Thrombectomy in M2 occlusion compared to M1 occlusion: treatment effects of Thrombolysis In Cerebral Infarction (TICI) 2b and TICI 3 recanalization on functional outcome

BACKGROUND

Emerging data suggest that mechanical thrombectomy (MT) might also be safe and efficient for medium and distal occlusions. This study aims to compare average treatment effects on functional outcome of different degrees of recanalization after MT in patients with M2 occlusion and M1 occlusion.

METHODS

All patients enrolled in the German Stroke Registry (GSR) between June 2015 and December 2021 were analyzed. Inclusion criteria were stroke with primary M1 occlusion or M2 occlusion, and availability of relevant clinical data. 4259 patients were included, thereof 1353 with M2 occlusion and 2906 with M1 occlusion. Treatment effects were analyzed using double-robust inverse-probability-weighted regression-adjustment (IPWRA) estimators to control for confounding covariates. Binarized endpoint metrics were defined as good outcome with modified Rankin Scale (mRS) ≤2 at 90 days, and linearized endpoint metrics were defined as mRS shift pre-stroke to 90 days. Effects were evaluated for near complete recanalization (Thrombolysis In Cerebral Infarction scale (TICI) 2b) and complete recanalization (TICI 3).

RESULTS

Treatment effect estimation for TICI ≥2b versus TICI <2b in M2 occlusions showed an increase in the probability of a good outcome from 27% to 47% with a number-needed-to-treat (NNT) of 5. For M1 occlusions the probability of a good outcome increased from 16% to 38% with NNT 4.5. TICI 3 versus TICI 2b increased the probability of a good outcome by 7 percentage points in M1 occlusions; for M2 occlusions the beneficial effect was not significant.

CONCLUSIONS

Results suggest that successful recanalization with TICI ≥2b versus TICI <2b after MT in M2 occlusions provides significant patient benefit with treatment effects comparable to M1 occlusions. The probability of functional independence increased by 20 percentage points (NNT 5) and stroke-related mRS increase was reduced by 0.9 mRS points. In contrast to M1 occlusions, complete recanalization TICI 3 versus TICI 2b had lower additional beneficial effect.

Predictors of functional outcome after thrombectomy for M2 occlusions: a large scale experience from clinical practice

Mechanical thrombectomy (MT) for acute ischemic stroke with medium vessel occlusions is still a matter of debate. We sought to identify factors associated with clinical outcome after MT for M2-occlusions based on data from the German Stroke Registry-Endovascular Treatment (GSR-ET). All patients prospectively enrolled in the GSR-ET from 05/2015 to 12/2021 were analyzed (NCT03356392). Inclusion criteria were primary M2-occlusions and availability of relevant clinical data. Factors associated with excellent/good outcome (modified Rankin scale mRS 0-1/0-2), poor outcome/death (mRS 5-6) and mRS-increase pre-stroke to day 90 were determined in multivariable logistic regression. 1348 patients were included. 1128(84%) had successful recanalization, 595(44%) achieved good outcome, 402 (30%) had poor outcome. Successful recanalization (odds ratio [OR] 4.27 [95% confidence interval 3.12-5.91], p < 0.001), higher Alberta stroke program early CT score (OR 1.25 [1.18-1.32], p < 0.001) and i.v. thrombolysis (OR 1.28 [1.07-1.54], p < 0.01) increased probability of good outcome, while age (OR 0.95 [0.94-0.95], p < 0.001), higher pre-stroke-mRS (OR 0.36 [0.31-0.40], p < 0.001), higher baseline NIHSS (OR 0.89 [0.88-0.91], p < 0.001), diabetes (OR 0.52 [0.42-0.64], p < 0.001), higher number of passes (OR 0.75 [0.70-0.80], p < 0.001) and intracranial hemorrhage (OR 0.26 [0.14-0.46], p < 0.001) decreased the probability of good outcome. Additional predictors of mRS-increase pre-stroke to 90d were dissections, perforations (OR 1.59 [1.11-2.29], p < 0.05) and clot migration, embolization (OR 1.67 [1.21-2.30], p < 0.01). Corresponding to large-vessel-occlusions, younger age, low pre-stroke-mRS, low severity of acute clinical disability, i.v. thrombolysis and successful recanalization were associated with good outcome while diabetes and higher number of passes decreased probability of good outcome after MT in M2 occlusions. Treatment related complications increased probability of mRS increase pre-stroke to 90d.

Mechanical thrombectomy in M1 and M2 segments of middle cerebral arteries: A meta-analysis of prospective cohort studies

BACKGROUND

Recent studies indicate that endovascular therapy is superior to intravenous thrombolysis in treating M1 segment MCA occlusions, however, the effectiveness of mechanical thrombectomy in MI vs. M2 segment occlusions is unclear.

METHODS

The meta-analysis was conducted by searching databases from January 2016 to January 2023, without language constraints. The quality of the studies was assessed using the Newcastle-Ottawa Scale. Pooled data analysis of outcomes, pre-existing medical comorbidities, and baseline scores were performed.

RESULTS

Six prospective cohort studies with 6356 patients were included (4405 vs. 1638). Patients with M2 occlusion had a significantly lower mean baseline NIHSS at admission (MD: -2.14; 95 %CI: -3.48 to -0.81; p = 0.002). Conversely, patients with M1 occlusion had a lower ASPECTS at admission score (MD: 0.29; 95 %CI: 0.00-0.59; p = 0.05). No significant difference was found between segments in terms of pre-existing medical comorbidities (OR: 0.96; 95 %CI: 0.87-1.05; p = 0.36), mortality rate at 90 days (OR: 0.88; 95 %CI: 0.76-1.02; p = 0.10), and hemorrhage occurrence within 24-hours (OR: 1.06; 95 %CI: 0.89-1.25; p = 0.53). Patients with M2 occlusion were more likely to have good outcomes after therapy (OR: 1.18; 95 %CI: 1.05-1.32; p = 0.006). Successful recanalization rates were comparatively higher among patients with an M1 occlusion (OR: 0.79; 95 %CI: 0.68-0.92; p = 0.003). Functional outcomes at 90 days are better in M2 occlusion patients, while successful recanalization rates are higher in M1 occlusion patients. No significant differences were found in mortality rates or hemorrhage incidence.

