Is intra-arterial thrombolysis beneficial for M2 occlusions? Subgroup analysis of the PROACT-II trial

Effect of incomplete reperfusion patterns on clinical outcome: insights from the ESCAPE-NA1 trial

BACKGROUND

Incomplete reperfusion (IR) after mechanical thrombectomy (MT) can be a consequence of residual occlusion, no-reflow phenomenon, or collateral counterpressure. Data on the impact of these phenomena on clinical outcome are limited.

METHODS

Patients from the ESCAPE-NA1 trial with IR (expanded Thrombolysis In Cerebral Infarction (eTICI) 2b) were compared with those with complete or near-complete reperfusion (eTICI 2c-3) on the final angiography run. Final runs were assessed for (a) an MT-accessible occlusion, or (b) a non-MT-accessible occlusion pattern. The primary clinical outcome was modified Rankin Scale (mRS) 0-2 at 90 days. Our imaging outcome was infarction in IR territory on follow-up imaging. Unadjusted and adjusted incidence rate ratios (aIRR) with 95% confidence intervals (95% CI) were obtained.

RESULTS

Of 1105 patients, 443 (40.1%) with IR and 506 (46.1%) with complete or near-complete reperfusion were included. An MT-accessible occlusion was identified in 147/443 patients (33.2%) and a non-MT-accessible occlusion in 296/443 (66.8%). As compared with patients with near-complete/complete reperfusion, patients with IR had significantly lower chances of achieving mRS 0-2 at 90 days (aIRR 0.82, 95% CI 0.74 to 0.91). Rates of mRS 0-2 were lower in the MT-accessible occlusion group as compared with the non-MT-accessible occlusion pattern group (aIRR 0.71, 95% CI 0.60 to 0.83, and aIRR 0.89, 95% CI 0.81 to 0.98, respectively). More patients with MT-accessible occlusion patterns developed infarcts in the non-reperfused territory as compared with patients with non-MT occlusion patterns (68.7% vs 46.3%).

CONCLUSION

IR was associated with worse clinical outcomes than near-complete/complete reperfusion. Two-thirds of our patients with IR had non-MT-accessible occlusion patterns which were associated with better clinical and imaging outcomes compared with those with MT-accessible occlusion patterns.

Intracranial thrombus composition is associated with occlusion location and endovascular treatment outcomes: results from ITACAT multicenter study

BACKGROUND

The impact of thrombolytics directed towards different thrombus components regarding site of occlusion in combination with mechanical thrombectomy (MT) to achieve endovascular complete recanalization is unclear.

METHODS

Retrospective analysis of a prospective database in two stroke centers. Intracranial thrombi retrieved by MT were analyzed using hematoxylin-eosin staining for fibrin and red blood cell proportions, and CD61 immunostaining for platelets proportion in thrombus (PLTPT) assessment. Thrombi composition, baseline variables, etiology, treatment features and occlusion location were analyzed.

RESULTS

Overall, 221 patients completed the per protocol analysis and 110 cases achieved a final expanded Thrombolysis in Cerebral Infarction (eTICI) 3 (49%) of which 70 were MT (32%) by first pass effect (FPE). Thrombi from medium distal vessel occlusions had higher PLTPT compared with thrombi from proximal large vessel occlusions (68% vs 61%, P=0.026). In particular, middle cerebral artery M2-M3 segment thrombi had the highest PLTPT (70%), and basilar artery thrombi the lowest PLTPT (41%). After logistic regression analysis adjusted for occlusion location and intravenous fibrinolysis, lower baseline National Institutes of Health Stroke Scale score (adjusted OR (aOR) 0.95, 95% CI 0.913 to 0.998) and PLTPT (aOR 0.97, 95% CI 0.963 to 0.993) were independently associated with FPE. Fewer MT passes (aOR 0.67, 95% CI 0.538 to 0.842) and platelet poor thrombus (<62% PLTPT; aOR 2.39, 95% CI 1.288 to 4.440) were independently associated with final eTICI 3.

CONCLUSIONS

Occlusion location might be a surrogate parameter for thrombus composition. Platelet poor clots and fewer MT passes were independently associated with complete endovascular recanalization. Clinical trials testing the benefits of combining selective intra-arterial platelet antagonists with MT to improve endovascular outcomes are warranted.

Endovascular therapy for acute ischemic stroke with distal medium vessel occlusion: a systematic review and meta-analysis

AIMS

Endovascular therapy (EVT) for distal medium vessel occlusions (DMVOs) is a potential frontier of acute ischemic stroke (AIS) treatment, but its efficacy against best medical therapy (BMT) remains unknown. We performed a systematic review and meta-analysis evaluating the efficacy and safety of EVT versus BMT in primary DMVO.

METHODS

We systematically searched PubMed, Cochrane Library and Embase, from inception to August 14, 2022, for studies comparing EVT with BMT in DMVO-AIS. We adopted the Distal Thrombectomy Summit Group's definition of DMVO. Efficacy outcomes were functional independence (90-day modified Rankin Scale (mRS) 0-2) and excellent functional outcomes (90-day mRS 0-1). Safety outcomes were symptomatic intracranial hemorrhage (sICH) and 90-day mortality.

RESULTS

Fourteen observational and two randomized-controlled studies were included, with 1202 patients receiving EVT and 1267 receiving BMT. After trim-and-fill correction, EVT achieved significantly better odds of functional independence than BMT (adjusted OR 1.61, 95% CI 1.06 to 2.43). There were no significant differences in overall excellent functional outcomes (OR 1.23, 95% CI 0.88 to 1.71), sICH (OR 1.44, 95% CI 0.78 to 2.66), and mortality (OR 1.03, 95% CI 0.73 to 1.45). Stratified by EVT method, mechanical thrombectomy±intra-arterial thrombolysis achieved more excellent functional outcomes than BMT (OR 1.59, 95% CI 1.13 to 2.23). In mild strokes (National Institutes of Health Stroke Scale score <6), EVT caused significantly more sICH (OR 6.30, 95% CI 1.55 to 25.64).

CONCLUSIONS

EVT shows promising efficacy benefit over BMT for primary DMVO-AIS. Further randomized controlled trials are necessary to evaluate the efficacy and safety of EVT in DMVO-AIS.

Contemporary Methods for Detection and Intervention of Distal Medium and Small Vessel Occlusions

The efficacy of using mechanical thrombectomy for proximal large vessel occlusions has been demonstrated in multiple large-scale trials and has further raised the question of its potential utility for distal medium and small vessel occlusions (DMSVOs). Their longer, more tortuous course and smaller corresponding vascular territories render a significant challenge for detection and intervention. The aim of this study is to provide a comprehensive overview of the current imaging and endovascular intervention options for DMSVOs and review the current works in the literature. Compared with traditional computed tomography angiography (CTA) and CT perfusion, recent advances such as multiphase CTA and maps derived from the time-to-maximum parameter coupled with artificial intelligence have demonstrated increased sensitivity for the detection of DMSVOs. Furthermore, newer generations of mini stent retrievers and thromboaspiration devices have allowed for the access and navigation of smaller and more fragile distal arteries. Preliminary studies have suggested that mechanical thrombectomy using this newer generation of devices is both safe and feasible in distal medium-sized vessels, such as M2. However, endovascular intervention utilizing such contemporary methods and devices must be balanced at the discretion of operator experience and favorable vascular anatomy. Further large-scale multicenter clinical trials are warranted to elucidate the indications for as well as to strengthen the safety and efficacy of this approach.

