Prognostic factors related to clinical outcome following thrombectomy in ischemic stroke (RECOST Study). 50 patients prospective study

An interpretable hybrid machine learning approach for predicting three-month unfavorable outcomes in patients with acute ischemic stroke

BACKGROUND

Acute ischemic stroke (AIS) is a clinical disorder caused by nontraumatic cerebrovascular disease with a high incidence, mortality, and disability rate. Most stroke survivors are left with speech and physical impairments, and emotional problems. Despite technological advances and improved treatment options, death and disability after stroke remain a major problem. Our research aims to develop interpretable hybrid machine learning (ML) models to accurately predict three-month unfavorable outcomes in patients with AIS.

METHODS

Within the framework of this analysis, the model was trained using data from 731 cases in the dataset and subsequently validated using data from both internal and external validation datasets. A total of 25 models (including ML and deep learning models) were initially employed, along with 14 evaluation metrics, and the results were subjected to cluster analysis to objectively validate the model's effectiveness and assess the similarity of evaluation metrics. For the final model evaluation, 10 metrics selected after metric screening and calibration analysis were utilized to evaluate model performance, while clinical decision analysis, cost curve analysis, and model fairness analysis were applied to assess the clinical applicability of the model. Nested cross-validation and optimal hyperparameter search were employed to determine the best hyperparameter for the ML models. The SHAP diagram is utilized to provide further visual explanations regarding the importance of features and their interaction effects, ultimately leading to the establishment of a practical AIS three-month prognostic prediction platform.

RESULTS

The frequencies of unfavorable outcomes in the internal dataset and external validation dataset were 389 / 1045 (37.2 %) and 161 / 411 (39.2 %), respectively. Through cluster analysis of the results of 14 evaluation metrics across 25 models and a comparison of clinical applicability, 12 ML models were ultimately selected for further analysis. The findings revealed that XGBoost and CatBoost performed the best. Further ensemble modeling of these two models and adjustment of decision thresholds using cost curves resulted in the final model performing as follows on the internal validation set: PRAUC of 0.856 (0.801, 0.902), ROCAUC of 0.856 (0.801, 0.901), specificity of 0.879 (0.797, 0.953), balanced accuracy of 0.840 (0.763, 0.912) and MCC of 0.678 (0.591, 0.760). Similarly, the model exhibited excellent performance on the external validation set, with a PRAUC of 0.823 (0.775, 0.872), ROCAUC of 0.842 (0.801, 0.890), specificity of 0.888 (0.822, 0.920), balanced accuracy of 0.814 (0.751, 0.869) and MCC of 0.639 (0.546, 0.721). In terms of the important features of AIS three-month outcomes, albumin ranked highest, followed by FBG, BMI, Scr, WBC, and age, while gender exhibited significant interactions with other indicators. Ultimately, based on the final ensemble model and optimal decision thresholds, a tailored short-term prognostic prediction platform for AIS patients was developed.

CONCLUSIONS

We constructed an interpretable hybrid ML model that maintained good performance on both internal and external validation datasets using the most readily accessible 30 clinical data variables, indicating its ability to accurately predict the three-month unfavorable outcomes for AIS patients. Meanwhile, our superior predictive model provides practicality for routine and more frequent initial risk assessments, making it easier to integrate into network or mobile-based telemedicine solutions.

The effects of admission hyperglycemia and diabetes mellitus on mechanical thrombectomy outcomes: A systematic review and meta-analysis

BACKGROUND

The impact of certain comorbidities on mechanical thrombectomy (MT) outcomes remains largely unexplored. Diabetes mellitus (DM) and admission hyperglycemia have been associated with poor clinical outcomes for patients treated with MT. In this study, we sought to investigate the effects of DM and admission hyperglycemia on MT outcomes.

METHODS

Following PRISMA guidelines, a systematic literature search was conducted in Medline, Embase, Scopus, and Web of Science databases. Data regarding successful recanalization (modified Thrombolysis in Cerebral Infarction [mTICI] ≥2b), functional independence (modified Rankin Scale [mRS] 0-2), excellent outcomes (mRS 0-1), symptomatic intracranial hemorrhage (sICH), and mortality were extracted from the included studies. The pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were calculated using random effects model.

RESULTS

Twenty-one studies comprising 9708 patients were included. A total of 2311 patients (24%) had a history of DM, and 2026 patients (21%) had admission hyperglycemia. Admission hyperglycemia was associated with significantly lower odds of mTICI ≥2b (OR = 0.7, 95% CI = 0.55-0.89), mRS 0-2 (OR = 0.47, 95% CI = 0.41-0.53), and mRS 0-1 (OR = 0.43, 95% CI = 0.34-0.55) as compared to normoglycemic state. Patients with hyperglycemia had significantly higher rates of sICH (OR = 2.05, 95% CI = 1.66-2.54) and mortality (OR = 1.99, 95% CI = 1.58-2.52) than normoglycemic patients. Diabetes mellitus was associated with significantly high rates of mortality (OR = 1.74, 95% CI = 1.31-2.3) and lower rates of mRS 0-2 (OR = 0.60, 95% CI = 0.48-0.76) in sensitivity analyses.

CONCLUSION

Our results indicate that admission blood glucose levels and DM can negatively affect MT outcomes. Further research should focus on optimizing MT outcomes for these patients.

Predictors of outcome in large vessel occlusion stroke patients with intravenous tirofiban treatment: a post hoc analysis of the RESCUE BT clinical trial

OBJECTIVE

The aim of this study was to investigate the factors influencing good outcomes in patients receiving only intravenous tirofiban with endovascular thrombectomy for large vessel occlusion stroke.

METHODS

Post hoc exploratory analysis using the RESCUE BT trial identified consecutive patients who received intravenous tirofiban with endovascular thrombectomy for large vessel occlusion stroke in 55 comprehensive stroke centers from October 2018 to January 2022 in China.

RESULTS

A total of 521 patients received intravenous tirofiban, 253 of whom achieved a good 90-day outcome (modified Rankin Scale [mRS] 0-2). Younger age (adjusted odds ratio [aOR]: 0.965, 95% confidence interval [CI]: 0.947-0.982; p < 0.001), lower serum glucose (aOR: 0.865, 95%CI: 0.807-0.928; p < 0.001), lower baseline National Institutes of Health Stroke Scale (NIHSS) score (aOR: 0.907, 95%CI: 0.869-0.947; p < 0.001), fewer total passes (aOR: 0.791, 95%CI: 0.665-0.939; p = 0.008), shorter punctures to recanalization time (aOR: 0.995, 95%CI:0.991-0.999; p = 0.017), and modified Thrombolysis in Cerebral Infarction (mTICI) score 2b to 3 (aOR: 8.330, 95%CI: 2.705-25.653; p < 0.001) were independent predictors of good outcomes after intravenous tirofiban with endovascular thrombectomy for large vessel occlusion stroke.

CONCLUSION

Younger age, lower serum glucose level, lower baseline NIHSS score, fewer total passes, shorter punctures to recanalization time, and mTICI scores of 2b to 3 were independent predictors of good outcomes after intravenous tirofiban with endovascular thrombectomy for large vessel occlusion stroke.

CHINESE CLINICAL TRIAL REGISTRY IDENTIFIER

ChiCTR-IOR-17014167.

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

BACKGROUND AND PURPOSE

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

A differential detailed diffusion-weighted imaging-ASPECTS for cerebral infarct volume measurement and outcome prediction

BACKGROUND

Diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) has been used to estimate infarct core volume in acute stroke. However, the same and indiscriminate score deduction for punctate or confluent DWI high-intensity lesion might lead to variation in performance.

AIMS

To develop and evaluate a differential detailed DWI-ASPECTS method in comparison with the conventional DWI-ASPECTS in core infarct volume measurement and clinical outcome prediction.

METHODS

We retrospectively recruited patients with acute ischemic stroke (AIS) treated with endovascular treatment between April 2013 and October 2019. In differential detailed DWI-ASPECTS, restricted diffusion lesion that was punctate or less than half of a cortical region (M1-M6) would not lead to subtraction of point. A favorable outcome was modified Rankin Scale score ⩽2 at 90 days after stroke onset.

RESULTS

Among 298 AIS patients, mean age was 75 years (interquartile range (IQR) 67-82), and 194 patients (65%) were males. Mean infarct core volume was 11 mL (IQR 3-37). Overall, the score by detailed DWI-ASPECTS was significantly higher than conventional DWI-ASPECTS (8 (7-9) vs. 7 (5-9); P < 0.01). The detailed DWI-ASPECTS resulted in a higher correlation coefficient (r) for core infarct volume estimation than the conventional DWI-ASPECTS (r = 0.832 vs. 0.773; P < 0.01). Upon re-classification of those scored ⩽6 in conventional DWI-ASPECTS (n = 134) by detailed DWI-ASPECTS, the rate of favorable outcome in patients with detailed DWI-ASPECTS >6 was significantly higher than those with ⩽6 (29 (48%) vs. 14 (19%); P < 0.01).

