Anterior Circulation Large Vessel Occlusion Research Articles

The Los Angeles motor scale (LAMS) is independently associated with CT perfusion collateral status markers

Background and aimThe Los Angeles Motor Scale (LAMS) is an objective tool that has been used to rapidly assess and predict the presence of large vessel occlusion (LVO) in the pre-hospital setting successfully in several studies. However, studies assessing the relationship between LAMS score and CT perfusion collateral status (CS) markers such as cerebral blood volume (CBV) index, and hypoperfusion intensity ratio (HIR) are sparse. Our study therefore aims to assess the association of admission LAMS score with established CTP CS markers CBV Index and HIR in AIS-LVO cases. Materials and MethodsIn this prospectively collected, retrospectively reviewed analysis, inclusion criteria were as follows: a) CT angiography (CTA) confirmed anterior circulation LVO from 9/1/2017 to 10/01/2023, and b) diagnostic CT perfusion (CTP). Logistic regression analysis was performed to assess the relationship between admission LAMS with CTP CS markers HIR and CBV Index. p ≤ 0.05 was considered significant. ResultsIn total, 285 consecutive patients (median age = 69 years; 56 % female) met our inclusion criteria. Multivariable logistic regression analysis adjusting for sex, age, ASPECTS, tPA, premorbid mRS, admission NIH stroke scale, prior history of TIA, stroke, atrial fibrillation, diabetes mellitus, hyperlipidemia, coronary artery disease and hypertension, admission LAMS was found to be independently associated with CBV Index (adjusted OR:0.82, p < 0.01), and HIR (adjusted OR:0.59, p < 0.05). ConclusionLAMS is independently associated with CTP CS markers, CBV index and HIR. This finding suggests that LAMS may also provide an indirect estimate of CS.

The impacts of venous outflow profiles on outcomes among large vessel occlusion patients receiving endovascular treatment in the late window.

To investigate the association between venous outflow (VO) profiles and outcomes among acute ischemic stroke caused by anterior circulation large vessel occlusion (AIS-LVO) patients who had undergone endovascular treatment (EVT) in the late window of 6-24 h from stroke onset. This was a post-hoc analysis of our preceding RESCUE-BT trial, with findings validated in an external cohort. Baseline computed tomographic angiography (CTA) was performed to assess VO using the Cortical Vein Opacification Score (COVES). The primary clinical outcome was functional independence at 90 days (modified Rankin Scale score of 0-2). The adjusted odd ratio (aOR) and confidence interval (CI) were obtained from multivariable logistic regressions. A total of 440 patients were included in the present study. After identifying the cutoff of COVES by marginal effects approach, enrolled patients were divided into the favorable VO group (COVES 4-6) and the poor VO (COVES 0-3) group. Multivariable logistic regression analysis showed that favorable VO (aOR 2.25; 95% CI 1.31-3.86; p = 0.003) was associated with functional independence. Similar results were detected in the external validation cohort. Among those with poor arterial collateralization, favorable VO was still an independent predictor of functional independence (aOR 2.09; 95% CI 1.06-4.10; p = 0.032). The robust VO profile indicated by COVES 4-6 could promote the frequency of functional independence among AIS-LVO patients receiving EVT in the late window, and the prognostic value of VO was independent of the arterial collateral status. The robust venous outflow profile was a valid predictor for functional independence among AIS-LVO patients receiving EVT in the late window (6-24 h) and the predictive role of venous outflow did not rely on the status of arterial collateral circulation.

A clinical and computed tomography-based nomogram to predict the outcome in patients with anterior circulation large vessel occlusion after endovascular mechanical thrombectomy.