Rescue thrombolysis for medium vessel occlusion (RESCUE-TNK): Rationale and design of a phase 2 randomized trial

Background

The best reperfusion strategy for medium-sized vessel occlusion (MeVO) is not well established. Given the proven treatment effect of intra-arterial thrombolysis in patients with large vessel occlusion (LVO), we hypothesized that intra-arterial tenecteplase (TNK) could increase the recanalization rate of MeVO and thus improve clinical outcome.

Aims

To explore the safety and efficacy of intra-arterial TNK in patients with MeVO.

Sample size estimates

A maximum of 80 patients are required to test the superiority hypothesis, using power = 80% and α = 0.025 to conduct the one-sided test.

Design

Rescue treatment for mEdium veSsel oCclUsion by intra-artErial TNK (RESCUE-TNK) is a pilot, randomized, open-label, blinded end point, and multicenter trial. Eligible patients including primary MeVO as detected by the first DSA examination or secondary MeVO after endovascular treatment (EVT) for LVO will be assigned into the experimental group and control group as a ratio of 1:1. The experimental group will be treated with intra-arterial TNK (0.2–0.3 mg/min, for 20–30 min) via a microcatheter placed proximal to the site of occlusion, and the control group will be treated with routine therapy. Both groups of patients will be given standard stroke care based on the guidelines.

Outcome

The primary efficacy end point is successful recanalization of MeVO, defined as the expanded treatment in cerebral ischemia (eTICI) score 2b67-3 after the procedure, while the primary safety end point is symptomatic intracranial hemorrhage (sICH), defined as National Institutes of Health Stroke Scale score increase ≥4 caused by intracranial hemorrhage within 24 (−6/+24) hours after randomization.

Conclusion

The results of RESCUE-TNK will provide evidence for the efficacy and safety of intra-arterial TNK in the recanalization of patients with MeVO.

Endovascular treatment achieves better outcomes than best medical management in patients with M2 occlusion and high stroke severity: a meta-analysis

BACKGROUND

The lack of randomized evidence makes it difficult to establish reliable treatment recommendations for patients with M2 occlusion. This study aims to compare the efficacy and safety of endovascular treatment (EVT) with best medical management (BMM) in patients with M2 occlusion, and to investigate whether the optimal treatment varies according to stroke severity.

METHODS

Comprehensive literature retrieval was conducted to identify studies that directly compared the outcomes of EVT and BMM. According to stroke severity, the study population were classified into those with moderate-severe stroke and those with mild stroke. National Institute of Health Stroke Scale (NIHSS) scores ≥ 6 was defined as moderate-severe stroke, and NIHSS scores 0-5 as mild stroke. Random-effects meta-analyses were performed to measure the symptomatic intracranial hemorrhage (sICH) within 72 h, and the modified Rankin Scale (mRS) scores 0-2 and the mortality at 90 days.

RESULTS

Totally, 20 studies were identified, including 4358 patients. In the moderate-severe stroke population, the EVT had 82% higher odds for mRS scores 0-2 (OR 1.82, 95% CI 1.34-2.49) and a 43% lower odds for mortality (OR 0.57, 95% CI 0.39-0.82) compared with the BMM. However, no difference was found in the sICH rate (OR 0.88, 95% CI 0.44-1.77). In the mild stroke population, no differences were observed in the mRS scores 0-2 (OR 0.81, 95% CI 0.59-1.10) or mortality (OR 1.23, 95% CI 0.72-2.10) between EVT and BMM, whereas EVT was associated with higher sICH rate (OR 4.21, 95% CI 1.86-9.49).

CONCLUSION

EVT may be only beneficial for patients with M2 occlusion and high stroke severity, but not for those with NIHSS scores 0-5.

Middle Cerebral Artery M2 Thrombectomy: Safety and Technical Considerations in the German Stroke Registry (GSR)

There is ongoing debate concerning the safety and efficacy of various mechanical thrombectomy (MT) approaches for M2 occlusions. We compared these for MT in M2 versus M1 occlusions. Subgroup analyses of different technical approaches within the M2 MT cohort were also performed. Patients were included from the German Stroke Registry (GSR), a multicenter registry of consecutive MT patients. Primary outcomes were reperfusion success events. Secondary outcomes were early clinical improvement (improvement in NIHSS score > 4) and independent survival at 90 days (mRS 0−2). Out of 3804 patients, 2689 presented with M1 (71%) and 1115 with isolated M2 occlusions (29%). The mean age was 76 (CI 65−82) and 77 (CI 66−83) years, respectively. Except for baseline NIHSS (15 (CI 10−18) vs. 11 (CI 6−16), p < 0.001) and ASPECTS (9 (CI 7−10) vs. 9 (CI 8−10, p < 0.001), baseline demographics were balanced. Apart from a more frequent use of dedicated small vessel stent retrievers (svSR) in M2 (17.4% vs. 3.0; p < 0.001), intraprocedural aspects were balanced. There was no difference in ICH at 24 h (11%; p = 1.0), adverse events (14.4% vs. 18.1%; p = 0.63), clinical improvement (62.5% vs. 61.4 %; p = 0.57), mortality (26.9% vs. 22.9%; p = 0.23). In M2 MT, conventional stent retriever (cSR) achieved higher rates of mTICI3 (54.0% vs. 37.7−42.0%; p < 0.001), requiring more MT-maneuvers (7, CI 2−8) vs. 2 (CI 2−7)/(CI 2−2); p < 0.001) and without impact on efficacy and outcome. Real-life MT in M2 can be performed with equal safety and efficacy as in M1 occlusions. Different recanalization techniques including the use of svSR did not result in significant differences regarding safety, efficacy and outcome.

Diminishing returns with successive device passes in mechanical thrombectomy for stroke

BACKGROUND

Multiple device passes are associated with complications and poor functional outcomes following mechanical thrombectomy (MT) for emergent large vessel occlusion (ELVO).

OBJECTIVE

To characterize the relationship between number of device passes, complications, angiographic outcomes, and clinical outcomes in MT for ELVO.

METHODS

This is a single-center, retrospective cohort study. Individual device passes for MT were evaluated for any change in Thrombolysis in Cerebral Infarction (TICI) score, successful revascularization (TICI 2b or 3), and complications. Outcomes were compared among groups requiring multiple passes with various cut-off points. Risk factors for unfavorable clinical outcome [90 day modified Rankin Scale > 2] were assessed using multivariate analysis.

RESULTS

Successful revascularization was achieved in 75% of 163 patients and 36% required only one device pass. After the second pass, the likelihood of angiographic improvement significantly decreased (p < 0.001). Using multiple cut-off points, higher post-procedural NIHSS scores, mortality rates, and unfavorable 90-day outcomes were associated with a greater number of passes. Multivariate analysis revealed ICA thrombus (comparison: M2, OR: 25, 95% CI 2-275, p = 0.01) and failed revascularization (OR: 68, 95% CI 3.12-1489, p = 0.01) as the only significant predictors of unfavorable clinical outcome. Nonetheless, the likelihood of favorable clinical outcome was higher in patients with an ICA occlusion who were revascularized in < 2 vs. ≥ 2 (44 vs 4%, p = 0.01) or < 3 vs. ≥ 3 (32 vs. 0%, p = 0.02) passes.

CONCLUSION

The likelihood of angiographic improvement in patients with ELVO significantly decreases after the second pass. A greater number of passes is associated with worsened clinical outcomes.

