Benefit of endovascular thrombectomy for M2 middle cerebral artery occlusion in the ARISE II study

Multicenter evaluation of mechanical thrombectomy for distal medium vessel occlusions with National Institute of Health Stroke Scale Scores ≥ 6 and ≤ 6

BACKGROUND

While mechanical thrombectomy is considered standard of care for large vessel occlusions, scientific evidence to support treatment for distal and medium vessel occlusions remains scarce.

PURPOSE

To evaluate feasibility, safety, and outcomes in patients with low National Institute of Health Stroke Scale scores undergoing mechanical thrombectomy for treatment of distal medium vessel occlusions.

MATERIALS AND METHODS

Retrospective data review and analysis of prospectively maintained databases at 41 academic centers in North America, Asia, and Europe between January 2017 and January 2022. Characteristics and outcomes were compared between groups with low stroke scale score (≤ 6) versus and higher stroke scale scores (> 6). Propensity score matching using the optimal pair matching method and 1:1 ratio was performed.

RESULTS

Data were collected on a total of 1068 patients. After propensity score matching, there were a total of 676 patients included in the final analysis, with 338 patients in each group. High successful reperfusion rates were seen in both groups, 90.2% in ≤ 6 and 88.7% in the > 6 stroke scale groups. The frequency of excellent and good functional outcome was seen more common in low versus higher stroke scale score patients (64.5% and 81.1% versus 39.3% and 58.6%, respectively). The 90-day mortality rate observed in the ≤ 6 stroke scale group was 5.3% versus 13.3% in the > 6 stroke scale group.

CONCLUSION

Mechanical thrombectomy in distal and medium vessel occlusions, specifically in patients with low stroke scale scores is feasible, though it may not necessarily improve outcomes over IVT.

Effect of General Anesthesia Versus Conscious Sedation/Local Anesthesia on the Outcome of Patients with Minor Stroke and Isolated M2 Occlusion Undergoing Immediate Thrombectomy: A Retrospective Multicenter Matched Analysis

BACKGROUND

This study investigates the impact of general anesthesia (GA) versus conscious sedation/local anesthesia (CS/LA) on the outcome of patients with minor stroke and isolated M2 occlusion undergoing immediate mechanical thrombectomy (iMT).

METHODS

The databases of 16 comprehensive stroke centers were retrospectively screened for consecutive patients with isolated M2 occlusion and a baseline National Institutes of Health Stroke Scale score ≤5 who received iMT. Propensity score matching was used to estimate the effect of GA versus CS/LA on clinical outcomes and procedure-related adverse events. The primary outcome measure was a 90-day modified Rankin Scale (mRS) score of 0-1. Secondary outcome measures were a 90-day mRS score of 0-2 and all-cause mortality, successful reperfusion, procedural-related symptomatic subarachnoid hemorrhage, intraprocedural dissections, and new territory embolism.

RESULTS

Of the 172 patients who were selected, 55 received GA and 117 CS/LA. After propensity score matching, 47 pairs of patients were available for analysis. We found no significant differences in clinical outcome, rates of efficient reperfusion, and procedural-related complications between patients receiving GA or LA/CS (mRS score 0-1, P = 0.815; mRS score 0-2, P = 0.401; all-cause mortality, P = 0.408; modified Treatment in Cerebral Infarction score 2b-3, P = 0.374; symptomatic subarachnoid hemorrhage, P = 0.082; intraprocedural dissection, P = 0.408; new territory embolism, P = 0.462).

CONCLUSIONS

In patients with minor stroke and isolated M2 occlusion undergoing iMT, the type of anesthesia does not affect clinical outcome or the rate of procedural-related complications. Our results agree with recent data showing no benefit of one specific anesthesiologic procedure over the other and confirm their generalizability also to patients with minor baseline symptoms.

Safety and efficacy of endovascular thrombectomy for primary and secondary MeVO

BACKGROUND

Medium-vessel occlusions (MeVO) are emerging as a new target for endovascular treatment (EVT). Primary MeVO occur de novo, while secondary MeVO arise from large vessel occlusion (LVO) through clot migration or fragmentation - spontaneously, following intravenous thrombolysis or EVT. We aimed to evaluate efficacy and safety of EVT in primary and EVT-induced secondary MeVO.

