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Background: The time frame for mechanical thrombectomy (MT) in acute ischemic stroke (AIS) is enlarging. Guidelines recommend MT until 6 h of symptom onset in M2 segment occlusions (grade IIB). In practice, it is frequently performed later., Aims: To assess the functional prognosis of AIS patients subjected to M2 segment's MT beyond 6 h, compared to standard intervention., Methods: Retrospective cohort study including all consecutive AIS patients subjected to MT of M2 occlusions between 1st January 2018 and 31st December 2020 in St Joseph's Local Health Unit, Lisbon, Portugal. Allocation to standard or extended groups was done according to the symptom-to-puncture time, whether within or beyond 6 h after symptom onset, respectively. The primary outcome was the modified Rankin Scale (mRS) at three months. Secondary outcomes were symptomatic intracranial hemorrhage (sICH) at 24 h and three-month mortality., Results: We included 155 patients, 51.0 % men, median age 76.0 years (P 25 :69.0;P 75 :86.0), baseline mRS "0-2" in 84.5 %, mean NIHSS 13.6(6.5). Initial Computed Tomography showed early ischemic changes in 27.1 %. Most patients belonged to the standard group (71.0 %). Groups had similar baseline features. The standard group underwent more frequent (68.2 % vs 44.4 %, p = 0.006) and earlier (2 h02 min, 3 h02 min, p < 0.001) fibrinolysis. Symptom-to-puncture times were 7 h13 min (extended) and 4h01 min (standard), p < 0.001. Outcomes were similar between groups (three months' mRS [p = 0.578]; sICH [p = 0.720]; three-month mortality [p = 0.422])., Conclusions: Our study suggests similar outcomes in M2 occlusions performing MT before and beyond 6 h of symptom onset, consistent with previous studies. Patients might benefit from widening inclusion criteria for MT in AIS., Competing Interests: Declaration of competing interest The authors have nothing to disclose., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background and Purpose: Endovascular thrombectomy (EVT) for acute ischemic stroke (AIS) with M2 segment occlusion of the middle cerebral artery (MCA) is debatable. This study assessed the efficacy, safety, and functional outcomes of EVT in M2 occlusion patients, examining differences in outcomes based on the dominance of the occluded segment (DomM2 vs. Non-DomM2)., Methods: A prospective cohort of 108 patients with AIS resulting from M2 segment occlusion of the MCA who underwent EVT was analyzed. We compared demographic, clinical, angiographic, and clinical outcome data (National Institutes of Health Stroke Scale [NIHSS] score at 24 h and modified Rankin Scale [mRS] score at 3 months) between patients with or without DomM2. The primary endpoint was the first-pass effect (FPE), defined as achieving modified Thrombolysis in Cerebral Infarction 2c-3 after one pass. We examined the symptomatic hemorrhagic transformation, 3-month functional outcomes, and mortality rates., Results: Seventy-five patients (69.44%) had DomM2. FPE rates (48.48% for DomM2; 42.66% for Non-DomM2, p = 0.521), final successful recanalization rate, and functional outcomes were comparable between subgroups. Direct aspiration yielded a higher FPE rate (56.25%). FPE was associated with lower NIHSS scores at discharge (median, 2 [interquartile range 0-4] vs. 5 [1-10]; p < 0.001) and higher 3-month functional independence (83.33% vs. 60.34%; p < 0.001). Direct aspiration independently predicted FPE, with a 75% likelihood compared to stent retriever (p = 0.007)., Conclusions: EVT is a safe and effective treatment for acute M2 occlusion regardless of the dominance of the M2 segment. Direct aspiration used as a frontline technique increases the likelihood of FPE., (© 2025 American Society of Neuroimaging.)