CONCLUSIONS

Detailed DWI-ASPECTS appeared to provide a more accurate infarct core volume measurement and clinical outcome correlation than conventional DWI-ASPECTS among AIS patients treated with endovascular therapy.

Diagnosis and management of tandem occlusion in acute ischemic stroke

Approximately 20-30% of patients with acute ischemic stroke, caused by large intracranial vessel occlusion, have a tandem lesion, defined as simultaneous presence of high-grade stenosis or occlusion of the cervical internal carotid artery and thromboembolic occlusion of the intracranial terminal internal carotid artery or its branches, usually the middle cerebral artery. Patients with tandem lesions have usually worse outcomes than patients with single intracranial occlusions, and intravenous thrombolysis is less effective in these patients. Although endovascular thrombectomy is currently a cornerstone therapy in the management of acute ischemic stroke due to large vessel occlusion, the optimal management of extracranial carotid lesions in tandem occlusion remains controversial. Acute placement of a stent in the cervical carotid artery lesion is the most used therapeutic strategy compared with stented balloon angioplasty and thrombectomy alone without carotid artery revascularization; however, treatment strategies in these patients are often more complex than with single occlusion, so treatment decisions can change based on clinical and technical considerations. The aim of this review is to analyze the results of different studies and trials, investigating the periprocedural neurointerventional management of patients with tandem lesions and the safety, efficacy of the different technical strategies available as well as their impact on the clinical outcome in these patients, to strengthen current recommendations and thus optimize patient care.

Association Between Admission Hyperglycemia and Outcomes After Endovascular Treatment in Acute Basilar Artery Occlusion

INTRODUCTION

Admission hyperglycemia and high admission blood glucose levels have been associated with poor outcomes in acute ischemic stroke. However, the relationship between admission hyperglycemia and outcomes after endovascular treatment (EVT) in acute basilar artery occlusion (ABAO) still remain unclear. This study aimed to investigate the association between admission hyperglycemia and clinical outcomes in ABAO following EVT.

METHODS

Patients from the BASILAR registry with admission blood glucose levels treated with EVT were included. We defined admission hyperglycemia as blood glucose levels ≥ 7.8 mmol/L. The primary outcome was favorable outcome [defined as a modified Rankin Scale score (mRS) of 0-3] at 90 days, Secondary outcomes included other functional outcomes (mRS 0-2, mRS 0-1) at 90 days, symptomatic intracerebral hemorrhage (sICH) within 48 h, and mortality at 90 days.

RESULTS

Of 545 eligible patients included, the median age was 65 (IQR, 56-73) years, and median blood glucose level was 7.36 (IQR, 6.10-9.66) mmol/L. Multivariable logistic regression analysis showed that admission hyperglycemia was associated with decreased favorable outcome (mRS 0-3) (adjusted odds ratio = 0.52; 95% CI 0.35-0.79; P = 0.001), and increased mortality (adjusted odds ratio = 2.67; 95% CI 1.82-3.91; P < 0.001). Restricted cubic spline regression analysis showed that the blood glucose level had a non-linearity association with favorable outcome and mortality, and that there was no association between admission hyperglycemia and sICH.

CONCLUSIONS

Our study suggest that admission hyperglycemia is associated with an increased risk of poor functional outcomes and mortality in patients with ABAO treated with EVT.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ( http://www.chictr.org.cn ), ChiCTR180001475.

Association of clinical factors to functional outcomes in patients with stroke with large-vessel occlusion after endovascular thrombectomy

BACKGROUND/PURPOSE

Multiple clinical factors have been reported to be associated with functional outcomes in patients with stroke. However, little is known about prognostic predictors of functional independence in patients with stroke undergoing endovascular thrombectomy (EVT). Our study aimed to investigate the correlation between multiple prognostic variables (including EVT and rehabilitation-related parameters) and functional outcomes in patients post-EVT.

METHODS

This retrospective cohort study recruited patients hospitalized between December 2018 and March 2022. Patients with stroke with large-vessel occlusion who underwent EVT were eligible for inclusion in the study. Prognostic factors, including premorbid characteristics, laboratory data, EVT- and rehabilitation-related parameters, functional activity level, balance ability, swallowing, and sphincter function, were collected. Logistic regression and generalized linear models were used to analyze their correlations with functional outcomes.

RESULTS

A total of 148 patients were included. In the univariate logistic regression analysis, younger age, premorbid functional independence, higher hemoglobin (Hb) level, lower National Institute of Health Stroke Scale (NIHSS) score, absence of hemorrhagic transformation in 14 days, no nasogastric (NG) tube placement, earlier rehabilitation, frequent daily rehabilitation sessions, more out-of-bed rehabilitation, better ability of sitting up, better initial sitting balance, higher Barthel index (BI), absence of immobility, and neurological complications were associated with favorable outcomes at 3 months. In the stepwise regression model, the predictors of favorable function at 3 months included age, ability to sit up, and frequency of daily rehabilitation sessions; favorable outcomes at 6 months were associated with age, ability to sit up, and swallowing function.

CONCLUSION

In patients with stroke post-EVT, better functional outcomes were associated with prognostic variables, including younger age, better ability to sit up, normal swallowing function, and frequent daily rehabilitation sessions.

Psychometric properties of the 12-item Stroke-Specific Quality of Life Scale among stroke survivors in Hong Kong

The present study examined the psychometric properties of the 12-item Stroke-Specific Quality of Life Scale (SSQOL-12) in 184 stroke survivors in Hong Kong. The participants completed a self-report questionnaire including the SSQOL-12, SF-12 health survey, and validating variables at baseline and 148 stroke survivors completed SSQOL-12 two months later. Confirmatory factor analysis investigated the construct validity, reliability, and measurement invariance of SSQOL-12 across two months. Concurrent, convergent, and divergent validity was examined with respect to SF-12, hope, self-esteem, functional disability, anxiety, and depression. The original 2-factor model did not reveal a superior fit over the 1-factor model and a modified 1-factor model provided an acceptable fit to the data in both waves. The SSQOL-12 factor displayed substantial factor loadings (λ = 0.40-0.87), good internal consistency (Ω = 0.88), temporal stability (r = 0.70), and scalar measurement invariance across time. Stroke-specific quality of life was significantly associated with higher levels of SF-12, hope, and self-esteem and lower levels of functional disability, anxiety, and depression. Most correlations remained significant after controlling for demographic covariates and SF-12. The present findings offered empirical support for the validity and reliability of the unidimensional structure for SSQOL-12 as a measure of stroke-specific quality of life among stroke survivors.

Role of Neurosurgeons in the Treatment of Acute Ischemic Stroke in the Emergency Room

OBJECTIVE

With the recent increase in mechanical thrombectomy (MT) for acute ischemic stroke (AIS), the role of neurosurgeons in AIS treatment has become increasingly important. This study aimed to assess the outcomes of patients with AIS treated by neurosurgeons and neurologists in the emergency room (ER) of a tertiary hospital in South Korea.

METHODS

From January 2020 to June 2021, 536 patients with AIS within 24 hours of symptom onset were admitted to our hospital via the ER. Based on the type of doctors who provided initial care for AIS in the ER, patients were divided into two groups : (a) neurosurgeon group (n=119, 22.2%) and (b) neurologist group (n=417, 77.8%).

RESULTS

Intravenous tissue plasminogen activator (tPA) was administered in 82 (15.3%) of 536 patients (n=17 [14.3%] in the neurosurgeon group and n=65 [15.6%] in the neurologist group). The door-to-tPA time was not significantly different between both groups (median, 53 minutes; interquartile range [IQR], 45-58 vs. median, 54 minutes; IQR, 46-74; p=0.372). MT was performed in 69 patients (12.9%) (n=25, 36.2% in the neurosurgeon group and n=44, 63.8% in the neurologist group). The neurosurgeon group achieved a shorter door-to-puncture time than the neurologist group (median, 115 minutes; IQR, 107-151 vs. median, 162 minutes; IQR, 117-189; p=0.049). Good clinical outcomes (3-month modified Rankin Scale 0-2) did not differ significantly between the two groups (96/119 [80.7%] vs. 322/417 [77.2%], p=0.454).

CONCLUSION

The neurosurgeon group showed similar door-to-treatment time and clinical outcomes to the neurologist group in patients with AIS in the ER. This study suggests that neurosurgeons have comparable abilities to care for patients with AIS in the ER.

Comparison of a direct aspiration first pass technique vs. stent retriever thrombectomy for the treatment of acute large vessel occlusion stroke in the anterior circulation with atrial fibrillation

Objectives

The stent retriever thrombectomy (SRT) and a direct aspiration first-pass technique (ADAPT) are the two main mechanical thrombectomy (MT) techniques for acute ischemic stroke. Few data are available for comparing the therapeutic effects associated with the two mechanical thrombectomy techniques in acute ischemic stroke with atrial fibrillation. The purpose of this study was to compare the efficacy and safety of both techniques for the treatment of acute large vessel occlusion stroke in the anterior circulation with atrial fibrillation.

