Cerebral Occlusion Research Articles

Abstract TP383: Neutrophil Extracellular Traps (NETs)-related LncRNAs Regulate Thrombus Formation in Acute Ischemic Stroke Patients with Underlying Medical Conditions

Introduction: Acute cerebral blood flow occlusion by thrombus is a major cause of ischemic stroke. The composition of the resulting thrombus varies depending on the underlying medical condition. Notably, neutrophils, the most abundant white blood cells, play a crucial role in acute ischemic stroke and can form neutrophil extracellular traps (NETs). NETs are web-like structures consisting of DNA, granule proteins, and histones. NETs contribute to thrombo-inflammation and stabilize the thrombus, potentially leading to worse outcomes. While long non-coding RNA (lncRNA) do not encode proteins, they are involved in essential biological processes. The link between lncRNAs and cardiovascular disease is increasingly studied, and their role in ischemic stroke has recently come to attention. We, therefore, hypothesize that lncRNAs within NETs play a critical role in the formation and regulation of thrombi. Method: Human thrombi obtained from endovascular thrombectomy were categorized based on their underlying medical conditions, such as dyslipidemia, hypertension, or a combination of two or more conditions. Frozen sections of the thrombi were immunostained with markers including Citrullinated H3 (CitH3), CD45, neutrophil elastase (NE), and DAPI, and then analyzed using holotomography, confocal microscopy, and spatial transcriptomics. In spatial transcriptomics analysis, NETs and other leukocytes were selected as distal and proximal ROIs for detailed gene expression profiling. The gene expression of HDAC class 1 genes (HDAC1, HDAC2, HDAC3, and HDAC8) was further examined by qPCR. Results: Holotomography analysis revealed that cells in the thrombi of patients with underlying conditions exhibited a high mean refractive index. Immunofluorescence imaging also identified a high percentage of NETs in these samples. Spatial transcriptomics analysis confirmed that NETs in patients with hypertension showed upregulated expression of lncRNAs. Additionally, qPCR results demonstrated increased expression of HDAC class 1 genes, which are associated with NET formation, in patients with underlying conditions. Conclusion: LncRNAs play a crucial role in the formation and regulation of thrombi. Therefore, NETs-related lncRNAs could serve as valuable therapeutic targets and diagnostic markers for acute ischemic stroke patients with underlying diseases.

A systematic review of deep learning in MRI-based cerebral vascular occlusion-based brain diseases.

Neurological disorders, including cerebral vascular occlusions and strokes, present a major global health challenge due to their high mortality rates and long-term disabilities. Early diagnosis, particularly within the first hours, is crucial for preventing irreversible damage and improving patient outcomes. Although neuroimaging techniques like magnetic resonance imaging (MRI) have advanced significantly, traditional methods often fail to fully capture the complexity of brain lesions. Deep learning has recently emerged as a powerful tool in medical imaging, offering high accuracy in detecting and segmenting brain anomalies. This review examines 61 MRI-based studies published between 2020 and 2024, focusing on the role of deep learning in diagnosing cerebral vascular occlusion-related conditions. It evaluates the successes and limitations of these studies, including the adequacy and diversity of datasets, and addresses challenges such as data privacy and algorithm explainability. Comparisons between convolutional neural network (CNN)-based and Vision Transformer (ViT)-based approaches reveal distinct advantages and limitations. The findings emphasize the importance of ethically secure frameworks, the inclusion of diverse datasets, and improved model interpretability. Advanced architectures like U-Net variants and transformer-based models are highlighted as promising tools to enhance reliability in clinical applications. By automating complex neuroimaging tasks and improving diagnostic accuracy, deep learning facilitates personalized treatment strategies. This review provides a roadmap for integrating technical advancements into clinical practice, underscoring the transformative potential of deep learning in managing neurological disorders and improving healthcare outcomes globally.

Stroke Triage Alpha Rescue Score (STARS): Prehospital phone-based tool to identify cerebral large vessel occlusion.

Prehospital identification of stroke patients with large vessel occlusion (LVO) is crucial to optimize transport to an endovascular thrombectomy (EVT)-capable center. Existing scores require medical or paramedical expertise and specific teachings. We aimed to validate a simple prehospital phone-based score for LVO identification. First, the Stroke Triage Alpha Rescue Score (STARS) was designed among a retrospective cohort of 3452 stroke alerts from the Emergency Medical Dispatch Centers (EMDC) registry. Phone-based neurological assessment, characteristics, final diagnosis, and brain imaging were analyzed. The items weighting was based on odds ratios (ORs) of significant variables after multivariate analysis. Secondly, STARS was assessed by dispatchers for all suspected strokes in a prospective cohort. Receiver operating curve (ROC) and predictive performances were calculated for the external validation. In the retrospective cohort, the best balance between specificity and sensitivity was obtained with a combination of six items (presence or absence of: upper, lower limbs motor deficits, language impairment, facial palsy, consciousness disorder, smoking). Each item value was determined according to their respective OR to obtain a total STARS between 0 and 13, with the most favorable cut-off higher or equal to 7 points. Then, STARS was prospectively assessed in 799 stroke alerts between March 2021 and March 2022. LVO was finally detected in 63 of 653 patients (9.6%). The area under the ROC was 0.83 [95% CI: 0.78; 0.88]. STARS≥7 had 0.83 accuracy, 0.65 sensitivity, and 0.85 specificity for detecting LVO. STARS is a simple and accurate phone-based score, without specific teaching, to detect LVO in prehospital network. STARS correctly classified 83% of stroke alerts and could be useful to identify patients with LVO eligible for EVT.

