M1 Middle Cerebral Artery Occlusion Research Articles

Filling Defect of Ipsilateral Transverse Sinus in Acute Large Artery Occlusion

Background and PurposeCerebral venous systems play a key role in regulating stroke outcomes. We aimed to elucidate the effect of the transverse sinus (TS) filling patterns on edema expansion and neurological outcomes in patients with acute large artery occlusion (LAO).Materials and MethodsWe recruited consecutive patients with acute M1 middle cerebral artery and/or internal carotid artery occlusion who underwent pretreatment computed tomographic perfusion (CTP). On the reconstructed 4-dimensional computed tomographic angiography derived from CTP, the filling defect of the ipsilateral transverse sinus (FDITS) was defined as the length of contrast filling defect occupying at least half of the ipsilateral TS. An unfavorable outcome was defined as having a modified Rankin Scale (mRS) score of 3–6 at 3 months.ResultsA total of 318 patients were enrolled in the final analysis and 70 (22.0%) patients had baseline FDITS. The presence of FDITS was associated with the baseline NIHSS (odds ratio [OR] 1.119; 95% CI, 1.051–1.192; p < 0.001) and poor arterial collaterals (OR 3.665; 95% CI 1.730–7.766; p = 0.001). In addition, FDITS was associated with 24-h brain edema expansion (OR 7.188; 95% CI, 3.095–16.696; p < 0.001) and 3-month unfavorable outcome (OR 8.143; 95% CI 2.547–26.041; p < 0.001) independent of arterial collateral status. In the subgroup analysis of patients with FDITS who received reperfusion therapy, no significant difference was found in the rate of edema expansion and unfavorable outcome between non-reperfusion and reperfusion subgroups (both p > 0.05).ConclusionFilling defect of the ipsilateral transverse sinus was associated with edema expansion and an unfavorable outcome irrespective of the baseline arterial collateral status in patients with acute LAO, indicating that FDITS may be an important stroke-related prognostic imaging marker.

First Pass Effect and Location of Occlusion in Recanalized MCA M1 Occlusions.

BackgroundThe first pass effect has been shown to improve clinical outcomes in patients with middle cerebral artery (MCA) M1 occlusions.ObjectiveTo determine the rates of first pass effect in MCA M1 occlusions and determine if proximal or distal location of occlusion modified clinical outcomes.MethodsPatients with recanalized MCA M1 occlusions who underwent endovascular thrombectomy (EVT) were reviewed to determine the effect of first pass effect (FPE) and location of occlusion on clinical outcomes. MCA occlusions were classified as proximal if they included the first two thirds of the MCA and involved the lenticulostriate vessels, or distal if they did not.ResultsWe included 261 patients of which 27% achieved FPE. Of the cohort, there were 91 (35%) proximal MCA occlusions and 170 (65%) distal MCA occlusions. Baseline demographics and treatment time metrics were comparable across both groups. There was a trend toward good clinical outcome in patients with or without a FPE (60 vs. 46%; p = 0.06), however a higher rate of excellent clinical outcome was noted in patients with FPE (46 vs. 30%; p = 0.02). When compared by location, patients with distal MCA occlusions had a higher rate of excellent clinical outcome (40 vs. 25%; p = 0.02). Multivariable analysis showed that distal MCA occlusion was the strongest predictor of an excellent clinical outcome and first pass effect.ConclusionPatients with MCA M1 occlusions with FPE have a higher rate of excellent clinical outcomes compared to those who did not. Location of MCA occlusion appears to modify rates of first pass effect and excellent clinical outcomes.