Purpose: This study aimed to clarify whether there is a relationship between vessel deviation during stent retrieval and successful recanalization in stent-based mechanical thrombectomy (MT) for M2 occlusion., Methods: The video of the MT was reviewed for each of the 25 included patients with M2 occlusion. The vertical distance of vessel deviation at the time of stent retrieval was defined as D, and the diameter of the balloon guide catheter shown on the same screen was defined as B. The D/B ratio was calculated as an index of the vessel deviation. The presence or absence of successful recanalization (thrombolysis in cerebral infarction (TICI) score of 2b/3) was compared based on the D/B ratio and clinical factors., Results: Of the 25 patients, successful recanalization was achieved in 18 (72%). The median D/B ratio with successful recanalization was 0.9, which was significantly lower than that without successful recanalization (2.5, p < 0.001, Mann-Whitney U test). Combined aspiration catheters were used in 24 cases. In nine (36%) cases, the tip of the aspiration catheter was in M2 during stent retrieval. The median D/B ratio with the position of the aspiration catheter tip in M1 or the internal carotid artery was 1.5, which was significantly higher than that with the position in M2 (0, p = 0.003, Mann-Whitney U test)., Conclusion: In stent-based MT for M2 occlusion, cases in which successful recanalization was achieved showed less vessel deviation during stent retrieval. To reduce vessel deviation, advancing the combined aspiration catheter up to M2 is useful., Competing Interests: Declarations. Ethics approval: This study was approved by the Ethics Committee of Suiseikai Kajikawa Hospital (number 202305) and conducted in accordance with the Declaration of Helsinki. Informed consent was waived by the Ethics Committee. Conflict of interest: The authors declare no conflict of interest in relation to this study., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: While revascularization for M2 occlusions is generally recommended and considered beneficial, the optimal approach (aspiration vs stentriever/combined) is less well defined in the literature. We sought to compare outcomes after thrombectomy with manual aspiration thrombectomy alone (MAT) or stentriever-mediated aspiration thrombectomy (SMAT) MATERIALS AND METHODS: To circumvent inter-operator technical variability, patients underwent thrombectomy for M2 occlusions by a single operator and were stratified by first pass approach: manual aspiration thrombectomy (MAT/aspiration alone) and stentriever-mediated manual aspiration thrombectomy (SMAT/combination). Efficacy outcomes included good reperfusion (mTICI score ≥2b) and a favorable 90-day functional outcome (mRS score of ≤2). Safety outcomes included 90-day mortality and symptomatic intracranial hemorrhage., Results: One hundred three patients were identified: 57 underwent MAT whereas 46 underwent SMAT. Good reperfusion (TICI 2b or greater) was comparable between groups (93.5 % vs. 87.7 %, P=0.33). The intracranial hemorrhage rate was higher with SMAT compared to MAT (13 % vs. 1.8 %, P=0.04). Puncture-to-recanalization time was longer in SMAT (34.4 vs. 19.9 minutes, P<0.001). In multivariable analysis, complete or good reperfusion was associated with shorter puncture-recanalization time (adjusted odds ratio [aOR], 0.85) or less total passes (aOR, 0.58), respectively. In a propensity score matched analysis of 66 patients with comparable baseline and technical efficiency, the safety outcomes were not different between SMAT and MAT groups., Conclusions: SMAT compared with MAT did not result in an improved revascularization rate or functional outcome, while it was related to more hemorrhagic complications and mortality. Given cost and time savings with manual aspiration alone, this approach may be optimal as first line for M2 occlusions., Competing Interests: Declaration of competing interest Dr. Gross is a consultant for Medtronic, Microvention and Stryker. The other authors have no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Endovascular therapy (EVT) for distal medium vessel occlusions requires prioritizing effectiveness and safety. We developed a technique combining the deployment of only the distal basket segment of the EMBOTRAP III and an aspiration catheter (AC) for M2 occlusions, called the "ONE-SEG technique," and evaluated its clinical and technical impacts., Methods: This was a retrospective review of 30 consecutive patients with M2 segment middle cerebral artery occlusion treated using the ONE-SEG technique. This method involves deploying the EMBOTRAP III through a microcatheter in only one segment and guiding the AC to the M2 origin or distal M1. The rates of final-pass expanded thrombolysis in cerebral infarction (eTICI) scores of 2c/3 or 2b/2c/3, safety (symptomatic intracranial hemorrhage [sICH]), and clinical outcomes (modified Rankin Scale [mRS] score 0-2, 0-3 at 90 days, and mortality at 90 days) were evaluated., Results: Of the 30 cases, 36.7% were female, and the mean age was 75.6 ± 11.0 years. The ONE-SEG technique was used for 17 cases (56.7%, median NIHSS 10 [5-15.5]) with primary M2 occlusion and 13 cases (43.3%, median NIHSS 20 [14-22.5]) with secondary M2 occlusion after proximal thrombus removal. The successful final reperfusion rate (eTICI 2b/2c/3) was 90% overall (27/30 cases). One case (3.3%) developed sICH with secondary M2 occlusion. At 3 months, mRS scores 0-2 were seen in 64.7% of patients with primary M2 occlusion (11/17 cases) and in 23.1% (3/13 cases) with secondary M2 occlusion., Conclusion: EVT using the ONE-SEG technique appears to be safe and effective for M2 occlusion., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Hamada, Matsuoka, Sato, Kawabata, Iwamoto, Ikeda, Sato, Takaguchi and Takashima.)