Influence of Vessel Geometry, Flow Conditions, and Thrombin Concentration on Fibrin Accumulation and Cerebral Aneurysm Occlusion After Flow Diversion.

As the number of cerebral aneurysms treated with flow diverters continues to increase, it is important to understand what factors influence not only thrombus formation within the aneurysm cavity but also fibrin accumulation across the device and its associated disruption and blockage of the inflow stream. Both processes contribute to the eventual occlusion of the aneurysm or its continued patency and incomplete occlusion which may require future re-treatment. To investigate fibrin accumulation on flow diverters placed across the neck of cerebral aneurysms, a previously developed computational model that couples flow and fibrin dynamics is used in combination with experimental invitro models of cerebral aneurysms treated with flow diverters. Fibrin accumulation was previously investigated in four glass models of cerebral aneurysms with varying parent artery geometries placed in a flow loop at different flow rates. Corresponding computational models were constructed and compared with the experimental findings. The computational model based on fibrin production stimulated from flow shear stress and subsequent adhesion to device wires was able to reproduce and explain the fibrin accumulation patterns observed in the experimental aneurysms treated with flow diverters. Specifically, these models indicated that increasing vessel curvature, flow rate, and thrombin concentration induced faster fibrin accumulation and associated aneurysm inflow disruption and blockage. The models described and tested in this paper are valuable to understand the detailed mechanisms leading to aneurysm occlusion and healing or incomplete occlusions after treatment with flow diverting devices.

Penumbral Imaging to Guide Endovascular Treatment for M2 Middle Cerebral Artery Stroke.

A potential benefit of mechanical thrombectomy for patients with distal medium vessel occlusions is currently being investigated in randomized trials. Computed tomography perfusion imaging has not yet been tested as a method to guide mechanical thrombectomy for distal medium vessel occlusions. The purpose of this study was to assess penumbral imaging as an imaging-based method for triaging patients with ischemic stroke and acute M2-middle cerebral artery occlusion. This observational retrospective study of M2-middle cerebral artery patients with ischemic stroke triaged by multimodal computed tomography undergoing mechanical thrombectomy at a high-volume stroke center between January 2015 and January 2023. The effect of recanalization was analyzed according to computed tomography perfusion-derived lesion volumes (defined using relative cerebral blood flow <30% and Tmax >6 seconds) using logistic regression analysis, and interaction terms between the independent variables and recanalization were tested. The primary end point was functional independence at day 90, defined using modified Rankin Scale scores of 0 to 2. A total of 140 patients with M2-middle cerebral artery occlusion were included. In multivariable logistic regression analysis, recanalization was not associated with better functional outcome (adjusted odds ratio, 1.85 [95% CI, 0.87-3.90]; P=0.11). After including interaction terms, a significant treatment effect between recanalization and computed tomography perfusion-derived lesion volumes was observed in patients with >150 mL hypoperfusion volume (adjusted odds ratio, 1.02 [95% CI, 1.00-1.03]; P=0.007) or >125 mL penumbral volumes (adjusted odds ratio, 1.02 [95% CI, 1.01-1.03]; P=0.005), as well as for baseline ischemic core volume within the range of 15 to 40 mL (adjusted odds ratio, 1.11 [95% CI, 1.01-1.22]; P=0.03). Penumbral imaging might serve as a useful tool for treatment decision-making in distal medium vessel occlusions, particularly in cases of suspected non- or codominant M2-middle cerebral artery vessel occlusions. A hypoperfusion volume threshold of >150 mL emphasizes the potential value of computed tomography perfusion as a standardized tool directly showing the volumetric relevance in distal medium vessel occlusion cases.

The potential role of cardiac CT in ischemic stroke: bridging cardiovascular and cerebrovascular health.