METHODS

Retrospective single-center study on consecutive EVT-treated acute ischemic stroke, from 2019-to-2021. We considered: (1) exclusive-LVO, patients with LVO and - in case of residual distal occlusion - no rescue endovascular procedure; (2) primary MeVO: initial A2, A3, M2 non-dominant, M3, P2, P3 occlusions; (3) EVT-induced secondary MeVO, presenting LVO with subsequent (treated) EVT-induced MeVO. We compared (univariable/multivariable logistic regression) EVT efficacy (eTICI≥2b, 3-month modified Rankin Scale [mRS] 0-2) and safety (EVT-complications [vessel dissection, perforation, persistent-SAH], symptomatic ICH) in all MeVO versus exclusive-LVO, primary MeVO versus exclusive-LVO, EVT-induced secondary MeVO versus exclusive-LVO and EVT-induced secondary MeVO versus primary MeVO.

RESULTS

We included 335 patients: 221 (66.0 %) exclusive-LVO and 114 (34.0 %) MeVO (55 [48.2 %] primary, 59 [51.8 %] secondary). Compared to exclusive-LVO, primary MeVO had higher rates of EVT complications (aOR 3.77 [95%CI 1.58-9.00],p=0.003), lower rates of eTICI≥2b (aOR 0.32 [95%CI 0.12-0.88],p=0.027) and mRS 0-2 (aOR 0.28 [95%CI 0.13-0.63],p=0.002). EVT-induced secondary MeVO had no major differences in efficacy and safety outcomes compared to exclusive-LVO, but a better mRS 0-2 (aOR 8.00 [95%CI 2.12-30.17],p=0.002) compared to primary MeVO.

CONCLUSIONS

Primary and EVT-induced secondary MeVO showed different safety/efficacy EVT-related profiles. Dedicated randomized data are needed to identify the best acute reperfusion strategy in the two categories.

Flow-diverter stents in intracranial aneurysm treatment: impact on covered cerebral artery branches

OBJECTIVE

Flow diverter stents (FDSs) have attracted interest for intracranial aneurysm (IA) treatment; however, occlusion of side branches and related complications have been reported. This study aimed to investigate the effects of FDSs in IA management when different branches of intracranial arteries are covered.

MATERIALS AND METHODS

A cross-sectional study was conducted using PUBMED, Embase, Web of Science, and Cochrane databases to include randomized or nonrandomized comparative-designed studies from January 2000 to August 2022 which reported outcomes of occlusion/narrowing of branches after IA treatment using FDSs. The PRISMA guidelines were used for our report. A random-effects meta-analysis was conducted to pool the outcomes, which included incidence rates of occlusion/narrowing of FDS-covered branches, branch occlusion-related symptoms, obliteration of IAs, and ideal clinical outcomes (modified Rankin Scale score ≤2).

RESULTS

The authors identified 57 studies involving 3789 patients with IA managed by FDSs covering different branches. During the median imaging follow-up at 12 months, the IA obliteration rate was satisfactory (>70%) when covering the ophthalmic artery (OA), posterior communicating artery (PComA), anterior choroidal artery (AChoA) or anterior cerebral artery (ACA), but not the middle cerebral artery-M2 segment (MCA-M2; 69.5%; 95% CI: 60.8-77.5%) and posterior inferior cerebellar artery (PICA; 59.1%, 13/22). The overall ideal clinical outcome was observed in 97.4% of patients (95% CI: 95.5-98.9%). Higher rates of occlusion/narrowing of branches were identified when FDSs covered the ACA (66.6%; 95% CI: 45.1-85.3%), PComA (44.3%; 95% CI: 34.2-54.6%), or MCA-M2 (39.2%; 95% CI: 24.5-54.7%); the risks were lower when covering the OA (11.8%; 95% CI: 8.8-15.1%), PICA (6.8%; 95% CI: 1.5-14.5%), and AchoA (0.5%; 95% CI: 0.0-2.9%). The risk of branch occlusion-related complications was low (incidence rate <5%) for each of the six evaluated branches.

CONCLUSIONS

Acceptable outcomes were identified following treatment of IAs when FDSs were placed across each of the six studied cerebral arteries. Treatment decisions regarding FDS placement across branch arteries should be made with the risk of complications from branch occlusion in mind.