Thrombolysis in Cerebral Infarction 2b Reperfusions: To Treat or to Stop?

In patients undergoing mechanical thrombectomy, achieving complete (Thrombolysis in Cerebral Infarction 3) rather than incomplete successful reperfusion (Thrombolysis in Cerebral Infarction 2b) is associated with better functional outcome. Despite technical improvements, incomplete reperfusion remains the final angiographic result in 40% of patients according to recent trials. As most incomplete reperfusions are caused by distal vessel occlusions, they are potentially amenable to rescue strategies. While observational data suggest a net benefit of up to 20% in functional independence of incomplete versus complete reperfusions, the net benefit of secondary improvement from Thrombolysis in Cerebral Infarction 2b to 3 reperfusion might differ due to lengthier procedures and delayed reperfusion. Current strategies to tackle distal vessel occlusions consist of distal (microcatheter) aspiration, small adjustable stent retrievers, and administration of intra-arterial thrombolytics. While there are promising reports evaluating those techniques, all available studies show relevant limitations in terms of selection bias, single-center design, or nonconsecutive patient inclusion. Besides an assessment of risks associated with rescue maneuvers, we advocate that the decision-making process should also include a consideration of potential outcomes if complete reperfusion would successfully be achieved. These include (1) a futile angiographic improvement (hypoperfused territory is already infarcted), (2) an unnecessary angiographic improvement (the patient would not have developed infarction if no rescue maneuver was performed), and (3) a successful rescue maneuver with clinical benefit. Currently there is paucity of data on how these scenarios can be predicted and the decision whether to treat or to stop in a patient with incomplete reperfusion involves many unknowns. To advance the status quo, we outline current knowledge gaps and avenues of potential research regarding this clinically important question.

Safety and Efficacy of Intra-arterial Urokinase After Failed, Unsuccessful, or Incomplete Mechanical Thrombectomy in Anterior Circulation Large-Vessel Occlusion Stroke

Importance

Achieving complete reperfusion is a key determinant of good outcome in patients treated with mechanical thrombectomy (MT). However, data on treatments geared toward improving reperfusion after incomplete MT are sparse.

Objective

To determine whether administration of intra-arterial urokinase is safe and improves reperfusion after failed or incomplete MT.

Design, Setting, and Participants

This observational cohort study included a consecutive sample of patients treated with second-generation MT from January 1, 2010, through August 4, 2017. Data were collected from the prospective registry of a tertiary care stroke center. Of 1274 patients screened, 69 refused to participate, and 993 met the observational studies inclusion criteria of a large vessel occlusion in the anterior circulation. Data were analyzed from September 1, 2017, through September 20, 2019.

Intervention

One hundred patients received intra-arterial urokinase after failed or incomplete MT using manual microcatheter injections.

Main Outcomes and Measures

Primary safety outcome was the occurrence of symptomatic intracranial hemorrhage (sICH) according to the Prolyse in Acute Cerebral Thromboembolism II criteria. Secondary end points included 90-day mortality and 90-day functional independence (defined as modified Rankin Scale score of ≤2). Efficacy was evaluated angiographically, applying the Thrombolysis in Cerebral Infarction (TICI) scale.

Results

After exclusion of patients with posterior circulation strokes and those treated with intra-arterial thrombolytics only, 993 patients were included in the final analyses (median age, 74.6 [interquartile range, 62.6-82.2] years; 505 [50.9%] women). Additional intra-arterial urokinase was administered in 100 patients (10.1%). The most common reason for administering intra-arterial urokinase was incomplete reperfusion (TICI<3) after MT (53 [53.0%]). After adjusting for baseline characteristics underlying case selection, intra-arterial urokinase was not associated with an increased risk of sICH (adjusted odds ratio [aOR], 0.81; 95% CI, 0.31-2.13) or 90-day mortality (aOR, 0.78; 95% CI, 0.43-1.40). Among 53 cases of partial or near-complete reperfusion and treated with intra-arterial urokinase, 32 (60.4%) had early reperfusion improvement, and 18 of 53 (34.0%) had an improvement in TICI grade. Correspondingly, patients treated with intra-arterial urokinase had higher rates of functional independence after adjusting for the selection bias favoring a priori poor TICI grades in the intra-arterial urokinase group (aOR, 1.93; 95% CI, 1.11-3.37).

Conclusions and Relevance

In selected patients, adjunctive treatment with intra-arterial urokinase during or after MT was safe and improved angiographic reperfusion. Systemic evaluation of this approach in a multicenter prospective registry or a randomized clinical trial seems warranted.

Mechanical Thrombectomy Outcome Predictors in Stroke Patients with M2 Occlusion: A Single-Center Retrospective Study

BACKGROUND

Mechanical thrombectomy (MT) has demonstrated benefit in patients with acute ischemic stroke due to proximal large-vessel occlusion. However, it is unclear whether these results can be extrapolated to patients with an occlusion of the second segment (M2) of the middle cerebral artery (MCA). We sought to study outcomes in patients with M2 occlusion treated with MT and to better understand clinical predictors of these outcomes.

METHODS

We performed a single-center retrospective analysis of consecutive patients with acute MCA M2 segment occlusion who underwent stent retriever MT. We correlated clinical and radiographic outcomes with demographic, clinical, and technical characteristics.

RESULTS

Thirty-seven patients were included in the analysis (median admission National Institutes of Health Stroke Scale [NIHSS] score, 15 [12-19], mean age 74 [67-80] years, 48.6% women). Good clinical outcome at 3 months (modified Rankin Scale ≤2) was achieved in 48.6% of patients. Baseline NIHSS was a predictor of clinical outcomes, based on modified Rankin Scale distribution at 3 months after MT (P = 0.015, odds ratio 1.63, 95% confidence interval 1.01-2.43).

CONCLUSIONS

The results of our single-institution experience suggest that MT-based endovascular therapy for M2 occlusions is safe and effective. Baseline NIHSS was a predictor of outcomes in patients treated with MT for M2 segment occlusion of the MCA.

Mechanical thrombectomy for acute ischemic stroke with occlusion of the M2 segment of the middle cerebral artery: a meta-analysis

BACKGROUND

Endovascular thrombectomy has demonstrated benefit for patients with acute ischemic stroke from proximal large vessel occlusion. However, limited evidence is available from recent randomized trials on the role of thrombectomy for M2 segment occlusions of the middle cerebral artery (MCA).

METHODS

We conducted a systematic review and meta-analysis to investigate clinical and radiographic outcomes, rates of hemorrhagic complications, and mortality after M2 occlusion thrombectomy using modern devices, and compared these outcomes against patients with M1 occlusions. Recanalization was defined as Thrombolysis in Cerebral Infarction (TICI) 2b/3 or modified TICI 2b/3.

RESULTS

A total of 12 studies with 1080 patients with M2 thrombectomy were included in our analysis. Functional independence (modified Rankin Scale 0-2) rate was 59% (95% CI 54% to 64%). Mortality and symptomatic intracranial hemorrhage rates were 16% (95% CI 11% to 23%) and 10% (95% CI 6% to 16%), respectively. Recanalization rates were 81% (95% CI 79% to 84%), and were equally comparable for stent-retriever versus aspiration (OR 1.05; 95% CI 0.91 to 1.21). Successful M2 recanalization was associated with greater rates of favorable outcome (OR 4.22; 95% CI 1.96 to 9.1) compared with poor M2 recanalization (TICI 0-2a). There was no significant difference in recanalization rates for M2 versus M1 thrombectomy (OR 1.05; 95% CI 0.77 to 1.42).