Ischemic stroke, accounting for approximately 80% of all stroke cases, remains a leading cause of death and disability worldwide. Effective management of ischemic stroke is heavily influenced by its etiology, which can range from large-artery atherosclerosis and cardiac embolism to cerebral small-vessel occlusions and cryptogenic strokes. Cardioembolic stroke, which makes up about 30% of ischemic strokes, often leads to more severe symptoms and worse outcomes, necessitating anticoagulation therapy for prevention. Cryptogenic strokes, comprising over 25% of ischemic strokes, pose significant challenges for treatment and prevention due to their elusive nature. Thorough investigation of cardioembolic sources during the acute phase of stroke is crucial. While transthoracic and transesophageal echocardiography are traditional methods for detecting intracardiac thrombi and patent foramen ovale (PFO), cardiac CT has emerged as a non-invasive, efficient alternative. Cardiac CT can effectively visualize intracardiac thrombi, PFO, valvular abnormalities, tumors, and complex aortic plaques. This review discusses the potential applications of cardiac CT in ischemic stroke, emphasizing its role in identifying stroke etiology, predicting stroke risk, and assessing patient prognosis. The integration of advanced imaging technologies and artificial intelligence further enhances its diagnostic accuracy and clinical utility, promising to improve outcomes and reduce the healthcare burden associated with ischemic stroke.

Stent-retriever alone vs. combined technique with balloon guide catheter in large vessel occlusion stroke: A single center experience

Background: Today, balloon guide catheters are widely used in thrombectomies. This study aimed to compare the demographic, angiographic, and clinical outcome parameters of thrombectomy for anterior circulation large vessel occlusion strokes (LVOS) using a first-line stent retriever (SR) alone with those of a thrombectomy using a technique combining a balloon guide catheter (BGC) with a distal access catheter (DAC) and an SR. Methods: We retrospectively analyzed the data of patients who had experienced anterior circulation LVOS and underwent mechanical thrombectomy with a BGC at our stroke center between January 2015 and December 2022. The patients were divided into two groups based on the techniques used in the thrombectomy: a stent retriever alone (BGC+SR) and a combined approach (BGC+DAC+SR). Baseline characteristics, procedure details, angiographic results, and clinical outcomes were assessed. The primary clinical outcome in this study was the rate of functional independence (mRS score ≤2) at 90 days. The primary technical outcome was the rate of first pass effect (FPE), defined as achieving near complete/complete revascularization (modified thrombolysis in cerebral infarction [mTICI] 2c-3) after a single treatment pass. Secondary outcomes included mortality at 90 days, procedural complications, embolic complications, and symptomatic intracranial hemorrhage. Results: Out of 234 patients, 137 (58.6%) were in the BGC +SR group, while 97 (41.4%) were in the BGC+SR+DAC group. Patients treated with BGC and SR alone were younger (median age 58 vs. 61 years, p=0.005) and had a higher prevalence of middle cerebral artery occlusions (M1 segment: 64.9% vs. 37.5%; M2 segment: 14.9% vs. 5.2%, p&lt;0.001) compared to those in the combined group. The BCG+SR group had a greater incidence of cardioembolism and embolic stroke of undetermined source (49.3% vs. 41.1%, 26.5% vs. 12.6%, respectively, p=0.007). The median NIHSS of the entire population was 15 (IQR, 11–18), and 108 (46%) patients received intravenous thrombolytics before thrombectomy. The patients treated with the combined technique tended to have higher rates of FPE compared to those in the BGC+SR (47.4% vs. 35.8%, p=0.074) and higher rates of successful (≥mTICI 2b) and excellent (≥mTICI 2c) recanalization overall (93.8% vs. 90.5% p=0.504; 78.4% vs. 71.5%, p=0.306, respectively). The groups had similar rates of good clinical outcome (mRS 0-2) and mortality at 90 days (61.7% vs. 53.3%, p=0.21;14.3% vs. 18.7%, p=0.495, respectively) with comparable rates of complications. Multivariate analyses identified higher baseline Alberta Stroke Program Early CT scores (OR=1.19; 95% CI, 1.09–1.28) and middle cerebral artery M1 occlusion locations (OR=1.90; 95% CI, 1.45–2.42) as independent predictors of first-pass success. Conclusion: In this study, treating acute ischemic strokes with an anterior system large vessel occlusion using a thrombectomy technique employing a BGC with an SR resulted in similar recanalization and FPE rates as using a technique employing a BGC in combination with an SR and a DAC. Both first-line strategy techniques had similar rates of good clinical outcome (mRS score ≤2) and mortality at 90 days.