CONCLUSIONS

These results suggest that mechanical thrombectomy is a safe and effective treatment for MCA occlusions in both M1 and M2 segments.

Distal medium vessel occlusions in acute ischaemic stroke - Stent retriever versus direct aspiration: A systematic review and meta-analysis

BACKGROUND

Acute ischaemic stroke due to distal medium vessel occlusion (AIS-DMVO) causes significant morbidity. Endovascular thrombectomy advancement has made treating AIS-DMVO with stent retrievers (SR) and aspiration catheters (AC) possible, however the optimal technique remains unknown. We performed a systematic review and meta-analysis to investigate the efficacy and safety of SR use compared to purely AC use in patients with AIS-DMVO.

METHODS

We systematically searched PubMed, Cochrane Library and EMBASE, from inception to 2nd September 2022, for studies comparing SR or primary combined (SR/PC) against AC in AIS-DMVO. We adopted the Distal Thrombectomy Summit Group's definition of DMVO. Efficacy outcomes were functional independence (modified Rankin Scale (mRS) 0-2 at 90 days), first pass effect (modified Thrombolysis in Cerebral Infarction scale (mTICI) 2c-3 or expanded Thrombolysis in Cerebral Infarction scale (eTICI) 2c-3 at first pass), successful final recanalisation (mTICI or eTICI 2b-3), and excellent final recanalisation (mTICI or eTICI 2c-3). Safety outcomes were symptomatic intracranial haemorrhage (sICH) and 90-day mortality.

RESULTS

12 cohort studies and 1 randomised-controlled trial were included, involving 1881 patients with 1274 receiving SR/PC and 607 receiving AC only. SR/PC achieved higher odds of functional independence (odds ratio (OR) 1.33, 95% confidence interval (CI) 1.06-1.67) and lower odds of mortality (OR 0.69, 95% CI 0.50-0.94) than AC. Odds of successful/excellent recanalisation and sICH were similar between both groups. Stratified to compare only SR and only AC, the use of only SR, achieved significantly higher odds of successful recanalisation as compared to only AC (OR 1.80, 95% CI 1.17-2.78).

CONCLUSION

There is potential for efficacy and safety benefits in SR/PC use as compared to AC only in AIS-DMVO. Further trials are necessary to validate the efficacy and safety of SR use in AIS-DMVO.

Aspiration thrombectomy of M2 middle cerebral artery occlusion to treat acute ischemic stroke: A core lab–adjudicated subset analysis from the COMPLETE registry and literature review

Background

Although the benefits of aspiration thrombectomy for treating acute ischemic stroke caused by proximal large vessel occlusion have been established, fewer data are available for evaluating aspiration thrombectomy of distal occlusion. The objective of this study was to evaluate, by means of prospectively collected data, the safety and efficacy of aspiration thrombectomy in patients with M2 middle cerebral artery (MCA) occlusion.

Methods

This study is a subset analysis of a global prospective multicenter observational registry that included patients who presented with either anterior or posterior large vessel occlusion and were eligible for mechanical thrombectomy using the Penumbra System including the Penumbra 3D Revascularization Device. For this analysis, all patients in the registry with M2 MCA occlusion were included.

Results

Of the 650 patients in the registry, 113 (17.4%) had M2 MCA occlusion. The rate of a modified treatment in cerebral infarction score of 2b to 3 after the procedure was 79.6% (90/113), the rate of a modified Rankin Scale score of 0–2 at 90 days was 72.5% (79/109), and the all-cause mortality rate at 90 days was 8.8% (10/113). Device-related serious adverse events occurred in one patient (0.9%) within 24 h and in two patients (1.8%) overall. Procedure-related serious adverse events occurred in four patients (3.5%) within 24 h and in six patients (5.3%) overall (nine events).

Conclusion

For appropriately selected patients, aspiration thrombectomy for acute ischemic stroke due to M2 MCA occlusion was safe and effective, with high rates of technical success and good functional outcome.

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.

Comparing data from thrombectomy in m2 occlusion and proximal middle cerebral artery

INTRODUCTION

Mechanical thrombectomy for large vessel occlusion in the anterior circulation has been shown to be beneficial. The question of whether this technique is safe and effective in the distal vasculature remains unanswered. We wanted to compare outcome data from mechanical thrombectomy of M2 branches of the middle cerebral artery (MCA) with those of the M1 segment, and better understand the clinical predictors of these M2 occlusions.

METHODS

A retrospective analysis was performed of data prospectively collected between January 2017 and July 2021 from patients with acute ischemic stroke undergoing mechanical thrombectomy of isolated M1 or M2 branches of the MCA.

RESULTS

350 patients were identified, 287 with M1 and 63 with M2 occlusions. Mean age was 70.71 ± 12.55 and 75.21 ± 10.21 years, respectively (p = 0.0083). Baseline Alberta Stroke Program Computed Tomography (ASPECT) score was worse in the M1 cohort (7.68 ± 1.73 vs. 8.32 ± 1.54; p = 0.0079), while there was no significant difference in National Institutes of Health Stroke Scale (NIHSS) scores. No statistical disparity existed in mean procedure duration for each cohort; fewer thrombectomy attempts were required in the M2 cohort (2.01 vs. 1.63; p = 0.0478). There was no statistical difference in total time to recanalization (559.19 vs. 629.97, p = 0.2506). Similar rates of successful reperfusion were observed (Thrombolysis in Ischaemic Stroke score [TICI] ≥ 2b 80.84% vs. 71.43% p = 0.1221). Good outcome (modified Rankin scale ≤ 2) was 56.10 in M1 occlusions and 63.49% on M2 groups. Intracranial haemorrhage rates were similar.

CONCLUSIONS

M2 thrombectomy is safe and a significant proportion of patients achieve a good clinical outcome. Advanced age, atrial fibrillation and previous treatment with anticoagulants were predictors for poor outcome. Good outcome was achieved when effective recanalization was obtained.

Comparing Tigertriever 13 to other thrombectomy devices for distal medium vessel occlusion: A systematic review and meta-analysis

BACKGROUND

There is limited evidence on the optimal endovascular strategy for treatment of distal medium-vessel occlusions (DMVO). The low-profile Tigertriever 13 stent-triever shows early promise as an adaptable device that can navigate the distal vasculature without increasing complication risk in DMVO.