Mechanical thrombectomy for the treatment of primary and secondary distal medium-vessel occlusion stroke: systematic review and meta-analysis

BACKGROUND

There is limited evidence on the indication and role of mechanical thrombectomy (MT) in patients with distal medium-vessel occlusions (DMVOs). The aim of this systematic review and meta-analysis was to evaluate all the evidence available on the efficacy and safety of MT techniques (stent retriever, aspiration) in primary and secondary DMVOs.

METHODS

Five databases were searched from inception to January 2023 for studies of MT in primary and secondary DMVOs. Outcomes of interest included favorable functional outcome (90-day modified Rankin scale (mRS) 0-2), successful reperfusion (modified Thrombolysis in Cerebral Infarction (mTICI) 2b-3), symptomatic intracerebral hemorrhage (sICH), and 90-day mortality. Prespecified subgroup meta-analyses according to the specific MT technique and to the vascular territory (distal M2-M5, A2-A5, P2-P5) were also performed.

RESULTS

A total of 29 studies with 1262 patients were included. For primary DMVOs (n=971 patients), pooled rates of successful reperfusion, favorable outcome, 90-day mortality and sICH were 84% (95% confidence interval (CI) 76 to 90%), 64% (95% CI 54 to 72%), 12% (95% CI 8 to 18%), and 6% (95% CI 4 to 10%), respectively. For secondary DMVOs (n=291 patients), pooled rates of successful reperfusion, favorable outcome, 90-day mortality and sICH were 82% (95% CI 73 to 88%), 54% (95% CI 39 to 69%), 11% (95% CI 5 to 20%), and 3% (95% CI 1 to 9%), respectively. Subgroup analyses by MT technique and by vascular territory showed no differences in primary and secondary DMVOs.

CONCLUSION

Our findings suggest that MT using aspiration or stent retriever techniques appears to be effective and safe in primary and secondary DMVOs. However, given the level of evidence of our results, further confirmation in well-designed randomized controlled trials is needed.

Early neurological deterioration in patients with minor stroke due to isolated M2 occlusion undergoing medical management: a retrospective multicenter study

BACKGROUND

Patients with minor stroke and M2 occlusion undergoing best medical management (BMM) may face early neurological deterioration (END) that can lead to poor long-term outcome. In case of END, rescue mechanical thrombectomy (rMT) seems beneficial. Our study aimed to define factors relevant to clinical outcome in patients undergoing BMM with the possibility of rMT on END, and find predictors of END.

METHODS

Patients with M2 occlusion and a baseline National Institutes of Health Stroke Scale (NIHSS) score≤5 that received either BMM only or rMT on END after BMM were extracted from the databases of 16 comprehensive stroke centers. Clinical outcome measures were a 90-day modified Rankin Scale (mRS) score of 0-1 or 0-2, and occurrence of END.

RESULTS

Among 10 169 consecutive patients with large vessel occlusion admitted between 2016 and 2021, 208 patients were available for analysis. END was reported in 87 patients that were therefore all subjected to rMT. In a logistic regression model, END (OR 3.386, 95% CI 1.428 to 8.032), baseline NIHSS score (OR 1.362, 95% CI 1.004 to 1.848) and a pre-event mRS score=1 (OR 3.226, 95% CI 1.229 to 8.465) were associated with unfavorable outcome. In patients with END, successful rMT was associated with favorable outcome (OR 4.549, 95% CI 1.098 to 18.851). Among baseline clinical and neuroradiological features, presence of atrial fibrillation was a predictor of END (OR 3.547, 95% CI 1.014 to 12.406).

CONCLUSION

Patients with minor stroke due to M2 occlusion and atrial fibrillation should be closely monitored for possible worsening during BMM and, in this case, promptly considered for rMT.

Influence of prior intravenous thrombolysis in patients treated with mechanical thrombectomy for M2 occlusions: insight from the Endovascular Treatment in Ischemic Stroke (ETIS) registry

BACKGROUND

Intravenous thrombolysis (IVT) for patients treated with mechanical thrombectomy (MT) for proximal occlusions has recently been questioned through randomized trials. However, few patients with M2 occlusions were included. We investigated the influence of prior IVT for patients presenting M2 occlusions treated with MT in comparison with MT alone.

METHODS

We conducted a retrospective analysis of the Endovascular Treatment in Ischemic Stroke (ETIS) registry, a multicenter observational study. Data from consecutive patients treated with MT for M2 occlusions between January 2015 and January 2022 at 26 comprehensive stroke centers were analyzed. The primary endpoint was 90-day modified Rankin Scale score of 0-2. Outcomes were compared using propensity score approaches. We also performed sensitivity analysis in relevant subgroups of patients.