Methods

Retrospective analysis was performed in stroke patients with atrial fibrillation admitted to Guangzhou Red Cross Hospital from January 2018 to June 2022 who received mechanical thrombectomy by either SRT or ADAPT. Comparisons were made with regards to the initial traits, course of therapy, effectiveness indicators, and complications of these individuals. The primary outcome is recanalization rate.

Results

In this study, after screening 431 patients, 92 eligible patients, with 48 patients received SRT and 44 patients received ADAPT, were included. There was no significant difference in the recanalization rate between the two groups (SRT 87.5% vs. ADAPT 84.1%, P = 0.639). Compared with SRT, patients in ADAPT group had a shorter puncture to recanalization time [33.5 min (27.0-59.5) vs. 50.5 min (31.5-91.5), P = 0.009], a higher first pass success recanalization rate (54.5 vs. 33.3%, p = 0.040), and a higher rate of patients with improvement of NIHSS scores ≥4 at discharge (84.1 vs. 56.3%, P = 0.004). However, distal embolization occurred more frequently in the ADAPT group than that in SRT group (50.0 vs. 22.9%, P = 0.007). There was no significant difference between the two groups in the 3-month mRS score, symptomatic cerebral hemorrhage, or mortality.

Conclusions

Compared with SRT, ADAPT has similar recanalization rate for the treatment of acute large vessel occlusion stroke in the anterior circulation with atrial fibrillation. However, ADAPT might be more effective in terms of shorter puncture to recanalization time and higher first pass success recanalization rate. Further studies are needed for confirming our results.

Dissective tandem stroke: an endovascular approach

Ischemic stroke due to internal carotid artery occlusion is a potential devastating condition. More frequently the occlusions are embolic in nature, but sometimes they are caused by arterial dissection and their treatment is a challenge. We describe an illustrative case where a young patient with middle cerebral artery stroke caused by carotid artery dissection was submitted to endovascular treatment of mechanical thrombectomy and stenting, giving an excellent outcome. We believe that tandem approach is a treatment of choice in these cases.

Role of diabetes in stroke: Recent advances in pathophysiology and clinical management

The increasing prevalence of diabetes and stroke is a major global public health concern. Specifically, acute stroke patients, with pre-existing diabetes, pose a clinical challenge. It is established that diabetes is associated with a worse prognosis after acute stroke and the various biological factors that mediate poor recovery profiles in diabetic patients is unknown. The level of association and impact of diabetes, in the setting of reperfusion therapy, is yet to be determined. This article presents a comprehensive overview of the current knowledge of the role of diabetes in stroke, therapeutic strategies for primary and secondary prevention of cardiovascular disease and/or stroke in diabetes, and various therapeutic considerations that may apply during pre-stroke, acute, sub-acute and post-stroke stages. The early diagnosis of diabetes as a comorbidity for stroke, as well as tailored post-stroke management of diabetes, is pivotal to our efforts to limit the burden. Increasing awareness and involvement of neurologists in the management of diabetes and other cardiovascular risk factors is desirable towards improving stroke prevention and efficacy of reperfusion therapy in acute stroke patients with diabetes.

Intra- and inter-rater consistency of dual assessment by radiologist and neurologist for evaluating DWI-ASPECTS in ischemic stroke

OBJECTIVES

To estimate the intra -and inter-rater consistency of radiologist and neurologist working in pairs attributing DWI-ASPECTS (Diffusion Alberta Stroke Program Early CT Score) in patients with acute middle cerebral artery ischemic stroke referred for mechanical thrombectomy, intravenous thrombolysis or bridging therapy.

METHODS

Five neurologists and 5 radiologists working in pairs and in hour period scored independently and in two reading sessions anonymized DWI-ASPECTS of 80 patients presenting with acute anterior ischaemic stroke in our center. We measured agreement between pairs using intraclass correlation coefficients (ICCs). A Fleiss kappa was used for dichotomized (0-6;7-10) and trichotomized (0-3;4-6;7-10) ASPECTS. The interrater distribution of the score in the trichotomized (0-3;4-6;7-10) ASPECTS was calculated. We determined the interrater (Cohen kappa) and intrarater (Fleiss kappa) agreement on the ASPECTS regions.

RESULTS

The average DWI-ASPECTS was 6.35 (SD±2.44) for the first reading, and 6.47 (SD±2.44) for the second one. The ICC was 0.853 (95%CI, 0.798-0.896) for the interrater, and 0.862 (95%CI, 0.834-0.885) for the intrarater evaluation. Kappa coefficients were high for dichotomized (k=0.75) and trichotomized (k=0.64) ASPECTS. Evaluators agreement on the ASPECTS category (0-3), (4-6) and (7-10) was 88, 76 and 93% respectively. The anatomic region infarcted was well identified (k=0.70-0.77), except for the internal capsula (k=0.57). Interrater agreement was fair for M5 (k=0.37), moderate for internal capsula (0.52) and substantial for the other regions (0.60-0.79).

CONCLUSIONS

Reliability of DWI-ASPECTS is good when determined by radiologist and neurologist working in pairs, which corresponds to our current clinical practice. However, discrepancies are possible for cut-off determination, which may impact the indication of thrombectomy, and for the determination of the exact infarcted region. Agreement to propose category (4-6) is lower than for (0-3) and (8-10) ASPECTS categories.

Cerebral white matter vasculature: still uncharted?

White matter vasculature plays a major role in the pathophysiology of permanent neurological deficits following a stroke or progressive cognitive alteration related to small vessel disease. Thus, knowledge of the complex vascularization and functional aspects of the deep white matter territories is paramount to comprehend clinical manifestations of brain ischemia. This review provides a structured presentation of the existing knowledge of the vascularization of the human cerebral white matter from seminal historical studies to the current literature. First, we revisit the highlights of prenatal development of the endoparenchymal telencephalic vascular system that are crucial for the understanding of vessel organization in the adult. Second, we reveal the tangled history of debates on the existence, clinical significance, and physiological role of leptomeningeal anastomoses. Then, we present how conceptions on white matter vascularization transitioned from the mixed ventriculopetal/ventriculofugal theory, in which a low-flow area was interposed in between concurrent arterial flows, to the purely ventriculopetal theory. The latter model explains variable white matter sensitivity to ischemia by various organizations of ventriculopetal vessel terminals having different origin/length properties and interconnection patterns. Next, arteries supplying primarily the white matter are described according to their length and overall structure. Furthermore, the known distribution territories, to date, are studied in relation to primary anatomical structures of the human cerebral white matter, emphasizing the sparsity of the "ground-truth" data available in the literature. Finally, the implications for both large vessel occlusion and chronic small vessel disease are discussed, as well as the insights from neuroimaging. All things considered, we identify the need for further research on deep white matter vascularization, especially regarding the arterial supply of white matter fiber tracts.

Influence of glucose levels on clinical outcome after mechanical thrombectomy for large-vessel occlusion: a systematic review and meta-analysis

Mechanical thrombectomy (MT) represents the mainstay of treatment for patients with acute ischemic stroke due to large-vessel occlusion (LVO). Intravenous thrombolysis has been associated with worse clinical outcome in patients presenting with high blood glucose levels at admission; to date the true effect of hyperglycemia in the setting of MT has not been fully elucidated. In this meta-analysis, we analyzed the influence of high blood glucose levels at admission on clinical outcome after MT. Ovid EMBASE, PubMed, Scopus, and Cochrane Library databases were searched from their dates of inception up to March 2021. An initial search identified 2118 articles representing 1235 unique studies. After applying selection criteria, three prospective and five retrospective studies were analyzed, yielding a pooled cohort of 5861 patients (2041 who presented with hyperglycemia, and 3820 who presented with normal blood glucose levels). Patients in the hyperglycemia group were less likely to have a modified Ranking Scale (mRS) score <3 (risk ratio (RR): 0.65; 95% CI 0.59 to 0.72; p<0.0001; I ²=13%), and had an increased risk of symptomatic intracranial hemorrhage (sICH) (RR: 2.07; 95% CI 1.65 to 2.60; p<0.0001; I ²=0%) and mortality (RR: 1.73; 95% CI 1.57 to 1.91; p<0.0001; I ²=0%). Patients who present with hyperglycemia and undergo MT for treatment of LVO have an increased risk of unfavorable clinical outcome, sICH, and mortality. Glucose levels at admission appear to be a prognostic factor in this subset of patients. Further studies should focus on evaluating control of the glucose level at admission as a modifiable risk factor in patients undergoing MT for LVO.

Endovascular Thrombectomy Treatment: Beyond Early Time Windows and Small Core

ABSTRACT

Tremendous advancements in the treatment of acute ischemic stroke in the last 25 years have been based on the principle of reperfusion in early time windows and identification of small core infarct for intravenous thrombolysis and mechanical thrombectomy. Advances in neuroimaging have made possible the safe treatment of patients with acute ischemic stroke in longer time windows and with more specific selection of patients with salvageable brain tissue. In this review, we discuss the history of endovascular stroke thrombectomy trials and highlight the neuroimaging-based trials that validated mechanical thrombectomy techniques in the extended time window with assessment of penumbral tissue. We conclude with a survey of currently open trials that seek to safely expand eligibility for this highly efficacious treatment.