Immediate Recanalization of Large‐Vessel Occlusions by Tissue Plasminogen Activator Occurs in 28% of Patients Treated in a Mobile Stroke Unit

Background Recanalization of cerebral large‐vessel occlusions (LVOs) by intravenous thrombolysis is infrequent but has been relatively unexplored with ultraearly treatment. We evaluated prehospital treatment with tissue plasminogen activator (tPA) in a mobile stroke unit to explore the recanalization rate in patients with LVOs and its effect on early clinical improvement and long‐term disability. Methods Prospectively collected data were analyzed from Houston mobile stroke unit patients who were treated with tPA and had LVOs identified by either hyperdense arteries on computed tomography or arterial occlusion on computed tomography angiography while on board the mobile stroke unit. The primary outcome was immediate recanalization (IRC), categorized as resolution of LVO on repeat vascular imaging in the emergency department (ED) or on emergent angiography. The secondary outcome was change in National Institutes of Health Stroke Scale from baseline and modified Rankin score at 90 days. Results Sixty‐nine patients with anterior or posterior circulation LVOs were enrolled; the median time from last known normal to tPA bolus was 64.0 minutes (interquartile range, 52.0–89.0). Nineteen patients (28%) had IRC, with 11 based on computed tomography angiography on ED arrival and 8 based on first run of emergent angiography. Median time from tPA bolus to documentation of IRC was 61.0 minutes (interquartile range, 42.0–111.0). IRC was associated with improvement in median National Institutes of Health Stroke Scale from baseline (17.0 [14.0–22.0]) to ED arrival (10.0 [5.5–16.5]) and to 24 hours (4.0 [0.5–10.5]). Of the non‐IRC patients, 41 had recanalization after endovascular thrombectomy and 9 did not receive recanalization. The IRC group, earlier last known normal to tPA bolus, greater baseline National Institutes of Health Stroke Scale, and M1 and M2 middle cerebral artery occlusion locations were independently associated with greater improvement in National Institutes of Health Stroke Scale from baseline to ED arrival. The 90‐day modified Rankin score distribution was best in the IRC group, followed by the delayed recanalization group, and both had significantly less disability than the no recanalization group ( P =0.002). Conclusions Recanalization by ED arrival occured in 28% of patients with LVO who received tPA treatment in a mobile stroke unit and results in early clinical improvement and less disability at 90 days.

Should Primary Stroke Centers Perform Advanced Imaging?

Should Primary Stroke Centers Perform Advanced Imaging?

Abstract TP210: Stroke Subtype-specific Association Of Systemic Blood Pressure And Cerebral Collateral Flow In Acute Ischemic Stroke With Large Vessel Occlusion

Introduction: Collateral flow in acute ischemic stroke is known as a predictor of acute treatment outcome and long-term prognosis. However, studies on the factors which determine the degree of initial collateral flow are not well known. We investigated the factors related to collateral degree in acute ischemic stroke caused by large vessel occlusion (AIS-LVO) and further analyzed the results according to stroke subtype. Methods: This was a retrospective cohort using prospective stroke registry data from October 2014 to May 2021. Patients admitted within 48 hours of symptom onset with middle cerebral artery M1 occlusion on multiphasic CT angiography were included. Collateral score was graded on a six-point scale according to pial arterial filling. Results: A total of 74 patients was enrolled (mean age=72.2±11.7 years; men=37.8%). Of whom 57 (77%) were in the cardioembolism (CE) group and 17 (23%) were in the large artery atherosclerosis (LAA) group. In ordinary logistic regression analysis, initial systolic blood pressure (SBP) was associated with the score of collateral flow (odds ratio [OR]=0.982; 95% confidence interval [CI]=0.968-0.997; p=0.017). Considering multivariate models adjusted for age, sex, and atrial fibrillation, initial SBP was an independent predictor of the score of collateral flow (OR=0.977; 95% CI=0.961-0.992; p=0.011). In subgroup analysis, the lower score of collateral flow was independently associated with increased initial SBP in CE group (OR=0.965; 95% CI=0.945-0.983; p&lt;0.001) but not in LAA group (OR=1.009; 95% CI=0.978-1.043; p=0.578). Echocardiographic parameters and anatomical variations of circle of Willis did not show significant association. Conclusions: Poor cerebral collaterals in AIS-LVO was associated with increased initial SBP. Subgroup analysis revealed the association was significant in CE group, but not in LAA group. Mechanism underlying differential effects of SBP on stroke subtypes may need further study.