To explore the positive predictors of the clinical outcome in acute ischemic stroke (AIS) patients with anterior circulation large vessel occlusion (ACLVO) after endovascular mechanical thrombectomy (EMT) at a 90-day follow-up, and to establish a nomogram model to predict the clinical outcome. AIS patients with ACLVO detected by multimodal Computed Tomography imaging who underwent EMT were collected. Patients were divided into the favorable and the unfavorable groups according to the 90-day modified Rankin Scale (mRS) score. Univariate and multivariate analyses were performed to investigate predictors of the favorable outcome (mRS of 0-2). A nomogram model for predicting the clinical outcome after EMT was drawn, and the receiver operating characteristic (ROC) curve was used to evaluate its predictive value. Totally 105 patients including 65 patients in the favorable group and 40 in the unfavorable group were enrolled. Multivariate logistic regression analysis showed that admission National Institute of Health Stroke scale (NIHSS) score [0.858 (95% CI 0.778-0.947)], ACLVO at M2 [20.023 (95% CI 2.204-181.907)] and infarct core (IC) volume [0.943 (95% CI 0.917-0.969)] was positively correlated with favorable outcome. The accuracy of the nomogram model in predicting the outcome was 0.923 (95% CI 0.870-0.976), with a cutoff value of 119.6 points. The area under the ROC curve was 0.848 (95% CI 0.780-0.917; sensitivity, 79.7%; specificity, 90.0%). A low Admission NIHSS score, ACLVO at M2, and a small IC volume were positive predictors for favorable outcome. The nomogram model may well predict the outcome in AIS patients with ACLVO after EMT.

Deep learning-based model for difficult transfemoral access prediction compared with human assessment in stroke thrombectomy

BackgroundIn mechanical thrombectomy (MT), extracranial vascular tortuosity is among the main determinants of procedure duration and success. Currently, no rapid and reliable method exists to identify the anatomical features precluding...

Contrast Staining in Noninfarcted Tissue after Endovascular Treatment of Acute Ischemic Stroke.

Contrast staining is a common finding after endovascular treatment of acute ischemic stroke. It typically occurs in infarcted tissue and is considered an indicator of irreversible brain damage. Contrast staining in noninfarcted tissue has not been systematically investigated. We sought to assess the incidence, risk factors, and clinical significance of contrast staining in noninfarcted tissue after endovascular treatment. We conducted a retrospective review of consecutive patients who underwent endovascular treatment for anterior circulation large-vessel occlusion acute ischemic stroke. Contrast staining, defined as new hyperdensity on CT after endovascular treatment, was categorized as either contrast staining in infarcted tissue if the stained region demonstrated restricted diffusion on follow-up MR imaging or contrast staining in noninfarcted tissue if the stained region demonstrated no restricted diffusion. Baseline differences between patients with and without contrast staining in noninfarcted tissue were compared. Logistic regression was used to identify independent associations for contrast staining in noninfarcted tissue after endovascular treatment. Among 194 patients who underwent endovascular treatment for large-vessel occlusion acute ischemic stroke and met the inclusion criteria, contrast staining in infarcted tissue was noted in 52/194 (26.8%) patients; contrast staining in noninfarcted tissue, in 26 (13.4%) patients. Both contrast staining in infarcted tissue and contrast staining in noninfarcted tissue were noted in 5.6% (11/194). Patients with contrast staining in noninfarcted tissue were found to have a higher likelihood of having an ASPECTS of 8-10, to be associated with contrast staining in infarcted tissue, and to achieve successful reperfusion compared with those without contrast staining in noninfarcted tissue. In contrast staining in noninfarcted tissue regions, the average attenuation was 40 HU, significantly lower than the contrast staining in infarcted tissue regions (53 HU). None of the patients with contrast staining in noninfarcted tissue had clinical worsening during their hospital stay. The median discharge mRS was significantly lower in patients with contrast staining in noninfarcted tissue than in those without (3 versus 4; P = .018). No independent predictors of contrast staining in noninfarcted tissue were found. Contrast staining can be seen outside the infarcted tissue after endovascular treatment of acute ischemic stroke, likely attributable to the reversible disruption of the BBB in ischemic but not infarcted tissue. While generally benign, understanding its characteristics is important because it may mimic pathologic conditions such as infarcted tissue and cerebral edema.