Abstract 418: Targeted tirofiban use for endovascular treatment of ischemic stroke

Purpose For complex thrombus events of intracranial atherosclerotic occlusion, tirofiban, a glycoprotein IIb/IIIa antagonist, could increase the success of endovascular treatment (EVT). This study investigated the applicability of this targeted tirofiban use. Methods Stroke patients undergoing EVT were enrolled with the approval of the prospective use of tirofiban in ongoing thrombosis, re‐occlusion, and in‐stent thrombus formation. The presumptive mechanism of cerebral occlusions was divided into atherosclerotic and other etiologies. Then, the efficacy and safety outcomes of target tirofiban use were evaluated according to the location and mechanism of occlusion. Results Among those with symptomatic intracranial occlusion, 41.8% had atherosclerotic occlusion (ICAO), while 56.2% had atherosclerotic occlusions in the case of extracranial vessels. Tirofiban use rates were 24.5% of ICAO and 20.6% of extracranial atherosclerotic occlusions, while 6.8% of non‐atherosclerotic occlusions. In ICAO, tirofiban use presented a similar successful recanalization rate compared to those who did not use tirofiban (88.9% versus 86.1%), also in symptomatic intracerebral hemorrhage (2.4% versus 1.9%, P=0.81) and stroke recurrence (22.2% versus 13.3%, P=0.11). Multivariate analyses showed that ICAO, with the reference of non‐atherosclerotic occlusion, had no different effect on the successful recanalization (adjusted odds ratio, 0.70; 95% confidence interval, 0.40 ‐ 1.23), stroke recurrence (0.97; 0.55 ‐ 1.65), and SHT (0.51; 0.15 ‐ 1.36) when tirofiban use was taken into consideration. Conclusion Targeted tirofiban use may enhance the chance of recanalization in atherosclerotic occlusion without increasing the risk of safety concerns.

Association of renal biomarkers with fast progressor phenotype and related outcomes in anterior circulation large vessel occlusion stroke.

Renal dysfunction is a known predictor of long-term functional dependency after anterior circulation large vessel occlusion (ACLVO) stroke. However, the impact of renal dysfunction on early infarct growth rate (IGR) has not been previously demonstrated. The objective of this study was to define the association of creatinine-based renal biomarkers with fast or slow progressor phenotypes and related clinical outcomes in ACLVO stroke. This retrospective study examined patients with acute intracranial internal carotid artery or middle cerebral artery-M1 occlusions admitted between 2014 and 2019. Patients were included if they received baseline CT perfusion (CTP) or MRI on presentation within 24 h of estimated stroke onset. Infarct growth rate (IGR) was determined by ischemic core volume on CTP or MRI divided by time from stroke onset to imaging. IGR was used to stratify fast progressor (IGR ≥10 mL/h) and slow progressor (IGR < 10 mL/h) status. Renal dysfunction was assessed based on serum creatinine and estimated glomerular filtration rate (eGFR) on presenting laboratories. Logistic regression models, adjusted for significant covariates, identified independent associations between renal dysfunction biomarkers, progressor status, and clinical outcomes based on modified Rankin Scale (mRS) at 90 days. Among 230 patients with ACLVO, 29% were fast progressors, with median serum creatinine levels higher than slow progressors (1.1 vs. 0.9 mg/dL, p < 0.05) and lower median eGFR (66.2 vs. 69.0 mL/min/1.73m2, p < 0.05). Elevated creatinine (≥1.2 mg/dL) was independently associated with fast progressor status (adjusted OR 2.37, 95% CI 1.18-4.77), worse 90-day mRS (adjusted OR 1.88, 95% CI 1.01-3.51) and mortality (adjusted OR 2.57, 95% CI 1.14-5.79). Reduced eGFR (<60 mL/min/1.73m2) was independently associated with fast progressor status (adjusted OR 2.38, 95% CI 1.14-4.94), but not with 90-day mRS or mortality. Serum creatinine-based biomarkers of renal dysfunction were associated with fast progressor phenotype of ACLVO stroke, and worse clinical outcomes, which may help identify such patients earlier during emergency evaluation for expedited access to EVT. Future prospective studies are warranted to confirm and test implementation of these findings.

Neuro- and vasoprotective potential of neuropeptide Y Y2 receptor agonist, NPY13-36, against transient focal cerebral ischemia in spontaneously hypertensive rats

Numerous in vitro and in vivo experimental studies indicate that neuropeptide Y Y2 receptors (Y2R) are potential targets for neuroprotective therapy, including neuroprotection against ischemic stroke in healthy rats. Since stroke in humans is typically associated with comorbidities and long-term hypertension is the most common comorbidity leading to stroke, this study aimed to assess the neuroprotective potential of the Y2R agonist NPY13–36 in the rats with essential hypertension (SHR) subjected to 90 min middle cerebral artery suture occlusion with subsequent reperfusion (MCAOR). The cerebrocortical microflow in the ischemic focus and penumbra was continuously monitored with a Laser-Doppler flowmeter. NPY13–36 (10 μg/6 μl physiological saline solution) was administered intracerebroventricularly (i.c.v.) during ischemia or early reperfusion. The infarct area (triphenyltetrazolium chloride staining), behavioral tests (gait, mobility, and sensorimotor functions), and the response of the cerebrocortical microcirculation in the penumbra to hypercapnia and to the inhibition of the synthesis of nitric oxide were studied. Our results demonstrate that administration of NPY13-36 reduces the size of the infarct, improves motor functions, and restores microcirculatory response to the blockade of nitric oxide synthase when administered during reperfusion. The novelty of this study is a finding of the vasoprotective effect of NPY13-36 in brain ischemia/reperfusion. Moreover, this study provides evidence of the beneficial effects of NPY13-36 in animals with essential hypertension and indicates that Y2R ligands may be promising candidates for treating the ischemic brain in the case of this disease.