Abstract TP153: First Pass Effect In Middle Cerebral Artery M1 Occlusions

Introduction: First pass effect (FPE) defined as TICI 3 recanalization or greater is an independent predictor of clinical outcome in patients who undergo mechanical thrombectomy (MT). The first pass effect may be impacted by device-related factors, thrombus composition, or collateral circulation flow dynamics. In this study, we aim to examine the impact of first pass effect on clinical outcomes in patients with MCA M1 occlusions. Methods: A retrospective analysis of all patients with MCA M1 occlusion who underwent successful mechanical thrombectomy (TICI 2b or greater) between 2014-2020 at two thrombectomy stroke centers was performed. Location of occlusion was recorded as proximal MCA (involvement of the lenticulostriate vessels) or distal. Patients were excluded if they were not successfully recanalized or if they had multifocal intracranial occlusions. Patient characteristics, time metrics, procedural data, and 90 day clinical outcomes were collected. The primary outcome of interest was first pass effect, defined as TICI 3 after a single pass. Results: A total of 261 patients achieved successful recanalization of MCA occlusions in our cohort, with 70 (26.8%) patients achieving a first pass effect. Baseline demographics, rates of IV-tPA administration, and time metrics were similar between the FPE and non-FPE group. Proportion of proximal MCA and distal MCA occlusions were similar between groups as well (38.2% vs. 25.7%; p=0.08). Rates of excellent clinical outcomes were significantly higher in the FPE group compared to the non-FPE group (46.3% vs. 29.9%; p=0.02). In a multivariate analysis, proximal MCA occlusion was a significant predictor of first pass effect. Conclusion: First pass effect in middle cerebral artery M1 occlusions is a significant predictor of an excellent clinical outcome. Patients with a proximal MCA M1 occlusion are more likely to achieve a first pass effect compared to patients with a distal MCA occlusion.

Abstract WMP6: Trendelenburg (Head Down) Positioning In Acute Large Vessel Occlusion Ischemic Stroke Improves Penumbral Perfusion And Is Well-tolerated: The Head-start Study

Introduction: It is uncertain whether lowered head position improves penumbral perfusion in ischemic stroke. Although a transcranial Doppler trial in large vessel occlusion (LVO) patients suggested improvement, a large pragmatic clinical trial in mixed stroke patients was neutral. We tested the tolerability and effect on penumbral perfusion of 20-degree head-down (Trendelenburg) positioning in patients with acute LVO stroke using automated quantitative CT perfusion (CTP). Methods: We enrolled LVO patients aged ≥60, 0-24h after onset, with ≥30mL anterior circulation CTP lesion volume (delay time [DT]&gt;3, MISTAR software). CTP was repeated after 5 minutes of 20-degree Trendelenburg positioning using a custom-designed foam wedge. Neurological status (National Institutes of Health Stroke Scale [NIHSS]) and blood pressure were recorded in routine (30 degree up) and Trendelenburg position. Trendelenburg positioning was maintained for 24h if perfusion lesion volume significantly decreased (≥5mL) and reperfusion treatment was suboptimal. Results: The target of 25 patients were enrolled (14 [56%] male, median age 76 (interquartile range [IQR]71-84), baseline modified Rankin scale score 0 [IQR0-0], median NIHSS 20 [IQR 13-24]). Most patients (15/25 [60%]) had an acute M1 middle cerebral artery (MCA) occlusion, 6 (24%) an occluded M2 MCA and 4 (16%) an occluded ICA. Stroke etiology was predominantly (15/25 [60%]) cardioembolic.Median (IQR) DT&gt;3seconds lesion volume was significantly reduced by Trendelenburg compared with conventional horizontal CT positioning (114mL [94-204] vs 149mL [76-153] p=0.0027)). This was not explained by changes in blood pressure, which was unaltered (mean 148mmHg (+/- standard deviation 29) vs 143 (+/-27); p=0.129). Head position did not alter clinical severity (NIHSS 13 [IQR 9-28]) in both positions). A significant lesion volume reduction with Trendelenburg positioning was seen in 15/25 patients (60%); 7 received continued Trendelenburg positioning due to incomplete reperfusion. Head down positioning was well tolerated in the majority (4/7 [57%]), without serious adverse events. Conclusion: Head-down (Trendelenburg) positioning improves penumbral perfusion in acute LVO ischemic stroke and is well-tolerated.

