M1 Occlusion Research Articles

The determinants of collateral circulation status in patients with chronic cerebral arterial circle occlusion: A STROBE Study.

The condition of collateral pathways is an important predictor of stroke prognoses; however the major determinants of collaterals are still unknown. The purpose of this study is to identify potentially determinants for collateral circulation status in patients with chronic occlusion of cerebral arterial circle.All patients with chronic occlusion of either unilateral internal carotid artery or middle cerebral artery M1 or M2 segment, diagnosed by digital subtraction angiography at the neurology department of the First Medical Centre of Chinese PLA General Hospital from January 2015 to December 2017, were retrospectively collected in our sample. After screening according to inclusion and exclusion criteria, the patients’ relevant clinical data were collected and analyzed. Collateral circulations were assessed by 2 independent raters using the American society of interventional and therapeutic neuroradiology/society of interventional radiology flow-grading system.Baseline characteristics (n = 163): our sample consists of 116 (71.2%) male and 47 (28.8%) female patients with an average age of 57.5 ± 11.9 years. Cerebral collateral flow was poor in 59 (36.2%) patients. Our univariate analyses showed that poor collateral circulation was associated with lower high-density lipoproteins cholesterol (HDL), elevated homocysteine levels, aging and hyperlipidemia. A multivariate analysis identified HDL, homocysteine levels and ageing as major predictors for collateral circulation status. In the subgroup analysis, the HDL contributed to collateral angiogenesis internal carotid artery occlusion group. In the middle cerebral artery occlusion group, the homocysteine and ageing were related to the poor collateral status.Low HDL, high levels of homocysteine and ageing are identified as possible risk factors for a poor collateral vessel blood flow in patients with chronic anterior circulation occlusion.

Predictive Factors for Clinical Outcome After Direct Mechanical Thrombectomy for Anterior Circulation Large Vessel Occlusion Within 4.5 h.

BackgroundRecent trials including DIRECT-MT, DEVT, and SKIP have found that direct mechanical thrombectomy (MT) is equally effective as the combination of MT and intravenous thrombolysis. However, the results of the other trials, namely MR-CLEAN NO-IV and the SWIFT-DIRECT trial have failed to confirm the non-inferiority of direct MT vs. the combination therapy.AimWe aimed to identify prognostic factors of direct MT for anterior circulation large vessel occlusion within 4.5 h.Materials and MethodsData from January 2018 to January 2022 were retrospectively collected and analyzed. Adult patients with confirmed anterior circulation large vessel occlusion within 4.5 h of onset with baseline NIHSS of ≥6 and baseline ASPECTS of ≥6 treated using direct MT within 6 h were recruited.ResultsA total of 140 patients were enrolled in the study with a median age of 65.5 years [interquartile range (IQR), 59–76.5], median baseline NIHSS of 13.5 (IQR, 11–16), and median baseline ASPECTS of 8 (IQR, 7–8). Direct MT was feasible in all patients (100%). Successful reperfusion (mTICI 2b-3) was achieved in 124/140 patients (88.6%) with a low rate of complications (8/140, 5.7%). Any type of intracranial hemorrhage (ICH) and symptomatic ICH occurred in 44/140 (31.4%) and 5/140 (3.6%), respectively. Overall, a good outcome (mRS 0–2) was achieved in 93/140 (66.4%), and the mortality rate was 9.3% (13/140 patients). Using multivariate analysis, lower age [odds ratio (OR), 0.96; 95% CI, 0.92–1.00; P = 0.05], low baseline NIHSS (OR, 0.82; 95% CI, 0.74–0.92; P = 0.00), and absence of ICH (OR, 0.29; 95% CI, 0.10–0.81; P = 0.02) were independently associated with favorable outcome. Independent predictors of mortality were baseline NIHSS (OR, 1.21; 95% CI, 1.01–1.46; P = 0.04), successful reperfusion (OR, 0.02; 95% CI, 0.00–0.58; P = 0.02), and ICH (OR, 0.12; 95% CI, 0.02–0.75; P = 0.02). Further analysis showed that the median mRS at 90 days was significantly better in the MCA occlusion group compared to the ICA plus M1 occlusion group [1 (IQR 0–3) vs. 2 (IQR 1–4); P = 0.05].ConclusionsOur findings suggest that direct thrombectomy may be an adequate clinical option for younger patients (≤70) experiencing proximal middle artery occlusion within 4.5 h and who have low baseline NIHSS (≤14).