METHODS

Using Nested Knowledge, we screened literature for RCTs and cohort studies on the endovascular treatment of DMVO. The primary outcome was reperfusion success, as measured by thrombolysis in cerebral infarction (TICI) ≥ 2b and secondary outcomes included rate of symptomatic intracranial hemorrhage (sICH), mortality at 90 days, and modified Rankin scale (mRS) scores 0-2 at 90 days. A random-effects model was used to compute pooled prevalence rates and their corresponding 95% confidence intervals (CI).

RESULTS

Eleven studies with 1402 patients, 167 patients treated by Tigertriever 13 and 1235 patients treated by other devices, were included in the meta-analysis. The rate of reperfusion success was similar in patients treated by Tigertriever 13 (83.2% [95% CI: 71.5-96.7%]) versus other devices (81.6% [95% CI: 75.3-88.4%], p > 0.05). The rate of sICH was also similar in patients treated by Tigertriever 13 (7.2% [95% CI: 4.1-12.5%]) versus other devices (6.9% [95% CI: 5.5-8.8%]). There was significant heterogeneity in the reporting of mortality and mRS.

CONCLUSIONS

Tigertriever 13 had similar rates of reperfusion success and sICH as other devices used for the treatment of DMVO. Heterogeneity in data element reporting prevented further analyses. Further studies evaluating Tigertriever 13 and other potential devices in DMVO should attempt to harmonize data element reporting.

Predictors of Mechanical Thrombectomy for Anterior Circulation Emergent Large-Vessel Occlusion in the Older Adults

Few studies have reported the clinical outcomes of older adult patients with acute anterior circulation large-vessel occlusion (LVO) who underwent mechanical thrombectomy (MT). Therefore, we investigated the safety, functional outcomes, and predictors of MT for anterior circulation LVO in older adults. We enrolled patients with acute anterior circulation LVO from May 2018 to October 2021 in this retrospective study. Patients were divided into older (≥80 years) and young (<80 years) groups. Multivariable logistic regression analyses determined the safety, functional outcomes, and predictors of MT for anterior circulation LVO. We divided 1182 patients with acute ischemic stroke into young (18-79 years; 1028 patients) and older (≥80 years; 154 patients) groups. Compared with the young group, the older group had more unfavorable functional outcomes and increased mortality (P = .003). In the older adult patients, lower initial NIHSS score and higher ASPECTS were correlated with good outcomes. On the contrary, higher initial NIHSS score and lower ASPECTS were related to increased mortality. No difference was detected in symptomatic intracranial hemorrhage within 48 h between two groups. Increasing age was associated with lower rates of favorable functional outcomes and higher mortality rates. The lower initial NIHSS score combined with the higher ASPECTS may predict functional outcomes post-thrombectomy in older adults.

First-line thrombectomy strategy for distal and medium vessel occlusions: a systematic review

BACKGROUND

The benefit of mechanical thrombectomy (MT) and efficacy of different first-line MT techniques remain unclear for distal and medium vessel occlusions (DMVOs). In this systematic review, we aimed to compare the performance of three first-line MT techniques in DMVOs.

METHODS

The PubMed database was searched for studies examining the utility of MT in DMVOs (middle cerebral artery M2-3-4, anterior cerebral artery, and posterior cerebral artery). Studies providing data for aspiration thrombectomy (ASP), stent retriever thrombectomy (SR), and combined SR+ASP technique were included. Non-comparative studies were excluded. Safety and efficacy data were collected for each technique. The Nested Knowledge AutoLit platform was utilized for literature search, screening, and data extraction. Pooled data were presented as descriptive statistics.

RESULTS

13 studies comprising 2422 MT procedures were identified. The overall successful recanalization rate was 77.0% (1513/1964) for DMVOs. SR+ASP had a successful recanalization rate of 83.7% (297/355), SR had a 75.6% rate (638/844), while ASP alone had a 74.2% rate (386/520). The overall functional independence rate was 51.3% (851/1659) among DMVOs. The ASP alone group had a functional independence rate of 46.9% (219/467), while functional independence rates of the SR and SR+ASP groups were 51.5% (372/723) and 61.7% (174/282), respectively. Finally, the subarachnoid hemorrhage rates were 1.8% (4/217) for the ASP group, 9.3% (26/281) for the SR group, and 11.9% (41/344) for the SR+ASP group.

CONCLUSIONS

Our systematic review supports the proposition that MT is a safe and effective treatment option for DMVOs. Additionally, while the SR+ASP group had consistently high rates of clot clearance and good neurological outcomes, the SR and SR+ASP groups also had higher rates of subarachnoid hemorrhage, highlighting the need for improved DMVO treatment devices.

First-line contact aspiration versus first-line stent retriever for acute ischemic stroke with M2 occlusion: A systematic review and meta-analysis

OBJECTIVE

Mechanical thrombectomy is widely used for acute ischemic stroke caused by middle cerebral artery M2 segment occlusion. However, the comparison between contact aspiration (CA) and stent retriever (SR) used as first-line techniques for acute M2 occlusion is still unclear. We aimed to perform a systematic review and meta-analysis on this issue.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement was followed. Three databases (Pubmed, Embase, and Cochrane) were searched. The Newcastle-Ottawa scale was used to assess the risk of bias for the included studies. We focused on two main outcomes, the final successful reperfusion (modified Thrombolysis in Cerebral Infarction mTICI 2b/3) and 90-day functional independence (modified Rankin Scale score 0-2). The meta-analyses were performed using the random-effects models.

RESULTS

Seven observational studies were included for systematic review. Only one study indicated a superiority of first-line SR in achieving final successful reperfusion, while the other six studies did not show significant difference between these two techniques. And all the seven studies showed comparable proportion of 90-day functional independence. Five studies were available for meta-analysis with 601 patients (239 received first-line CA, 362 received first-line SR). The pooled results also suggested that the proportion of final successful reperfusion (OR=1.18, 95%CI 0.72-1.93, I2 =0%) and 90-day functional independence (OR=1.18, 95%CI 0.82-1.68, I2 =0%) were comparable between these two strategies.

CONCLUSION

For patients with acute M2 occlusion, first-line CA and SR techniques could achieve similar final reperfusion outcomes and 90-day clinical prognosis. Further studies with randomized controlled design are needed.