The clinical outcomes of mechanical thrombectomy for proximal M1 occlusion involving lenticulostriate perforators: Is it worse than distal M1 occlusion? Retrospective observational study.

Although the success rate of recanalization in acute intracranial artery occlusion is high, there is a poor rate of improvement in functional clinical outcome. The purpose of this study was to assess the functional outcome of mechanical thrombectomy for proximal M1 occlusion involving lenticulostriate arteries (LSAs) compared with distal M1 occlusion-sparing the LSAs.A retrospective analysis was conducted in patients with middle cerebral artery (MCA) M1 occlusions who had a successful recanalization subsequent to mechanical thrombectomy. The recanalization results were estimated using the thrombolysis in cerebral infarction grade assessed by digital subtraction angiography. To confirm the ischemic change resulting from the lenticulostriate artery occlusion, we reviewed the neuroimaging findings from magnetic resonance imaging 1 day after mechanical thrombectomy. The functional outcomes were then evaluated using the modified Rankin scale at 90 days.In total, 28 patients with MCA M1 occlusion had successful recanalization outcomes with thrombolysis in cerebral infarction grades IIa, IIb, and III. Among the 28 patients, 17 had proximal M1 occlusions and 11 had distal M1 occlusions. Demographic factors, including initial National Institutes of Health Stroke Scale score, time from symptom to recanalization, and recanalization rate did not differ considerably between patients with proximal and distal M1 occlusions. Regarding infarctions in the basal ganglia, internal capsule, and corona radiata, there were statistically significant differences between the proximal and distal M1 occlusions. However, there were no significant differences in good functional outcome (modified Rankin scale ≤2) observed between the groups at 90 days after mechanical thrombectomy.Although proximal M1 occlusion had more frequent infarctions associated with the LSA territories, these were not related to poor functional outcomes. Both proximal and distal M1 occlusion demonstrated comparably good outcomes.

Mechanical thrombectomy in acute ischemic stroke with tandem occlusions: impact of extracranial carotid lesion etiology on endovascular management and outcome.

Different etiologies of extracranial internal carotid artery steno-occlusive lesions (ECLs) in patients with acute ischemic stroke (AIS) and tandem occlusion (TO) have been pooled together in randomized trials. However, carotid atherosclerosis (CA) and carotid dissection (CD), the two most common ECL etiologies, are distinct nosological entities. The authors aimed to determine if ECL etiology has impacts on the endovascular management and outcome of patients with TO. A multicenter, retrospective study of prospectively collected data was conducted. AIS patients were included who had TO due to internal CA or CD and ipsilateral M1 middle cerebral artery occlusion and underwent endovascular treatment (EVT). Comparative analyses including demographic data, safety, successful recanalization rates, and clinical outcome were performed according to EVT and ECL etiology. In total, 214 AIS patients with TOs were included (77.6% CA related, 22.4% CD related). Patients treated with a retrograde approach were more often functionally independent at 3 months than patients treated with an antegrade approach (OR 0.6, 95% CI 0.4-0.9). Patients with CD-related TOs achieved 90-day clinical independence more often than patients with CA-related TOs (OR 1.4, 95% CI 1.1-2.0). Emergency stenting use was associated with good 3-month clinical outcome only in patients with CA-related TOs (OR 1.4, 95% CI 1.1-2.1). Symptomatic intracranial hemorrhage (sICH) occurred in 10.7% of patients, without differences associated with ECL etiology. ECL etiology impacts both EVT approach and clinical outcome in patients with TOs. Patients with CD-related TO achieved higher 3-month functional independence rates than patients with CA-related TOs. A retrograde approach can be desirable for both CA- and CD-related TOs, and emergency stenting is likely better justified in CA-related TOs.

Validation of an artificial intelligence-driven large vessel occlusion detection algorithm for acute ischemic stroke patients.