ASPECT scores of patients with focal intracerebral hemorrhage were correlated with their short- and medium-term functional outcomes

PURPOSE

The Alberta Stroke Program Early CT Score (ASPECTS) is widely used to guide thrombolytic therapy and predict the functional outcome of patients with acute ischemic stroke (AIS). Whether ASPECTS can predict the functional outcome of patients with intracerebral hemorrhage (ASPECTS-H) remains unclear.

METHODS

Patients with primary intracerebral hemorrhage (ICH) were collected and retrospectively analyzed. ASPECTS-H was assessed at admission. Patients were followed up at 30 days and 90 days after the onset of ICH. Occurrence of death within 90 days after ICH was the primary endpoint. Modified Rankin Scale (mRS) ≥ 3 was considered a poor functional outcome.

RESULTS

A total of 149 patients met eligibility criteria; 61 (40.9%) had poor functional outcome at 30 days, and 37 (24.8%) had poor functional outcome at 90 days. Using binary logistic regression modeling, we found that a low ASPECTS-H was associated with a poor functional outcome. The risk ratio of a low ASPECTS-H was 2.31 at 30 days (P = 0.000; 95% CI, 1.560-3.421) and 2.711 at 90 days (P = 0.000; 95% CI, 1.677-4.381). The optimal cutoff value of ASPECTS-H to discriminate good and poor 30-day and 90-day outcomes was 7.5 (Sensitivity_30-day = 0.636, 1-Specificity_{30 - day} = 0.311; Sensitivity_90-day = 0.580, 1-Specificity_90-day = 0.270).

CONCLUSIONS

A low ASPECTS-H was an indicator of poor short-term and long-term functional outcomes of ICH.

RECO Flow Restoration Device Versus Solitaire FR With the Intention for Thrombectomy Study (REDIRECT): a prospective randomized controlled trial

OBJECTIVE

The RECO flow restoration (FR) device is a new stent retriever designed for rapid flow restoration in acute ischemic stroke (AIS) caused by large vessel occlusion (LVO). Here, the authors compared the efficacy and safety of the RECO device with the predicate Solitaire FR stent retriever.

METHODS

The RECO Flow Restoration Device Versus Solitaire FR With the Intention for Thrombectomy Study (REDIRECT) was a multicenter, prospective, open randomized controlled trial. Patients with acute LVO at 7 Chinese stroke centers participated in the study. The primary efficacy endpoint was defined as a modified thrombolysis in cerebral infarction (mTICI) reperfusion grade ≥ 2 within three passes. The primary safety endpoint comprised any serious adverse device effect, symptomatic intracerebral hemorrhage (sICH), and any serious adverse event (SAE; defined as cerebral palsy or death) within 24 hours after the procedure. The secondary efficacy endpoints consisted of functional independence (modified Rankin Scale score 0-2), procedure duration, and 90-day all-cause mortality.

RESULTS

Between January 2014 and August 2016, 67 patients were randomly allocated to the RECO group and 69 patients to the Solitaire FR group. The primary efficacy endpoint (mTICI grade ≥ 2 within three passes) was similar in the two treatment groups (91% vs 87%, respectively, p = 0.5861), and the rate of reperfusion with an mTICI grade 2b/3 was 87% versus 75% (p = 0.1272). There were no serious adverse device effects in any patient. The rates of sICH (1.5% vs 7.2%, p = 0.1027) and SAEs (6.0% vs 1.4%, p = 0.2050) within 24 hours after the procedure were similar in the two treatment groups. There was no significant difference in the rate of functional independence (63% vs 46%, p = 0.0609) or 90-day all-cause mortality (13% vs 23%, p = 0.1848) or in procedure duration (85.39 ± 47.01 vs 89.94 ± 53.34 minutes, p = 0.5986) between the two groups.

CONCLUSIONS

The RECO stent retriever is effective and safe as a mechanical thrombectomy device for AIS due to LVO. Clinical trial registration no.: NCT01983644 (clinicaltrials.gov).

Absent hyperdense middle cerebral artery sign is associated with poor functional outcome after mechanical thrombectomy

BACKGROUND

The hyperdense middle cerebral artery sign on computed tomography indicates proximal middle cerebral artery occlusion. Recent reports suggest an association between the hyperdense sign and successful reperfusion. The prognostic value of the hyperdense middle cerebral artery sign in patients receiving mechanical thrombectomy has not been extensively studied.

AIMS

Our study aims to evaluate the association between the hyperdense middle cerebral artery sign and functional outcome in patients with M1 occlusions that had undergone mechanical thrombectomy.

METHODS

We conducted a single-center retrospective observational cohort study of 102 consecutive patients presenting with acute M1 occlusions that had undergone mechanical thrombectomy. Patients were stratified into cohorts based on the presence of hyperdense middle cerebral artery sign visually assessed on computed tomography by two readers. The outcomes of interests were functional disability measured by the ordinal Modified Rankin Scale (mRS) at 90 days, mortality, reperfusion status and hemorrhagic conversion.

RESULTS

Out of the 102 patients with M1 occlusions, 71 had hyperdense middle cerebral artery sign. There was no significant difference between the cohorts in age, baseline mRS, NIHSS, ASPECTS, and time to reperfusion. The absence of hyperdense middle cerebral artery sign was associated with increased odds of being dependent or dying (higher mRS) (OR: 3.24, 95% CI: 1.30-8.06, p = 0.011) after adjusting for other significant predictors, including age, female sex, hypertension, presenting serum glucose, ASPECTS, CTA collateral score, and successful reperfusion.

CONCLUSION

The absence of hyperdense middle cerebral artery sign is associated with worse functional outcome in patients presenting with M1 occlusions undergoing thrombectomy.

Characteristics and prognosis of acute basilar artery occlusion in minor to moderate stroke and severe stroke after endovascular treatment: A multicenter retrospective study

OBJECTIVE

We aimed to investigate characteristics and outcomes of patients receiving mechanical thrombectomy (MT) between minor to moderate stroke and severe stroke caused by acute basilar artery occlusion (BAO).

METHODS

We retrospectively reviewed the data of all patients with BAO who underwent MT from three stroke centers between January 2016 and January 2020. The patients were dichotomized as minor to moderate or severe stroke group according to their admission National Institutes of Health Stroke Scale (NIHSS) score <21and ≥21. Patient characteristics, imaging findings, and outcomes were compared between the two groups.

RESULTS

A total of 72 patients were included in this study. The posterior circulation Alberta Stroke Program Early CT Score (PC-ASPECTS) in the minor to moderate stroke patients were significantly higher than that of patients with severe stroke (P = 0.013). The good posterior circulation collateral scores (PC-CS) (6-10) were more commonly found in patients with minor to moderate stroke than in patients with severe stroke (58.14 % vs 10.34 %,P < 0.001). There were similar rates of successful recanalization between the two groups. Patients with minor to moderate stroke had a higher rate of favorable outcomes (mRS score 0-2, 60.47 % vs 20.69 %, P = 0.002) and a lower rate of periprocedural complications (4.65 % vs 31.03 %, P = 0.005) and mortality (4.65 % vs 24.14 %, P = 0.026) at 3 months after MT compared with the patients with severe stroke.

CONCLUSIONS

Acute BAO patients with minor to moderate stroke had better posterior circulation collateral and had better outcomes after MT than those patients with severe stroke.

Value of high-density sign on CT images after mechanical thrombectomy for large vessel occlusion in predicting hemorrhage and unfavorable outcome

PURPOSE

Cerebral hyperdensities can appear on head computed tomography (CT) images performed early after endovascular treatment (EVT) in patients with acute ischemic stroke and may be secondary to contrast staining or hemorrhagic transformation. The aim of this study was to determine how the high-density sign on CT affects mortality and clinical outcome and whether CT parameters predict hemorrhagic conversion or unfavorable outcome.

METHODS

We retrospectively reviewed a database of patients who underwent EVT with mechanical thrombectomy for acute ischemic stroke over 7 years. Included were acute stroke patients with a CT examination within 24 h post-EVT with mechanical thrombectomy, demonstrating areas of hyperdensity. We evaluated morphologic characteristics of these lesions, location, CT Hounsfield units and largest area, as well as patient demographics, EVT methods and patient outcome.

RESULTS

A total of 29 patients met the strict inclusion criteria. Complete recanalization was achieved in 58.6% (17/29). Seventeen (58.6%) cases of post-intervention cerebral hyperdensities were related to contrast staining and 12 (41.4%) cases to contrast staining and hemorrhage. Patient mortality was significantly higher in the hemorrhagic group (50.0% versus 5.9%, p = 0.003). The increased density on CT was associated with higher hemorrhagic risk (odds ratio 1.05, p = 0.036).

