Predictors of malignant middle cerebral artery infarction after mechanical thrombectomy

Neuroimaging predictors of malignant brain oedema after thrombectomy in ischemic stroke: a systematic review and meta-analysis

BACKGROUND

We systematically reviewed neuroimaging predictors for malignant brain oedema (MBE) after thrombectomy in patients with ischemic stroke.

METHODS

We searched MEDLINE and EMBASE in November 2023 for studies of patients with ischemic stroke. We included studies investigating neuroimaging predictors or prediction models for MBE after thrombectomy. We estimated effect size for the association between predictors and MBE by odds ratios (ORs) or standardized mean differences (SMDs), and pooled results using random-effects modelling.

RESULTS

We included 19 studies (n = 6007) with 17 neuroimaging factors and 5 models. Lower Alberta Stroke Program Early CT scores (ASPECTS, n = 3052, SMD -1.84, 95% CI -2.52 - -1.16; df = 9) and longer extent of arterial occlusion at baseline were associated with higher risk of MBE. Post-thrombectomy ASPECTS was associated with MBE in general stroke patients (n = 453, SMD -2.91, -4.02 - -1.79; df = 1), but not in successfully reperfused patients (n = 110, SMD 0.24, -0.16 - 0.65). Successful reperfusion reduced risk of MBE (n = 4851, OR 0.39, 0.30-0.51; df = 13). Contrast enhancement on CT after thrombectomy was associated with higher risk of MBE (n = 998, OR 4.82, 2.53-9.20; df = 4). More reserved brain volume capacity (baseline: n = 683, OR 0.83, 0.77-0.91, p < .001; post-thrombectomy: n = 329, OR 0.53, 0.37-0.77, p < .001) and good collaterals (baseline: n = 2301, OR 0.14, 0.10-0.20, df = 3; post-thrombectomy: n = 1006, OR 0.28, 0.15-0.51; df = 2) were associated with lower risk of MBE.

CONCLUSION

Lower ASPECTS and longer arterial occlusion at baseline, and post-thrombectomy CT contrast enhancement increased risk of MBE. Reperfusion after thrombectomy, more reserved brain volume and good collaterals at baseline and post-thrombectomy reduced its risk.

Hyponatremia is associated with malignant brain edema after mechanical thrombectomy in acute ischemic stroke

BACKGROUND

Hyponatremia (< 135 mmol/L) is the most common electrolyte disturbance in patients with stroke. However, few studies have reported the relationship between hyponatremia at admission and outcomes in patients with acute ischemic stroke (AIS) treated with mechanical thrombectomy (MT). This study is aimed to explore the association between hyponatremia and clinical outcomes following MT.

METHODS

A retrospective study was conducted at our center. The primary outcome was postoperative malignant brain edema (MBE). The secondary outcomes included mortality and adverse function at the 90-day follow-up, which were defined as modified Rankin scale scores of 6 and > 2, respectively. Patients were classified into hyponatremia and nonhyponatremia groups based on their serum sodium concentration at admission before drug use. The occurrence of MBE was evaluated via computed tomography after MT, and 90-day outcomes were obtained through in-person interviews at the clinic or via telephone. Multivariate analysis was performed to investigate the associations among postoperative MBE, 90-day mortality, adverse function and hyponatremia.

RESULTS

A total of 342 patients were enrolled into the study, of whom 52 (15.2%) had hyponatremia, 86 (25.1%) developed postoperative MBE, 93 (27.2%) died within 90 days after MT, and 201 (58.8%) had adverse functions at the 90-day follow-up. Multivariate analysis revealed that hyponatremia was significantly associated with postoperative MBE (odds ratio [OR] 3.91, 95% confidence interval [CI] 1.66 - 9.23, p = 0.002), 90-day mortality (OR 5.49, 95% CI 2.48 - 12.14, p < 0.001), and 90-day adverse function (OR 3.25, 95% CI 1.29 - 8.12, p = 0.012). In addition, mediation analysis revealed that postoperative MBE may partially account for the 90-day mortality/adverse function of patients with hyponatremia (regression coefficients changed by 18.6% and 23.9%, respectively).

CONCLUSION

Hyponatremia is an independent predictor of postoperative MBE, 90-day mortality, and adverse function. Correction of hyponatremia may reduce the postoperative MBE to improve the prognosis of patients.