Rapid and accurate diagnosis of large vessel occlusions (LVOs) in acute ischemic stroke (AIS) patients using automated software could improve clinical workflow in determining thrombectomy in eligible patients. Artificial intelligence-based methods could accomplish this; however, their performance in various clinical scenarios, relative to clinical experts, must be thoroughly investigated. We aimed to assess the ability of Canon's AUTOStroke Solution LVO application in properly detecting and locating LVOs in AIS patients. Data from 202 LVO and 101 non-LVO AIS patients who presented with stroke-like symptoms between March 2019 and February 2020 were collected retrospectively. LVO patients had either an internal carotid artery (ICA) (n = 59), M1 middle cerebral artery (MCA) (n = 82) or M2 MCA (n = 61) occlusion. Computed tomography angiography (CTA) scans from each patient were pushed to the automation platform and analyzed. The algorithm's ability to detect LVOs was assessed using accuracy, sensitivity and Matthews correlation coefficients (MCCs) for each occlusion type. The following results were calculated for each occlusion type in the study (accuracy, sensitivity, MCC): ICA = (0.95, 0.90, 0.89), M1 MCA = (0.89, 0.77, 0.78) and M2 MCA = (0.80, 0.51, 0.59). For the non-LVO cohort, 98% (99/101) of cases were correctly predicted as LVO negative. Processing time for each case was 69.8 ± 1.1 seconds (95% confidence interval). Canon's AUTOStroke Solution LVO application was able to accurately identify ICA and M1 MCA occlusions in addition to almost perfectly assessing when an LVO was not present. M2 MCA occlusion detection needs further improvement based on the sensitivity results displayed by the LVO detection algorithm.

Detailed histological analysis of a thrombectomy-resistant ischemic stroke thrombus: a case report

BackgroundMechanical removal of a thrombus by thrombectomy can be quite challenging. For reasons that are not fully understood, some thrombi require multiple passes to achieve successful recanalization, whereas other thrombi are efficiently removed in a single pass. Since first pass success is associated with better clinical outcome, it is important to better understand the nature of thrombectomy resistant thrombi. The aim of this study was therefore to characterize the cellular and molecular composition of a thrombus that was very hard to retrieve via mechanical thrombectomy.Case presentationIn a patient that was admitted with a right middle cerebral artery M1-occlusion, 11 attempts using various thrombectomy devices and techniques were required for removal of the thrombus. This peculiar case provided a rare opportunity to perform an in-depth histopathological study of a difficult to retrieve thrombus. Thrombus material was histologically analyzed using hematoxylin and eosin, Martius Scarlet Blue stain (red blood cells and fibrin), Feulgen stain (DNA), von Kossa stain (calcifications) and immunohistochemical analysis of von Willebrand factor, platelets, leukocytes and neutrophil extracellular traps. Histological analysis revealed abnormally high amounts of extracellular DNA, leukocytes, von Willebrand factor and calcifications. Extracellular DNA stained positive for markers of leukocytes and NETs, suggesting that a significant portion of DNA is derived from neutrophil extracellular traps.ConclusionIn this unique case of a nearly thrombectomy-resistant stroke thrombus, our study showed an atypical composition compared to the common structural features found in ischemic stroke thrombi. The core of the retrieved thrombus consisted of extracellular DNA that colocalized with von Willebrand factor and microcalcifications. These results support the hypothesis that von Willebrand factor, neutrophil extracellular traps and microcalcifications contribute to mechanical thrombectomy resistance. Such information is important to identify novel targets in order to optimize technical treatment protocols and techniques to increase first pass success rates.

Distance to Thrombus in Endovascular Treatment of Middle Cerebral Artery M1 Occlusion Predicts Recanalization Success and Clinical Outcome.