CONCLUSIONS

This meta-analysis suggests that mechanical thrombectomy for M2 occlusions that can be safely accessed is associated with high functional independence and recanalization rates, but may be associated with an increased risk of hemorrhage.

Comparison of Endovascular Treatment with Intravenous Thrombolysis for Isolated M2 Segment of Middle Cerebral Artery Occlusion in Acute Ischemic Stroke

BACKGROUND

The benefit of endovascular treatment for distal large artery ischemic occlusions such as M2 segment of middle cerebral artery is not clear.

METHODS

We retrospectively analyzed data from 51 subjects who had an isolated M2 segment occlusion on baseline computed tomographic (CT) angiogram who were randomized to either intravenous (IV) recombinant tissue plasminogen activator (rt-PA) followed by endovascular treatment or IV rt-PA alone in a multicenter trial. We determined the effect of endovascular treatment on occurrence of excellent [mRS (modified Rankin scale) scores of 0-1] functional outcomes at three months and any death within 3 and 12 months. We also performed proportional odds logistic regression analysis to compare the distribution of mRS scores between the two groups. Each of the analyses was adjusted for age, baseline Alberta stroke program early CT score strata, and baseline National Institutes of Health Stroke scale score strata.

RESULTS

At three months, the rate of excellent functional outcome (38.2% versus 17.6%, unadjusted odds ratio 2.9; 95% confidence interval ; 0.7-12.1; p = 0.15) was non-significantly higher among subjects with M2 segment occlusion who were randomized to endovascular treatment. In multivariate analysis, the odds of excellent functional outcome at three months were non-significantly higher among subjects who were randomized to endovascular treatment at three months (OR 2.7; 95% CI; 0.6-13.6; p = 0.22). There was a trend toward lower disability grades in subject randomized to endovascular treatment when distribution of the mRS score at three months were compared (common OR 2.6; p = 0.084), adjusting for potential confounders. The rates of any death within 3 (adjusted OR 0.1; 95% CI; 0.1-0.8; p = 0.031) and within 12 months (adjusted OR 0.1; 95% CI; 0.1-0.7; p = 0.022) were significantly lower among those who were randomized to endovascular treatment.

CONCLUSION

In this post-hoc analysis, acute ischemic stroke subjects who had isolated M2 segment occlusion randomized to endovascular treatment appeared to have lower mortality and a trend toward lower grades of disability.

Endovascular Mechanical Thrombectomy for Acute Middle Cerebral Artery M2 Segment Occlusion: A Systematic Review

INTRODUCTION

The benefit of endovascular mechanical thrombectomy (EMT) for acute distal occlusions of the middle cerebral artery M2 segment is incompletely defined. The aim of this systematic review is to analyze the recent literature regarding EMT for acute M2 occlusions.

METHODS

We reviewed the literature to identify all studies of patients with acute M2 occlusions who underwent EMT that were published after January 1, 2015. Excellent and good outcomes were defined as modified Rankin Scale score of 0-1 and 0-2, respectively, at 3 months. Successful reperfusion was defined as modified Thrombolysis In Cerebral Infarction (mTICI) score of 2b-3.

RESULTS

Eight studies, comprising 630 EMT-treated patients with acute M2 occlusions, were included in the analysis. The median National Institute of Health Stroke Scale score ranged from 10 to 16, and the median Alberta Stroke Program Computed Tomography Score ranged from 9 to 10. Excellent and good outcomes at 3-month follow-up were observed in 40% and 62%, respectively, of patients with acute M2 occlusion who underwent EMT, with a mortality of 11%. Successful reperfusion was achieved in 78% of cases. Postprocedural intracerebral hemorrhage (ICH) occurred in 14% of patients, including a symptomatic ICH rate of 5%.

CONCLUSIONS

EMT for acute M2 occlusion affords functional independence to most patients, with a modest rate of symptomatic ICH. However, compared with the natural history of distal MCA occlusions, the benefit of M2 thrombectomy using stent retriever or direct aspiration techniques remains unclear.

Alberta Stroke Program Early CT Score Infarct Location Predicts Outcome Following M2 Occlusion

Background

Although it is generally thought that patients with distal middle cerebral artery (M2) occlusion have a favorable outcome, it has previously been demonstrated that a substantial minority will have a poor outcome by 90 days. We sought to determine whether assessing the Alberta Stroke Program Early CT Score (ASPECTS) infarct location allows for identifying patients at risk for a poor 90-day outcome.

Methods

We retrospectively analyzed patients with isolated acute M2 occlusion admitted to a single academic center between January 2010 and August 2012. Infarct regions were defined according to ASPECTS system on the initial head computed tomography. Discriminant function analysis was used to define specific ASPECTS regions that are predictive of the 90-day functional outcome as defined as a modified Rankin Scale score of 3–6. In addition, logistic regression was used to model the relationship between each individual ASPECT region with poor outcome; for evaluation and comparison, odds ratios, c-statistics, and Akaike information criterion values were estimated for each region.

Results

Ninety patients with isolated M2 were included in the final analysis. ASPECTS score ≤6 predicted poor outcome in this cohort (sensitivity = 0.591, specificity = 0.838, p < 0.001). Using multiple approaches, we found that infarction in ASPECTS regions M3 and M6 were strongly associated with poor functional status by 90 days.

Conclusion

Infarction in ASPECTS regions M3 and M6 are key predictors of functional outcome following isolated distal M2 occlusion. These findings will be helpful in stratifying outcomes if validated in future studies.

Mechanical Thrombectomy for M2 Occlusions: A Single-Centre Experience

Background

The recent success of several mechanical thrombectomy trials has resulted in a significant change in the management of patients presenting with stroke. However, questions still remain as to whether certain groups will benefit from mechanical thrombectomy. In particular, it is still uncertain whether mechanical thrombectomy should be performed in the M2 branches and, more generally, in the distal vasculature.

Methods

We retrospectively analysed our prospectively maintained database of all patients undergoing mechanical thrombectomy between January 2008 and August 2016. We collected demographic, radiological, procedural and outcome data.

Results

We identified 106 patients that met our inclusion criteria. The mean age of the patients was 68 ± 13.8 years, and there were 58 (54.7%) male patients. Associated medical conditions were common with hypertension seen in 71% of the patients. The average Alberta Stroke Program Early CT (ASPECT) score on admission was 8.5 ± 1.7. The mean National Institutes of Health Stroke Scale score was 11.8 ± 7.02. The mean duration of the procedure was 103 ± 3.4 min, and the average number of thrombectomy attempts required was 1.8 (range 1-8). Angiographically, Thrombolysis in Cerebral Infarction Scale (TICI) ≥2b was obtained in 90.5% of the patients. Five patients (4.7%) had symptomatic intracranial haemorrhage on follow-up. At 90-day follow-up, 54.6% of the patients had a modified Rankin Scale (mRS) score 0-2, and 71.5% had an mRS score ≤3. There were 15 deaths at 90 days (14.1%).

Conclusion

Mechanical thrombectomy in patients with solitary M2 clots is technically possible and carries a high degree of success with a good safety profile. Patients with confirmed M2 occlusion should be considered for mechanical thrombectomy.