Predictors of Good Clinical Outcome after Thrombectomy for Distal Medium Vessel Occlusions

OBJECTIVE

Good clinical outcome predictors have been emphasized in mechanical thrombectomy (MT) for acute ischemic stroke (AIS) with large vessel occlusion (LVO). MT for distal, medium vessel occlusions (DMVO) is still debated. We sought to assess the factors associated with clinical outcome after MT for DMVO.

METHODS

We retrospectively analyzed the data of consecutive patients who underwent MT for a primary DMVO in one large academic center and aimed to identify the baseline clinical, imaging and MT factors associated with good clinical outcome (defined as modified Rankin scale [mRS] of 0-2) at 3 months.

RESULTS

Between January 2018 and January 2021, 61 patients underwent a MT for an AIS with a primary DMVO. Overall, good clinical outcome was achieved in 56% (34/61) of our patients. In multivariate analysis, an older age (ODDS ratio 0.89 [0.83-0.96], p=0.003), longer puncture to recanalization time (ODDS ratio 0.97 [0.93-0.99], p=0.033), and higher baseline core volume (ODDS ratio 0.84 [0.75-0.94], p=0.003) decreased the probability of good clinical outcomes, while a final complete (or near-) recanalization (mTICI 2c-3) increased the probability of good outcome (ODDS ratio 14.19 [1.99-101.4], p=0.008).

CONCLUSION

An older age, a longer puncture to recanalization time and a higher baseline core volume decreased the probability of good clinical outcomes, while successful recanalization (mTICI 2c-3) was associated with better outcomes after MT for DMVO.

Should the direct aspiration first pass technique be advocated over the stent-retriever technique for acute ischemic stroke? A systematic review and meta-analysis of 7692 patients

Background:

The present meta-analysis aimed to synthesize evidence from all published studies with head-to-head data on the outcomes of a direct aspiration first pass technique (ADAPT) and the stent-retriever (SR) in acute ischemic stroke (AIS) patients.

Methods:

We searched PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials from inception to March 2021 for relevant clinical trials and observational studies. Eligible studies were identified, and all relevant outcomes were pooled in the meta-analysis random-effects model of DerSimonian-Laird.

Results:

Thirty studies were included in the meta-analysis with a total of 7868 patients. Compared with the SR, the ADAPT provides slightly higher rates of successful recanalization (RR 1.06, 95% CI [1.02 to 1.10]) and complete recanalization (RR 1.20, 95% CI [1.01 to 1.43]) but with more need for rescue therapy (RR 1.81, 95% CI [1.29 to 2.54]). There were no significant differences between the two techniques in terms of mortality at discharge, mortality at 90 days, change in the National Institutes of Health Stroke Scale score, the favorable outcome (modified Rankin scale (mRS) of 0-2), time to the groin puncture, or frequency of complications as intracerebral hemorrhage (ICH), symptomatic intracranial hemorrhage (sICH), embolus in a new territory (ENT), hemorrhagic infarction, parenchymal hematoma, subarachnoid hemorrhage, or procedural complications (all P > 0.05).

Conclusion:

Current evidence supports the use of the ADAPT technique to achieve successful and complete recanalization while considering the higher need for rescue therapy in some patients.

Stent-retriever alone versus combined use of stent-retriever and contact aspiration technique for middle cerebral artery M2 occlusions: a propensity score analysis

BACKGROUND

The optimal endovascular treatment (EVT) technique for middle cerebral artery (MCA) M2 segment occlusions remains unknown. We aim to analyze whether reperfusion rate, procedure times, procedure-related complications, and clinical outcome differed between patients with isolated M2 occlusions who underwent stent-retriever (SR) alone versus combined SR and contact aspiration (CA) as a front-line EVT.

METHODS

Patients who underwent EVT for isolated MCA-M2 occlusion were recruited from the prospectively ongoing ROSSETTI registry. Patients were divided regarding the EVT approach into SR alone versus SR+CA and propensity score matching was used to achieve baseline balance. Demographic, procedural, safety, and clinical outcomes were compared between groups. Multivariable logistic regression analysis was performed to identify independent predictors of first-pass effect (FPE) and 90-day modified Rankin scale (mRS) 0-2.

RESULTS

214 patients underwent EVT for M2 occlusion, 125 treated with SR alone and 89 with SR+CA. Propensity score matchnig analysis selected 134 matched patients. The rates of FPE (42% vs 40%, p=1.000) and 90-day mRS 0-2 (60% vs 51%, p=0.281) were comparable between groups. Patients treated with SR alone had lower need of rescue therapy (p=0.006), faster times to reperfusion (p<0.001), and lower procedure-related complications (p=0.031). Higher initial Alberta Stroke Program Early CT Score was an independent predictor of FPE. Age, baseline National Institutes of Health Stroke Scale score, and procedure duration were significant predictors of good clinical outcome at 3 months.

CONCLUSIONS

As front-line modality in M2 occlusions, the SR alone approach results in similar rates of reperfusion and good clinical outcomes to combined SR+CA and might be advantageous due to faster reperfusion times and fewer adverse events.

Mechanical thrombectomy beyond the circle of Willis: efficacy and safety of different techniques for M2 occlusions

BACKGROUND

M2 segment occlusions represent approximately one-third of non-lacunar ischemic stroke and can lead to permanent neurological deficits. Various techniques are available for mechanical thrombectomy beyond the circle of Willis, but data evaluating their effectiveness and safety are lacking.

METHODS

A retrospective review of patients with ischemic stroke undergoing mechanical thrombectomy for M2 occlusions from 13 centers in North American and Europe was performed. Tandem or multiple-territory occlusions were excluded. The primary outcome was 90-day modified Rankin Scale and reperfusion rates across stent-retriever, direct aspiration and combined techniques.

RESULTS

There were 465 patients (mean age 71.48±14.03 years, 53.1% female) with M2 occlusions who underwent mechanical thrombectomy. Stent-retriever alone was used in 133 (28.6%), direct aspiration alone in 93 (20.0%) and the combined technique in 239 (51.4%) patients. Successful reperfusion was achieved with the combined technique in 198 (82.2%; OR 2.6 (1.1-6.9)), with stent-retriever alone in 112 (84.2%; OR 9.2 (1.9-44.6)) and with direct aspiration alone in 62 (66.7%; referencecategory). Intraprocedural subarachnoid hemorrhages (iSAH) were 36 (7.7%) and were more likely to occur in patients treated with the stent-retrievers (OR 5.0 (1.1-24.3)) and combined technique (OR 4.6 (1.1-20.9)). Good clinical outcome was achieved in 260 (61.8%) patients, while 59 (14.0%) patients died. Older age, higher baseline NIHSS (National Institutes of Health Stroke Scale), parenchymal hemorrhage and iSAH were associated with poor outcome while successful recanalization and higher baseline ASPECTS (Alberta Stroke Program Early CT Score) were associated with good outcome. No differences were found among the three techniques in terms of clinical outcome.