Importance of computed tomography perfusion on assessing collateral circulation and prognosis of patients with acute anterior circulation large vessel occlusion after endovascular therapy

This study probed the importance of computed tomography perfusion (CTP) on assessing collateral circulation and prognosis in patients with acute anterior circulation large vessel occlusion (AAC-LVO) after endovascular therapy (EVT). Retrospective analysis was performed on the case data of 124 AAC-LVO patients who achieved EVT in the First People's Hospital of Lianyungang. All patients received computed tomography (CT) examination. Based on the multi-phase computed tomography angiography (mCTA) score, patients were separated into poor collateral circulation group and good collateral circulation group. Based on modified Rankin scale (mRS) score, patients were separated into good prognosis group and poor prognosis group. The receiver operating characteristic (ROC) curve was used to measure the efficacy of CTP parameters in predicting good collateral circulation or good prognosis. Correlation between CTP parameters with mCTA collateral and 90-day mRS circulation score was analyzed using the Spearman correlation analysis. The age and admission national Institutes of Health stroke scale (NIHSS) scores of the good collateral circulation group were lower than the poor collateral circulation group, and low perfusion area volume with Tmax > 6 s (VTmax>6s), infarct core area volume (VCBF<30%)and hypoperfusion intensity ratio (HIR) were also lower. The mCTA collateral cycle score was negatively related to VTmax>6 s, VCBF<30% and HIR. The area under the curve (AUC) values of VTmax>6 s and VCBF<30% and HIR for predicting good collateral circulation were 0.763, 0.884 and 0.842, respectively, which suggested that perfusion parameters VTmax>6 s, VCBF<30% and HIR could effectively indicate the status of patients’ collateral circulation. Relative to the poor prognosis group, patients in the good prognosis group possessed lower admission NIHSS score, younger age, smaller final infarct volume, lower HIR, VCBF<30%, VTmax>6s, Alberta Stroke Program Early CT(ASPECT) score, and higher mCTA score. Spearman correlation analysis unveiled that ASPECT score, mCTA score and 90-day mRS were negatively correlated. The final infarct volume, perfusion parameters HIR and VCBF<30% were positively correlated with 90-day mRS. ROC analysis showed that all variates had good prognostic value for acute anterior circulation great vessel occlusion patients, while VCBF<30% and HIR had high diagnostic value for prognosis. To sum up, CTP can provide a comprehensive imaging assessment of the collateral circulation of patients with AAC-LVO and has a higher predictive value for the prognosis assessment of patients with EVT in terms of VCBF<30%, HIR score and mCTA collateral circulation score.

Comparison of outcomes between stent retriever combined with contact aspiration versus contact aspiration alone in patients without hyperdense artery sign/susceptibility vessel sign

PurposeTo examine the relationship between hyperdense artery sign/susceptibility vessel sign (HAS/SVS) and thrombus composition, and evaluate the effect of HAS/SVS status on the association between first-line thrombectomy techniques and outcomes in patients with acute anterior-circulation large vessel occlusion (LVO). Materials and MethodsFrom January 2018 to June 2021, 103 consecutive acute anterior-circulation LVO patients (75 [63.1%] male; median age, 66 years) who underwent thrombectomy, and for whom the removed clot was available for histological analyses were retrospectively reviewed. The presence of HAS and SVS was respectively assessed in noncontrast computed tomography (NCCT) and susceptibility-weighted imaging (SWI). Association of first-line thrombectomy techniques [stent retriever combined with contact aspiration (SR+CA) versus contact aspiration (CA)] with outcomes was assessed by the HAS/SVS status. ResultsAmong the included patients, 55 (53.4%) were HAS/SVS(-), and 69 (67.0%) chose first-line SR+CA. Higher relative densities of fibrin/platelets (0.56 vs. 0.51, p<0.001) and lower relative densities of erythrocytes (0.32 vs. 0.42, p<0.001) were observed in HAS/SVS(-) than HAS/SVS(+) patients. First-line SR+CA was associated with reduced odds of distal embolization (aOR, 0.18; 95% CI, 0.04–0.83; p=0.027) and a more favorable 90-day functional outcome (aOR, 5.29; 95% CI, 1.06–26.34; p=0.042) in HAS/SVS(-) patients, and a longer recanalization time (53 min vs. 25 min, p=0.025) and higher risk of subarachnoid hemorrhage (24.2% vs. 0%, p=0.044) in HAS/SVS(+) patients. ConclusionsHAS/SVS(-) may indicate a higher density of fibrin/platelets in the thrombus, and first-line SR+CA may have a possible better performance than CA in acute LVO patients without HAS/SVS.