Poor venous outflow is associated with hyperintense acute reperfusion marker on follow-up MRI in patients with acute ischemic stroke with a large vessel occlusion

BackgroundHyperintense acute reperfusion marker (HARM) refers to delayed enhancement in the subarachnoid or subpial space on post-contrast fluid attenuated inversion recovery (FLAIR) images. HARM is a measure of blood–brain barrier...

Acute middle cerebral artery occlusion due to a small internal carotid aneurysm cavity with blood stagnation: illustrative case.

In cerebral large vessel occlusion, even when an aneurysm is close to the target vessel, if the aneurysm is relatively small and angiography shows no thrombus within the aneurysm, it is difficult to identify the aneurysm as the embolic source. A 67-year-old man with a history of two left-sided cerebral infarctions developed a small left-sided cerebral infarction. On hospital day 3, he developed a left M2 occlusion and underwent thrombectomy with retraction of a stent retriever into an aspiration catheter at the proximal end of the thrombus. A red thrombus was retrieved, and M2 recanalization was successfully achieved. Angiography revealed a large partially thrombotic aneurysm with a small cavity with blood stagnation in the left cervical internal carotid artery, which was considered the embolic source. Stent-assisted coil embolization was performed on the aneurysm, and no recurrent cerebral infarction was observed after embolization. In cerebral large vessel occlusion, an aneurysm cavity with blood stagnation may be the embolic source. Using an aspiration catheter alone or retracting a stent retriever into an aspiration catheter could be a useful technique and help to avoid interference between the aneurysm and the stent retriever. https://thejns.org/doi/10.3171/CASE24406.

Predictive value of follow-up infarct volume on functional outcomes in middle cerebral artery M2 segment vessel occlusion stroke treated with mechanical thrombectomy.

Medium vessel occlusion (MeVO) strokes, particularly affecting the M2 segment of the middle cerebral artery, represent a critical proportion of acute ischemic strokes, posing significant challenges in management and outcome prediction. The efficacy of mechanical thrombectomy (MT) in MeVO stroke may warrant reliable predictors of functional outcomes. This study aimed to investigate the prognostic value of follow-up infarct volume (FIV) for predicting 90-day functional outcomes in MeVO stroke patients undergoing MT. This multicenter, retrospective cohort study analyzed data from the Multicenter Analysis of primary Distal medium vessel occlusions: effect of Mechanical Thrombectomy (MAD-MT) registry, covering patients with acute ischemic stroke due to M2 segment occlusion treated with MT. We examined the relationship between 90-day functional outcomes, measured by the modified Rankin Scale (mRS), and follow-up infarct volume (FIV), assessed through CT or MRI within 12-36 h post-MT. Among 130 participants, specific FIV thresholds were identified with high specificity and sensitivity for predicting outcomes. A FIV ⩽5 ml was highly specific for predicting favorable and excellent outcomes. The optimal cut-off for both prognostications was identified at ⩽15 ml by the Youden Index, with significant reductions in the likelihood of favorable outcomes observed above a 40 ml threshold. Receiver Operator Curve (ROC) analyses confirmed FIV as a superior predictor of functional outcomes compared to traditional recanalization scores, such as final modified thrombolysis in cerebral infarction score (mTICI). Multivariable analysis further highlighted the inverse relationship between FIV and positive functional outcomes. FIV within 36 h post-MT serves as a potent predictor of 90-day functional outcomes in patients with M2 segment MeVO strokes. Establishing FIV thresholds may aid in the prognostication of stroke outcomes, suggesting a role for FIV in guiding post intervention treatment decisions and informing clinical practice. Future research should focus on validating these findings across diverse patient populations and exploring the integration of FIV measurements with other clinical and imaging markers to enhance outcome prediction accuracy.

Validation of a model for outcome prediction after endovascular treatment for ischemic stroke.