Meniscus Sign in Patients with Anterior Circulation Large Vessel Occlusion Stroke does not Predict Outcome

PurposeThe angiographic appearance of the occlusion site was suggested to influence outcomes of stroke patients with large vessel occlusion (LVO) who undergo endovascular treatment (EVT). We aimed to study the impact of the meniscus sign (MS) on outcomes of stroke patients with anterior circulation LVO.MethodsBased on two prospective registries of acute ischemic stroke, we selected patients with carotid‑T, M1 or M2 occlusion who underwent EVT. Clinical characteristics and outcomes were collected from the registries or from individual records. Two independent observers blinded to outcomes assessed the presence of MS in digital subtraction angiography before thrombectomy. Angiographic and clinical outcomes of patients with and without MS were compared.ResultsWe included 903 patients, with median age of 78 years, 59.8% were male, median baseline NIHSS was 14 and 39.5% received intravenous thrombolysis. Patients with MS (n = 170, 18.8%) were more frequently female, presented with higher NIHSS scores and more frequently underwent intravenous thrombolysis. Presence of MS was significantly associated with cardioembolic etiology. Successful reperfusion, number of passes, first pass effect, procedural time, symptomatic intracerebral hemorrhage, in-hospital mortality and favorable 3‑month functional outcome were similar in the groups of patients with and without MS. In the multivariable analyses, MS was not associated with successful reperfusion (odds ratio, OR = 1.08, 95% confidence interval, CI = 0.76–1.55), first pass effect (OR = 0.96, 95%CI = 0.48–1.92) or favorable 3‑month outcome (OR = 1.40, 95%CI = 0.88–2.24).ConclusionThe presence of MS in acute ischemic stroke patients with anterior circulation large vessel occlusion who undergo EVT does not appear to influence angiographic or clinical outcomes.

Mechanical Thrombectomy for M2 Segment Occlusion in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

The safety and benefit of mechanical thrombectomy (MT) in the treatment of acute ischemic stroke (AIS) patients with M2 segment middle cerebral artery occlusions remain uncertain. To investigate the benefit of mechanical thrombectomy for M2 occlusion compared with M1 occlusion in patients with AIS. The PubMed, Embase, and Cochrane Library databases were searched from inception to April 2021 to identify relevant articles. The main results comprised 90-day functional independence (modified Rankin Score from 0-2), successful recanalization (thrombectomy in cerebral infarction [TICI] 2b/3), mortality, and rates of symptomatic intracerebral hemorrhage after using modern thrombectomy devices. Odds ratios (ORs) were generated for binary variants. ReviewManager 5.3 software was used. Ultimately, a total of 14 trials were included, with 3454 participants enrolled. MT for M2 occlusion had a higher rate of 3-month functional independence than M1 occlusion, but the difference was nonsignificant (OR: 1.19, 95% confidence interval [CI]: 0.98 to 1.46). The TICI2b/3 scores (OR: 0.71, 95% CI: 0.58-0.88) in M2 occlusion were remarkably lower than those in M1. The mortality and symptomatic intracerebral hemorrhage rates were comparable between the 2 groups. When comparing M2 and M1 occlusions, we found that there was no significant difference between stent retriever and aspiration in the modified Rankin Score (0-2) after AIS, but aspiration exerted an eminently higher recanalization rate with regard to TICI2b/3 (OR: 0.77, 95% CI: 0.61-0.96). Compared with M1 occlusion, patients with M2 occlusion treated by MT demonstrated similar clinical outcomes in this study. Moreover, there was no difference between stent retriever and aspiration in treating M2 occlusion in terms of functional independence at 90days. However, aspiration exerted a conspicuously higher recanalization rate in M2 occlusion than in M1 occlusion.

Thrombectomy in Acute Ischemic Stroke in the Extended Time Window: Real-Life Experience in a High-Volume Center

ObjectivesSelected 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 methodsWe 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. ResultsOf 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. ConclusionsOur 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.