Comparison the Perfusion/Diffusion Mismatching Judging From CT-Based and MR-Based Study

Background: The development of endovascular devices and clinical experience, recanalization rate after intraarterial thrombectomy (IA-Tx) has increased. Recent papers reported that the amount of perfusion/diffusion (P/D)-mismatching in digital analysis from computer tomography perfusion (CTP) image is well correlated well with P/D-mismatching from magnetic resonance image. The purpose of this study is compare the patient clinical outcomes after IA-Tx, judging from CTP based and magnetic resonance imaging (MRI) based study. Methods : 218 patients with anterior circulation large vessel occlusion (LVO) treated by IA-Tx were included in this analysis. In the MRI group (n=80), P/D-mismatching from MRI based image analysis by visual method and in the CTP group (n=138), and recently, P/D-mismatching was decided by automatized computer programmatic analyzed from CTP based image (Syngo.via program). Results: Favorable outcome (modified Rankin Score: 0–2), mortality, recanalization, and clinically significant hemorrhage was 56.3% (45/80), 6.25% (5/80), 81.3% (65/80) and 25% (20/80) in MRI group and 4.9% (62/138), 8.9%(18/138), 91.3%(126/138) and 40.6% (56/138) in CTP group (p=0.000, 0.235, 0.007 and 0.013). Reperfusion injury (27.5% vs, 15.0%, p=0.018) but favorable outcome was high 55.0% vs. 44.9 $, p=0.00) in the MRI study group. Conclusion : In our study, patient selection according to the P/D-mismatching from MR-based imaging and CTP-based image was not different in final clinical outcome. Recent IA-Tx, showed high recanalization rate but it also cause high incidence of reperfusion injury.

Predicting haemorrhagic transformation through serum biochemical indices for patients after endovascular treatment: a retrospective study.

The aim of this study was to determine the serum biochemical markers that can predict the risk of haemorrhagic transformation (HT) before and after endovascular treatment (EVT). This study included patients with anterior circulation large vessel occlusion (ACLVO) who underwent EVT within six hours of symptom onset between September 2017 and September 2022. These patients were retrospectively categorised into two groups: an HT group and a No-HT group. A total of 180 patients were included in the study, of whom 55 (30.6%) had HT. The monocyte count before EVT (p = = 0.005, OR = 0.694, 95% CI 0.536-0.898), the activated partial thromboplastin time before EVT (p = 0.009, OR = 0.186, 95% CI 0.699-0.952), and the eosinophil count after EVT (p = 0.038, OR = 0.001, 95% CI 0.000-0.018) were all found to be independent predictors of HT, with warning values of 6.65%, 22.95 seconds, and 0.035*10^9/L, respectively. When compared to prediction using only demographic data [AUC = 0.662,95% CI (0.545, 0.780)], adding biochemical indices before EVT [AUC = 0.719,95% CI (0.617, 0.821)], adding biochemical indices after EVT [AUC = 0.670,95% CI (0.566, 0.773)], and adding both [AUC = 0.778,95% CI (0.686, 0.870)], the prediction efficiency of HT was improved among all three combinations, with no statistical significance. The levels of serum biochemical markers were found to show significant changes before and after EVT in ACLVO patients. A combination of demographic data and serum biochemical markers proved to be effective in predicting the occurrence of HT in patients with ACLVO who underwent EVT.