The recently developed MR-PREDICTS@24 h model showed excellent performance in the MR-CLEAN Registry cohort in patients presenting within 12 h from onset. However, its applicability to an U.S. population and to patients presenting beyond 12 h from last known normal are still undetermined. We aim to externally validate the MR-PREDICTS@24 h model in a new geographic setting and in the late window. In this retrospective analysis of a prospectively collected database from a comprehensive stroke center in the United States, we included patients with intracranial carotid artery or middle cerebral artery M1 or M2 segment occlusions who underwent endovascular therapy and applied the MR-PREDICTS@24 h formula to estimate the probabilities of functional outcome at day 90. The primary endpoint was the modified Rankin Scale (mRS) at 90 days. We included 1246 patients, 879 in the early (<12 h) and 367 in the late (≥12 h) cohort. For both cohorts, calibration and discrimination of the model were accurate throughout mRS levels, with absolute differences between estimated and predicted proportions ranging from 1% to 5%. Calibration metrics and curve inspections showed good performance for estimating the probabilities of mRS ≤ 1 to mRS ≤ 5 for the early cohort. For the late cohort, predictions were reliable for the probabilities of mRS ≤ 1 to mRS ≤ 4. The MR-PREDICTS@24 h was transferrable to a real-world U.S.-based cohort in the early window and showed consistently accurate predictions for patients presenting in the late window without need for updating.

Comparative Analysis of Mechanical Thrombectomy Outcomes of Middle Cerebral Artery M1, M2 Superior, and M2 Inferior Occlusion Strokes

BackgroundThe M1 middle cerebral artery (MCA) commonly bifurcates into an M2 superior and an M2 inferior segment. However, MCA anatomy is highly variable rendering classification for mechanical thrombectomy (MT) trials difficult. Safety and effectiveness of M2 MCA stroke thrombectomy stratified by M2 MCA anatomy remains to be explored. MethodsLarge vessel occlusion strokes undergoing MT between 02/2016-08/2022 were reviewed (n=784). M1 (n=431) and M2 MCA (n=118) occlusions were assessed. Among M2 MCA occlusions only prototypical MCA bifurcation anatomy cases were included (n=99). Dominance was assessed based on angiography. Procedural and outcome data was compared between M1, M2 superior and M2 inferior MCA occlusions. ResultsBaseline demographics and periprocedural criteria of M2 superior (n=56) and M2 inferior (n=43) occlusion MTs were comparable. Among M2 inferior cases, the occluded branch was dominant in 41/43 (95.3%) but only in 37/56 (66.1%) among M2 superior cases (p<0.001). The 90-day favorable functional outcome (mRS 0-2) and mortality (mRS 6) rates were 60.0% and 8.9% in the M2 superior, 42.9% and 32.6% in the M2 inferior, and 44.1% and 26.0% in the M1 group (n=431). Compared to M2 superior, M2 inferior favorable outcome rates were lower (p=0.094) and mortality rates were higher (p=0.003) and resembled M1 outcome rates (p=0.750 and p=0.355, respectively). ConclusionIn setting of prototypical MCA bifurcation anatomy, thrombectomy of dominant M2 inferior occlusions had outcome rates like M1 occlusions. In contrast, M2 superior occlusions had significantly lower mortality rates and a trend towards better favorable functional outcome rates.

Endovascular thrombectomy versus medical management on outcomes with infarct volumes more than 70 mL.

Endovascular thrombectomy (EVT) in patients with large infarct volume remains controversial. The aim of this study is to compare clinical outcomes between EVT and medical management in acute large vessel occlusion with infarct volumes larger than 70 mL on diffusion-weighted magnetic resonance imaging (DWI). A prospective observational cohort study was conducted, including patients with anterior cerebral circulation occlusion due to ischemic stroke with infarct volumes larger than 70 mL within 24 h of onset between July 2018 and June 2023. Eligible patients were divided into two groups: the EVT group and the medical management (non-EVT) group. The main outcomes were functional independence and mortality at 90 days. To assess clinical endpoints, we selected variables including age, NIHSS score, infarct volume, and occlusion location for 1:1 propensity score (PS) matching and PS adjustment using inverse probability of treatment weighting (IPTW). Among the 131 identified patients (mean [SD] age, 69.9 [13.7] years; 58 female), the median infarct volume was 123.6 mL. Of these patients, 75 (57.3%) underwent EVT. After PS adjustment, EVT was not associated with functional independence (10.9% vs. 10.9%; p = 1.000) or mortality (43.5% vs. 47.8%; p = 0.675). Additionally, after PS adjustment using IPTW, EVT was also not associated with a functional independence (15.8% vs. 13.7%; p = 0.767) or mortality (46.8% vs. 44.0%; p = 0.762). This study provides real-world evidence regarding infarct volumes larger than 70 mL, indicating that EVT does not provide benefits compared to medical management alone when considering age, NIHSS score, infarct volume, and occlusion location.

Comparing Outcomes of Thrombectomy Versus Intravenous Thrombolysis Based on Middle Cerebral Artery M2 Occlusion Features.