Background: The safety and efficacy of mechanical thrombectomy (MT) for proximal large vessel occlusion after acute ischemic stroke (AIS) have been demonstrated. Clinical investigations of endovascular approaches for treating AIS due to M2 occlusions have been ongoing., Purpose: To assess the outcomes of M2 occlusions according to treatment modality and anatomical division., Methods: A total of 113 consecutive M2 occlusions treated with endovascular treatment (EVT) at our tertiary stroke center between January 2019 and December 2022 were retrospectively analyzed. Patients were divided into three groups: mechanical thrombectomy (MT); intravenous thrombolysis plus MT (IVT + MT); and IVT alone. The primary outcomes were good prognosis (mRS = 0-2) and mortality (mRS = 6) on day 90. The secondary outcome was to determine the differences in outcomes between lesions in the superior and inferior branches of M2., Results: In total, 55 (48.7%) patients underwent MT. In 42 (37.2%) patients, bridging IVT was performed with MT, and IVT alone was applied in 16 (14.2%) patients. Neither the prognosis at 90 days nor the mortality rate significantly differed among the groups. The outcomes did not significantly differ between occlusions in the superior and inferior branches of M2., Conclusion: MT was found to be safe and effective for treating M2 occlusions in this series., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

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., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

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., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

Background: We compared the efficacy and safety of endovascular therapy (EVT), intravenous (IV) thrombolysis and conservative treatment in M2 segment occlusion stroke based on a real-world database., Methods: We retrospectively analyzed the database of admitted patients with M2 segment occlusion between January 2018 and December 2020. The patients who were eligible for reperfusion treatment were assigned to EVT, IV thrombolysis or conservative treatment according to the exact management proceeding. The primary outcome was a score of 0 and 1 on the modified Rankin scale (mRS) at 90 days. The odds ratio (OR) for the primary outcome was adjusted for age, baseline National Institute of Health Stroke Scale score, and door-to-treatment time. The secondary outcomes were based on a mRS score from 0 to 2 at 90 days and the safety outcomes including symptomatic intracranial hemorrhage, and all-cause mortality. The data were analyzed by the logistical regression model, including baseline adjustments., Results: A total of 109 patients were included. Among them, 42 (38.5%) patients received EVT, 45 (42.5%) received IV thrombolysis and 22 (20.8%) received conservative treatment. The primary outcome based on a mRS score of 0 and 1, occurred in 66.7% of patients in the EVT group and 40% in the IV thrombolysis group (adjusted OR, 1.79; 95% confidence interval [CI], 1.19-2.68; P = 0.01). Symptomatic intracranial hemorrhage occurred in 1 patient (2.3%) in the EVT group and in 2 patients (4.4%) in the IV thrombolysis group (adjusted OR = 0.71, 95% CI: 0.13-4.07)., Conclusion: EVT showed better functional outcomes than IV thrombolysis and conservative treatment in moderate to severe acute stoke patients with M2 occlusion. There was no significant difference in the three groups concerning the incidence of symptomatic intracranial hemorrhage., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Xu, Fu, Wang, Bi, Wang, Yang, Zhang and Wang.)