HEMERA‐1 CarboxyHEMoglobin OxygEn Delivery for Evascularization in Acute Stroke: A Prospective, Randomized Phase 1 Clinical Trial

BACKGROUND PP‐007 is a polyethylene glycol (PEG)ylated bovine carboxyhemoglobin gas transfer molecule with pleotropic cytoprotective effects, vasodilatation, plasma expansion, and optimization of oxygen delivery. Rodent middle cerebral artery occlusion models have demonstrated that PP‐007 increases blood flow in the collateral circulation and reduces final infarct volumes, supporting a potential role as neuroprotective agent in acute ischemic stroke. We aim to evaluate the safety and feasibility of PP‐007 as an adjunctive treatment to mechanical thrombectomy (MT) in patients with stroke secondary to large vessel occlusion. METHODS HEMERA‐1 (CarboxyHEMoglobin OxygEn delivery for Revascularization in Acute Stroke) was a multicenter, prospective, randomized, controlled phase 1 clinical trial. Anterior circulation large vessel occlusion patients were assigned in a 3:1 ratio to receive either PP‐007 (320 mg/kg: 30 min bolus followed by 2‐h infusion) plus MT or MT alone within 24 hours after symptom onset. Comprehensive safety evaluation was performed by independent Data Monitoring Safety Board and Imaging Core Lab. RESULTS From October 1, 2021 to June 30, 2022, a total of 17 patients were recruited. Age, baseline National Institutes of Health Stroke Scale score, and Alberta Stroke Program Early CT Score were 74.8±12.7 years, 17.3±4.2, and 7.9±1.8, respectively. Twelve patients were randomized to PP‐007 plus MT, 1 was randomized but not treated, 4 patients were randomized to MT alone. Recanalization of the occluded vessel was achieved in all patients. A transient systolic blood pressure increase (20–40 mm Hg) during the bolus was observed in all PP‐007 patients without any clinical consequences. There were no other safety concerns. CONCLUSION No significant safety concerns were identified for the adjunctive use of PP‐007 in patients undergoing MT. (The study was funded by Prolong Pharmaceuticals. REGISTRATION URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04677777.

CT Perfusion Derived rCBV < 42% Lesion Volume Is Independently Associated with Followup FLAIR Infarct Volume in Anterior Circulation Large Vessel Occlusion.

Pretreatment CT Perfusion (CTP) parameter rCBV < 42% lesion volume has recently been shown to predict 90-day mRS. In this study, we aim to assess the relationship between rCBV < 42% and a radiographic follow-up infarct volume delineated on FLAIR images. In this retrospective evaluation of our prospectively collected database, we included acute stroke patients triaged by multimodal CT imaging, including CT angiography and perfusion imaging, with confirmed anterior circulation large vessel occlusion between 9 January 2017 and 10 January 2023. Follow-up FLAIR imaging was used to determine the final infarct volume. Student t, Mann-Whitney-U, and Chi-Square tests were used to assess differences. Spearman's rank correlation and linear regression analysis were used to assess associations between rCBV < 42% and follow-up infarct volume on FLAIR. In total, 158 patients (median age: 68 years, 52.5% female) met our inclusion criteria. rCBV < 42% (ρ = 0.56, p < 0.001) significantly correlated with follow-up-FLAIR infarct volume. On multivariable linear regression analysis, rCBV < 42% lesion volume (beta = 0.60, p < 0.001), ASPECTS (beta = -0.214, p < 0.01), mTICI (beta = -0.277, p < 0.001), and diabetes (beta = 0.16, p < 0.05) were independently associated with follow-up infarct volume. The rCBV < 42% lesion volume is independently associated with FLAIR follow-up infarct volume.