RESULTS

Among 1132 patients with M2 occlusions treated with MT, 570 received prior IVT. The two groups were comparable after propensity analysis. The rate of favorable functional outcome was significantly higher in the IVT+MT group compared with the MT alone group (59.8% vs 44.7%; adjusted OR 1.38, 95% CI 1.10 to 1.75, P=0.008). Hemorrhagic and procedural complications were similar in both groups. In sensitivity analysis excluding patients with anticoagulation treatment, favorable recanalization was more frequent in the IVT+MT group (OR 1.37, 95% CI 1.11 to 1.70, P=0.004).

CONCLUSIONS

In cases of M2 occlusions, prior IVT combined with MT resulted in better functional outcome than MT alone, without increasing the rate of hemorrhagic or procedural complications. These results suggest the benefit of IVT in patients undergoing MT for M2 occlusions.

Mechanical thrombectomy in minor stroke due to isolated M2 occlusion: a multicenter retrospective matched analysis

BACKGROUND

The purpose of this study was to evaluate the effectiveness of mechanical thrombectomy (MT) in patients with isolated M2 occlusion and minor symptoms and identify possible baseline predictors of clinical outcome.

METHODS

The databases of 16 high-volume stroke centers were retrospectively screened for consecutive patients with isolated M2 occlusion and a baseline National Institutes of Health Stroke Scale (NIHSS) score ≤5 who received either early MT (eMT) or best medical management (BMM) with the possibility of rescue MT (rMT) on early neurological worsening. Because our patients were not randomized, we used propensity score matching (PSM) to estimate the treatment effect of eMT compared with the BMM/rMT. The primary clinical outcome measure was a 90-day modified Rankin Scale score of 0-1.

RESULTS

388 patients were initially selected and, after PSM, 100 pairs of patients receiving eMT or BMM/rMT were available for analysis. We found no significant differences in clinical outcome and in safety measures between patients receiving eMT or BMM/rMT. Similar results were also observed after comparison between eMT and rMT. Concerning baseline predicting factors of outcome, the involvement of the M2 inferior branch was associated with a favorable outcome.

CONCLUSION

Our multicenter retrospective analysis has shown no benefit of eMT in minor stroke patients with isolated M2 occlusion over a more conservative therapeutic approach. Although our results must be viewed with caution, in these patients it appears reasonable to consider BMM as the first option and rMT in the presence of early neurological deterioration.

The diagnostic performance of artificial intelligence algorithms for identifying M2 segment middle cerebral artery occlusions: A systematic review and meta-analysis

BACKGROUND

Artificial intelligence (AI)-based algorithms have been developed to facilitate rapid and accurate computed tomography angiography (CTA) assessment in proximal large vessel occlusion (LVO) acute ischemic stroke, including internal carotid artery and M1 occlusions. In clinical practice, however, the detection of medium vessel occlusion (MeVO) represents an ongoing diagnostic challenge in which the added value of AI remains unclear.

PURPOSE

To assess the diagnostic performance of AI platforms for detecting M2 occlusions.

METHODS

Studies that report the diagnostic performance of AI-based detection of M2 occlusions were screened, and sensitivity and specificity data were extracted using the semi-automated AutoLit software (Nested Knowledge, MN) platform. STATA (version 16 IC; Stata Corporation, College Station, Texas, USA) was used to conduct all analyses.

RESULTS

Eight studies with a low risk of bias and significant heterogeneity were included in the quantitative and qualitative synthesis. The pooled estimates of sensitivity and specificity of AI platforms for M2 occlusion detection were 64% (95% CI, 53 to 74%) and 97% (95% CI, 84 to 100%), respectively. The area under the curve (AUC) in the SROC curve was 0.79 (95% CI, 0.74 to 0.83).

CONCLUSION

The current performance of the AI-based algorithm makes it more suitable as an adjunctive confirmatory tool rather than as an independent one for M2 occlusions. With the rapid development of such algorithms, it is anticipated that newer generations will likely perform much better.

Outcomes with Endovascular Treatment of Patients with M2 Segment MCA Occlusion in the Late Time Window

BACKGROUND AND PURPOSE

Randomized trials in the late window have demonstrated the efficacy and safety of endovascular thrombectomy in large-vessel occlusions. Patients with M2-segment MCA occlusions were excluded from these trials. We compared outcomes with endovascular thrombectomy in patients with M2-versus-M1 occlusions presenting 6-24 hours after symptom onset.