Current evidence provides limited support for the superiority of endovascular thrombectomy (EVT) in patients with M2 segment middle cerebral artery occlusion. We aim to investigate whether imaging features of M2 segment occlusion impact the effectiveness of EVT. We conducted a retrospective cohort study from January 2017 to January 2022, drawing data from the CASE II registry (Computer-Based Online Database of Acute Stroke Patients for Stroke Management Quality Evaluation), which specifically documented patients with acute ischemic stroke presenting with M2 segment occlusion undergoing reperfusion therapy. Patients were stratified into the intravenous thrombolysis (IVT) group (IVT alone) and EVT group (IVT plus EVT or EVT alone). The primary outcome was a modified Rankin Scale score 0 to 2 at 90 days. Secondary outcomes included additional thresholds and distribution of modified Rankin Scale scores, 24-hour recanalization, early neurological deterioration, and relevant complications during hospitalization. Safety outcomes encompassed intracranial hemorrhagic events at 24 hours and mortality at 90 days. Binary logistic regression analyses with propensity score matching were used. Subgroup analyses were performed based on the anatomic site of occlusion, including right versus left, proximal versus distal, dominant/co-dominant versus nondominant, single versus double/triple branch(es), and anterior versus central/posterior branch. Among 734 patients (43.3% were females; median age, 73 years) with M2 segment occlusion, 342 (46.6%) were in the EVT group. Propensity score matching analysis revealed no statistical difference in the primary outcome (odds ratio, 0.860 [95% CI, 0.611-1.209]; P=0.385) between the EVT group and IVT group. However, EVT was associated with a higher incidence of subarachnoid hemorrhage (odds ratio, 6.655 [95% CI, 1.487-29.788]; P=0.004) and pneumonia (odds ratio, 2.015 [95% CI, 1.364-2.977]; P<0.001). Subgroup analyses indicated that patients in the IVT group achieved better outcomes when presenting with right, distal, or nondominant branch occlusion (Pall interaction<0.05). Our study showed similar efficiency of EVT versus IVT alone in acute M2 segment middle cerebral artery occlusion. This suggested that only specific patient subpopulations might have a potentially higher benefit of EVT over IVT alone. URL: https://clinicaltrials.gov; Unique identifier: NCT04487340.

Synthesizing 4D Magnetic Resonance Angiography From 3D Time-of-Flight Using Deep Learning: A Feasibility Study.

Objective and background This study aimed to develop a deep convolutional neural network (DCNN) model capable of generating synthetic 4D magnetic resonance angiography (MRA) from 3D time-of-flight (TOF) images, allowing estimation of temporal changes in arterial flow. TOF MRA provides static information about arterial structures through maximum intensity projection (MIP) processing, but it does not capture the dynamic information of contrast agent circulation, which is lost during MIP processing. Considering the principles of TOF, it is hypothesized that dynamic information about arterial blood flow is latent within TOF signals. Although arterial spin labeling (ASL) can extract dynamic arterial information, ASL MRA has drawbacks, such as longer imaging times and lower spatial resolution than TOF MRA. This study's primary aim is to extend the utility of TOF MRA by training a machine-learning model on paired TOF and ASL data to extract latent dynamic information from TOF signals. Methods A DCNN combining a modified U-Net and a long-short-term memory (LSTM) network was trained on a dataset of 13 subjects (11 menand two women, aged 42-77 years) using paired 3D TOF MRA and 4D ASL MRA images. Subjects had no history of cerebral vessel occlusion or significant stenosis. The dataset was acquired using a 3T MRI system with a 32-channel head coil. Preprocessing involved resampling and intensity normalization of TOF and ASL images, followed by data augmentation and arterial mask generation. The model learned to extract flow information from TOF images and generate 8-phase 4D MRA images. The precision of flow estimation was evaluated using the coefficient of determination (R²) and Bland-Altman analysis. A board-certified neuroradiologist validated the quality of the images and the absence of significant stenosis in the major cerebral arteries. Results The generated 4D MRA images closely resembled the ground-truth ASL MRA data, with R² values of 0.92, 0.85, and 0.84 for the internal carotid artery (ICA), proximal middle cerebral artery (MCA), and distal MCA, respectively. Bland-Altman analysis revealed a systematic error of -0.06, with 95% agreement limits ranging from -0.18 to 0.12. Additionally, the model successfully identified flow abnormalities in a subject with left MCA stenosis, displaying a delayed peak and subsequent flattening distal to the stenosis, indicative of reduced blood flow. Visualization of the predicted arterial flow overlaid on the original TOF MRA images highlighted the spatial progression and dynamics of the flow. Conclusions The DCNN model effectively generated synthetic 4D MRA images from TOF images, demonstrating its potential to estimate temporal changes in arterial flow accurately. This non-invasive technique offers a promising alternative to conventional methods for visualizing and evaluating healthy and pathological flow dynamics. It has significant potential to improve the diagnosis and treatment of cerebrovascular diseases by providing detailed temporal flow information without the need for contrast agents or invasive procedures. The practical implementation of this model could enable the extraction of dynamic cerebral blood flow information from routine brain MRI examinations, contributing to the early diagnosis and management of cerebrovascular disorders.