Malignant Brain Edema and Associated Factors in Large Hemispheric Infarction Following Reperfusion Therapy

OBJECTIVE

This study aimed to explore Malignant Brain Edema (MBE) and associated factors in patients with Large Hemispheric Infarction (LHI) following early reperfusion therapy.

METHODS

We consecutively and retrospectively enrolled a cohort of 114 LHI patients who had received early reperfusion therapy, including Intravenous Thrombolysis (IVT) or Endovascular Therapy (EVT) at the hyperacute stage of stroke between January 2009 and December 2018. MBE was defined as a midline shift ≥5 mm, accompanied by signs of herniation. Multivariate logistic analyses were conducted to identify independent factors associated with MBE in LHI patients following early reperfusion therapy.

RESULTS

Among the enrolled patients, 69 (60.53%) were treated with IVT alone and 45 (39.47%) with EVT. Successful recanalization was achieved in 56 (49.12%) patients, while complete recanalization was achieved in 38 (33.33%) patients. After early reperfusion therapy, 50 (43.86%) developed MBE in LHI patients. The MBE group showed higher rates of in-hospital death (54% vs. 4.69%), 3-month mortality (64% vs. 10.94%), and 3-month unfavorable outcomes (90% vs. 64.06%) (all p<0.01). Neither different reperfusion therapy (EVT vs. IVT alone) nor different recanalization status (complete recanalization or not) was independently associated with the development of MBE in LHI patients following reperfusion therapy in multivariate analyses. MBE was independently associated with age [Odds Ratio (OR) 0.953, 95% confidence interval (CI) 0.910-0.999, p =0.044], right hemisphere stroke (OR 4.051, 95% CI 1.035-15.860, p =0.045), previous ischemic stroke or TIA (OR 0.090, 95% CI 0.014-0.571, p =0.011), and hypodensity >1/3 MCA territory (OR 8.071, 95% CI 1.878-34.693, p =0.005). Meanwhile, patients with lower baseline Alberta Stroke Program Early CT Score (ASPECTS) had a trend of higher incidence of MBE following reperfusion therapy (OR 0.710, 95% CI 0.483-1.043, p =0.081).

CONCLUSION

MBE occurred in nearly one-half of LHI patients following early reperfusion therapy and was related to poor outcomes. An increased risk of MBE was found to be associated with younger age, right hemisphere stroke, absence of a history of ischemic stroke or TIA, and hypodensity >1/3 MCA region on baseline CT images.

A CT-based machine learning model for using clinical-radiomics to predict malignant cerebral edema after stroke: a two-center study

Purpose

This research aimed to create a machine learning model for clinical-radiomics that utilizes unenhanced computed tomography images to assess the likelihood of malignant cerebral edema (MCE) in individuals suffering from acute ischemic stroke (AIS).

Methods

The research included 179 consecutive patients with AIS from two different hospitals. These patients were randomly assigned to training (n = 143) and validation (n = 36) sets with an 8:2 ratio. Using 3DSlicer software, the radiomics features of regions impacted by infarction were derived from unenhanced CT scans. The radiomics features linked to MCE were pinpointed through a consistency test, Student's t test and the least absolute shrinkage and selection operator (LASSO) method for selecting features. Clinical parameters associated with MCE were also identified. Subsequently, machine learning models were constructed based on clinical, radiomics, and clinical-radiomics. Ultimately, the efficacy of these models was evaluated by measuring the operating characteristics of the subjects through their area under the curve (AUCs).

Results

Logistic regression (LR) was found to be the most effective machine learning algorithm, for forecasting the MCE. In the training and validation cohorts, the AUCs of clinical model were 0.836 and 0.773, respectively, for differentiating MCE patients; the AUCs of radiomics model were 0.849 and 0.818, respectively; the AUCs of clinical and radiomics model were 0.912 and 0.916, respectively.

Conclusion

This model can assist in predicting MCE after acute ischemic stroke and can provide guidance for clinical treatment and prognostic assessment.

Proper Indication of Decompressive Craniectomy for the Patients with Massive Brain Edema after Intra-arterial Thrombectomy

OBJECTIVE

Numerous studies have indicated that early decompressive craniectomy (DC) for patients with major infarction can be life-saving and enhance neurological outcomes. However, most of these studies were conducted by neurologists before the advent of intra-arterial thrombectomy (IA-Tx). This study aims to determine whether neurological status significantly impacts the final clinical outcome of patients who underwent DC following IA-Tx in major infarction.