Endovascular Therapy of M2 Occlusion in IMS III: Role of M2 Segment Definition and Location on Clinical and Revascularization Outcomes

BACKGROUND AND PURPOSE

Uncertainty persists regarding the safety and efficacy of endovascular therapy of M2 occlusions following IV tPA. We reviewed the impact of revascularization on clinical outcomes in 83 patients with M2 occlusions in the Interventional Management of Stroke III trial according to specific M1-M2 segment anatomic features.

MATERIALS AND METHODS

Perfusion of any M2 branch distinguished M2-versus-M1 occlusion. Prespecified modified TICI and arterial occlusive lesion revascularization and clinical mRS 0-2 end points at 90 days for endovascular therapy-treated M2 occlusions were analyzed. Post hoc analyses of the relationship of outcomes to multiple baseline angiographic M2 and M1 subgroup characteristics were performed.

RESULTS

Of 83 participants with M2 occlusion who underwent endovascular therapy, 41.0% achieved mRS 0-2 at 90 days, including 46.6% with modified TICI 2-3 reperfusion compared with 26.1% with modified TICI 0-1 reperfusion (risk difference, 20.6%; 95% CI, -1.4%-42.5%). mRS 0-2 outcome was associated with reperfusion for M2 trunk (n = 9) or M2 division (n = 42) occlusions, but not for M2 branch occlusions (n = 28). Of participants with trunk and division occlusions, 63.2% with modified TICI 2a and 42.9% with modified TICI 2b reperfusion achieved mRS 0-2 outcomes; mRS 0-2 outcomes for M2 trunk occlusions (33%) did not differ from distal (38.2%) and proximal (26.9%) M1 occlusions.

CONCLUSIONS

mRS 0-2 at 90 days was dependent on reperfusion for M2 trunk but not for M2 branch occlusions. For M2 division occlusions, good outcome with modified TICI 2b reperfusion did not differ from that in modified TICI 2a. M2 segment definition and occlusion location may contribute to differences in revascularization and good outcome between Interventional Management of Stroke III and other endovascular therapy studies.

Manual Aspiration Thrombectomy Using Penumbra Catheter in Patients with Acute M2 Occlusion : A Single-Center Analysis

OBJECTIVE

The efficacy and safety of manual aspiration thrombectomy using Penumbra in an acute occlusion of large intracranial arteries has been proven in many previous studies. Our study aimed to retrospectively assess the efficacy and safety of manual aspiration thrombectomy using Penumbra in patients with small vessel occlusions (M2 segment of the MCA).

METHODS

We conducted a retrospective review of 32 patients who underwent manual aspiration thrombectomy using the Penumbra 4 MAX Reperfusion Catheter for treatment of an M2 occlusion between January 2013 and November 2014. We evaluated immediate angiographic results and clinical outcomes through review of patient electronic medical records.

RESULTS

There were slightly more men in this study (M : F=18 : 14) and the median age was 72.5 (age range : 41-90). The rate of successful recanalization (TICI grade ≥2b) was 84% (27/32). NIHSS at discharge and favorable clinical outcomes at 3 months were significantly improved than baseline. Median initial NIHSS score was 10 (range : 4-25) and was 4 (range : 0-14) at discharge. Favorable clinical outcomes (mRS score ≤2 at 3 months) were seen in 25 out of 32 patients (78%). There were no procedure-related symptomatic intracerebral hemorrhages. One patient expired after discharge due to a cardiac problem.

CONCLUSION

Manual aspiration thrombectomy might be safe and is capable of achieving a high rate of successful recanalization and favorable clinical outcomes in patients with distal cerebral vessel occlusion (M2).

Effect of endovascular reperfusion in relation to site of arterial occlusion

OBJECTIVE

To assess whether the association between reperfusion and improved clinical outcomes after stroke differs depending on the site of the arterial occlusive lesion (AOL).

METHODS

We pooled data from Solitaire With the Intention for Thrombectomy (SWIFT), Solitaire FR Thrombectomy for Acute Revascularisation (STAR), Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution Study 2 (DEFUSE 2), and Interventional Management of Stroke Trial (IMS III) to compare the strength of the associations between reperfusion and clinical outcomes in patients with internal carotid artery (ICA), proximal middle cerebral artery (MCA) (M1), and distal MCA (M2/3/4) occlusions.

RESULTS

Among 710 included patients, the site of the AOL was the ICA in 161, the proximal MCA in 389, and the distal MCA in 160 patients (M2 = 131, M3 = 23, and M4 = 6). Reperfusion was associated with an increase in the rate of good functional outcome (modified Rankin Scale [mRS] score 0-2) in patients with ICA (odds ratio [OR] 3.5, 95% confidence interval [CI] 1.7-7.2) and proximal MCA occlusions (OR 6.2, 95% CI 3.8-10.2), but not in patients with distal MCA occlusions (OR 1.4, 95% CI 0.8-2.6). Among patients with M2 occlusions, a subset of the distal MCA cohort, reperfusion was associated with excellent functional outcome (mRS 0-1; OR 2.2, 95% CI 1.0-4.7).

CONCLUSIONS

The association between endovascular reperfusion and better clinical outcomes is more profound in patients with ICA and proximal MCA occlusions compared to patients with distal MCA occlusions. Because there are limited data from randomized controlled trials on the effect of endovascular therapy in patients with distal MCA occlusions, these results underscore the need for inclusion of this subgroup in future endovascular therapy trials.

Direct Microsurgical Embolectomy for Acute Occlusion of the Internal Carotid Artery and Middle Cerebral Artery

BACKGROUND

Surgical embolectomy is the most promising therapy for physically removing emboli from major cerebral arteries. However, it requires an experienced surgical team, time-consuming steps, and is not incorporated into acute stroke therapy.

METHODS

We established seamless collaboration between services, refined surgical techniques, and conducted a prospective trial of emergency surgical embolectomy. Surgical indications included the presence of acute hemispheric symptoms, absence of low-density area on computed tomography, evidence of internal carotid artery terminus or proximal middle cerebral artery occlusion, and availability of resources to start surgery within 3 hours of symptom onset. The indications were confirmed by an interdisciplinary team. We assessed revascularization rates, time from admission to surgery and from surgery to recanalization, procedural complications, and clinical outcomes.

RESULTS

Between 2005 and 2014, 14 consecutive patients with acute proximal middle cerebral artery or internal carotid artery terminus occlusion underwent emergency surgical embolectomy. All patients showed complete recanalization. Twelve patients survived and 7 had fair functional outcome (Rankin Scale score, ≤3). No significant procedural adverse events occurred. The mean times from admission to start of surgery, from surgery to recanalization, and from onset to recanalization were 14 minutes, 79 minutes, and 223 minutes, respectively.

CONCLUSIONS

Our results suggest that microsurgical embolectomy can rapidly, safely, and effectively retrieve clots and deserves reappraisal, although the choice largely depends on local institutional expertise.

To Treat or Not to Treat M2 Occlusions? The Question (and Answer) From a Single Institution

BACKGROUND:

Occlusions of the M2 segment of the middle cerebral artery may cause significant clinical effects, especially when occurring in the dominant cerebral hemisphere, yet endovascular treatment of these lesions remains controversial.

OBJECTIVE:

To examine the safety and efficacy of endovascular treatment of M2 occlusions at our institution.

METHODS:

We retrospectively examined radiographic and clinical data of 53 patients presenting with M2 occlusions to our institution.