Objective: There are insufficient coherent reports on mechanical thrombectomy (MT) for occlusion of the second segment of the middle cerebral artery (M2 occlusion) in a real-world clinical setting. We evaluated the efficacy and safety of MT for M2 occlusions and compared the primary thrombectomy strategies (stent retriever, aspiration catheter, and combined technique) to analyze factors predicting good functional outcomes., Methods: We evaluated background factors, preprocedural factors, procedural factors, and procedural time for patients who underwent MT for M2 occlusions from our retrospective cohort. According to the modified Rankin Scale (mRS) score three months after MT, patients were divided into good (mRS ≤2) and poor (mRS ≥3) prognosis groups., Results: A total of 29 patients (median age, 78 years; 11 [37.9%] females) were included in the study. In this cohort, rates of successful reperfusion, thrombolysis in cerebral infarction (TICI) 3, postprocedural hemorrhage (PPH), and symptomatic PPH were 82.8, 34.5, 31.0, and 0%, respectively. Good prognoses were achieved in 13 (45%) cases. A prognostic factor of MT for M2 occlusions is TICI 3 from multivariate analysis (OR, 11.7; 95% CI, 1.003-136; p = 0.0497). There was no statistically significant difference in the functional outcome three months after MT based on the choice of the primary thrombectomy strategy., Conclusion: MT for M2 occlusions is a reliable and relatively safe procedure. The presence of TICI 3 was a prognostic factor in this cohort. Future studies are warranted to investigate the optimal thrombectomy strategy for medium vessel occlusion., Competing Interests: The authors declare that they have no conflicts of interest., (©2023 The Japanese Society for Neuroendovascular Therapy.)

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, I 2 =0%) and 90-day functional independence (OR=1.18, 95%CI 0.82-1.68, I 2 =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., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Introduction: The usefulness of the blind exchange with mini-pinning (BEMP) technique has recently been reported for mechanical thrombectomy in patients with stroke owing to medium vessel occlusion (MeVO). The Tron stent retriever can be delivered and deployed through a 0.0165-inch microcatheter. This retriever has potential as an effective and safe treatment for acute ischemic stroke (AIS) due to occlusion of the M2 segment of the middle cerebral artery (MCA). Here, we report the outcomes of the BEMP technique using Tron stent retrievers for M2 occlusion thrombectomy. Methods: Consecutive patients with AIS owing to M2 occlusion who underwent the BEMP technique using 2 × 15-mm or 4 × 20-mm Tron stent retrievers were included. The technique involves deploying a Tron stent retriever through a 0.0165-inch microcatheter, followed by microcatheter removal and blind navigation of a 3MAX or 4MAX aspiration catheter over the bare Tron delivery wire until the aspiration catheter reaches the clot. A Tron stent retriever is inserted into the aspiration catheter like a cork and subsequently pulled as a unit. We assessed procedural outcomes [first-pass expanded thrombolysis in cerebral infarction (eTICI) score 2c/3 and 2b/2c/3], safety outcomes [symptomatic intracranial hemorrhage (sICH)], and clinical outcomes (good outcome rate defined as modified Rankin Scale score 0-2 at 90 days and mortality at 90 days). Results: Eighteen M2 vessels were treated in 15 patients (six female, median age: 80 years, and median National Institutes of Health Stroke Scale score: 18). The BEMP technique was performed successfully in all cases. Whether to use a 3MAX or 4MAX catheter was determined by considering one of the following target vessels: dominant, non-dominant, or co-dominant M2 (3MAX, n = 9; 4MAX, n = 9). The first-pass eTICI 2c/3 and 2b/2c/3 rates were 47 (7/15) and 60% (9/15), respectively; sICH was not observed. Seven patients (47%) achieved good outcomes, and one patient (7%) died within 90 days. Conclusions: The Tron stent retriever was safely and effectively used in the BEMP technique for acute MCA M2 occlusion and can be combined with a 0.0165-inch microcatheter, which may be useful for treating MeVO, in general., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Yoshimoto, Tanaka, Koge, Shiozawa, Yamagami, Inoue, Kamogawa, Satow, Kataoka, Toyoda, Ihara and Koga.)