METHODS

This analysis included 67 patients with major anterior circulation major infarction who underwent DC after IA-Tx, with or without intravenous tissue plasminogen activator. We retrospectively reviewed the medical records, radiological findings, and compared the neurological outcomes based on the "surgical time window" and neurological status at the time of surgery.

RESULTS

For patients treated with DC following IA-Tx, a Glasgow coma scale (GCS) score of 7 was the lowest score correlated with a favorable outcome (p=0.013). Favorable outcomes were significantly associated with successful recanalization after IA-Tx (p=0.001) and perfusion/diffusion (P/D)-mismatch evident on magnetic resonance imaging performed immediately prior to IA-Tx (p=0.007). However, the surgical time window (within 36 hours, p=0.389; within 48 hours, p=0.283) did not correlate with neurological outcomes.

CONCLUSION

To date, early DC surgery after major infarction is crucial for patient outcomes. However, this study suggests that the indication for DC following IA-Tx should include neurological status (GCS ≤7), as some patients treated with early DC without considering the neurological status may undergo unnecessary surgery. Recanalization of the occluded vessel and P/D-mismatch are important for long-term neurological outcomes.

The effect of butylphthalide on improving the neurological function of patients with acute anterior circulation cerebral infarction after mechanical thrombectomy

Butylphthalide can improve blood circulation in patients with acute cerebral infarction. Complement 3a receptor 1 (C3aR1) is involved in the regulation of innate immune response and pathogen monitoring, which is closely related to the pathophysiological processes of breast cancer, neurogenesis and lipid catabolism. Our study explored the therapeutic effect of butylphthalide on improving the neurological function of patients with acute anterior circulation cerebral infarction after mechanical thrombectomy, and evaluated the correlation between serum C3aR1 and butylphthalide on improving the neurological function after mechanical thrombectomy. 288 patients with acute anterior circulation cerebral infarction who were admitted to our hospital from January 2019 to November 2022 and were treated with mechanical thrombectomy for the first time were included in this retrospective study and divided into the butylphthalide group and control group that they received treatment methods. The National Institutes of Health Stroke Scale (NIHSS) scale was used to evaluate the patient neurological function treatment efficacy, and the modified Rankin Scale (mRS) scale was used to measure the patient neurological function status 3 months after surgery. Enzyme-linked immunosorbent assay method was used to determine the content of C3aR1 in serum. Two weeks after thrombus removal, the NIHSS efficacy of the butylphthalide group and the control group were 94.44% and 72.22%, respectively. The butylphthalide group was significantly higher than the control group (P < .001). Three months after the operation, the mRS score of the butylphthalide group was significantly lower than that of the control group (P = .001), and the excellent and good rate was significantly higher than that of the control group (P < .001). The serum C3aR1 level of the butylphthalide group was significantly lower than that of the control group 2 weeks after operation and 3 months after operation (P < .001). The serum C3aR1 was positively correlated with the efficacy of NIHSS (R = 0.815, P = .004), which was positively correlated with mRS score (R = 0.774, P = .007). Butylphthalide can improve the therapeutic effect of neurological function in patients with acute anterior circulation cerebral infarction after mechanical thrombus removal. The patient serum C3aR1 is related to the patient neurotherapy efficacy and neurological function status, and its level can reflect the patient neurological function recovery to a certain extent.

Machine learning prediction of malignant middle cerebral artery infarction after mechanical thrombectomy for anterior circulation large vessel occlusion

OBJECTIVE

Prediction of malignant middle cerebral artery infarction (MMI) could identify patients for early intervention. We trained and internally validated a ML model that predicts MMI following mechanical thrombectomy (MT) for ACLVO.

METHODS

All patients who underwent MT for ACLVO between 2015 - 2021 at a single institution were reviewed. Data was divided into 80% training and 20% test sets. 10 models were evaluated on the training set. The top 3 models underwent hyperparameter tuning using grid search with nested 5-fold CV to optimize the area under the receiver operating curve (AUROC). Tuned models were evaluated on the test set and compared to logistic regression.