Safety of Sheathless Transradial Balloon Guide Catheter Placement for Acute Stroke Thrombectomy

Transradial access has been described for mechanical thrombectomy in acute stroke, and proximal balloon occlusion has been shown to improve recanalization and outcomes. However, sheathed access requires a larger total catheter diameter at the access site. We aimed to characterize the safety of sheathless transradial balloon guide catheter use in acute stroke intervention. Consecutive patients who underwent sheathless right-sided transradial access for thrombectomy with a balloon guide catheter were identified in a prospectively collected dataset from 2019 to 2021. Demographics, procedure details, and short-term outcomes were collected and reported with descriptive statistics. A total of 48 patients (20 women) with a mean age of 72.3 years were identified. Of patients, 56.3% had occlusions in the left-sided circulation; 35 (72.9%) had M1 occlusions, 7 (14.6%) had M2 occlusions, and 6 (12.5%) had internal carotid artery occlusions. Tissue plasminogen activator was administered to 16 (33.3%) patients. Five (10.4%) patients underwent intraprocedural carotid stenting. The cohort had successful reperfusion after a median of 1 (interquartile range: 1, 2) pass. Median time from access to recanalization was 31 (interquartile range: 25, 53) minutes. A postprocedural Thrombolysis In Cerebral Infarction score of ≥2b was achieved in 46 (95.8%) patients. Five patients had wrist access site hematomas. All hematomas resolved with warm compresses, and no further intervention was required. Sheathless radial access using a balloon guide catheter may be safely performed for acute ischemic stroke with excellent radiographic outcomes. Further investigation is warranted to evaluate the comparative effectiveness of sheathless compared with sheathed transradial balloon guide access.

Machine Learning–Based Identification of Target Groups for Thrombectomy in Acute Stroke

Whether endovascular thrombectomy (EVT) improves functional outcome in patients with large-vessel occlusion (LVO) stroke that do not comply with inclusion criteria of randomized controlled trials (RCTs) but that are considered for EVT in clinical practice is uncertain. We aimed to systematically identify patients with LVO stroke underrepresented in RCTs who might benefit from EVT. Following the premises that (i) patients without reperfusion after EVT represent a non-treated control group and (ii) the level of reperfusion affects outcome in patients with benefit from EVT but not in patients without treatment benefit, we systematically assessed the importance of reperfusion level on functional outcome prediction using machine learning in patients with LVO stroke treated with EVT in clinical practice (N = 5235, German-Stroke-Registry) and in patients treated with EVT or best medical management from RCTs (N = 1488, Virtual-International-Stroke-Trials-Archive). The importance of reperfusion level on outcome prediction in an RCT-like real-world cohort equaled the importance of EVT treatment allocation for outcome prediction in RCT data and was higher compared to an unselected real-world population. The importance of reperfusion level was magnified in patient groups underrepresented in RCTs, including patients with lower NIHSS scores (0–10), M2 occlusions, and lower ASPECTS (0–5 and 6–8). Reperfusion level was equally important in patients with vertebrobasilar as with anterior LVO stroke. The importance of reperfusion level for outcome prediction identifies patient target groups who likely benefit from EVT, including vertebrobasilar stroke patients and among patients underrepresented in RCT patients with low NIHSS scores, low ASPECTS, and M2 occlusions.

Tortuosity of middle cerebral artery M1 segment and outcomes after mechanical thrombectomy.

We aimed to quantify the tortuosity of the middle cerebral artery (MCA) and assess its effects on radiological and clinical outcomes in patients with acute MCA occlusions who received mechanical thrombectomy (MT). This retrospective study enrolled 53 patients with acute ischemic stroke due to MCA M1 or M2 segment occlusion who underwent MT using stent retrievers (SRs). Tortuosity index (TI) was defined to quantify the tortuosity of the MCA M1 segment using the following formula: (actual distance / straight distance) × 100. For each patient, four TIs were measured in the anteroposterior and caudal views for both ipsilateral and contralateral sides to the occluded site (TI-APi, TI-APc, TI-CAUi, and TI-CAUc, respectively) using magnetic resonance angiography (MRA) or computed tomography angiography (CTA). We defined the first-pass effect (FPE) as first-pass mTICI classification ≥2b reperfusion. Patients who did not achieve FPE had significantly higher TI-APi (112 vs. 106; P = 0.004), TI-APc (111 vs. 105; P = 0.005), TI-CAUi (110 vs. 105; P = 0.002), and TI-CAUc (110 vs. 105; P = 0.001) than those who achieved FPE. In multivariable analysis, higher TI-APi, TI-CAUi, and TI-APc were independently associated with an increased rate of unsuccessful FPE (odds ratio (OR) [95% confidence interval (CI)]: 1.25 [1.02-1.61], 1.21 [1.01-1.45], and 1.27 [1.03-1.73], respectively). TI-CAUi, TI-APc, and TI-CAUc were also independent predictors of the occurrence of intracranial hemorrhage after MT (OR [95% CI]: 1.15 [1.01-1.38], 1.14 [1.01-1.38], 1.25 [1.02-1.52], respectively). The TIs of the MCA M1 segment on both ipsilateral and contralateral sides were associated with unfavourable outcomes after MT.