CONCLUSION

Stent-retrievers and a combined approach for M2 occlusions seem more effective than direct aspiration, but with higher rates of iSAH. This leads to no detectable difference in clinical outcome at 3 months.

Current Status of Endovascular Treatment for Acute Large Vessel Occlusion in China: A Real-World Nationwide Registry

BACKGROUND AND PURPOSE

The benefit of endovascular treatment (EVT) for large vessel occlusion in clinical practice in developing countries like China needs to be confirmed. The aim of the study was to determine whether the benefit of EVT for acute ischemic stroke in randomized trials could be generalized to clinical practice in Chinese population.

METHODS

We conducted a prospective registry of EVT at 111 centers in China. Patients with acute ischemic stroke caused by imaging-confirmed intracranial large vessel occlusion and receiving EVT were included. The primary outcome was functional independence at 90 days defined as a modified Rankin Scale score of 0 to 2. Outcomes of specific subgroups in the anterior circulation were reported and logistic regression was performed to predict the primary outcome.

RESULTS

Among the 1793 enrolled patients, 1396 (77.9%) had anterior circulation large vessel occlusion (median age, 66 [56-73] years) and 397 (22.1%) had posterior circulation large vessel occlusion (median age, 64 [55-72] years). Functional independence at 90 days was reached in 45% and 44% in anterior and posterior circulation groups, respectively. For anterior circulation population, underlying intracranial atherosclerotic disease was identified in 29% of patients, with higher functional independence at 90 days (52% versus 44%; P=0.0122) than patients without intracranial atherosclerotic disease. In the anterior circulation population, after adjusting for baseline characteristics, procedure details, and early outcomes, the independent predictors for functional independence at 90 days were age <66 years (odds ratio [OR], 1.733 [95% CI, 1.213-2.476]), time from onset to puncture >6 hours (OR, 1.536 [95% CI, 1.065-2.216]), local anesthesia (OR, 2.194 [95% CI, 1.325-3.633]), final modified Thrombolysis in Cerebral Infarction 2b/3 (OR, 2.052 [95% CI, 1.085-3.878]), puncture-to-reperfusion time ≤1.5 hours (OR, 1.628 [95% CI, 1.098-2.413]), and National Institutes of Health Stroke Scale score 24 hours after the procedure <11 (OR, 9.126 [95% CI, 6.222-13.385]).

CONCLUSIONS

Despite distinct characteristics in the Chinese population, favorable outcome of EVT can be achieved in clinical practice in China. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03370939.

Emergent surgical embolectomy for middle cerebral artery occlusion related to cerebral angiography followed by neck clipping for an unruptured aneurysm in the anterior communicating artery

Background:

Intracranial embolism related to cerebral angiography is rare but one of the complications of the procedure. However, the standard management of acute intracranial embolism for this etiology has not been established, and there have been very few reports in the past.

Case Description:

A 68-year-old male was incidentally found to have an unruptured aneurysm of anterior communicating artery (ACoA). Immediately after the cerebral angiography for the purpose of detailed examination of the aneurysm, the right partial hemiparalysis and mild aphasia developed. Magnetic resonance imaging/angiography (MRI/A) revealed an occlusion in the peripheral part of the left middle cerebral artery (MCA). Due to the existence of magnetic resonance angiography-diffusion mismatch, emergent craniotomy was immediately performed to remove intra-arterial thrombus. We also performed clipping for an unruptured ACoA aneurysm with this approach. Postoperative MRI/A showed that the occluded artery was recanalized and a slight infarction was observed in the left cerebral hemisphere. The patient was discharged on foot and followed at outpatient clinic over 4 years without no neurological deficit.

Conclusion:

Emergent surgical embolectomy for distal MCA occlusion related to cerebral angiography followed by neck clipping for an unruptured aneurysm of the ACoA was successful in treating acute occlusion of the peripheral part of the MCA in a patient with an unruptured aneurysm. As there are few similar cases, there is controversy about the best management, but this surgical method can be a safe and effective treatment.

Mechanical Thrombectomy in Acute Ischemic Stroke: A Meta-Analysis of Stent Retrievers vs Direct Aspiration vs a Combined Approach

BACKGROUND

Recent randomized control trials (RCTs) established that mechanical thrombectomy is superior to medical therapy for patients with stroke due to a large vessel occlusion.

OBJECTIVE

To compare the safety and efficacy profile of the different mechanical thrombectomy strategies.

METHODS

A random-effects meta-analysis was performed and the I2 statistic was used to assess heterogeneity according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.

RESULTS

Nineteen studies with a total of 2449 patients were included. No differences were identified between the stent retrieval and direct aspiration groups in terms of modified Thrombolysis in Cerebral Infarction (mTICI) 2b/3 and mTICI 3 recanalization rates, and favorable outcomes (modified Rankin Scale [mRS] ≤ 2). Adverse event rates, including 90-d mortality, symptomatic intracerebral hemorrhage (sICH), and subarachnoid hemorrhage (SAH), were similar between the stent retrieval and direct aspiration groups. The use of the stent retrieval was associated with a higher risk of vasospasm (odds ratio [OR]: 2.98; 95% confidence interval [CI]: 1.10-8.09; I2: 0%) compared to direct aspiration. When compared with the direct aspiration group, the subgroup of patients who underwent thrombectomy with the combined approach as a first-line strategy had a higher likelihood of successful mTICI 2b/3 (OR: 1.47; 95% CI: 1.02-2.12; I2: 0%) and mTICI 3 recanalization (OR: 3.65; 95% CI: 1.56-8.54), although with a higher risk of SAH (OR: 4.33; 95% CI: 1.15-16.32).