Older Age Is Associated with Frequent Clinical-core Mismatch in Stroke due to Anterior Circulation Large Vessel Occlusion (P10-5.028)

Older Age Is Associated with Frequent Clinical-core Mismatch in Stroke due to Anterior Circulation Large Vessel Occlusion (P10-5.028)

A systematic review of randomized controlled trials of endovascular therapy for stroke on mortality and disability

BackgroundEndovascular treatment (EVT) has become standard of care for patients with anterior circulation large vessel occlusion (LVO) stroke, with indications having recently expanded to late time-window and large ischemic core patients. There is conflicting evidence on whether EVT reduces mortality or only disability. We performed a meta-analysis of randomized controlled trials (RCTs) to assess the effect of EVT on mortality and severe disability. MethodsWe systematically searched PubMed, Web of Science, Scopus, and Embase on November 15, 2023, to identify phase 3 RCTs comparing EVT to best medical treatment (BMT) in patients with anterior circulation LVO stroke in a common effects meta-analysis. The primary outcome was mortality at 3 months. Secondary outcomes were moderately severe or severe disability (modified Rankin Scale (mRS) score 4–5) at 3 months. Results18 studies comparing EVT to BMT were included, with a total of 4309 patients; 2159 that were treated with EVT, and 2150 treated with BMT. Mortality was significantly lower in the EVT group than in the BMT group (odds ratio (OR): 0.81, 95% CI: 0.70–0.94). Proportions of moderately severe or severe disability (OR: 0.55, 95% CI: 0.48–0.62) were also significantly lower in patients treated with EVT. ConclusionsThis meta-analysis suggests that EVT reduces both mortality and moderately severe or severe disability in patients with anterior circulation LVO stroke.

Thrombus Imaging Characteristics to Predict Early Recanalization in Anterior Circulation Large Vessel Occlusion Stroke.

The early management of transferred patients with a large vessel occlusion (LVO) stroke could be improved by identifying patients who are likely to recanalize early. We aim to predict early recanalization based on patient clinical and thrombus imaging characteristics. We included 81 transferred anterior-circulation LVO patients with an early recanalization, defined as the resolution of the LVO or the migration to a distal location not reachable with endovascular treatment upon repeated radiological imaging. We compared their clinical and imaging characteristics with all (322) transferred patients with a persistent LVO in the MR CLEAN Registry. We measured distance from carotid terminus to thrombus (DT), thrombus length, density, and perviousness on baseline CT images. We built logistic regression models to predict early recanalization. We validated the predictive ability by computing the median area-under-the-curve (AUC) of the receiver operating characteristics curve for 100 5-fold cross-validations. The administration of intravenous thrombolysis (IVT), longer transfer times, more distal occlusions, and shorter, pervious, less dense thrombi were characteristic of early recanalization. After backward elimination, IVT administration, DT and thrombus density remained in the multivariable model, with an AUC of 0.77 (IQR 0.72-0.83). Baseline thrombus imaging characteristics are valuable in predicting early recanalization and can potentially be used to optimize repeated imaging workflow.

CT perfusion based rCBF

Collateral status (CS) is an important biomarker of functional outcomes in patients with acute ischemic stroke secondary to large vessel occlusion (AIS-LVO). Pretreatment CT perfusion (CTP) parameters serve as reliable surrogates of collateral status (CS). In this study, we aim to assess the relationship between the relative cerebral blood flow less than 38% (rCBF <38%), with the reference standard American Society of Interventional and Therapeutic Neuroradiology (ASITN) collateral score (CS) on DSA. In this prospectively collected, retrospectively reviewed analysis, inclusion criteria were as follows: (a) CT angiography (CTA) confirmed anterior circulation large vessel occlusion from 9/1/2017 to 10/01/2023; (b) diagnostic CT perfusion; and (c) underwent mechanical thrombectomy with documented ASITN CS. The ratios of the CTP-derived CBF values were calculated by dividing the values of the ischemic lesion by the corresponding values of the contralateral normal region (which were defined as rCBF). Spearman's rank correlation and logistic regression analysis were performed to determine the relationship of rCBF <38% lesion volume with DSA ASITN CS. p ≤ .05 was considered significant. In total, 223 patients [mean age: 67.77 ± 15.76 years, 56.1% (n = 125) female] met our inclusion criteria. Significant negative correlation was noted between rCBF <38% volume and DSA CS (ρ = -0.37, p < .001). On multivariate logistic regression analysis, rCBF <38% volume was found to be independently associated with worse ASITN CS (unadjusted OR: 3.03, 95% CI: 1.60-5.69, p < .001, and adjusted OR: 2.73, 95% CI: 1.34-5.50, p < .01). Greater volume of tissue with rCBF <38% is independently associated with better DSA CS. rCBF <38% is a useful adjunct tool in collateralization-based prognostication. Future studies are needed to expand our understanding of the role of rCBF <38% within the decision-making in patients with AIS-LVO.