RESULTS:

Successful recanalization (Thrombolysis in Cerebral Infarction grade 2b or 3) was achieved in 40 patients (76.9%). No symptomatic intracranial hemorrhage occurred. The mean National Institutes of Health Stroke Scale score at discharge was 6.4 (median, 5.5). In the 38 patients who had follow-up after discharge, the mean follow-up duration was 11.1 months (range, 0.5-36.5 months) and mean National Institutes of Health Stroke Scale score was 3.5 (median, 1).

CONCLUSION:

The results of our single-institution experience suggest that endovascular therapy for M2 occlusions is safe and effective. Additional evaluation with randomized, controlled studies is warranted.

Emergent mechanical thrombectomy for acute stroke using the Mindframe Capture LP system: initial single-center experience

Background

Mechanical thrombectomy using stentrievers is the standard of care for emergent large vessel occlusion stroke. Data on the use of stentrievers in smaller caliber vessels are sparse.

Objective

To present our initial experience with the Mindframe Capture LP device, which was designed for mechanical thrombectomy in small cerebral arteries.

Methods

A retrospective chart review was conducted of patients who underwent Mindframe device assisted emergent thrombectomy. Clinical, imaging, procedural and early follow-up data were obtained.

Results

Nine patients met inclusion criteria (5 men, median age 62 years). Median National Institute of Health Stroke Scale (NIHSS) score was 18 (IQR 9–22), and 6 patients received intravenous tissue plasminogen activator. Six patients had M2 segment occlusions, and 2 patients had distal M1 segment occlusions of the middle cerebral artery. One had distal basilar artery occlusion. Median vessel diameter at the thrombus was 1.7 mm (IQR 1.5–2.5). In all 9 patients the Mindframe device was used together with manual aspiration, with median groin puncture to recanalization time of 35 min (IQR 27–54), and median procedural time of 67 min (IQR 51–91). Final Thrombolysis in Cerebral Infarction score was 3 and 2b in 4 patients each (89% total), and 2a in 1 patient. No patient had any postprocedural complications or symptomatic intracerebral hemorrhage. Median postprocedure and discharge NIHSS were 4 and 1, respectively.

Conclusions

Our data suggest that the Mindframe device is safe and effective for rapid treatment of acute strokes involving small caliber intracranial vessels. Further study in a larger cohort is warranted.

Large-Vessel Occlusion Stroke: Effect of Recanalization on Outcome Depends on the National Institutes of Health Stroke Scale Score

BACKGROUND

Arterial recanalization is currently considered the main standard of successful early management of acute ischemic stroke. Intravenous (IV) thrombolysis with tissue plasminogen activator (tPa) is the only Food and Drug Administration-approved medical treatment. Large-vessel occlusion, estimated to account for up to 40% of all acute ischemic strokes, is often refractory to IV thrombolysis and is associated with a poor patient outcome. Mechanical recanalization procedures are therefore increasingly used in the treatment of large-vessel occlusion refractory to, or presenting outside the accepted time window for, IV thrombolysis. The aim of this study was to investigate the effect of early vessel recanalization on clinical outcome in patients with large-vessel occlusion stroke.

METHODS

This is a single-center cohort study, analyzing prospectively collected data on 152 patients with large-vessel occlusion and acute ischemic stroke. Seventy-one patients received endovascular treatment (of whom 57.7% also received IV tPA), and 81 (55.6% of whom also received IV tPa) were not treated with endovascular therapy. Clinical outcome was compared for 2 cohorts: patients who recanalized (n = 46) and patients with persisting large-vessel occlusion (n = 106).

RESULTS

Early recanalization was an independent predictor of a good clinical outcome in only those patients who presented with a severe ischemic stroke (National Institutes of Health Stroke Scale [NIHSS] score >15; P = .017). This was not the case for less severe strokes (NIHSS score ≤ 15) where recanalization did not lead to more patients with functional independence at 90-day follow-up (P = .21).

CONCLUSIONS

In this study of acute large-vessel occlusion stroke, we found that clinical outcome following early recanalization was dependent on the patient's pretreatment NIHSS score. A non-negligible proportion of patients with milder strokes did well despite persistent large-vessel occlusion. These results may suggest that in patients who are able to maintain adequate collateral flow despite proximal arterial occlusion, effective adaptive mechanisms are present, which for some patients are long-lasting. This may influence the process of appropriate patient selection for endovascular therapy.

Endovascular treatment for M2 occlusions in the era of stentrievers: a descriptive multicenter experience

BACKGROUND

Patients with M2 middle cerebral artery (MCA) occlusions are not always considered for endovascular treatment.

OBJECTIVE

To study outcomes in patients with M2 occlusion treated with endovascular procedures in the era of stentrievers.

METHODS

We studied patients prospectively included in the SONIIA registry (years 2011-2012)-a mandatory, externally audited registry that monitors the quality of reperfusion therapies in Catalonia in routine practice. Good recanalization was defined as postprocedure Thrombolysis in Cerebral Infarction (TICI) score 2b-3; dramatic recovery as drop in National Institutes of Health Stroke Scale (NIHSS) score >10 points or NIHSS score <2 at 24-36 h; and good outcome as modified Rankin score (mRS) 0-2 at 3months. A 24 h CT scan determined symptomatic intracranial hemorrhage (SICH) and infarct volume.

RESULTS

Of 571 patients who received endovascular treatment, 65 (11.4%) presented an M2 occlusion on initial angiogram, preprocedure NIHSS 16 (IQR 6). Mean time from symptom onset to groin puncture was 289 ± 195 min. According to interventionalist preferences 86.2% (n=56) were treated with stentrievers (n=7 in combination with intra-arterial tissue plasminogen activator (tPA), 4.6% (n=3) received intra-arterial tPA only, and 9.2% (n=6) diagnostic angiography only. Good recanalization (78.5%) was associated with dramatic improvement (48% vs 14.8%; p=0.02), smaller infarct volumes (8 vs 82 cc; p=0.01) and better outcome (mRS 0-2: 66.3% vs 30%; p=0.03). SICH (9%) was not associated with treatment modality or device used. After adjusting for age and preprocedure NIHSS, good recanalization emerged as an independent predictor of dramatic improvement (OR=5.9 (95% CI 1.2 to 29.2), p=0.03). Independent predictors of good outcome at 3 months were age ( OR=1.067 (95% CI 1.005 to 1132), p=0.03) and baseline NIHSS ( OR=1.162 (95% CI 1.041 to 1.297), p<0.01).

CONCLUSIONS

Endovascular treatment of M2 MCA occlusion with stentrievers seems safe. Induced recanalization may double the chances of achieving a favorable outcome, especially for patients with moderate or severe deficit.

Early reperfusion and clinical outcomes in patients with M2 occlusion: pooled analysis of the PROACT II, IMS, and IMS II studies

OBJECT

The role of endovascular therapy in patients with acute ischemic stroke and a solitary M2 occlusion remains unclear. Through a pooled analysis of 3 interventional stroke trials, the authors sought to analyze the impact of successful early reperfusion of M2 occlusions on patient outcome.

METHODS

Patients with a solitary M2 occlusion were identified from the Prolyse in Acute Cerebral Thromboembolism (PROACT) II, Interventional Management of Stroke (IMS), and IMS II trial databases and were divided into 2 groups: successful reperfusion (thrombolysis in cerebral infarction [TICI] 2-3) at 2 hours and failed reperfusion (TICI 0-1) at 2 hours. Baseline characteristics and clinical outcomes were compared.