CONCLUSION

Stent retrieval thrombectomy and direct aspiration did not show significant differences. Current available evidence is not sufficient to draw conclusions on the best surgical approach. The combined use of a stent retriever and aspiration as a first-line strategy was associated with higher mTICI 2b/3 and mTICI 3 recanalization rates, although with a higher risk of 24-h SAH, when compared with direct aspiration.

Direct aspiration stroke thrombectomy: a comprehensive review

Mechanical thrombectomy is now the standard of care for acute ischemic stroke patients with large vessel occlusions, and can be performed with several devices and techniques. One of these techniques, direct aspiration (DA), consists of navigating a large-bore catheter up to the face of the clot and initiating forceful suction. This comprehensive review has three objectives: (1) to describe the direct aspiration technique; (2) to present the available evidence regarding predictive factors of DA success and performance compared with other techniques; and (3) to discuss the forthcoming improvements in distal aspiration.

Aspiration Thrombectomy Versus Stent Retriever Thrombectomy Alone for Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

Introduction This meta-analysis was conducted to assess the safety and efficacy of aspiration thrombectomy versus stent retriever thrombectomy for acute ischemic stroke (AIS). Methods We queried online databases for original studies comparing aspiration thrombectomy with stent retriever thrombectomy in patients with AIS. After article selection, data were extracted on multiple baseline characteristics and prespecified endpoints. Dichotomous data were presented as risk ratios (RRs) and corresponding 95% confidence intervals (CIs); continuous data as mean differences and 95% CIs. The data were pooled using a random-effects model. Subgroup analysis was conducted based on study type, site of occlusion, and age. Results We shortlisted nine relevant studies (n=1453 patients; n=690 receiving aspiration thrombectomy and n=763 receiving stent retriever thrombectomy). Meta-analysis demonstrated no significant difference between the two groups in the rates of successful recanalization (RR: 0.96 [0.87, 1.06]; p=0.42), excellent functional outcome (RR: 0.90 [0.80, 1.01]; p=0.06), or procedure time (weighted mean difference (WMD): -5.39 minutes [-11.81, 1.04]; p=0.10). However, when removing the study by Nishi et al., sensitivity analysis resulted in a significant reduction in procedure time with aspiration (WMD: -11.01 [-15.54, -6.49]; p<0.0001). No significant difference was observed in safety outcomes, including all-cause mortality (RR: 0.82 [0.57, 1.19]; p=0.30), intracranial hemorrhage (RR: 0.93 [0.55, 1.59]; p=0.80), symptomatic intracranial hemorrhage (RR: 0.72[0.42, 1.21]; p=0.57), or embolization to new territory (RR: 0.71 [0.42, 1.19]; p=0.19). Subgroup analysis revealed that aspiration thrombectomy led to significantly better outcomes in patients with a mean age ≤65 (RR: 1.15 [1.03, 1.29]; p=0.001), and stent retriever thrombectomy led to increased recanalization success in patients with a mean age >65 (RR: 0.89 [0.80, 1.00]; p=0.05). Conclusions Our updated meta-analysis reveals that both aspiration and stent retriever thrombectomy are comparably effective in the management of AIS. Shorter procedure times may potentially be attained with aspiration thrombectomy, and outcomes with each procedure may be age-dependent.

Aspiration thrombectomy as the first-line treatment of M2 occlusions

PURPOSE

The aim of the present study was (i) to evaluate the safety and efficacy of aspiration thrombectomy in patients with M2 occlusions and (ii) to compare outcome of treatment of occlusion of different M2 segments.

MATERIALS AND METHODS

Between March 2016 and June 2019, 82 patients with acute ischemic stroke and isolated M2 occlusions were treated in cerebrovascular stroke center with aspiration thrombectomy as the first-line treatment. Functional outcomes of patients with different types of M2 occlusions were statistically compared. Multivariable logistic regression analysis was performed to determine the factors associated with good clinical outcome.

RESULTS

The mean age was 71.9 ± 13.4 years, 47.6% were men. Aspiration thrombectomy alone was utilized in 72.5% of patients, with 27.5% of patients being treated with a combination of aspiration thrombectomy and stent retriever. At the three-month follow-up, there was no statistically significant difference in functional outcome between different types of M2 occlusions (p = 0.662), however in the underpowered analysis because of the small sample size of patients, with good clinical outcome mRS 0-2 in 50% of all treated patients. Symptomatic intracranial hemorrhage was found in 6.1% of patients. Lower age (OR 0.932, 95% CI 0.878-0.988) and lower NIHSS score upon admission (OR 0.893, 95% CI 0.805-0.991) were independent predictors of good clinical outcome.

CONCLUSION

Aspiration thrombectomy appeared to be a safe and effective first-line treatment option for patients with M2 occlusion, being the first-line option for almost three-quarters of patients.

Effectiveness of Endovascular Recanalization Treatment for M2 Segment Occlusion: Comparison Between Intracranial ICA, M1, and M2 Segment Thrombectomy

RATIONALE AND OBJECTIVES

Mechanical thrombectomy is common practice in proximal anterior vessel occlusion. However, it remains unclear whether peripheral artery occlusions should be treated as well. This retrospective study aimed to prove the effectiveness of endovascular recanalization treatment for the M2 segment by comparison of intracranial internal carotid artery (ICA), M1 segment, and M2 segment thrombectomy.

MATERIALS AND METHODS

All patients who received endovascular treatment for distal ICA, M1, or M2 segment occlusions between January 2010 and July 2017 at our center were re-analyzed with respect to reperfusion success, interventional and clinical parameters. Statistical analysis was performed by Mann Whitney test, Chi square test, and Spearman correlation analysis.

RESULTS

A total of 261 patients (median age, 72 years), 100 with ICA, 137 with M1, and 24 with M2 segment occlusion, were included. Duration of endovascular treatment was significantly longer in ICA occlusions (median, 83 minutes, p < 0.001) compared to M1 (56 minutes) or M2 segment occlusions (49 minutes). Recanalization and reperfusion success and rate of endovascular complications did not differ between occlusion sites (AOL, p = 0.071; mTICI, p = 0.540; complications, p = 0.064). No significant difference in revascularization success was found between the different thrombectomy devices (direct thrombus aspiration, stent retrieving, or a sequential combined approach; p = 0.112). Successful M2 recanalization (mTICI 2b-3) correlated significantly with stronger posttherapeutic NIHSS reduction (r = 0.691, p < 0.001).