Portable cerebral blood flow monitor to detect large vessel occlusion in patients with suspected stroke

BackgroundEarly detection of large vessel occlusion (LVO) facilitates triage to an appropriate stroke center to reduce treatment times and improve outcomes. Prehospital stroke scales are not sufficiently sensitive, so we...

Absent leptomeningeal collateralization is associated with greatest benefit from mechanical thrombectomy in the 6-24 hour time window.

The impact of leptomeningeal collateralization on the efficacy of mechanical thrombectomy (MT) in patients with anterior circulation large vessel occlusion (aLVO) presenting in the 6-24 h time window remains poorly elucidated. Retrospective multicenter study of aLVO patients presenting between 6 and 24 h after stroke onset who received MT plus Best Medical Treatment (BMT) or BMT alone. Leptomeningeal collateralization was assessed using single-phase computed tomography angiography (grade 0: no filling; grade 1: filling ⩽50%; grade 2: filling >50% but <100%; grade 3: filling 100% of the occluded territory). Inverse probability of treatment weighted ordinal regression was performed to assess the association between treatment and shift of the modified Rankin Scale (mRS) score toward lower categories at 3 months. We used interaction analysis to explore differential treatment effects on functional outcomes (probabilities for each mRS subcategory at 3 months) at different collateral grades. Among 363 included patients, 62% received MT + BMT. Better collateralization was associated with better functional outcomes at 3 months in the BMT alone group (collateral grade 1 vs 0: acOR 5.06, 95% CI 2.33-10.99). MT + BMT was associated with higher odds of favorable functional outcome at 3 months (acOR 1.70, 95% CI 1.11-2.62) which was consistent after adjustment for collateral status (acOR 1.54, 95% CI 1.01-2.35). Regarding treatment effect modification, patients with absent collateralization had higher probabilities for a mRS of 0-4 and a lower mortality at 3 months for the MT + BMT group. In the 6-to-24-h time window, aLVO patients with absent leptomeningeal collateralization benefit most from MT + BMT, indicating potential advantages for this group despite their poorer baseline prognosis.

Impact of Procedure Time on First Pass Effect in Mechanical Thrombectomy for Anterior Circulation Acute Ischemic Stroke.

First pass effect (FPE) is a metric increasingly used to determine the success of mechanical thrombectomy (MT) procedures. However, few studies have investigated whether the duration of the procedure can modify the clinical benefit of FPE. We sought to determine whether FPE after MT for anterior circulation large vessel occlusion acute ischemic stroke is modified by procedural time (PT). A multicenter, international data set was retrospectively analyzed for anterior circulation large vessel occlusion acute ischemic stroke treated by MT who achieved excellent reperfusion (thrombolysis in cerebral infarction 2c/3). The primary outcome was good functional outcome defined by 90-day modified Rankin scale scores of 0-2. The primary study exposure was first pass success (FPS, 1 pass vs ≥2 passes) and the secondary exposure was PT. We fit-adjusted logistic regression models and used marginal effects to assess the interaction between PT (≤30 vs >30 minutes) and FPS, adjusting for potential confounders including time from stroke presentation. A total of 1310 patients had excellent reperfusion. These patients were divided into 2 cohorts based on PT: ≤30 minutes (777 patients, 59.3%) and >30 minutes (533 patients, 40.7%). Good functional outcome was observed in 658 patients (50.2%). The interaction term between FPS and PT was significant ( P = .018). Individuals with FPS in ≤30 minutes had 11.5% higher adjusted predicted probability of good outcome compared with those who required ≥2 passes (58.2% vs 46.7%, P = .001). However, there was no significant difference in the adjusted predicted probability of good outcome in individuals with PT >30 minutes. This relationship appeared identical in models with PT treated as a continuous variable. FPE is modified by PT, with the added clinical benefit lost in longer procedures greater than 30 minutes. A comprehensive metric for MT procedures, namely, FPE 30 , may better represent the ideal of fast, complete reperfusion with a single pass of a thrombectomy device.