MATERIALS AND METHODS

Analyses were on pooled data from studies enrolling patients with stroke treated with endovascular thrombectomy 6-24 hours after symptom onset. We compared 90-day functional independence (mRS ≤ 2), mortality, symptomatic intracranial hemorrhage, and successful reperfusion (expanded TICI = 2b-3) between patients with M2 and M1 occlusions. The benefit of successful reperfusion was then assessed among patients with M2 occlusion.

RESULTS

Of 461 patients, 367 (79.6%) had M1 occlusions and 94 (20.4%) had M2 occlusions. Patients with M2 occlusions were older and had lower median baseline NIHSS scores. Patients with M2 occlusion were more likely to achieve 90-day functional independence than those with M1 occlusion (adjusted OR = 2.13; 95% CI, 1.25-3.65). There were no significant differences in the proportion of successful reperfusion (82.9% versus 81.1%) or mortality (11.2% versus 17.2%). Symptomatic intracranial hemorrhage risk was lower in patients with M2-versus-M1 occlusions (4.3% versus 12.2%, P = .03). Successful reperfusion was independently associated with functional independence among patients with M2 occlusions (adjusted OR = 2.84; 95% CI, 1.11-7.29).

CONCLUSIONS

In the late time window, patients with M2 occlusions treated with endovascular thrombectomy achieved better clinical outcomes, similar reperfusion, and lower symptomatic intracranial hemorrhage rates compared with patients with M1 occlusion. These results support the safety and benefit of endovascular thrombectomy in patients with M2 occlusions in the late window.

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.

Prediction of Functional Outcome in Stroke Patients with Proximal Middle Cerebral Artery Occlusions Using Machine Learning Models

At present, clinicians are expected to manage a large volume of complex clinical, laboratory, and imaging data, necessitating sophisticated analytic approaches. Machine learning-based models can use this vast amount of data to create forecasting models. We aimed to predict short- and medium-term functional outcomes in acute ischemic stroke (AIS) patients with proximal middle cerebral artery (MCA) occlusions using machine learning models with clinical, laboratory, and quantitative imaging data as inputs. Included were consecutive AIS patients with MCA M1 and proximal M2 occlusions. The XGBoost, LightGBM, CatBoost, and Random Forest were used to predict the outcome. Minimum redundancy maximum relevancy was used for selecting features. The primary outcomes were the National Institutes of Health Stroke Scale (NIHSS) shift and the modified Rankin Score (mRS) at 90 days. The algorithm with the highest area under the receiver operating characteristic curve (AUROC) for predicting the favorable and unfavorable outcome groups at 90 days was LightGBM. Random Forest had the highest AUROC when predicting the favorable and unfavorable groups based on the NIHSS shift. Using clinical, laboratory, and imaging parameters in conjunction with machine learning, we accurately predicted the functional outcome of AIS patients with proximal MCA occlusions.

The initial experience with the Embotrap III stent-retriever in a real world setting

MATERIALS AND METHODS

We performed a retrospective review of our prospectively maintained database to identify all patients treated with the Embotrap 3 stent-retriever between January 2021 and January 2022. We recorded the baseline demographics, NIHSS, ASPECT score and clot characteristics, first pass and final eTICI scores, complications and 90 day mRS.

RESULTS

One hundred and ten patients met the inclusion criteria, average age 69 ± 14 years, 50% were male (n = 55). The median NIHSS at presentation was 18 (range 3-30) and 58.2% received IV tPA prior to MT. The median ASPECT score on plain CT was 8 with average clot length 20.2 ± 14.8 mm (n = 93). The first pass effect (FPE) was seen in 41.8% of cases with modified FPE seen in 59.1%. A 24-hour CT scan (n = 97) showed median ASPECTs of 7. 43.8% of patients achieve mRS ≤ 2 at 90-day mRS (n = 64).

CONCLUSION

The Embotrap 3 stent-retriever has a high rate of FPE and final recanalization in this real world cohort of patients.

Predictors and Impact of Sulcal SAH after Mechanical Thrombectomy in Patients with Isolated M2 Occlusion

BACKGROUND AND PURPOSE

Data on SAH after M2 mechanical thrombectomy are limited. We aimed to determine the prevalence of sulcal SAH after mechanical thrombectomy for M2 occlusion, its associated predictors, and the resulting clinical outcome.