RESULTS

Sixty-three patients, 40 from PROACT II and 23 from IMS and IMS II, were identified. Successful early angiographic reperfusion (TICI 2-3) was observed in 31 patients (49.2%). No statistically significant difference in the rates of intracerebral hemorrhage (60.9% vs 47.6%, p = 0.55) or mortality (19.4% vs 15.6%, p = 0.75) was observed. However, there was a trend toward higher incidence of symptomatic hemorrhage in the TICI 2-3 group (17.4% vs 0%, p = 0.11). There was also a trend toward higher baseline glucose levels in this group (151.5 mg/dl vs 129.6 mg/ dl, p = 0.09). Despite these differences, the rate of functional independence (modified Rankin Scale Score 0-2) at 3 months was similar (TICI 2-3, 58.1% vs TICI 0-1, 53.1%; p = 0.80).

CONCLUSIONS

A positive correlation between successful early reperfusion and clinical outcome could not be demonstrated for patients with M2 occlusion. Irrespective of reperfusion status, such patients have better outcomes than those with more proximal occlusions, with more than 50% achieving functional independence at 3 months.

Thrombolysis for acute ischaemic stroke

BACKGROUND

Most strokes are due to blockage of an artery in the brain by a blood clot. Prompt treatment with thrombolytic drugs can restore blood flow before major brain damage has occurred and improve recovery after stroke in some people. Thrombolytic drugs, however, can also cause serious bleeding in the brain, which can be fatal. One drug, recombinant tissue plasminogen activator (rt-PA), is licensed for use in selected patients within 4.5 hours of stroke in Europe and within three hours in the USA. There is an upper age limit of 80 years in some countries, and a limitation to mainly non-severe stroke in others. Forty per cent more data are available since this review was last updated in 2009.

OBJECTIVES

To determine whether, and in what circumstances, thrombolytic therapy might be an effective and safe treatment for acute ischaemic stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched November 2013), MEDLINE (1966 to November 2013) and EMBASE (1980 to November 2013). We also handsearched conference proceedings and journals, searched reference lists and contacted pharmaceutical companies and trialists.

SELECTION CRITERIA

Randomised trials of any thrombolytic agent compared with control in people with definite ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two review authors applied the inclusion criteria, extracted data and assessed trial quality. We verified the extracted data with investigators of all major trials, obtaining additional unpublished data if available.

MAIN RESULTS

We included 27 trials, involving 10,187 participants, testing urokinase, streptokinase, rt-PA, recombinant pro-urokinase or desmoteplase. Four trials used intra-arterial administration, while the rest used the intravenous route. Most data come from trials that started treatment up to six hours after stroke. About 44% of the trials (about 70% of the participants) were testing intravenous rt-PA. In earlier studies very few of the participants (0.5%) were aged over 80 years; in this update, 16% of participants are over 80 years of age due to the inclusion of IST-3 (53% of participants in this trial were aged over 80 years). Trials published more recently utilised computerised randomisation, so there are less likely to be baseline imbalances than in previous versions of the review. More than 50% of trials fulfilled criteria for high-grade concealment; there were few losses to follow-up for the main outcomes.Thrombolytic therapy, mostly administered up to six hours after ischaemic stroke, significantly reduced the proportion of participants who were dead or dependent (modified Rankin 3 to 6) at three to six months after stroke (odds ratio (OR) 0.85, 95% confidence interval (CI) 0.78 to 0.93). Thrombolytic therapy increased the risk of symptomatic intracranial haemorrhage (OR 3.75, 95% CI 3.11 to 4.51), early death (OR 1.69, 95% CI 1.44 to 1.98; 13 trials, 7458 participants) and death by three to six months after stroke (OR 1.18, 95% CI 1.06 to 1.30). Early death after thrombolysis was mostly attributable to intracranial haemorrhage. Treatment within three hours of stroke was more effective in reducing death or dependency (OR 0.66, 95% CI 0.56 to 0.79) without any increase in death (OR 0.99, 95% CI 0.82 to 1.21; 11 trials, 2187 participants). There was heterogeneity between the trials. Contemporaneous antithrombotic drugs increased the risk of death. Trials testing rt-PA showed a significant reduction in death or dependency with treatment up to six hours (OR 0.84, 95% CI 0.77 to 0.93, P = 0.0006; 8 trials, 6729 participants) with significant heterogeneity; treatment within three hours was more beneficial (OR 0.65, 95% CI 0.54 to 0.80, P < 0.0001; 6 trials, 1779 participants) without heterogeneity. Participants aged over 80 years benefited equally to those aged under 80 years, particularly if treated within three hours of stroke.

AUTHORS' CONCLUSIONS

Thrombolytic therapy given up to six hours after stroke reduces the proportion of dead or dependent people. Those treated within the first three hours derive substantially more benefit than with later treatment. This overall benefit was apparent despite an increase in symptomatic intracranial haemorrhage, deaths at seven to 10 days, and deaths at final follow-up (except for trials testing rt-PA, which had no effect on death at final follow-up). Further trials are needed to identify the latest time window, whether people with mild stroke benefit from thrombolysis, to find ways of reducing symptomatic intracranial haemorrhage and deaths, and to identify the environment in which thrombolysis may best be given in routine practice.

M2 occlusions as targets for endovascular therapy: comprehensive analysis of diffusion/perfusion MRI, angiography, and clinical outcomes

BACKGROUND

The ideal population of patients for endovascular therapy (ET) in acute ischemic stroke remains undefined. Recent ET trials have moved towards selecting patients with proximal middle cerebral artery (MCA) or internal carotid artery occlusions, which will likely leave a gap in our understanding of the treatment outcomes of M2 occlusions.

OBJECTIVE AND METHODS

To examine the presentation, treatment, and outcomes of M2 compared with M1 MCA occlusions in patients undergoing ET by assessing comprehensive MRI, angiography, and clinical data.

RESULTS

We found that M2 occlusions can lead to massive strokes defined by hypoperfused and infarcted volumes as well as death or moderate to severe disability in nearly 50% of patients at discharge. Compared with M1 occlusions, M2 occlusions achieved similar Thrombolysis in Cerebral Infarction (TICI) 2b/3 recanalization rates, with significantly less hemorrhage. M2 occlusions presented with smaller infarct and hypoperfused volumes and had smaller final infarct volumes regardless of recanalization. TICI 2b/3 recanalization of M2 occlusions was associated with smaller infarct volumes compared with TICI 0-2a recanalization, as well as less infarct expansion, in patients who received IV tissue plasminogen activator as well as those that did not. Successful reperfusion of M2 occlusions was associated with improved discharge modified Rankin scale.

CONCLUSIONS

If suitable as targets of ET, M2 occlusions should be given the same consideration as M1 occlusions.

Predictors of Outcome following Stroke due to Isolated M2 Occlusions

Background

Factors influencing outcome after cerebral artery occlusion are not completely understood. Although it is well accepted that the site of arterial occlusion critically influences outcome, the majority of studies investigating this issue has focused on proximal large artery occlusion. To gain a better understanding of factors influencing outcome after distal large artery occlusion, we sought to assess predictors of outcome following isolated M2 middle cerebral artery occlusion infarcts.