Visualization of the Anterior Temporal Artery as a Predictor of Outcome in Middle Cerebral Artery Occlusion Patients Achieving Successful Recanalization After Transfer.

IntroductionAnterior temporal artery (ATA) visualization on computed tomography angiography (CTA) has been previously associated with good outcomes in middle cerebral artery (MCA) occlusions, but not in the setting of patients who initially present to non-thrombectomy centers.MethodsWe retrospectively identified acute MCA (M1) occlusion patients who underwent mechanical thrombectomy after transfer from non-thrombectomy-capable centers. Neuroradiologists confirmed the MCA (M1) as the most proximal site of occlusion on CTA and assessed for visualization of the ATA. Thrombolysis in Cerebral Infarction (TICI) 2b or greater revascularization scores were confirmed by neurointerventionalists blinded to patient outcomes. Ninety-day modified Rankin scale (mRS) scores were obtained via a structured telephone questionnaire.ResultsWe identified 102 M1 occlusion patients over a three-and-a-half-year period presenting to a non-thrombectomy-capable center who underwent transfer and mechanical thrombectomy. There were no significant differences in age, gender, race, comorbidities, or median National Institute of Health Stroke Scale (NIHSS) scores between the ATA visualized (n = 47) versus non-visualized (n = 55) cohort, and no significant differences in baseline Alberta Stroke Program Early Computed Tomography (ASPECT) scores, post-intervention TICI scores, or interval from last known well to revascularization. There was a strong trend in functional independent outcome (mRS ≤ 2) for patients with ATA visualization (63.8% vs. 45.5%, p = 0.064).ConclusionFor patients presenting to non-thrombectomy centers without CT perfusion capability, ATA visualization should be further investigated as an outcome predictor, given its association with functional independence after successful recanalization.This article was previously presented as a meeting abstract at the 2021 International Stroke Conference on March 17-19, 2021.

Outcome after Thrombectomy of Acute M1 and Carotid-T Occlusions with Involvement of the Corticospinal Tract in Postinterventional Imaging.

Objectives: Until now, thrombectomy studies have provided little reliable information about the correlation between the infarct topography and clinical outcome of acute stroke patients with embolic large-vessel occlusions. Therefore, we aimed to analyze whether infarcts of the corticospinal tracts in the central white matter (CWM) or the internal capsule on postinterventional imaging controls are associated with poor clinical outcome after thrombectomy. Materials and Methods: We retrospectively analyzed imaging data from 70 patients who underwent endovascular thrombectomy for emergent middle cerebral artery or carotid-T occlusions. Inclusion criteria were postinterventional infarct demarcation in the regions of the internal capsule, caudate, lentiform nucleus, and CWM. Primary outcome was the mRS after 90 days and secondary endpoints were subgroup analyses regarding additional cortical infarction. Conclusions: In this exploratory study, we found no indication that infarcts in the course of the corticospinal tracts predict poor clinical outcome after successful thrombectomy in patients with embolic carotid-T or M1 occlusions. In our analysis, a significant number of patients showed a favorable 90 day outcome. Additional cortical infarcts may have a greater impact on the risk of an unfavorable outcome. Results: Good clinical outcome after 90 days (mRS 0–2) was shown in 36 out of 70 patients (51.4%), with excellent clinical outcome (mRS 0–1) in 23 patients (32.9%). Here, 58.6% patients lived at home without nursing service after 90 days. Patients with minimal additional cortical infarction in postinterventional imaging had a 75.6% better chance of excellent outcome.