MATERIALS AND METHODS

The study retrospectively reviewed the data of patients with acute ischemic stroke who underwent mechanical thrombectomy for isolated M2 occlusion. The patients were divided into 2 groups according to the presence of sulcal SAH after M2 mechanical thrombectomy. Angiographic and clinical outcomes were compared. Multivariable analysis was performed to identify independent predictors of sulcal SAH and unfavorable outcome (90-day mRS, 3-6).

RESULTS

Of the 209 enrolled patients, sulcal SAH was observed in 33 (15.8%) patients. The sulcal SAH group showed a higher rate of distal M2 occlusion (69.7% versus 22.7%), a higher of rate of superior division occlusion (63.6% versus 43.8%), and a higher M2 angulation (median, 128° versus 106°) than the non-sulcal SAH group. Of the 33 sulcal SAH cases, 23 (66.7%) were covert without visible intraprocedural contrast extravasation. Distal M2 occlusion (OR, 12.04; 95% CI, 4.56-35.67; P < .001), superior division (OR, 3.83; 95% CI, 1.43-11.26; P = .010), M2 angulation (OR, 1.02; 95% CI, 1.01-1.04; P < .001), and the number of passes (OR, 1.58; 95% CI, 1.22-2.09; P < .001) were independent predictors of sulcal SAH. However, covert sulcal SAH was not associated with an unfavorable outcome (P = .830).

CONCLUSIONS

After mechanical thrombectomy for M2 occlusion, sulcal SAH was not uncommon and occurred more frequently with distal M2 occlusion, superior division, acute M2 angulation, and multiple thrombectomy passes (≥3). The impact of covert sulcal SAH was mostly benign and was not associated with an unfavorable outcome.

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.

Thrombectomy in acute ischemic stroke in the extended time window: Real-life experience in a high-volume center

OBJECTIVES

Selected patients with acute ischemic stroke (AIS) caused by proximal middle cerebral artery (MCA) or internal carotid artery occlusion benefit from endovascular thrombectomy (EVT) in extended time window (6-24 h from last seen well) based on two landmark randomized controlled trials (RCTs) DAWN and DEFUSE-3. We evaluated patients' outcome in the real-life with the focus on adherence to protocol of the two RCTs.

MATERIALS AND METHODS

We included consecutive patients with AIS (excluding basilar artery occlusions) referred to EVT in our stroke center in the extended time window between January 2018 and December 2019 and compared the outcome of patients who fulfilled criteria of the RCTs with those who did not.

RESULTS

Of the total of 100 patients, 23 complied with RCT's criteria and 18 presented with minor non-adherence (lower NIHSS score or longer treatment delay), whereas 22 patients had large baseline ischemia (>1/3 MCA), 28 presented with M2 and more distal occlusions, and 9 patients did not undergo perfusion imaging prior to EVT. Good 3-month outcome (modified Rankin Scale 0-2) was observed in 54% of those who either met the RCT criteria or presented with lower NIHSS score or longer treatment delay, but only in 30% of M2 occlusions, and in none of the patients with large baseline ischemia.

CONCLUSIONS

Our findings highlight the impact of mostly large baseline ischemia but also vessel status when selecting patients for EVT in the extended time window and emphasize the need for further data in these patient subgroups.

Endovascular Thrombectomy for Distal Medium Vessel Occlusions of the Middle Cerebral Artery: A Safe and Effective Procedure

BACKGROUND

Distal medium vessel occlusions (DMVOs) are increasingly recognized as a next target for endovascular thrombectomy (EVT). Our objective was to investigate safety and clinical outcomes of EVT for DMVO of the middle cerebral artery (MCA).

METHODS

We analyzed data of the Lille Reperfusion Registry from January 2017 to September 2020. Patients with a primary or secondary DMVO of the MCA seen on pretreatment angiogram were included. Only patients with a eTICI score 2b50-2b67 on initial angiogram were considered. Baseline characteristics, angiographic clinical, and safety outcomes were compared between patients treated with EVT or standard medical treatment (no-EVT).