CONCLUSION

Patients with the high-density sign on CT images after mechanical thrombectomy for acute ischemic stroke demonstrated increased mortality and worse clinical outcome, primarily when these hyperdensities were related to hemorrhage. CT imaging parameters as higher density areas can help in the differentiation of hemorrhage from contrast staining.

Differentiation between Cerebral Hemorrhage and Contrast Extravasation Using Dual Energy Computed Tomography after Intra-Arterial Neuro Interventional Procedures

Purpose:

To evaluate the value of dual-energy computed tomography (DECT) in differentiating cerebral hemorrhage from blood brain barrier (BBB) disruption after neuro-interventional procedures with intra-arterial injection of iodinated contrast material.

Material and methods:

This prospective study was approved by the local ethics committee, and informed consent was obtained for all patients. Thirty five patients with acute ischemic stroke or un-ruptured brain aneurysm who had received intra-arterial administration of iodinated contrast material were evaluated using DECT at 80 and 150 kV immediately after the procedure.

A three-material decomposition algorithm was used to obtain virtual non-contrast (VNC) images and iodine overlay maps (IOM). A follow-up examination (brain magnetic resonance imaging MRI or conventional CT) was used as the standard of reference for hemorrhage, defined as a persistant hyperdensity on a conventional CT or T2* hypo-intensity on brain MRI. The diagnostic values of DECT in differentiating hemorrhage and iodinated contrast material were obtained.

Results:

Mixed images obtained with DECT showed intra-parenchymal or subarachnoid hyperattenuation in 18/35 patients. Among these, 16 were classified (according to VNC images and IOM) as contrast extravasations and two with a mixture of hemorrhage and contrast material. On follow-up imaging, there were two patients with hemorrhage. The sensitivity, specificity, and accuracy of DECT in the identifying hemorrhage was calculated as 67% (2/3), 100% (32/32) and 97% (32/33) respectively.

Conclusion:

DECT allows an early and accurate differentiation between cerebral hemorrhage and BBB disruption after intra-arterial neuro-interventional procedures.

Predictors of Good Outcomes in Patients with Failed Endovascular Thrombectomy

OBJECTIVE

Endovascular thrombectomy (EVT) fails in approximately 20% of anterior circulation large vessel occlusion (AC-LVO). Nonetheless, the factors that affect clinical outcomes of non-recanalized AC-LVO despite EVT are less studied. The purpose of this study was to identify the factors affecting clinical outcomes in non-recanalized AC-LVO patients despite EVT.

MATERIALS AND METHODS

This was a retrospective analysis of clinical and imaging data from 136 consecutive patients who demonstrated recanalization failure (modified thrombolysis in cerebral ischemia [mTICI], 0-2a) despite EVT for AC-LVO. Data were collected in prospectively maintained registries at 16 stroke centers. Collateral status was categorized into good or poor based on the CT angiogram, and the mTICI was categorized as 0-1 or 2a on the final angiogram. Patients with good (modified Rankin Scale [mRS], 0-2) and poor outcomes (mRS, 3-6) were compared in multivariate analysis to evaluate the factors associated with a good outcome.

RESULTS

Thirty-five patients (25.7%) had good outcomes. The good outcome group was younger (odds ratio [OR], 0.962; 95% confidence interval [CI], 0.932-0.992; p = 0.015), had a lower incidence of hypertension (OR, 0.380; 95% CI, 0.173-0.839; p = 0.017) and distal internal carotid artery involvement (OR, 0.149; 95% CI, 0.043-0.520; p = 0.003), lower initial National Institute of Health Stroke Scale (NIHSS) (OR, 0.789; 95% CI, 0.713-0.873; p < 0.001) and good collateral status (OR, 13.818; 95% CI, 3.971-48.090; p < 0.001). In multivariate analysis, the initial NIHSS (OR, 0.760; 95% CI, 0.638-0.905; p = 0.002), good collateral status (OR, 14.130; 95% CI, 2.264-88.212; p = 0.005) and mTICI 2a recanalization (OR, 5.636; 95% CI, 1.216-26.119; p = 0.027) remained as independent factors with good outcome in non-recanalized patients.

CONCLUSION

Baseline NIHSS score, good collateral status, and mTICI 2a recanalization remained independently associated with clinical outcome in non-recanalized patients. mTICI 2a recanalization would benefit patients with good collaterals in non-recanalized AC-LVO patients despite EVT.

Prediction of mTICI 3 recanalization and clinical outcomes in endovascular thrombectomy for acute ischemic stroke: a retrospective study in the Taiwan registry

PURPOSE

Early recanalization for acute ischemic stroke (AIS) due to large vessel occlusion (LVO) by endovascular thrombectomy (EVT) is strongly related to improved functional outcomes. With data obtained from the Taiwan registry, the factors associated with mTICI 3 recanalization and clinical outcomes in EVT are investigated.

METHODS

From January 2014 to September 2016, 108 patients who underwent EVT for AIS due to LVO in 11 medical centers throughout Taiwan were included. Complete recanalization is defined as achieving modified thrombolysis in cerebral infarction (mTICI) grade 3. Good clinical outcomes are defined by the modified Rankin scale (mRS) 0-2 at 3 months after EVT. Clinical and imaging parameters for predicting mTICI 3 recanalization and good clinical outcomes are analyzed.

RESULTS

Of the 108 patients who received EVT, 54 (50%) patients had mTICI 3 recanalization. Having received aspiration only and the use of IV-tPA are shown to be significant predictors for mTICI 3 recanalization with odds ratios of 2.61 and 2.53 respectively. Forty-six (42.6%) patients experienced good 3-month clinical outcomes (mRS 0-2). Pretreatment collateral statuses, NIHSS scores, time lapses between symptoms to needle, and the occurrence of hemorrhage at 24 h are all significant predictors for good outcomes with odds ratios of 2.88, 0.91, 0.99, and 0.31 respectively.

CONCLUSIONS

Prediction of mTICI 3 recanalization and clinical outcomes offer valuable clinical information for treatment planning in EVT.

A novel toolkit for the prediction of clinical outcomes following mechanical thrombectomy

AIM

To develop a robust toolkit to aid decision-making for mechanical thrombectomy (MT) based on readily available patient variables that could accurately predict functional outcome following MT.

MATERIALS AND METHODS

Data from patients with anterior circulation stroke who underwent MT between October 2009 and January 2018 (n=239) were identified from our MT database. Patient explanatory variables were age, sex, National Institutes of Health Stroke Scale (NIHSS), Alberta Stroke Program Early CT Score (ASPECTS), collateral score, and Glasgow Coma Scale. Five models were developed from the data to predict five outcomes of interest: model 1: prediction of survival: modified Rankin Scale (mRS) of 0-5 (alive) or 6 (dead); model 2: prediction of good/poor outcome: mRS of 0-3 (good), or 4-6 (poor); model 3: prediction of good/poor outcome: mRS of 0-2 (good), or 3-6 (poor); model 4: prediction of mRS category: mRS of 0-2 (no disability), 3 (minor disability), 4-5 (severe disability) or 6 (dead); model 5: prediction of the exact mRs score (mRs as a continuous variable). The accuracy and discriminative power of each predictive model were tested.

RESULTS

Prediction of survival was 87% accurate (area under the curve [AUC] 0.89). Prediction of good/poor outcome was 91% accurate (AUC 0.94) for Model 2 and 95% accurate (AUC 0.98) for Model 3. Prediction of mRS category was 76% accurate, and increased to 98% using the "one-score-out rule". Prediction of the exact mRS value was accurate to an error of 0.89.

CONCLUSIONS

This novel toolkit provided accurate estimations of outcome for MT.

Validation of the simplified modified Rankin scale for stroke trials: Experience from the ENCHANTED alteplase-dose arm

Background and aims

The structured, simplified modified Rankin scale questionnaire (smRSq) may increase reliability over the interrogative approach to scoring the modified Rankin scale (mRS) in acute stroke research and practice. During the conduct of the alteplase-dose arm of the international ENhanced Control of Hypertension ANd Thrombolysis StrokE stuDy (ENCHANTED), we had an opportunity to compare each of these approaches to outcome measurement.

Methods

Baseline demographic data were recorded together with the National Institutes of Health Stroke Scale (NIHSS). Follow-up measures obtained at 90 days included mRS, smRSq, and the 5-Dimension European Quality of life scale (EQ-5D). Agreements between smRSq and mRS were assessed with the Kappa statistic. Multiple logistic regression was used to identify baseline predictors of Day 90 smRSq and mRS scores. Treatment effects, based on Day 90 smRSq/mRS scores, were tested in logistic and ordinal logistic regression models.

Results

SmRSq and mRS scores had good agreement (weighted Kappa 0.79, 95% confidence interval (CI) 0.78–0.81), while variables of age, atrial fibrillation, diabetes mellitus, pre-morbid mRS (1 vs. 0), baseline NIHSS scores, and imaging signs of cerebral ischemia, similarly predicted their scores. Odds ratios for death or disability, and ordinal shift, 90-day mRS scores using smRSq were 1.05 (95% CI 0.91–1.20; one-sided P = 0.23 for non-inferiority) and 0.98 (95% CI 0.87–1.11; P = 0.02 for non-inferiority), similar to those using mRS.

