. IMS III, MR RESCUE, and SYTHESIS Expansion were three RCTs that failed to show a benefit from endovascular stroke therapy. Major criticisms of these studies included a lack of routine screening for LAO, resulting in the selection of AIS patients without LAO for endovascular intervention, and a low utilization rate of modern endovascular thrombectomy devices, leading to substandard rates of successful recanalization. MR CLEAN was the first phase III RCT to show a significant clinical benefit from endovascular stroke therapy. The dissemination of its findings elicited a cascade of positive results from, to date, six additional endovascular stroke RCTs, ESCAPE, EXTEND-IA, SWIFT PRIME, REVASCAT, THERAPY, and THRACE, which were halted prematurely for efficacy. The cumulative evidence from these studies shows an overwhelming benefit from the endovascular treatment of acute LAO, therefore effectively establishing a new standard of care for the management of AIS.