RESULTS

Of the 171 patients included, 96 received EVT (46.9% male, 68.7 ± 15.8 years) and 75 received standard medical treatment (44% male, 73.9 ± 13.1 years). EVT patients had a better improvement of the NIHSS score at discharge (adjusted mean difference: 3.71; 95% CI: 1.18-6.24). In the distal M2 occlusions subgroup, EVT was significantly associated with a higher rate of early neurologic improvement (adjusted OR: 3.62 95% CI: 1.31-10.03), NIHSS improvement at discharge (adjusted mean difference: 5.23; 95% CI: 2.18-8.29), and improved modified Rankin Scale score at 3 months (adjusted common OR for 1 point improvement: 3.06; 95% CI: 1.30 to 7.23). Symptomatic intracranial hemorrhage occurred in 3.1% in the EVT group and in 9.5% in the no-EVT group.

CONCLUSIONS

EVT for DMVO of the MCA appears to be safe and may lead to improved clinical outcomes. This effect was especially pronounced in patients with distal M2 occlusions, warranting randomized trials to validate this result.

Outcomes after reperfusion therapies in patients with ACA stroke: A multicenter cohort study from the EVATRISP collaboration

BACKGROUND

Patients with stroke secondary to occlusions of the anterior cerebral artery (ACA) often have poor outcomes. The optimal acute therapeutic intervention for these patients remains unknown.

METHODS

Patients with isolated ACA-stroke were identified from 10 centers participating in the EndoVascular treatment And ThRombolysis in Ischemic Stroke Patients (EVATRISP) prospective registry. Patients treated with endovascular thrombectomy (EVT) were compared to those treated with intravenous thrombolysis (IVT). Odds ratios with 95% confidence intervals (OR; 95%CI) were calculated using multivariate regression analysis.

RESULTS

Included were 92 patients with ACA-stroke. Of the 92 ACA patients, 55 (60%) were treated with IVT only and 37 (40%) with EVT (±bridging IVT). ACA patients treated with EVT had more often wake-up stroke (24% vs. 6%, p = 0.044) and proximal ACA occlusions (43% vs. 24%, p = 0.047) and tended to have higher stroke severity on admission [NIHSS: 10.0 vs 7.0, p = 0.054). However, odds for favorable outcome, mortality or symptomatic intracranial hemorrhage did not differ significantly between both groups. Exploration of the effect of clot location inside the ACA showed that in patients with A1 or A2/A3 ACA occlusions the chances of favorable outcome were not influenced by treatment allocation to IVT or EVT.

DISCUSSION

Treatment with either IVT or EVT could be safe with similar effect in patients with ACA-strokes and these effects may be independent of clot location within the occluded ACA.

3D Turbo Spin-echo MRI-based Mechanical Thrombectomy at Middle Cerebral Artery Bifurcations

We describe three cases with acute middle cerebral artery (MCA) occlusion. From the pre-operative MRI, including three-dimensional turbo spin-echo sequences using T1WI and T2WI, we assessed both thrombus configuration and arterial anatomy at the MCA bifurcations. For efficient endovascular thrombectomy, we identified the applied MCA segment 2 (M2) branch, in which the main thrombus was buried. Sufficient recanalization after a single pass was achieved and the patients made a marked recovery. Although mechanical thrombectomy for M2 occlusion has not been of proven benefit, the endovascular procedure based on three-dimensional turbo spin-echo imaging is useful for more complete thrombus removal at MCA bifurcations.

Middle Cerebral Artery M2 Thrombectomy in the STRATIS Registry

BACKGROUND AND PURPOSE

The safety and benefit of mechanical thrombectomy in the treatment of acute ischemic stroke patients with M2 segment middle cerebral artery occlusions remain uncertain. Here, we compare clinical and angiographic outcomes in M2 versus M1 occlusions in the STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) Registry.

METHODS

The STRATIS Registry was a prospective, multicenter, nonrandomized, observational study of acute ischemic stroke large vessel occlusion patients treated with the Solitaire stent-retriever as the first-choice therapy within 8 hours from symptoms onset. Primary outcome was defined as functional disability at 3 months measured by dichotomized modified Rankin Scale. Secondary outcomes included reperfusion rates and rates of symptomatic intracranial hemorrhage.