Background: Mechanical thrombectomy (MT) is the standard of care for the treatment of acute ischemic stroke (AIS) caused by anterior circulation large-vessel occlusion. However, the true safety and efficacy of MT in medium-size vessel occlusions such as the M2 segment of the middle cerebral artery have yet to be completely defined. In this study, we analyze the safety and efficacy of MT in M2 occlusions compared with M1 occlusions., Methods: A retrospective analysis was performed of patients with AIS secondary to M1 and M2 occlusions between 2011 and 2018. The inclusion criteria were 1) AIS secondary to M1 or M2 occlusion, 2) MT performed by stentrieval technique alone, aspiration technique, or combined stentrieval-aspiration techniques. Basic patient characteristics, number of passages, first passage recanalization success (≥TICI [Thrombolysis in Cerebral Ischemia] grade 2b), total recanalization success, hemorrhagic complications (including intracerebral hemorrhage [ICH] and subarachnoid hemorrhage), and clinical outcomes were compared between both groups., Results: Two hundred and sixty patients met the inclusion criteria; 171 patients had M1 occlusion versus 89 with M2 occlusion. First passage recanalization success rate was significantly higher in the M2 group (55.1% vs. 39.2%; P = 0.015). Total recanalization success rate was higher in the M2 group but did not reach significance (83% vs. 75%; P = 0.128). Subarachnoid hemorrhage rate was significantly higher in the M2 group (25% vs. 12%; P = 0.010) but there was no difference for ICH complications (14.6% vs. 16.4%; P = 0.711)., Conclusions: MT for M2 occlusions has similar overall efficacy to that for M1 occlusions, but with higher first-pass successful recanalization rates. MT for M2 occlusions has a higher risk of associated subarachnoid hemorrhage., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background and Purpose: Mechanical thrombectomy is an effective recanalization technique in acute ischemic stroke patients with large vessel occlusions; however, it is unclear to what extent stent retriever thrombectomy may be applicable to occlusions of smaller peripheral cerebral vessels. The outcome of patients with isolated M2 occlusions treated with the Mindframe Capture low profile (LP) stent retriever was reviewed., Material and Methods: A retrospective review of prospectively collected data on all consecutive patients treated for isolated M2 occlusions between June 2013 and December 2017 using the Mindframe Capture LP was performed. Technical aspects of the recanalization procedure, recanalization rate, complication rate, and clinical outcome were analyzed., Results: Mechanical thrombectomy with the Mindframe Capture LP was performed in 38 patients (median age 79 years) with an isolated M2 occlusion. The median National Institutes of Health Stroke Scale (NIHSS) score on admission was 7.5 (interquartile range, IQR 5-12) and successful reperfusion modified Thrombolysis in Cerebral Infarction (mTICI 2b or 3) was achieved in 28 patients (74%). A compensated/adjusted modified Rankin Scale (mRS) 0-2 at 3 months was observed in 65% when taking pre-stroke disability into account. Symptomatic intracranial hemorrhage (sICH) occurred in 1 patient (2.6%). Asymptomatic intracranial hemorrhage (aICH) was noted in 8 patients (21%) and a small subarachnoid hemorrhage (SAH) in the immediate vicinity of the target vessel was apparent in 8 patients (21%)., Conclusion: The Mindframe Capture LP is a technically effective thrombectomy device for the treatment of isolated M2 occlusions. The lower profile of the device is advantageous when targeting peripheral intracranial occlusions.

Introduction: The benefits of thrombectomy for occlusion of M2 segments remain controversial. The aim of this study is to assess thrombectomy's efficacy and safety in patients with M2 segment occlusion and associations between occlusion sites and anatomic variations of M1 division., Materials and Methods: A prospective series of 30 patients with acute ischemic stroke (AIS) resulting from M2 segment occlusion of the middle cerebral artery (MCA) who underwent thrombectomy was analyzed. The primary endpoint was assessed by the Extended Treatment in Cerebral Infarction scale (eTICI). The secondary endpoints were the incidence of symptomatic hemorrhagic transformation (sICH), mortality and good functional outcome at three months., Results: The mean patient age was 69.2 years. The mean National Institutes Health Stroke Scale score (NIHSS) upon hospital admission was 16. The recanalization rates were eTICI 2b/3 in 90% and 2c/3 in 60% of the patients. Total recanalization of the M2 branch was achieved in 53% of patients. sICH incidence was 6.6%, the mortality rate was 30%, and a good functional outcome (mRS ≤2) was observed in 50% of the patients. Twenty-seven patients (90%) had a dominant M2 branch and all were occluded. Regarding the site of M2 occlusions, 74% of patients had proximal M2 occlusions., Conclusions: Thrombectomy appears to be a safe and effective method for the treatment of acute M2 segment occlusions of the MCA. Most of the cases had a dominant M2 branch, and all of them were occluded. Larger studies are needed to verify the benefits of thrombectomy for different settings of M2 occlusions.