Conclusions

This study demonstrates the utility of the smRSq in a large, ethnically diverse clinical trial population. Scoring of the smRSq shows adequate agreement with the standard mRS, thus confirming it is a reliable, valid, and useful alternative measure of functional status after acute ischemic stroke.

Clinical Trial registration

URL: http://www.clinicaltrials.gov . Unique identifier: NCT01422616.

Predictors of Balloon Guide Catheter Assistance Success in Stent-retrieval Thrombectomy for an Anterior Circulation Acute Ischemic Stroke

Introduction Mechanical thrombectomy has become the standard treatment for large vessel occlusion (LVO) in acute ischemic stroke (AIS) in well-selected patients. Although many devices and strategies exist, the use of a balloon-tip guide catheter (BGC) with stent-retriever (SR) may hold several advantages. We aim to assess the efficacy and identify predictors of technical success of this unique approach. Methods From our prospectively maintained database, we identified consecutive cases in which a BGC was used for stent-retriever thrombectomy in anterior circulation LVO between 2015 and 2016. Baseline and procedural characteristics were captured and analyzed. Predictors of technical and clinical outcomes were identified by multivariable logistic regression analysis. Results Ninety-three patients with AIS-LVO were treated with BGC-assisted mechanical thrombectomy. The mean age was 71 years old (SD 14), with 49.5% male (n=46). Pre-operative IV-tPA was administered in 55.9% (n=52) of cases. The most common location of occlusive thrombus was M1 (64.5%, n=60). Successful recanalization (mTICI=2b-3) was achieved in 86.0% (n=80) of cases while complete revascularization (mTICI-3) was achieved in 56.5% (n=52). There was a first-pass success rate of 52.7% (n=49). At discharge, 38.7% of the patients were functionally independent (mRS≤2). Multivariate analysis revealed that the middle cerebral artery location was strongly predictive of first-pass success, resulting in mTICI =2b revascularization (OR 7.10, p=0.018). Additionally, female gender (OR 2.85, p=0.042) and decreasing mTICI were associated with a poor clinical outcome (mRS≥4; OR 1.76, p=0.008). Conclusions BGC assistance in stent retrieval thrombectomy is safe and effective for AIS due to anterior circulation LVO. Further investigation is required to elucidate the optimal treatment strategy based on patient and disease characteristics.

Image-based analysis and simulation of the effect of platelet storage temperature on clot mechanics under uniaxial strain

Optimal strength and stability of blood clots are keys to hemostasis and in prevention of hemorrhagic or thrombotic complications. Clots are biocomposite materials composed of fibrin network enmeshing platelets and other blood cells. We have previously shown that the storage temperature of platelets significantly impacts clot structure and stiffness. The objective of this work is to delineate the relationship between morphological characteristics and mechanical response of clot networks. We examined scanning electron microscope images of clots prepared from fresh apheresis platelets, and from apheresis platelets stored for 5 days at room temperature or at 4 °C, suspended in pooled plasma. Principal component analysis of nine different morphometric parameters revealed that a single principal component (PC1) can distinguish the effect of platelet storage on clot ultrastructure. Finite element analysis of clot response to uniaxial strain was used to map the spatially heterogeneous distribution of strain energy density for each clot. At modest deformations (25% strain), a single principal component (PC2) was able to predict these heterogeneities as quantified by variability in strain energy density distribution and in linear elastic stiffness, respectively. We have identified structural parameters that are primary regulators of stress distribution, and the observations provide insights into the importance of spatial heterogeneity on hemostasis and thrombosis.

Glucose Modifies the Effect of Endovascular Thrombectomy in Patients With Acute Stroke

Background and Purpose- Hyperglycemia is a negative prognostic factor after acute ischemic stroke but is not known whether glucose is associated with the effects of endovascular thrombectomy (EVT) in patients with large-vessel stroke. In a pooled-data meta-analysis, we analyzed whether serum glucose is a treatment modifier of the efficacy of EVT in acute stroke. Methods- Seven randomized trials compared EVT with standard care between 2010 and 2017 (HERMES Collaboration [highly effective reperfusion using multiple endovascular devices]). One thousand seven hundred and sixty-four patients with large-vessel stroke were allocated to EVT (n=871) or standard care (n=893). Measurements included blood glucose on admission and functional outcome (modified Rankin Scale range, 0-6; lower scores indicating less disability) at 3 months. The primary analysis evaluated whether glucose modified the effect of EVT over standard care on functional outcome, using ordinal logistic regression to test the interaction between treatment and glucose level. Results- Median (interquartile range) serum glucose on admission was 120 (104-140) mg/dL (6.6 mmol/L [5.7-7.7] mmol/L). EVT was better than standard care in the overall pooled-data analysis adjusted common odds ratio (acOR), 2.00 (95% CI, 1.69-2.38); however, lower glucose levels were associated with greater effects of EVT over standard care. The interaction was nonlinear such that significant interactions were found in subgroups of patients split at glucose < or >90 mg/dL (5.0 mmol/L; P=0.019 for interaction; acOR, 3.81; 95% CI, 1.73-8.41 for patients < 90 mg/dL versus 1.83; 95% CI, 1.53-2.19 for patients >90 mg/dL), and glucose < or >100 mg/dL (5.5 mmol/L; P=0.004 for interaction; acOR, 3.17; 95% CI, 2.04-4.93 versus acOR, 1.72; 95% CI, 1.42-2.08) but not between subgroups above these levels of glucose. Conclusions- EVT improved stroke outcomes compared with standard treatment regardless of glucose levels, but the treatment effects were larger at lower glucose levels, with significant interaction effects persisting up to 90 to 100 mg/dL (5.0-5.5 mmol/L). Whether tight control of glucose improves the efficacy of EVT after large-vessel stroke warrants appropriate testing.

Acute ischemic stroke patients with diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score ≤ 5 can benefit from endovascular treatment: a single-center experience and literature review

PURPOSE

The recommendation strength of the guidelines for mechanical thrombectomy among patients with large pre-treatment core infarct is weak. We evaluated the safety and outcome of endovascular treatment for acute ischemic stroke with diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) ≤ 5.

METHODS

Data on acute ischemic stroke patients with DWI-ASPECTS ≤ 5 who underwent endovascular treatment within 6 h, or presented an arterial spin labeling-DWI (ASL-DWI) mismatch within 12 h, at our center were retrospectively collected. We report the clinical characteristics and outcome of every patient, and review the relevant literature.

RESULTS

Among the 19 patients who were enrolled, all experienced successful reperfusion, and 10 achieved a favorable outcome (modified Rankin scale (mRS) ≤ 2). Two patients presented with symptomatic intracranial hemorrhage (sICH); both of them had a poor outcome (mRS > 2).

CONCLUSION

Acute ischemic stroke patients with large DWI lesions caused by large vessel occlusion can achieve a favorable clinical outcome with endovascular treatment if recanalization is performed within 6 h, or after 6 h in case of an ASL-DWI mismatch.

Significance of simulated conventional images on dual energy CT after endovascular treatment for ischemic stroke

BACKGROUND AND PURPOSE

CT scans often reveal post-interventional cerebral hyperdensities (PCHDs) immediately after intra-arterial thrombectomy (IAT) for ischemic stroke. Dual energy CT (DE-CT) can indicate whether PCHDs are caused by hemorrhage or iodinated contrast. Hyperdense lesions, detected on DE-CT with the use of iodinated contrast, could be associated with delayed hemorrhagic transformation and poor outcome. However, the quantitative indicators in DE-CT for predicting delayed hemorrhagic transformation remain unclear. We assessed such indicators for predicting delayed hemorrhagic transformation.

MATERIAL AND METHODS

We retrospectively analyzed 52 consecutive acute ischemic stroke patients who underwent IAT. Simulated conventional CT (sCCT) images were obtained immediately after a DE-CT scan. Virtual, unenhanced, non-contrast (VNC) imaging was performed after reconstruction. Hounsfield units (HU) of the infarct areas observed on the sCCT were measured. The association of HU on sCCT with hemorrhage on VNC and delayed parenchymal hemorrhage (PH) was evaluated.

RESULTS

The HU of sCCT with hemorrhage on VNC was significantly higher than without it (377.9±385 HU vs 83.5±37.9 HU; P<0.0001). The cut-off index was 80 HU, which displayed 100% sensitivity, 63.8% specificity, 22.3% positive predictive value, and 100% negative predictive value (P=0.0001, area under the curve (AUC)=0.89). The HU with delayed PH was substantially higher than without it (250.8±382.2 HU vs 93.7±64.8 HU; P=0.01). The cut-off index was 78 HU, which showed 100% sensitivity, 61% specificity, 25% positive predictive value, and 100% negative predictive value (P=0.049, AUC=0.76).

CONCLUSION

sCCT images on DE-CT are useful for excluding intracerebral hemorrhage and delayed PH.