RESULTS

A total of 984 patients were included, of which 538 (54.7%) had M1 and 170 (17.3%) had M2 occlusions. Baseline demographics were well balanced within the groups, with the exception of mean baseline National Institutes of Health Stroke Scale score which was significantly higher in the M1 population (17.3±5.5 versus 15.7±5.0, P≤0.001). No difference was seen in mean puncture to revascularization times between the cohorts (46.0±27.8 versus 45.1±29.5 minutes, P=0.75). Rates of successful reperfusion (modified Thrombolysis in Cerebral Infarction≥2b) were similar between the groups (91% versus 95%, P=0.09). M2 patients had significantly increased rates of symptomatic ICH at 24 hours (4% versus 1%, P=0.01). Rates of good functional outcome (modified Rankin Scale score of 0-2; 58% versus 59%, P=0.83) and mortality (15% versus 14%, P=0.75) were similar between the 2 groups. There was no difference in the association of outcome and onset to groin puncture or onset to successful reperfusion in M1 and M2 occlusions.

CONCLUSIONS

In the STRATIS Registry, M2 occlusions achieved similar rates of successful reperfusion, good functional outcome, and mortality, although increased rates of symptomatic ICH were demonstrated when compared with M1 occlusions. The time dependence of benefit was also similar between the 2 groups. Further studies are needed to understand the benefit of mechanical thrombectomy for M2 occlusions.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02239640.

Per-pass analysis of recanalization and good neurological outcome in thrombectomy for stroke: Systematic review and meta-analysis

BACKGROUND AND AIM

First pass effect (FPE) is defined as achieving a complete recanalization with a single thrombectomy device pass. Although clinically desired, FPE is reached in less than 30% of thrombectomy procedures. Multiple device passes are often necessary to achieve successful or complete recanalization. We performed a systematic review and meta-analysis to determine the recanalization rate after each pass of mechanical thrombectomy and its association with good neurological outcome.

METHODS

A literature search was performed for studies reporting the number of device passes required for either successful (mTICI 2b or higher) or complete (mTICI 2c or higher) recanalization. Using random-effect meta-analysis, we evaluated the likelihood of recanalization and good neurological outcome (measured with the modified Rankin Score <2 at 90 days) after each device pass.

RESULTS

Thirteen studies comprising 4197 patients were included. Among cases with failed first pass, 24% of them achieved final complete recanalization and 45% of them achieved final successful recanalization. Independently to the total number of previously failed attempts, the likelihood of achieving successful recanalization was 30% per pass, and the likelihood to achieve complete recanalization was about 20% per pass. The likelihood of good neurological outcome in patients with final successful recanalization decreased after each device pass: 55% after the first pass, 48% after the second pass, 42% after the third pass, 36% after the fourth pass, and 26% for 5 passes or more.

CONCLUSION

Each pass is associated with a stable likelihood of recanalization but a decreased likelihood of good neurological outcome.

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.

Endovascular reperfusion of M2 occlusions in acute ischemic stroke reduced disability and mortality: ETIS Registry results

BACKGROUND

The predictors of successful reperfusion and the effect of reperfusion after endovascular treatment (EVT) for M2 occlusions have not been well studied. We aimed to identify predictors of successful reperfusion and the effect of reperfusion on outcomes of EVT for M2 occlusions in current practice.

METHODS

Patients with acute ischemic stroke due to isolated M2 occlusions who were enrolled in the prospective multicenter Endovascular Treatment in Ischemic Stroke (ETIS) Registry in France between January 2015 and March 2020 were included. The primary outcome was a favorable outcome, defined as modified Rankin Scale (mRS) score of 0-2 at 90 days. Successful reperfusion was defined as an improvement of ≥1 points in the modified Thrombolysis In Cerebral Infarction score between the first and the last intracranial angiogram.

RESULTS

A total of 458 patients were included (median National Institutes of Health Stroke Scale (NIHSS) score 14; 61.4% received prior intravenous thrombolysis). Compared with the non-reperfused patients, reperfused patients had an increased rate of excellent outcome (OR 2.3, 95% CI 0.98 to 5.36; p=0.053), favorable outcome (OR 2.79, 95% CI 1.31 to 5.93; p=0.007), and reduced 90-day mortality (OR 0.39, 95% CI 0.19 to 0.79; p<0.01). Admission NIHSS score was the only predictor of successful reperfusion. First-line strategy was not a predictor of successful reperfusion or favorable outcome, but the use of a stent retriever, alone or with an aspiration catheter, was associated with higher rates of procedural complications and 90-day mortality.

CONCLUSIONS

Successful reperfusion of M2 occlusions reduced disability and mortality. However, safety is a concern, especially if the procedure failed.