CONCLUSION

We found endovascular treatment of M2 segment occlusions as safe and successful as endovascular therapy of the ICA or M1 segment, with stronger posttherapeutic NIHSS reduction after successful compared to insufficient M2 recanalization.

Stent Retriever-Assisted Continuous Aspiration for Distal Intracranial Vessel Embolectomy: The Distal Combined Technique

OBJECTIVE

We investigated the efficacy of a combined approach with stent retriever-assisted aspiration catheter for distal intracranial vessel occlusion (distal combined technique [DCT]).

METHODS

We evaluated consecutive patients with acute ischemic stroke with distal occlusion in anterior circulation, including occlusions of the M2/M3 or A2/A3 segments, who received endovascular therapy (EVT) in a single center. Modified Thrombolysis in Cerebral Infraction (mTICI) score including TICI 2C category, processing time from puncture to reperfusion, proportion of a favorable clinical outcome at discharge (modified Rankin Scale [mRS] score ≤2), and incidence of symptomatic intracranial hemorrhage (sICH) were compared between the DCT and single device approach technique (non-DCT) groups.

RESULTS

Of 65 patients, 28 were treated with EVT using the DCT and 37 were treated with EVT with a single device approach (non-DCT). In the DCT group, a higher reperfusion rate at the first pass (mTICI score ≥2B, 92% vs. 54%; P = 0.0008; mTICI score ≥2C, 71% vs. 16%; P < 0.0001; mTICI score 3, 57% vs. 14%; P = 0.0004) and shorter time from puncture to successful reperfusion (median, 31 vs. 43 minutes; P = 0.0006) were achieved, respectively. The final successful reperfusion rate was also higher in the DCT group than in the non-DCT group (mTICI score ≥2C, 85% vs. 51%; P = 0.004; mTICI score 3, 75% vs. 43%; P = 0.012), respectively. sICH occurred in 2 patients in the non-DCT group. Patients with mRS score ≤2 at discharge were more prevalent in the DCT than in the non-DCT group (57% vs. 27%, respectively; P = 0.021).

CONCLUSIONS

This retrospective analysis indicated that the DCT is a useful and safe strategy for patients with distal anterior intracranial vessel occlusion.

Left M2 Occlusion With Thrombolysis in Cerebral Infarction (TICI) 2b Recanalization Using "Solumbra" Technique: Video Case

Mechanical thrombectomy has become the accepted standard of care in patients with large-vessel occlusions; however, the management of more distal occlusions is more variable. Although often less clinically severe than proximal occlusions, M2 occlusions can cause significant disability, particularly when they occur in the dominant cerebral hemisphere. Recanalization of M2 occlusions with intravenous recombinant tissue plasminogen activator has been reported to be unreliable (only successful in 30.8% of cases).1 Reliable recanalization of M2 occlusions (thrombolysis in cerebral infarction [TICI] grade 2b or 3 in 76.9% of cases) using contemporary endovascular techniques has been reported.2 A multi-institutional experience demonstrated similar radiographic and clinical success rates when comparing direct aspiration and primary stent retrieval to treat M2 occlusions.3  In this video, we present the case of a 62-yr-old woman with a left M2 occlusion treated using the "Solumbra" technique.4 This technique utilizes a stent retriever in conjunction with aspiration, which is achieved by advancing the aspiration catheter adjacent to the clot. The small caliber of the M2 segment prohibits the advancement of the large-bore aspiration catheter into this segment. However, as demonstrated in this video, placement of the aspiration catheter at the M2 ostia with deployment of the stent retriever in the M2 clot can provide effective recanalization. It should be noted that care should be taken when advancing a guide catheter into the petrous carotid artery for support as this is an advanced maneuver and may increase the risk of iatrogenic injury in inexperienced hands.  Consent was obtained from the patient prior to performing the procedure. Institutional Review Board approval is not required for the report of a single case.

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.

Endovascular therapy for middle cerebral artery M2 segment occlusion: subanalyses of RESCUE-Japan Registry 2

OBJECTIVE

To compare the efficacy of endovascular therapy (EVT) with that of medical treatment in 'real-world 'patients with M2 occlusion.

METHODS

This was a post hoc analysis of the Recovery by Endovascular Salvage for Cerebral Ultra-acute Embolism Japan Registry 2. Among 2420 patients in the registry, we evaluated patients with isolated M2 occlusion and those with functional independence before the stroke. Multivariable logistic regression analysis was used to evaluate and compare clinical outcomes between EVT and medical treatment. Additional propensity score-matched (PSM) analyses were performed. We performed subgroup analyses of the primary outcome (modified Rankin Scale score 0-2 at 90 days) using forest plots of treatment effects.

RESULTS

Overall, 372 patients with M2 occlusion (n=184 EVT; n=188, medical treatment) were evaluated. The EVT group had a higher baseline National Institutes of Health Stroke Scale score (median (IQR), 15 [9-19] vs 10 [5-16]) and earlier onset to hospital door time (110 [50-258] vs 150 [60-343] min) than the medical treatment group. After adjustment, EVT was significantly associated with higher odds of primary outcome (adjusted OR=2.09; 95% CI 1.26 to 3.47) and lower odds of mortality at 90 days (adjusted OR= 0.27; 95% CI 0.08 to 0.93). After PSM analyses (184 patients were 1:1 matched with each group), EVT was effective and safe relative to medical treatment. Effects favoring EVT were present in several subgroups of interest.

CONCLUSION

In patients with M2 occlusion, our registry suggests that EVT is effective and safe.

Single-center experience using the 3MAX or 4MAX reperfusion catheter for the treatment of acute ischemic stroke with distal arterial occlusions in patients not eligible for intravenous fibrinolysis

BACKGROUND

In acute stroke, distal cerebrovascular occlusions can be linked to severe clinical symptoms, and treatment by mechanical thrombectomy may have an important clinical impact. When intravenous fibrinolytic therapy is firmly contraindicated, it remains the only treatment option.

METHODS

A total of 42 patients with isolated distal arterial occlusions and absolute contraindication for intravenous fibrinolytic therapy were retrospectively included. Mechanical thrombectomy was performed using Penumbra 4MAX or 3MAX aspiration catheters. When aspiration alone did not result in successful revascularization, a stent retriever was added.