The occlusion site of the cerebral artery can help to determine recanalization success, treatment and prognosis in acute stroke patients. In current studies, different measurement techniques and different length values have been considered. We aimed to determine the relationship between the location of occlusion and recanalization success following endovascular therapy of acute middle cerebral artery (MCA) M1 occlusion. This study was conducted from January 2015 to March 2019. The "M1 distance-to-thrombus length" was determined on curve-linear reformat reconstruction of the MCA, and measured from the center of internal carotid artery (ICA) bifurcation to the beginning of the thrombus on digital subtraction angiography (DSA). A successful recanalization was defined as ≥ modified thrombolysis in cerebral infarction (mTICI) 2b and full recanalization as mTICI 3. Evaluation of patients at the end of the third month was carried out with modified Rankin Scale (mRS) and mortality. We eventually included 95 patients treated with endovascular therapy. The patients with distance to thrombus (DT) ≤13.2 mm showed significantly higher rates of full recanalization (AUC = 0.639 ± 0.06; P=0.014, 95% confidence interval [CI]). Additionally, DT could predict successful recanalization with an AUC of 0.639. The possibility to distinguish unsuccessful recanalization cases after the endovascular treatment by considering DT had 85.7% sensitivity (95% CI). Of the 82 (86.3%) patients who were treated with successful recanalization (≥mTICI 2b), 46 (48.4%) achieved mRS (0-3) and 38 (40%) expired at the end of the 3 months. Shorter DT was associated with higher rate of full recanalization (mTICI 3) after endovascular therapy. Having a longer DT reduces the chance of successful recanalization without distal embolism. However, there was no statistically significant effect for DT on a favorable outcome at third months or mortality with endovascular treatment of MCA M1 occlusions.

Hyperintense Vessel Sign in Large-Vessel Occlusion Stroke of Mild-to-Moderate Severity Ineligible for Recanalization.

Background and PurposeThe impact of fluid-attenuated inversion recovery hyperintense vessels (FHVs) on outcomes in patients ineligible for recanalization therapy with large-vessel occlusion (LVO) is unclear. We investigated the impact of FHVs determined using the FHV–Alberta Stroke Program Early CT Score (ASPECTS) on clinical outcomes in patients with LVO stroke of mild-to-moderate severity ineligible for recanalization therapy.MethodsSixty-eight consecutive patients with M1-middle cerebral artery occlusion who underwent magnetic resonance imaging within 24 hours of symptom onset and were ineligible for recanalization were included. Patients were dichotomized into a severe-FHV group (FHV-ASPECTS ≤4; n=33) and a mild-FHV group (FHV-ASPECTS >4; n=35), and multiple logistic regression analysis was used to examine the relationships of FHV scores with early neurological deterioration (END) and an unfavorable 3-month outcome (modified Rankin Scale score ≥3).ResultsMean age was 66.2±13.5 years (mean±SD), and 30 (44%) were female. The severe-FHV group had a larger infarct volume (median, 5.5 mL vs. 3 mL) and more frequently exhibited the susceptibility vessel sign (30% vs. 3%) than the mild-FHV group. Ipsilateral old nonlacunar infarct was more frequent in the mild-FHV group than in the severe-FHV group (37% vs. 15%). The severe-FHV group had a fivefold higher risk of END (odds ratio [OR] 5.02, 95% confidence interval [CI] 1.36–18.45) and unfavorable outcome (OR 5.97, 95% CI 1.18–33.31, p=0.03) compared with the mild-FHV group.ConclusionsGreater FHV extent was associated with higher risk of END and unfavorable outcome in patients with LVO stroke of mild-to-moderate severity.

Machine-learning-based outcome prediction in stroke patients with middle cerebral artery-M1 occlusions and early thrombectomy.

Background and purposeClinical outcomes vary substantially among individuals with large vessel occlusion (LVO) stroke. A small infarct core and large imaging mismatch were found to be associated with good recovery. The aim of this study was to investigate whether those imaging variables would improve individual prediction of functional outcome after early (<6 h) endovascular treatment (EVT) in LVO stroke.MethodsWe included 222 patients with acute ischemic stroke due to middle cerebral artery (MCA)‐M1 occlusion who received EVT. As predictors, we used clinical variables and region of interest (ROI)‐based magnetic resonance imaging features. We developed different machine‐learning models and quantified their prediction performance according to the area under the receiver‐operating characteristic curves and the Brier score.ResultsThe rate of successful recanalization was 78%, with 54% patients having a favorable outcome (modified Rankin scale score 0–2). Small infarct core was associated with favorable functional outcome. Outcome prediction improved only slightly when imaging was added to patient variables. Age was the driving factor, with a sharp decrease in likelihood of favorable functional outcome above the age of 78 years.ConclusionsIn patients with MCA‐M1 occlusion strokes referred to EVT within 6 h of symptom onset, infarct core volume was associated with outcome. However, ROI‐based imaging variables led to no significant improvement in outcome prediction at an individual patient level when added to a set of clinical predictors. Our study is in concordance with current practice, where imaging mismatch or collateral readouts are not recommended as factors for excluding patients with MCA‐M1 occlusion for early EVT.