Association of thrombus density and endovascular treatment outcomes in patients with acute ischemic stroke due to M1 occlusions

PurposeWe aimed to study the association of non-contrast CT (NCCT) thrombus density with procedural and clinical outcomes in patients with acute ischemic stroke who underwent endovascular treatment (EVT). Since thrombus density is associated with thrombus location, we focused on M1 occlusions only.MethodsPatients with available thin-slice (< 2.5 mm) NCCT were included from a nationwide registry. Regression models were used to assess the relation between thrombus density (per Hounsfield unit [HU]) and the following outcomes. For reperfusion grade, adjusted common odds ratios (acOR) indicated a 1-step shift towards improved outcome per HU increase in thrombus density. For the binary outcomes of first-pass reperfusion (first-pass extended thrombolysis in cerebral infarction [eTICI] 2C-3, FPR), functional independence [90-day modified Rankin Scale (mRS) score of 0–2] and mortality), aORs were reported. Adjusted β coefficients (aβ) were reported for 24-h NIHSS and procedure duration in minutes. Outcome differences between first-line treatment devices (stent retriever versus aspiration) were assessed with interaction terms.ResultsIn 566 patients with M1 occlusions, thrombus density was not associated with reperfusion (acOR 1.01, 95% CI 0.99–1.02), FPR (aOR 1.01, 95% CI 0.99–1.03), mortality (aOR 0.98, 95% CI 0.95–1.00), 24-h NIHSS (aβ − 0.7%, 95% CI − 1.4–0.2), or procedure duration (aβ 0.27, 95% CI − 0.05–0.58). In multivariable analysis, thrombus density was associated with functional independence (aOR 1.02, 95% CI 1.00–1.05). No interaction was found between thrombus density and first-line treatment device for any outcome.ConclusionIn patients with M1 occlusions, thrombus density was not clearly associated with procedural and clinical outcomes after EVT.

Association of Systolic Blood Pressure and Cerebral Collateral Flow in Acute Ischemic Stroke by Stroke Subtype.

Background and PurposeCollateral flow in acute ischemic stroke is known as a predictor of treatment outcome and long-term prognosis. However, factors determining the initial collateral flow remain unclear. We investigated factors related to collateral flow in patients with acute ischemic stroke caused by large vessel occlusion (AIS-LVO) and further analyzed the results according to stroke etiology.MethodsThis was a retrospective study using prospective stroke registry data from a single university hospital from October 2014 to May 2021. AIS-LVO with middle cerebral artery M1 occlusion identified by pre-treatment multiphasic computed tomography angiography was included. Collateral flow score was graded on a 6-point ordinal scale according to pial arterial filling.ResultsA total of 74 patients [cardioembolism (CE): 57; large artery atherosclerosis (LAA): 17] was included. The mean age of all patients was 72.2 ± 11.7 years, and 37.8 % (n = 28) were men. Multivariate regression analysis showed that initial SBP [odds ratio (OR): 0.994; 95% confidence interval (CI): 0.990–0.998; p = 0.002] and stroke etiology (OR: 0.718; 95% CI: 0.548–0.940; p = 0.019) were independent factors of the collateral flow grade. Collateral flow grade was independently associated with initial SBP in the CE group (OR: 0.993; 95% CI: 0.989–0.998; p = 0.004) but not in the LAA group (OR: 0.992; 95% CI: 0.980–1.004; p = 0.218). Initial SBP was significantly correlated with NIHSS score in the CE group but not in the LAA group (r2= 0.091, p = 0.023; r2 = 0.043, p = 0.426, respectively).ConclusionsElevated initial SBP was associated with poor cerebral collateral flow and more severe symptoms in the CE group, but not in the LAA group in patients with AIS-LVO. These findings suggest differential effects of initial SBP elevation on collateral flow by stroke subtypes.

Reader Response: Thrombectomy vs Medical Management in Low NIHSS Acute Anterior Circulation Stroke.

The study by Volny et al. adds to the recent literature showing similar outcomes between mechanical thrombectomy (MT) and medical management (MM) in patients with minor stroke.1 However, a closer look at most of these studies shows selection bias in included patients. A significantly higher proportion of patients undergoing thrombectomy had ICA/proximal M1 occlusions relative to M2 occlusions in patients selected for medical management. Further, there was an 8.6% (95% CI − 8.8% to 26.1%) higher rate of excellent outcome after mechanical thrombectomy in the propensity-matched group.

Pseudo-continuous arterial spin labeling with short post-labeling delay time sensitively reflects the hemodynamics of symptomatic patients with permanent large vessel occlusion before and after revascularization.