A Regional Network Organization for Thrombectomy for Acute Ischemic Stroke in the Anterior Circulation; Timing, Safety, and Effectiveness

BACKGROUND

Mechanical thrombectomy (MT) in association with intravenous thrombolysis is recommended for treatment of acute ischemic stroke (AIS), with large vessel occlusion (LVO) in the anterior circulation. Because MT is only available in comprehensive stroke centers (CSC), the challenge of stroke organization is to ensure equitable access to the fastest endovascular suite. Our aim was to evaluate the feasibility, efficacy, and safety of MT in patients initially managed in 1 CSC (mothership), compared with patients first managed in primary stroke center (PSC), and then transferred to the CSC for MT (drip-and-ship).

METHODS

We retrospectively analyzed 179 consecutive patients (93 in the mothership group and 86 in the drip-and-ship group), with AIS secondary to LVO in the anterior cerebral circulation and a clinical-radiological mismatch (NIHSS ≥ 8 and DWI-ASPECT score ≥5), up to 6 hours after symptoms onset. We evaluated 3-month functional modified Rankin scale (mRS), periprocedural time management, mortality, and symptomatic intracranial haemorrhage (sICH).

RESULTS

Despite significant longer process time in the drip-and-ship group, mRS ≤ 2 at 3 months (39.8% versus 44.1%, P = .562), Thrombolysis in cerebral infarction 2b-3 (85% versus 78%, P = .256), and sICH (7.0% versus 9.7%, P = .515) were similar in both group regardless of baseline clinical or radiological characteristics. After multivariate logistic regression, the predictive factors for favorable outcome were age (odds ratio [OR] _-5years= 1.32, P < .001), initial NIHSS (OR _-5points = 1.59, P = .010), absence of diabetes (OR = 3.35, P = .075), and the delay magnetic resonance imagining-puncture (OR _-30min = 1.16, P = .048).

CONCLUSIONS

Our study showed encouraging results from a regional protocol of MT comparing patients transferred from PSC or brought directly in CSC.

Clinical Outcome After Mechanical Thrombectomy in Patients with Diabetes with Major Ischemic Stroke of the Anterior Circulation

BACKGROUND

Among patients with acute ischemic stroke treated with mechanical thrombectomy (MT), patients with diabetes (DP) show a poorer outcome compared with patients without diabetes (NDP). This study aims to provide a comprehensive analysis of factors associated with unfavorable outcome in DP receiving MT for stroke of the anterior circulation.

METHODS

This study included 317 of 498 consecutive patients who received interventional treatment for acute ischemic stroke in the terminal internal carotid artery and/or middle cerebral artery, including 46 DP. The study data included pre- and posttreatment stroke computed tomography, including perfusion data, collateral status, treatment data including treatment times, pre-existing cardiovascular risk factors, cerebrovascular events, comorbidities, laboratory parameters, and medication. Neurologic status was assessed at baseline (National Institute of Health Stroke Scale [NIHSS]/modified Rankin Scale [mRS]) and after 90 days (mRS 90).

RESULTS

Compared with NDP, DP showed a significantly poorer outcome (mRS90 >2) (P < 0.05). Collateralization and infarct core size did not differ between groups, whereas the penumbra was significantly smaller in DP than in NDP (P < 0.05). The poorer mRS90 outcome (mRS90 > 2) in DP was associated with poor collaterals (P = 0.01) and hyperglycemia on admission (P < 0.05). Shorter time to reperfusion was associated with favorable mRS90 in the NDP (P < 0.001) but not the DP (P = 0.49) group. In univariate logistic regression, the following parameters were significantly associated with mRS90: diabetes, hyperglycemia at admission, time to reperfusion, and the NIHSS score (P < 0.05 each). In multivariate analyses and partition regression models of all variables, DP with admission hyperglycemia (≥132 mg/dL) and older age (≥66 years) showed a particularly poor outcome.

CONCLUSIONS

The main factors for an unfavorable outcome of DP after MT are admission hyperglycemia, age, and NIHSS score.

Posterior Circulation Occlusions May Be Associated with Distal Emboli During Thrombectomy : Factors for Distal Embolization and a Review of the Literature

Background

Distal embolization or movement of the thrombus to previously uninvolved vasculature are feared complications during stroke thrombectomy. We looked at associated factors in a consecutive series of patients who underwent thrombectomy with the same endovascular device.

Methods

We included all patients with acute ischemic stroke in the anterior or posterior circulation, who underwent thrombectomy with the same thrombectomy device for acute stroke from 2013 to 2016. Distal embolization was defined as any movement of the thrombus into a previously uninvolved portion of the cerebral vasculature or the presence of thrombotic material further downstream in the affected vessel, which occurred after the initial angiogram. We studied patient-related as well as technical factors to determine their association with distal emboli.

Results

In this study 167 consecutive acute stroke patients treated with the emboTrap® device (Cerenovus, Irvine, CA, USA) were included with a median National Institutes of Health Stroke Scale (NIHSS) of 15 (range 2–30) and mean age of 67 years (SD 13.1 years). Of the patients in our cohort 20 (11.9%) experienced distal emboli, with 2.3% into a new territory and 9.6% into a territory distal to the primary occlusion. On univariate analysis, age, intravenous tissue plasminogen activator (tPA), posterior circulation occlusions, and general anesthesia were associated with distal emboli. On multivariate analysis, only posterior circulation occlusions (odds ratio OR 4.506 95% confidence interval CI 1.483–13.692, p = 0.008) were significantly associated with distal emboli. Distal embolization was not significantly associated with worse functional outcomes at 3 months, increased mortality or increased bleeding risk.

Conclusion

Posterior circulation occlusions were significantly associated with distal emboli during thrombectomy, possibly due to the lack of flow arrest during such procedures. New techniques and devices should be developed to protect against embolic complications during posterior circulation stroke thrombectomy.

Early Blood-Brain Barrier Disruption after Mechanical Thrombectomy in Acute Ischemic Stroke

BACKGROUND AND PURPOSE

The impact of blood-brain barrier (BBB) disruption can be detected by intraparenchymal hyperdense lesion on the computed tomography (CT) scan after endovascular stroke therapy. The purpose of this study was to determine whether early BBB disruption predicts intracranial hemorrhage and poor outcome in patients with acute ischemic stroke treated with mechanical thrombectomy.

METHODS

We analyzed patients with anterior circulation stroke treated with mechanical thrombectomy and identified BBB disruption on the noncontrast CT images immediately after endovascular treatment. Follow-up CT or magnetic resonance imaging scan was performed at 24 hours to assess intracranial hemorrhage. We dichotomized patients into those with moderate BBB disruption versus those with minor BBB disruption and no BBB disruption. We evaluated the association of moderate BBB disruption after mechanical thrombectomy with intracranial hemorrhage and clinical outcomes.

RESULTS

Moderate BBB disruption after mechanical thrombectomy was found in 56 of 210 patients (26.7%). Moderate BBB disruption was independently associated with higher rates of hemorrhagic transformation (OR 25.33; 95% CI 9.93-64.65; P < .001), parenchymal hematoma (OR 20.57; 95% CI 5.64-74.99; P < .001), and poor outcome at discharge (OR 2.35; 95% CI 1.09-5.07; P = .03). The association of BBB disruption with intracranial hemorrhage remained in patients with successful reperfusion after mechanical thrombectomy. The location of BBB disruption was not associated with intracranial hemorrhage and poor outcome.

CONCLUSIONS

Moderate BBB disruption is common after mechanical thrombectomy in a quarter of patients with acute ischemic stroke and increases the risk of intracranial hemorrhage and poor outcome.

Importance of Reperfusion Status after Intra-Arterial Thrombectomy for Prediction of Outcome in Anterior Circulation Large Vessel Stroke

Background

Reperfusion status after intra-arterial thrombectomy (IAT) is a critical predictor of functional outcome after acute ischemic stroke. However, most prognostic models have not included a detailed assessment of reperfusion status after IAT.

Objective

The aim of this work was to assess the association between successful reperfusion and clinical outcome.

Methods

Clinical, radiological, and procedural variables of patients treated with IAT were extracted from our prospective stroke registry. The association with functional outcome using the modified Rankin Scale (mRS) after 3 months was assessed using multivariable logistic regression. An extension of the modified TICI score, eTICI, was used to classify reperfusion status. The prognostic value of reperfusion status after IAT in addition to age, stroke severity, imaging characteristics, treatment with intravenous thrombolysis, and time from symptom onset to the end of IAT was assessed with logistic regression and summarized with receiver operating characteristic curves.

Results

In total, 119 patients were included (mean age 66 years). In multivariable analysis, age >80 years (OR 6.8, 95% CI 1.2-39.8), NIHSS at presentation >15 (OR 7.3, 95% CI 2.3-23.5), and incomplete reperfusion status (eTICI score <2C; OR 10.3, 95% CI 3.5-30.6) were the strongest predictors of a poor outcome (mRS 3-6). Adding reperfusion status to the model improved the prognostic accuracy (AUC 0.88, 95% CI 0.91-0.94). Our results indicate a large difference between using an eTICI cutoff of ≥2C versus ≥2B: a cutoff ≥2C improved the predictive value for a good clinical outcome (2C: positive predictive value, PPV, 0.78; 2B: PPV 0.32).