Large Vessel Occlusion Strokes After the DIRECT-MT and SKIP Trials: Is the Alteplase Syringe Half Empty or Half Full?

Large Vessel Occlusion Strokes After the DIRECT-MT and SKIP Trials: Is the Alteplase Syringe Half Empty or Half Full?

Collateral Activation of the Early Temporal Branch - A Neurosonological Sign of Distal M1 Middle Cerebral Artery Occlusion

Collateral Activation of the Early Temporal Branch - A Neurosonological Sign of Distal M1 Middle Cerebral Artery Occlusion

Severe Leukoaraiosis Is Associated with Poor Outcome after Successful Recanalization of M1 Middle Cerebral Artery Occlusion Strokes

Background: Severe leukoaraiosis (LA) is an established risk factor for poor outcome after mechanical thrombectomy (MT) for large vessel occlusion stroke. There is uncertainty whether this association also applies to successfully recanalized patients with M1 segment middle cerebral artery (MCA) occlusions. Methods: A retrospective single-centre study of patients with successful reperfusion (thrombolysis in cerebral infarction, TICI 2b or 3) after MT for an M1 MCA occlusion was performed over a 7-year period. LA score (LAS) was assessed using the age-related white matter change scale on pre-interventional brain imaging. Results: A total of 209 patients (median age 75.0 years) were included. LAS was assessed on pre-interventional imaging by computed tomography in 177 (84.7%) patients and magnetic resonance imaging in 32 (15.3%) patients. The median LAS was 1 (IQR 0–8), and severe LA consisted of the top 25 percentile, ranging from 9 to 24. Multivariable analysis demonstrated an association of severe LA (OR 0.32, 95% CI 0.12–0.88, p = 0.023), higher NIHSS on admission (OR 0.89, 95% CI 0.84–0.94, p < 0.001), advanced age (OR 0.97, 95% CI 0.95–1.00, p = 0.039), good leptomeningeal collaterals (OR 3.65, 95% CI 1.46–8.15, p = 0.001), and TICI 3 score (OR 3.26, 95% CI 10.52–7.01) with good clinical outcome after 3 months as measured with the modified Rankin scale. Conclusion: Severe LA is associated with poor clinical outcome at 3 months in acute stroke patients undergoing MT due to emergent M1 MCA occlusion.

Differences in Safety and Efficacy of Endovascular Treatment for Acute Ischemic Stroke : APropensity Score Analysis of Intracranial Atherosclerosis-Related Occlusion versus Embolism.

The prognosis after endovascular treatment (EVT) of acute arterial occlusions due to intracranial atherosclerotic disease (ICAD) may differ from those due to embolism. The aim was to evaluate whether safety and efficacy of EVT differ among patients with middle cerebral artery (MCA) M1 occlusion from ICAD or embolism. Adatabase review was conducted to identify EVT patients with acute MCA M1 occlusion from November 2013 to December 2018.The patients were divided into the ICAD group and embolic group according to the etiology of occlusion. Using propensity score analysis, patients with ICAD-related occlusion and embolism underwent 1:1 matching. Angiographic results, complications, and clinical outcomes were compared. Atotal of 217 patients (ICAD: 51; embolism: 166) were identified. After propensity score matching, 45patients with ICAD-related occlusion and 45 with embolism were matched. All baseline covariates except atrial fibrillation were statistically indistinguishable. The rate of successful reperfusion (modified Thrombolysis in Cerebral Infarction [mTICI]2b-3) was similar between the two groups, while the rate of mTICI3 in the ICAD group was higher. No statistical difference was observed in the rate of postprocedural intracranial hemorrhage. The rate of favorable outcome (modified Rankin Scale [mRS] ≤2) and mortality at 90days was comparable. This propensity score analysis demonstrated that the EVT patients with acute ICAD-related MCA M1 occlusion had similar angiographic and clinical outcomes compared to those with M1 embolism on asimilar baseline condition.