This study evaluated the feasibility of arterial spin labeling (ASL) for diagnosing hemodynamic stroke due to permanent anterior circulation large vessel occlusion. Three-dimensional pseudo-continuous ASL data at two post-labeling delay (PLD) times (1.5 and 2.5s) in patients with unilateral permanent middle cerebral artery (MCA) segment 1 (M1) or internal cerebral artery (ICA) occlusion were acquired during routine magnetic resonance angiography. Sixty-one patients with symptomatic occlusion (M1, 24; ICA, 37) and 69 patients with asymptomatic occlusion (M1, 21; ICA, 48) were enrolled. Regions of interest were automatically placed in the MCA region using a template. The respective scans were compared with asymptomatic M1 or ICA occlusion scans. The ratio of signal intensity (occlusion side/non-occlusion side) in the perfusion area of MCA (asymmetry index [AI]) was compared between both groups. In both PLD groups, AI was significantly lower in symptomatic patients than in asymptomatic patients. The receiver operating characteristic curve showed moderate capacity for the prediction of symptomatic AI in both groups (area under the curve, 0.739 and 0.712, respectively). As a result of extracranial-intracranial bypass operation in 28 symptomatic (M1, eight; ICA, 20) patients, AI was significantly higher postoperatively in the PLD 1.5s group than in the PLD 2.5s group. In symptomatic patients with permanent large vessel occlusion, the signal intensity ratio of pseudo-continuous ASL with short PLD sensitively reflects the hemodynamics before and after revascularization; therefore, this technique may be an alternative method in situations where PET or SPECT cannot be performed.

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.

Editors' Note: Thrombectomy vs Medical Management in Low NIHSS Acute Anterior Circulation Stroke

Patients with a low NIH Stroke Scale (NIHSS) score have been historically excluded from randomized clinical trials evaluating mechanical thrombectomy (MT), and therefore, the efficacy of intervention in patients with milder symptoms is less well established. In their pooled analysis of 3 prospective registries (n = 236 patients), Dr. Volny et al. compared patients according to treatment with MT vs medical management if they fit the following criteria: NIHSS ≤6; prestroke modified Rankin Scale (mRS) 0–2; occlusion of the internal carotid, or M1 or M2 middle cerebral arteries; and arrival within 12 hours of last known well. The investigators found no difference in the rate of the primary outcome, mRS 0–1 at 90 days, between MT and medically managed groups (62% vs 64%, p = 0.79). With propensity matching, there remained no significant difference in the proportion of patients achieving the primary outcome (absolute difference of 8.6%, 95%CI −8.8% to 26.1%). Hypothetically, if the patients with missing 90-day outcomes all achieved excellent functional outcome (n = 13)—“best-case scenario”—MT would have been significantly associated with excellent functional outcome as compared to medical management (17.6%, 95%CI 0.01%–35.4%). Drs. Malhotra and Khunte address other potential important factors that could have contributed to functional outcome, such as less frequent use of thrombolysis in the MT arm (suggesting that these patients had more delay in MT and, therefore, more progressive ischemic injury) and a higher proportion of patients with internal carotid and M1 occlusions treated with MT (suggesting potentially greater volume of brain tissue at risk of infarction). Drs. Zerna and Volny respond that some of the patient-level data were missing from the consolidated registries. For example, there are no time-to-treatment data in any data source and no data regarding CT angiography or other imaging findings from 1 of the 3 registries. Patients with a low NIH Stroke Scale (NIHSS) score have been historically excluded from randomized clinical trials evaluating mechanical thrombectomy (MT), and therefore, the efficacy of intervention in patients with milder symptoms is less well established. In their pooled analysis of 3 prospective registries (n = 236 patients), Dr. Volny et al. compared patients according to treatment with MT vs medical management if they fit the following criteria: NIHSS ≤6; prestroke modified Rankin Scale (mRS) 0–2; occlusion of the internal carotid, or M1 or M2 middle cerebral arteries; and arrival within 12 hours of last known well. The investigators found no difference in the rate of the primary outcome, mRS 0–1 at 90 days, between MT and medically managed groups (62% vs 64%, p = 0.79). With propensity matching, there remained no significant difference in the proportion of patients achieving the primary outcome (absolute difference of 8.6%, 95%CI −8.8% to 26.1%). Hypothetically, if the patients with missing 90-day outcomes all achieved excellent functional outcome (n = 13)—“best-case scenario”—MT would have been significantly associated with excellent functional outcome as compared to medical management (17.6%, 95%CI 0.01%–35.4%). Drs. Malhotra and Khunte address other potential important factors that could have contributed to functional outcome, such as less frequent use of thrombolysis in the MT arm (suggesting that these patients had more delay in MT and, therefore, more progressive ischemic injury) and a higher proportion of patients with internal carotid and M1 occlusions treated with MT (suggesting potentially greater volume of brain tissue at risk of infarction). Drs. Zerna and Volny respond that some of the patient-level data were missing from the consolidated registries. For example, there are no time-to-treatment data in any data source and no data regarding CT angiography or other imaging findings from 1 of the 3 registries.