Conclusion

Our results promote using reperfusion status for assessing prognosis in ischemic stroke patients treated with IAT. A model using eTICI ≥2C had greater PPV than eTICI ≥2B and could improve prognostic accuracy.

Equivalent favorable outcomes possible after thrombectomy for posterior circulation large vessel occlusion compared with the anterior circulation: the MUSC experience

Introduction

In acute ischemic stroke (AIS), posterior circulation large vessel occlusions (LVOs) have been associated with poorer outcomes compared with anterior circulation LVOs. The outcomes of anterior versus posterior circulation thrombectomy for LVOs were compared at a high volume center employing a direct aspiration first pass technique (ADAPT).

Methods

We retrospectively studied a database of AIS cases that underwent ADAPT thrombectomy for LVOs. Cases were grouped by anatomical location of thrombectomy (posterior vs anterior circulation), and analysis was performed on both entire sample size.

Results

A total of 436 AIS patients (50.2% women, mean age 67.3 years) underwent ADAPT thrombectomy for LVO during the study period, of whom 13% of had posterior circulation thrombectomy. Patients with posterior circulation thrombectomy did not show a significant difference in preprocedural variables, including age, baseline National Institutes of Health Stroke Scale (NIHSS), and onset to groin time, compared with anterior circulation (P>0.05). There were also no differences in procedural variables between the two groups. Patients in the posterior group were found to have a similar likelihood of good outcome (modified Rankin Scale score 0—2) at 90 days compared with the anterior group (42.9% vs 43.2%, respectively), and a small but not significant increase in mortality at 90 days. Multilogistic regression analysis showed that the anatomical location (anterior vs posterior) was not an independent predictor of good outcome or mortality after thrombectomy. Prominent predictors of outcome/mortality included age, female gender, procedure time, and baseline NIHSS.

Conclusions

Our findings demonstrate that when patients are carefully selected for thrombectomy, those with posterior circulation LVOs can achieve similar outcomes compared with anterior circulation thrombectomy, indicating comparable safety and efficacy profiles.

The Role of Simulation in the Design of a Semi-Enclosed Tubular Embolus Retrieval

A numerical analysis of a semi-enclosed tubular mechanical embolus retrieval device (MERD) for the treatment of acute ischemic stroke (AIS) is presented. In this research, the finite element analysis (FEA) methodology is used to evaluate mechanical performance and provide suggestions for optimizing the geometric design. A MERD fabricated from nickel-titanium alloy (Nitinol) tubing is simulated and analyzed under complex in vivo loading conditions involving shape-setting, crimping, deployment, and embolus retrieval. As a result, the peak strain of the shape-setting procedure is proved to be safe for the device pattern. However, the MERD shows poor mechanical behavior after crimping into a catheter, because the peak crimping strain obtains a value of 12.1%. The delivery and deployment step demonstrates that the artery wall has little risk of serious injuries or rupture. In addition, the process of simulation of embolus retrieval and device system migration inside the cerebral artery lumen provides useful information during the design process.

e-ASPECTS Correlates with and Is Predictive of Outcome after Mechanical Thrombectomy

BACKGROUND AND PURPOSE

The e-ASPECTS software is a tool for the automated use of ASPECTS. Our aim was to analyze whether baseline e-ASPECT scores correlate with outcome after mechanical thrombectomy.

MATERIALS AND METHODS

Patients with ischemic strokes in the anterior circulation who were admitted between 2010 and 2015, diagnosed by CT, and received mechanical thrombectomy were included. The ASPECTS on baseline CT was scored by e-ASPECTS and 3 expert raters, and interclass correlation coefficients were calculated. The e-ASPECTS was correlated with functional outcome (modified Rankin Scale) at 3 months by using the Spearman rank correlation coefficient. Unfavorable outcome was defined as mRS 4-6 at 3 months, and a poor scan was defined as e-ASPECTS 0-5.

RESULTS

Two hundred twenty patients were included, and 147 (67%) were treated with bridging protocols. The median e-ASPECTS was 9 (interquartile range, 8-10). Intraclass correlation coefficients between e-ASPECTS and raters were 0.72, 0.74, and 0.76 (all, P < .001). e-ASPECTS (Spearman rank correlation coefficient = -0.15, P = .027) correlated with mRS at 3 months. Patients with unfavorable outcome had lower e-ASPECTS (median, 8; interquartile range, 7-10 versus median, 9; interquartile range, 8-10; P = .014). Sixteen patients (7.4%) had a poor scan, which was associated with unfavorable outcome (OR, 13.6; 95% CI, 1.8-104). Independent predictors of unfavorable outcome were e-ASPECTS (OR, 0.79; 95% CI, 0.63-0.99), blood sugar (OR, 1.01; 95% CI, 1.004-1.02), atrial fibrillation (OR, 2.64; 95% CI, 1.22-5.69), premorbid mRS (OR, 1.77; 95% CI, 1.21-2.58), NIHSS (OR, 1.11; 95% CI, 1.04-1.19), general anesthesia (OR, 0.24; 95% CI, 0.07-0.84), failed recanalization (OR, 8.47; 95% CI, 3.5-20.2), and symptomatic intracerebral hemorrhage (OR, 25.8; 95% CI, 2.5-268).

CONCLUSIONS

The e-ASPECTS correlated with mRS at 3 months and was predictive of unfavorable outcome after mechanical thrombectomy, but further studies in patients with poor scan are needed.

Admission Glucose and Effect of Intra-Arterial Treatment in Patients With Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Hyperglycemia on admission is common after ischemic stroke. It is associated with unfavorable outcome after treatment with intravenous thrombolysis and after intra-arterial treatment. Whether hyperglycemia influences the effect of reperfusion treatment is unknown. We assessed whether increased admission serum glucose modifies the effect of intra-arterial treatment in patients with acute ischemic stroke.

METHODS

We used data from the MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands). Hyperglycemia was defined as admission serum glucose >7.8 mmol/L. The primary outcome measure was the adjusted common odds ratio for a shift in the direction of a better outcome on the modified Rankin Scale at 90 days, estimated with ordinal logistic regression. Secondary outcome variable was symptomatic intracranial hemorrhage. We assessed treatment effect modification of hyperglycemia and admission serum glucose levels with multiplicative interaction factors and adjusted for prognostic variables.

RESULTS

Four hundred eighty-seven patients were included. Mean admission serum glucose was 7.2 mmol/L (SD, 2.2). Fifty-seven of 226 patients (25%) randomized to intra-arterial treatment were hyperglycemic compared with 61 of 261 patients (23%) in the control group. The interaction of either hyperglycemia or admission serum glucose levels and treatment effect on modified Rankin Scale scores was not significant (P=0.67 and P=0.87, respectively). The same applied for occurrence of symptomatic hemorrhage (P=0.39 for hyperglycemia, P=0.39 for admission serum glucose).

CONCLUSIONS

We found no evidence for effect modification of intra-arterial treatment by admission serum glucose in patients with acute ischemic stroke.

CLINICAL TRIAL REGISTRATION

URL: www.isrctn.com. Unique identifier: ISRCTN10888758.

Efficacy of Balloon-Guiding Catheter for Mechanical Thrombectomy in Patients with Anterior Circulation Ischemic Stroke

Objective

To evaluate the efficacy of balloon guiding catheter (BGC) during thrombectomy in anterior circulation ischemic stroke.

Methods

Sixty-two patients with acute anterior circulation ischemic stroke were treated with thrombectomy using a Solitaire stent from 2011 to 2016. Patients were divided into the BGC group (n=24, 39%) and the non-BGC group (n=38, 61%). The number of retrievals, procedure time, thrombolysis in cerebral infarction (TICI) grade, presence of distal emboli, and clinical outcomes at 3 months were evaluated.

Results

Successful recanalization was more frequent in BGC than in non-BGC (83% vs. 66%, p=0.13). Distal emboli occurred less in BGC than in non-BGC (23.1% vs. 57.1%, p=0.02). Good clinical outcome was more frequent in BGC than in non-BGC (50% vs. 16%, p=0.03). The multivariate analysis showed that use of BGC was the only independent predictor of good clinical outcome (odds ratio, 5.19: 95% confidence interval, 1.07–25.11). More patients in BGC were successfully recanalized in internal carotid artery (ICA) occlusion with small retrieval numbers (<3) than those in non-BGC (70% vs. 24%, p=0.005). In successfully recanalized ICA occlusion, distal emboli did not occur in BGC, whereas nine patients had distal emboli in non-BGC (0% vs. 75%, p=0.001) and good clinical outcome was superior in BGC than in non-BGC (55.6% vs. 8.3%, p=0.01).

Conclusion

A BGC significantly reduces the number of retrievals and the occurrence of distal emboli, thereby resulting in better clinical outcomes in patients with anterior circulation ischemic stroke, particularly with ICA occlusion.