Hypoperfusion intensity ratio correlates with angiographic collaterals in acute ischaemic stroke with M1 occlusion

Among patients with an acute ischaemic stroke secondary to large-vessel occlusion, the hypoperfusion intensity ratio (HIR) [time to maximum (TMax)>10volume/TMax>6volume] is a strong predictor of infarct growth. We studied the correlation between HIR and collaterals assessed with digital subtraction angiography (DSA) before thrombectomy. Between January 2014 and March 2018, consecutive patients with an acute ischaemic stroke and an M1 middle cerebral artery (MCA) occlusion who underwent perfusion imaging and endovascular treatment at our center were screened. Ischaemic core (mL), HIR and perfusion mismatch (TMax>6s minus core volume) were assessed through magnetic resonance imaging or computed tomography perfusion. Collaterals were assessed on pre-intervention DSA using the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) scale. Baseline clinical and perfusion characteristics were compared between patients with good (ASITN/SIR score 3-4) and those with poor (ASITN/SIR score 0-2) DSA collaterals. Correlation between HIR and ASITN/SIR scores was evaluated using Pearson's correlation. Receiver operating characteristic analysis was performed to determine the optimal HIR threshold for the prediction of good DSA collaterals. A total of 98 patients were included; 49% (48/98) had good DSA collaterals and these patients had significantly smaller hypoperfusion volumes (TMax>6s, 89 vs. 125mL; P=0.007) and perfusion mismatch volumes (72 vs. 89mL; P=0.016). HIR was significantly correlated with DSA collaterals (-0.327; 95% confidence interval, -0.494 to -0.138; P=0.01). An HIR cut-off of <0.4 best predicted good DSA collaterals with an odds ratio of 4.3 (95% confidence interval, 1.8-10.1) (sensitivity, 0.792; specificity, 0.560; area under curve, 0.708). The HIR is a robust indicator of angiographic collaterals and might be used as a surrogate of collateral assessment in patients undergoing magnetic resonance imaging. HIR <0.4 best predicted good DSA collaterals.

Abstract WP45: Outcomes of Patients With Cerebral Large Vessel Occlusions Undergoing Mechanical Endovascular Revascularization Based on the Quantification of Pial Collateral Perfusion

Introduction: Patient outcomes after Mechanical Endovascular Revascularization (MER) are dependent on both patient-specific and procedure-specific factors. The pial collateral perfusion to the ischemic penumbra during a cerebral large vessel occlusion (LVO) is one of the most important factors in overall patient outcome. Using our technique of Quantifying of Pial Collateral Perfusion (QPCP) previously described, patient outcomes after MER for cerebral LVO were assessed. Methods: Fifty consecutive patients with proximal middle cerebral artery M1 occlusions for whom QPCP were recorded were included in the study. In addition to patient demographics, the primary outcomes investigated were National Institutes of Health Stroke Scale (NIHSS) scores post-procedure reduction compared to pre-procedure score, and modified Rankin Scale (mRS) score at 30-day and 3-month follow-up. In addition, overall stroke volume, time spent in hospital, and the incidence of hemorrhagic conversion were also assessed. Regression models were used to estimate the association between pial collateral perfusion pressure and the above outcomes. Results: Patients demonstrated for every 5-unit increase in pial collateral perfusion pressure (measured in mmHg) an association with a 0.54-unit decrease in the post-procedure NIHSS score with a P-value of 0.07 (β= -0.54; 95% CI -1.12,0.03). A 5-unit increase in pial collateral perfusion pressure was also associated with 11% lower odds of having a 30-day mRS of 4-5 vs. 0-1 or 2-3 with a P-value of 0.18 (OR=0.89; 95% CI 0.75,1.06). A higher pial collateral perfusion pressure was also associated with a 0.07-unit decrease in the log of the stroke volume (P-value - 0.32). There was no association with higher pial collateral perfusion pressure and incidence of hemorrhagic conversion on post-procedure imaging. Conclusions: The QPCP is an objective measure for predicting patient outcomes after MER for cerebral LVO. Higher pial collateral perfusion pressures are associated with greater improvements in post-reperfusion NIHSS scores and 30-day mRS scores.