Relationship between ω3 and ω6 polyunsaturated fatty acids and atrial fibrillation in acute ischemic stroke

Some ω3 polyunsaturated fatty acids (PUFAs) are said to demonstrate a dose-related risk of atrial fibrillation (AF), conversely, some ω6 PUFAs might have AF protective potential. However, few investigated the relation among ischemic strokes. Primarily, we aimed to examine a relation between ω3 and ω6 PUFAs and the presence of AF in ischemic strokes. Further, since, some PUFAs are said to affect the cardiac load, we secondarily aimed to investigate the association between ω3 and ω6 PUFAs and brain natriuretic peptide (BNP) and the occurrence of cerebral large vessel occlusion (LVO) in ischemic strokes with AF. Consecutive patients with ischemic stroke admitted between 2012 and 2022 were retrospectively screened. Plasma levels of PUFAs, including eicosapentaenoic acid (EPA), docosahexaenoic acid, dihomo-γ-linolenic acid (DGLA) and arachidonic acid (AA), were assayed. Data were analyzed using a Poisson regression analysis with a robust variance estimator and a multiple linear regression analysis. We screened 2112 consecutive ischemic strokes, including 1574 (1119 [71%] males, median age 69 years). Lower DGLA (prevalence ratio (PR) 0.885, 95% CI 0.811-0.966, p=0.006), lower AA (PR 0.797, 95% CI 0.649-0.978, p=0.030), and higher EPA/AA ratio (PR 1.353, 95% CI 1.036-1.767, p=0.026) were associated with AF. Checking the linearity between AF and PUFAs, negative linear trends were observed between DGLA quartiles (Q1: PR 1.901, Q2: PR 1.550, Q3: PR 1.423, Q4: 1.000, p<0.001 for trend) and AA quartiles (Q1: PR 1.499, Q2: PR 1.204, Q3: PR 1.125, Q4: 1.000, p=0.004 for trend), with positive linear trends between EPA/AA ratio quartiles (Q1: 1.000, Q2: PR 1.555, Q3: PR 1.612, Q4: PR 1.797, p=0.001 for trend). Among patients with AF, a negative association between AA and BNP (unstandardized coefficient-1.316, 95% CI -2.290∼-0.342, p=0.008) was observed, and lower AA was associated with LVO (PR 0.707, 95% CI 0.527-0.950, p=0.021). Lower DGLA and AA and a higher EPA/AA ratio might be related to the development of AF in ischemic strokes. Further, AA might have a cardio-cerebrovascular protective role in ischemic strokes with AF.

Trial of Thrombectomy for Stroke with a Large Infarct of Unrestricted Size

BackgroundThe use of thrombectomy in patients with acute stroke and a large infarct of unrestricted size has not been well studied.MethodsWe assigned, in a 1:1 ratio, patients with proximal cerebral vessel occlusion in the anterior circulation and a large infarct (as defined by an Alberta Stroke Program Early Computed Tomographic Score of ≤5; values range from 0 to 10) detected on magnetic resonance imaging or computed tomography within 6.5 hours after symptom onset to undergo endovascular thrombectomy and receive medical care (thrombectomy group) or to receive medical care alone (control group). The primary outcome was the score on the modified Rankin scale at 90 days (scores range from 0 to 6, with higher scores indicating greater disability). The primary safety outcome was death from any cause at 90 days, and an ancillary safety outcome was symptomatic intracerebral hemorrhage.ResultsA total of 333 patients were assigned to either the thrombectomy group (166 patients) or the control group (167 patients); 9 were excluded from the analysis because of consent withdrawal or legal reasons. The trial was stopped early because results of similar trials favored thrombectomy. Approximately 35% of the patients received thrombolysis therapy. The median modified Rankin scale score at 90 days was 4 in the thrombectomy group and 6 in the control group (generalized odds ratio, 1.63; 95% confidence interval [CI], 1.29 to 2.06; P<0.001). Death from any cause at 90 days occurred in 36.1% of the patients in the thrombectomy group and in 55.5% of those in the control group (adjusted relative risk, 0.65; 95% CI, 0.50 to 0.84), and the percentage of patients with symptomatic intracerebral hemorrhage was 9.6% and 5.7%, respectively (adjusted relative risk, 1.73; 95% CI, 0.78 to 4.68). Eleven procedure-related complications occurred in the thrombectomy group.ConclusionsIn patients with acute stroke and a large infarct of unrestricted size, thrombectomy plus medical care resulted in better functional outcomes and lower mortality than medical care alone but led to a higher incidence of symptomatic intracerebral hemorrhage. (Funded by Montpellier University Hospital; LASTE ClinicalTrials.gov number, NCT03811769.)