Impact of Increasing Aspiration Catheter Size and Refinement of Technique: Experience of Over 1000 Strokes Treated With ADAPT.

We present longitudinal data regarding the outcomes and evolution of mechanical thrombectomy (MT) using a direct aspiration first pass technique. To evaluate the impact of increasing aspiration catheter size. This is a planned analysis of a prospective cohort study that enrolled all patients who underwent a direct aspiration first pass technique MT in a comprehensive stroke center from January 2013 to December 2020. We did exploratory analysis of the characteristics and outcomes of patients who had intracranial internal carotid artery or M1 segment of middle cerebral artery occlusion based on the aspiration catheter bore size (small [041, 054, 058, and 060 inch] vs medium [0.064 and 0.068 inch] and medium vs large [0.071, 0.072, and 0.074 inch]). During the 8-year study period, a total of 1004 patients were included. Median age was 69 years, 49% were female patients, and 60.6% were White. Symptomatic hemorrhagic transformation was observed in 47 patients (4.7%), and 366 patients (36.5%) achieved the modified Rankin scale of 0 to 2 at 90 days after the stroke. For patients with intracranial internal carotid artery or M1 occlusion, medium-bore aspiration catheters were more likely to achieve successful recanalization after first aspiration attempt (63.9% vs 51.4%, P = .015) and had a faster groin-to-reperfusion time (16 vs 20 minutes, P = .001) when compared with small-bore catheters. However, these differences were not significant when comparing medium-bore with large-bore catheters. Medium-bore catheters had better performance measures compared with small-bore catheters. However, large-bore catheters did not show significantly better performance results that suggest a plateau effect.

Evaluation of time-resolved whole brain flat panel detector perfusion imaging using RAPID ANGIO in patients with acute stroke: comparison with CT perfusion imaging

BackgroundIn contrast to conventional CT perfusion (CTP) imaging, flat panel detector CT perfusion (FD-CTP) imaging can be acquired directly in the angiosuite.ObjectiveTo evaluate time-resolved whole brain FD-CTP imaging and assess...

Double Trouble: Biventricular Thrombi And Embolic Complications

<h3>Case Summary</h3> A 49 year old with peripheral vascular disease presented to his vascular surgeon with leg pain and it was found cold and pulseless. He was diagnosed with critical limb ischemia and was directly admitted to the vascular surgery. CT found a femoral artery occlusion, cardiomegaly and bi-ventricular clots. Cardiology was consulted and a TTE noted bi-ventricular thrombi and a severely dilated LV with EF=20%. Palliative care was consulted. He was taken to the OR for BKA. Post-operatively he had a PEA arrest. He was in shock and given inotropes. Invasive hemodynamics, mechanical support, and coronary angiography were limited by renal failure, vascular access and thrombi. His shock improved, but he was not a candidate for advanced therapies. Coronary angiography showed multi-vessel disease. Cardiac MR showed viability in most regions but while awaiting revascularization, he became unresponsive. CT showed R ICA occlusion, R MCA occlusion, L M1 occlusion, and R watershed infarct. He was taken for mechanical thrombectomy. MRI showed multifocal infarcts in the L MCA, left pons, and left PCA. Fluids were trialed to improve perfusion, but he became hypoxic and repeat MRI did not show any improvement. He was unresponsive. The family enrolled the patient in hospice. <h3>Discussion</h3> Our patient had no history of HFrEF. While he had risk factors, symptoms were masked by severe peripheral vascular disease. Bi-ventricular thrombi are uncommon and place the patient at risk for systemic and pulmonary embolization. Aside from anticoagulation, there is little consensus on the management of intracardiac thrombi and the risk varies significantly within published data. In severe HF, complications and inability to tolerate GDMT should warrant advanced HF consultation. Early involvement of palliative care helped guide family during end of life care. More research is needed to better inform management options in heart failure complicated by intracardiac thrombi.

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

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