Background and Purpose: During mechanical thrombectomy for acute main trunk occlusion, we sometimes encounter difficult situation; 1 M2 branch of the middle cerebral artery is successfully recanalized, while the other remains occluded. In this study, we focused on the angiographical findings of remnant occlusion., Methods: Among 83 patients who underwent mechanical thrombectomy for the acute internal carotid artery or proximal middle cerebral artery (M1) occlusion, 25 patients (30%) intraoperatively exhibited the remnant M2 occlusion, in spite of the recanalization of the other M2. We classified the angiographical findings of the remnant M2 occlusion and examined the clinical features, prognosis, and complications, in relation to additional thrombectomy., Results: The remnant M2 occlusion was classified into stump type (40%, 10 cases), round deficit type (28%, 7 cases), and jaggy type (32%, 8 cases). Multivariate analysis suggested that noncardioembolic stroke may lead to jaggy type remnant occlusion with marginal significance (P = .051). Additional thrombectomy for the remnant M2 occlusion resulted in failed recanalization in 6% in the nonjaggy (stump or round deficit) type, whereas in 50% in the jaggy type groups (P = .023). Symptomatic intracranial hemorrhage occurred in 6% in the nonjaggy and 38% in the jaggy groups (P = .081), and poor outcome at discharge in 29% and in 50%, respectively., Conclusions: Angiographical jaggy sign in the remnant M2 occlusion suggests the pre-existing or procedure-related pathology, such as atherosclerosis, vasospasm, or arterial dissection. Additional thrombectomy should be carefully determined, as which might lead to adverse events and poor outcomes., (Copyright © 2019 Elsevier Inc. All rights reserved.)

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., (Copyright © 2019 by the Congress of Neurological Surgeons.)

The recently reported superiority of mechanical thrombectomy to intravenous thrombolytics has jettisoned endovascular intervention into the forefront of acute ischemic stroke (AIS) management. These successes have allowed a chance for recanalization for patients not meeting the strict eligibility criteria for intravenous thrombolytics. Stent retrieval and aspiration have emerged as two of the most popular and effective approaches for AIS thrombectomy. Since the beginning of mechanical thrombectomy with the Merci device (Stryker) and first-generation Penumbra aspiration system (Penumbra Inc), contemporary techniques have demonstrated reliable recanalization and improved clinical outcomes. Here, we review the use of stent retrieval and aspiration, as well as their synergy, in the management of AIS., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Background: Factors influencing outcome after cerebral artery occlusion are not completely understood. Although it is well accepted that the site of arterial occlusion critically influences outcome, the majority of studies investigating this issue has focused on proximal large artery occlusion. To gain a better understanding of factors influencing outcome after distal large artery occlusion, we sought to assess predictors of outcome following isolated M2 middle cerebral artery occlusion infarcts., Methods: We retrospectively analyzed patients with isolated acute M2 occlusion admitted to a single academic center from January 2010 to August 2012. Baseline clinical, laboratory imaging, and outcome data were assessed from a prospectively collected database. Factors associated with a modified Rankin Scale (mRS) score ≤2 in univariable analyses (p < 0.05) were entered into multivariable logistic regression analysis. The Admission National Institutes of Health Stroke Scale (aNIHSS) score, age, and infarct volume were also entered as dichotomized variables. Receiver operating characteristic curves were plotted to determine the optimal aNIHSS score, infarct volume, and age cut points predicting an mRS score ≤2. Optimal thresholds were determined by maximizing the Youden index. Respective multivariable logistic regression analyses were used to identify independent predictors of a good 90-day outcome (mRS score ≤2; primary analysis) as well as 90-day mortality (secondary outcome)., Results: 90 patients with isolated M2 occlusion were included in the final analyses. Of these, 69% had a good 90-day outcome which was associated with age <80 years (p = 0.007), aNIHSS <10 (p = 0.002), and infarct volume ≤26 ml (p < 0.001). Notably, 20% of patients (64% of those with a poor outcome) had died by 90 days. Secondary analysis for 90-day mortality was performed. This analysis indicated that infarct volume >28 ml (OR 11.874, 95% CI 2.630-53.604, p = 0.001), age >80 years (OR 4.953, 95% CI 1.087-22.563, p = 0.039), need for intubation (OR 7.788, 95% CI 1.072-56.604), and history of congestive heart failure (OR 5.819, 95% CI 1.140-29.695) were independent predictors of 90-day mortality (20% of all included patients)., Conclusion: While the majority of patients with isolated M2 occlusion stroke has a good 90-day outcome, a substantial proportion of subjects dies by 90 days, as identified by a unique subset of predictors. The knowledge gained from our study may lead to an improvement in the prognostic accuracy, clinical management, and resource utilization in this patient population.