Methods

We retrospectively analyzed patients with isolated acute M2 occlusion admitted to a single academic center from January 2010 to August 2012. Baseline clinical, laboratory imaging, and outcome data were assessed from a prospectively collected database. Factors associated with a modified Rankin Scale (mRS) score ≤2 in univariable analyses (p < 0.05) were entered into multivariable logistic regression analysis. The Admission National Institutes of Health Stroke Scale (aNIHSS) score, age, and infarct volume were also entered as dichotomized variables. Receiver operating characteristic curves were plotted to determine the optimal aNIHSS score, infarct volume, and age cut points predicting an mRS score ≤2. Optimal thresholds were determined by maximizing the Youden index. Respective multivariable logistic regression analyses were used to identify independent predictors of a good 90-day outcome (mRS score ≤2; primary analysis) as well as 90-day mortality (secondary outcome).

Results

90 patients with isolated M2 occlusion were included in the final analyses. Of these, 69% had a good 90-day outcome which was associated with age <80 years (p = 0.007), aNIHSS <10 (p = 0.002), and infarct volume ≤26 ml (p < 0.001). Notably, 20% of patients (64% of those with a poor outcome) had died by 90 days. Secondary analysis for 90-day mortality was performed. This analysis indicated that infarct volume >28 ml (OR 11.874, 95% CI 2.630-53.604, p = 0.001), age >80 years (OR 4.953, 95% CI 1.087-22.563, p = 0.039), need for intubation (OR 7.788, 95% CI 1.072-56.604), and history of congestive heart failure (OR 5.819, 95% CI 1.140-29.695) were independent predictors of 90-day mortality (20% of all included patients).

Conclusion

While the majority of patients with isolated M2 occlusion stroke has a good 90-day outcome, a substantial proportion of subjects dies by 90 days, as identified by a unique subset of predictors. The knowledge gained from our study may lead to an improvement in the prognostic accuracy, clinical management, and resource utilization in this patient population.

Prehospital stroke diagnostics based on neurological examination and transcranial ultrasound

BACKGROUND

Transcranial color-coded sonography (TCCS) has proved to be a fast and reliable tool for the detection of middle cerebral artery (MCA) occlusions in a hospital setting. In this feasibility study on prehospital sonography, our aim was to investigate the accuracy of TCCS for neurovascular emergency diagnostics when performed in a prehospital setting using mobile ultrasound equipment as part of a neurological examination.

METHODS

Following a '911 stroke code' call, stroke neurologists experienced in TCCS rendezvoused with the paramedic team. In patients with suspected stroke, TCCS examination including ultrasound contrast agents was performed. Results were compared with neurovascular imaging (CTA, MRA) and the final discharge diagnosis from standard patient-centered stroke care.

RESULTS

We enrolled '232 stroke code' patients with follow-up data available in 102 patients with complete TCCS examination. A diagnosis of ischemic stroke was made in 73 cases; 29 patients were identified as 'stroke mimics'. MCA occlusion was diagnosed in ten patients, while internal carotid artery (ICA) occlusion/high-grade stenosis leading to reversal of anterior cerebral artery flow was diagnosed in four patients. The initial working diagnosis 'any stroke' showed a sensitivity of 94% and a specificity of 48%. 'Major MCA or ICA stroke' diagnosed by mobile ultrasound showed an overall sensitivity of 78% and specificity of 98%.

CONCLUSIONS

The study demonstrates the feasibility and high diagnostic accuracy of emergency transcranial ultrasound assessment combined with neurological examinations for major ischemic stroke. Future combination with telemedical support, point-of-care analysis of blood serum markers, and probability algorithms of prehospital stroke diagnosis including ultrasound may help to speed up stroke treatment.

Patients with single distal MCA perfusion lesions have a high rate of good outcome with or without reperfusion

BACKGROUND

Reperfusion is associated with good functional outcome after stroke. However, minimal data are available regarding the effect of reperfusion on clinical outcome and infarct growth in patients with distal MCA branch occlusions.

AIM

The aim of this study was to evaluate this association and to determine the impact of the perfusion-diffusion mismatch.

METHODS

Individual patient data from three stroke studies (EPITHET, DEFUSE and DEFUSE 2) with baseline MRI profiles and reperfusion status were pooled. Patients were included if they had a single cortical perfusion lesion on their baseline MRI that was consistent with a distal MCA branch occlusion. Good functional outcome was defined as a score of 0-2 on the modified Rankin Scale at day 90 and infarct growth was defined as change in lesion volume between the baseline DWI and the final T2/FLAIR.

RESULTS

Thirty patients met inclusion criteria. Eighteen (60%) had a good functional outcome and twenty (67%) had reperfusion. Reperfusion was not associated with good functional outcome in the overall cohort (OR: 1·0, 95% CI 0·2-4·7) and also not in the subset of patients with a PWI-DWI mismatch (n = 17; OR: 0·7, 95% CI 0·1-5·5). Median infarct growth was modest and not significantly different between patients with (0 ml) and without reperfusion (6 ml); P = 0·2.

CONCLUSIONS

The overall high rate of good outcomes in patients with distal MCA perfusion lesions might obscure a potential benefit from reperfusion in this population. A larger pooled analysis evaluating the effect of reperfusion in patients with distal MCA branch occlusions is warranted as confirmation of our results could have implications for the design of future stroke trials.

Endovascular therapy in hyperacute ischaemic stroke: history and current status

This is a literature review on to the use of endovascular therapy in hyperacute ischaemic stroke secondary to large vessel occlusion (LVO). The prognosis for LVO is generally poor and the efficacy of intravenous tissue plasminogen activator (IV TPA) in the treatment of this subtype of stroke is questionable. It is well documented that recanalisation is associated with improved outcomes but IV TPA has limited efficacy in LVO recanalisation and the complication rates are higher for IV TPA in this stroke subset. Improved recanalisation rates have been demonstrated with intra-arterial TPA and first and second generation mechanical techniques but the rate of favourable outcome has not overtly mirrored this improvement. Several controversial trials using these early techniques have recently been published but fail to reflect modern practice which centres on the use of stent-retriever technology. This has been proven to be superior to older techniques. Not only are recanalisation rates higher, but the speed of recanalisation is greater and clinical results are improved. Multiple observational studies demonstrate consistently high rates of LVO recanalisation; TICI 2b/3 in the order of 65-95% and, rates of favourable outcome (mRS 0-2) in the order of 55% (42.5-77%) in clinically moderate to severe stroke with complicating symptomatic haemorrhage in the order of 1.5-15%. A major factor determining outcome is time to treatment but success has been demonstrated using these devices with bridging therapy, after IV TPA failure or as a stand-alone treatment.

Thrombectomy in patients with large cerebral artery occlusion: a single-center experience with a new stent retriever

INTRODUCTION

The Trevo device, a new stent retriever, may be utilized in patients with large cerebral artery occlusion.

METHODS

Fifty patients with large cerebral artery occlusion and treated with the Trevo device were analyzed. Patients may have received intravenous thrombolysis as a bridging concept in addition to thrombectomy. Outcome and recanalization parameters were documented using the National Institutes of Health Scale, the modified Ranking Scale (mRS) and Thrombolysis in Cerebral Infarction (TICI) score.

RESULTS

In all, 82% (95% confidence interval [CI]: 69%-91%) were documented with TICI 2b and 3. Good clinical outcome after 90 days (mRS ≤ 2) was assessed in 61% (95% CI: 46%-75%). Symptomatic intracerebral hemorrhage occurred in 6 patients (12%, 95% CI: 1%-17%). The overall mortality rate was 14% (95% CI: 6%-27%).

CONCLUSION

Thrombectomy with the new stent retriever device is feasible and effective and has an acceptable risk of intra-cerebral hemorrhage even in combination with pharmacological revascularization techniques.