Inter-hospital transfer for thrombectomy: transfer time is brain.

Patients with acute ischaemic stroke and a large vessel occlusion who present to a non-endovascular-capable centre often require inter-hospital transfer for thrombectomy. Whether the inter-hospital transfer time is associated with 3-month functional outcome is poorly known. Acute stroke patients enrolled between January 2015 and December 2022 in the prospective French multicentre Endovascular Treatment of Ischaemic Stroke registry were retrospectively analysed. Patients with an anterior circulation large vessel occlusion transferred from a non-endovascular to a comprehensive stroke centre for thrombectomy were eligible. Inter-hospital transfer time was defined as the time between imaging in the referring hospital and groin puncture for thrombectomy. The relationship between transfer time and favourable 3-month functional outcome (modified Rankin Scale 0-2) was assessed through a mixed logistic regression model adjusting for centre and symptom-onset-to-referring-hospital imaging time, age, sex, diabetes, referring hospital National Institutes of Health Stroke Scale score, Alberta Stroke Programme Early Computed Tomography Score, occlusion site and intravenous thrombolysis use. Overall, 3769 patients were included (median inter-hospital transfer time 161 min, interquartile range 128-195; 46% with favourable outcome). A longer transfer time was independently associated with lower rates of favourable outcome (p < 0.001). Compared to patients with transfer time below 120 min, there was a 15% reduction in the odds of achieving favourable outcome for transfer times between 120 and 180 min (adjusted odds ratio 0.85; 95% confidence interval 0.67-1.07), and a 36% reduction for transfer times beyond 180 min (adjusted odds ratio 0.64; 95% confidence interval 0.50-0.81). A shorter inter-hospital transfer time is strongly associated with favourable 3-month functional outcome. A speedier inter-hospital transfer is of critical importance to improve outcome.

The Relative Cerebral Blood Volume (rCBV) < 42% Is Independently Associated with Collateral Status in Anterior Circulation Large Vessel Occlusion.

Background: The pretreatment CT perfusion (CTP) marker the relative cerebral blood volume (rCBV) < 42% lesion volume has recently been shown to predict 90-day functional outcomes; however, studies assessing correlations of the rCBV < 42% lesion volume with other outcomes remain sparse. Here, we aim to assess the relationship between the rCBV < 42% lesion volume and the reference standard digital subtraction angiography (DSA)-derived American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN) collateral score, hereby referred as the DSA CS. Methods: In this retrospective evaluation of our prospectively collected database, we included acute stroke patients triaged by multimodal CT imaging, including CT angiography and perfusion imaging, with confirmed anterior circulation large vessel occlusion between 1 September 2017 and 1 October 2023. Group differences were assessed using the Student's t test, Mann-Whitney U test and Chi-Square test. Spearman's rank correlation and logistic regression analyses were used to assess associations between rCBV < 42% and DSA CS. Results: In total, 222 patients (median age: 69 years, 56.3% female) met our inclusion criteria. In the multivariable logistic regression analysis, taking into account age, sex, race, hypertension, hyperlipidemia, diabetes, atrial fibrillation, prior stroke or transient ischemic attack, the admission National Institute of Health stroke scale, the premorbid modified Rankin score, the Alberta stroke program early CT score (ASPECTS), and segment occlusion, the rCBV < 42% lesion volume (adjusted OR: 0.98, p < 0.05) was independently associated with the DSA CS. Conclusion: The rCBV < 42% lesion volume is independently associated with the DSA CS.