RESULTS

Direct thromboaspiration was the first treatment option in all patients. 16.7% of cases required the additional use of a stent retriever. A TICI score ≥ 2b reperfusion at the end of the procedure was obtained in 76.2% and a Rankin Score of 2 or less at 90 days in 45.7%. Two hemorrhagic complications were observed.

CONCLUSIONS

Direct thromboaspiration appears a safe technique in acute isolated distal arterial occlusions. In a cohort of patients with absolute contraindication for intravenous fibrinolytic therapy, a significant percentage achieved good revascularization.

Outcomes of Stent Retriever versus Aspiration-First Thrombectomy in Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

There is ongoing debate regarding the optimal first-line thrombectomy technique for large-vessel occlusion.

PURPOSE

We performed a systematic review and meta-analysis of comparative studies on stent retriever-first and aspiration-first thrombectomy.

DATA SOURCES

We searched Ovid MEDLINE, PubMed, and EMBASE from 2009 to February 2018.

STUDY SELECTION

Two reviewers independently selected the studies. The primary end point was successful reperfusion (TICI 2b/3).

DATA ANALYSIS

Random-effects meta-analysis was used for analysis.

DATA SYNTHESIS

Eighteen studies including 2893 patients were included. There was no significant difference in the rate of final successful reperfusion (83.9% versus 83.3%; OR = 0.87; 95% CI, 0.62%-1.27%) or good functional outcome (mRS 0-2) at 90 days (OR = 1.07; 95% CI, 0.80-1.44) between the stent-retriever thrombectomy and aspiration groups. The stent-retriever thrombectomy-first group achieved a statistically significant higher TICI 2b/3 rate after the first-line device than the aspiration-first group (74.9% versus 66.4%; OR = 1.53; 95% CI, 1.14%-2.05%) and resulted in lower use of a rescue device (19.9% versus 32.5%; OR = 0.36; 95% CI, 0.14%-0.90%). The aspiration-first approach resulted in a statistically shorter groin-to-reperfusion time (weighted mean difference, 7.15 minutes; 95% CI, 1.63-12.67 minutes). There was no difference in the number of passes, symptomatic intracerebral hemorrhage, vessel dissection or perforation, and mortality between groups.

LIMITATIONS

Most of the included studies were nonrandomized. There was significant heterogeneity in some of the outcome variables.

CONCLUSIONS

Stent-retriever thrombectomy-first and aspiration-first thrombectomy were associated with comparable final reperfusion rates and functional outcome. Stent-retriever thrombectomy was superior in achieving reperfusion as a stand-alone first-line technique, with lower use of rescue devices but a longer groin-to-reperfusion time.

Contact Aspiration versus Stent-Retriever Thrombectomy for Distal Middle Cerebral Artery Occlusions in Acute Ischemic Stroke: Meta-Analysis

PURPOSE

The evidence for endovascular therapy and choice of technique in distal middle cerebral artery (MCA) M2 segment occlusions in acute ischemic stroke remains controversial. We aimed to conduct a systematic review and meta-analysis primarily comparing reperfusion rates of stent-retrieval versus contact aspiration for M2 occlusions.

MATERIALS AND METHODS

Study selection included cohorts of patients with distal MCA occlusions in acute ischemic strokes treated with an endovascular approach including stent-retrieval or contact aspiration. Twelve studies were selected for meta-analysis for a total of 835 cases. Meta-analysis by proportions was conducted on parameters including baseline and procedural characteristics, thrombolysis in cerebral infarction (TICI) 2b-3 outcomes, and 90-day modified Rankin scale (mRS) outcomes.

RESULTS

Hypertension and hyperlipidemia were more prevalent in stent-retriever patients. Pooled baseline National Institute of Health Stroke Scale scores and Alberta Stroke Program Early Computed Tomography Score imaging scores were similar. Pooled time onset of symptoms to door arrival was higher for the stent-retrieval group (154 vs. 97.4 minutes, P=0.01), as was time to groin puncture (259.9 vs. 156.2 minutes, P=0.02), but there was no difference in procedure time. The TICI 2b-3 recanalization rate was similar (80.5% vs. 86.8%, P=0.168). The frequency of mRS 0-2 at 90-day was also similar (74.5% vs. 59.9%, P=0.120), and an excellent mRS 0-1 was lower for stent-retrievers (39.9% vs. 65.6%, P=0.003). A significant negative correlation was found between onset to groin puncture time and the proportion of patients with a good mRS (r=-0.71, P=0.048).

CONCLUSION

Both endovascular techniques achieved recanalization rates greater than 80% and 90-day outcomes of minimal disability with similar complication rates. The literature is skewed by aspiration cases being performed sooner after onset of stroke compared to stent-retriever cases.

Thrombectomy 6-24 hours after stroke in trial ineligible patients

Background and purpose

The DAWN and DEFUSE-3 trials demonstrated the benefit of endovascular thrombectomy (ET) in late-presenting acute ischemic strokes due to anterior circulation large vessel occlusion (ACLVO). Strict criteria were employed for patient selection. We sought to evaluate the characteristics and outcomes of patients treated outside these trials.

Methods

A retrospective review of acute ischemic stroke admissions to a single comprehensive stroke center was performed during the DAWN trial enrollment period (November 2014 to February 2017) to identify all patients presenting in the 6–24 hour time window. These patients were further investigated for trial eligibility, baseline characteristics, treatment, and outcomes.

Results

Approximately 70% (n=142) of the 204 patients presenting 6–24 hours after last known well with NIH Stroke Scale score ≥6 and harboring an ACLVO are DAWN and/or DEFUSE-3 ineligible, most commonly due to large infarct burden (38%). 26% (n=37) of trial ineligible patients with large vessel occlusion strokes received off-label ET and 30% of them achieved functional independence (modified Rankin Scale 0–2) at 90 days. Rates of symptomatic intracranial hemorrhage and mortality were 8% and 24%, respectively

Conclusion

Trial ineligible patients with large vessel occlusion strokes receiving off-label ET achieved outcomes comparable to DAWN and DEFUSE-3 eligible patients. Patients aged <80 years are most likely to benefit from ET in this subgroup. These data indicate a larger population of patients who can potentially benefit from ET in the expanded time window if more permissive criteria are applied.

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

Background and Purpose—

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

Methods—

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

Results—

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

Conclusions—

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

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.

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.