RESULTS

A total of 381 patients met the inclusion criteria. There were 50 (13.1%) patients who developed MMI. Out of the 10 ML models screened on the training set, the top 3 performing were neural network (median AUROC 0.78, IQR 0.72 - 0.83), support vector machine ([SVM] median AUROC 0.77, IQR 0.72 - 0.83), and random forest (median AUROC 0.75, IQR 0.68 - 0.81). On the test set, random forest (median AUROC 0.78, IQR 0.73 - 0.83) and neural network (median AUROC 0.78, IQR 0.73 - 0.83) were the top performing models, followed by SVM (median AUROC 0.77, IQR 0.70 - 0.83). These scores were significantly better than those for logistic regression (AUROC 0.72, IQR 0.66 - 0.78), individual risk factors, and the Malignant Brain Edema score (p < 0.001 for all).

CONCLUSION

ML models predicted MMI with good discriminative ability. They outperformed standard statistical techniques and individual risk factors.

Malignant Middle Cerebral Artery Infarction during Early versus Late Endovascular Treatment in Acute Ischemic Stroke

INTRODUCTION

Endovascular treatment (EVT) performed in the early time window has been shown to decrease the incidence of malignant middle cerebral artery infarction (MMI). However, the incidence of MMI in patients undergoing EVT during the late time window is unclear. This study aimed to investigate the prevalence of MMI in patients undergoing late EVT and compare it with that in patients undergoing early EVT.

METHODS

We retrospectively analyzed consecutive patients with anterior large vessel occlusion stroke who underwent EVT at Xuanwu Hospital between January 2013 and June 2021. Eligible patients were divided into early EVT (within 6 h) and late EVT (6-24 h) groups according to the time from their stroke onset to puncture and compared. The occurrence of MMI post-EVT was the primary outcome.

RESULTS

A total of 605 patients were recruited, of whom 300 (50.4%) underwent EVT within 6 h and 305 (49.6%) underwent EVT within 6-24 h. A total of 119 patients (19.7%) developed MMI. 68 patients (22.7%) in the early EVT group and 51 patients (16.7 %) in the late EVT group developed MMI (p = 0.066). After adjusting for covariate variables, late EVT was independently associated with a lower incidence of MMI (odds ratio, 0.404; 95% confidence interval, 0.242-0.675; p = 0.001).

CONCLUSION

MMI is not an uncommon phenomenon in the modern thrombectomy era. Compared with the early time window, patients selected by stricter radiological criteria to undergo EVT in the late time window are independently associated with a lower incidence of MMI.

A nomogram for predicting malignant cerebral artery infarction in the modern thrombectomy era

Objective

This study aimed to develop and validate a nomogram to predict malignant cerebral artery infarction (MMI) after endovascular treatment (EVT) in patients with acute ischemic stroke (AIS) in the modern thrombectomy era.

Methods

We retrospectively analyzed data from a prospective cohort of consecutive patients with AIS who underwent EVT at Xuanwu hospital between January 2013 and June 2021. A multivariable logistic regression model was employed to construct the nomogram for predicting MMI after EVT. The discrimination and calibration of the nomogram were assessed both in the derivation and validation cohorts.

Results

A total of 605 patients were enrolled in this study, with 425 in the derivation cohort and 180 in the validation cohort. The nomogram was developed based on admission systolic blood pressure (SBP), the National Institute of Health Stroke Score (NIHSS), the Alberta Stroke Program Early Computed Tomography Score (ASPECTS), vessel occlusion site, EVT time window, and recanalization status. The nomogram displayed good discrimination with the area under the receiver operating characteristics (ROCs) curve (AUC) of 0.783 [95% confidence interval (CI), 0.726–0.840] in the derivation cohort and 0.806 (95% CI, 0.738–0.874) in the validation cohort. The calibration of the nomogram was good as well, with the Hosmer–Lemeshow test of p = 0.857 in the derivation cohort and p = 0.275 in the validation cohort.

Conclusion

In the modern thrombectomy era, a nomogram containing admission SBP, NIHSS, ASPECTS, vessel occlusion site, EVT time window, and recanalization status may predict the risk of MMI after EVT in patients with AIS.

Intravenous Thrombolysis Combined with Arterial Thrombolysis (Bridging Therapy) Effectively Improves Vascular Recanalization Rate in Patients with Cerebral Infarction

Objective

To explore the efficacy of intravenous thrombolysis combined with arterial thrombolysis (bridging therapy) in patients with acute cerebral infarction and its effect on serum inflammatory factors.

Methods

The case data of 138 patients with acute cerebral infarction admitted to our hospital from February 2019 to February 2021 were retrospectively analyzed. According to the treatment plan they received, patients were assigned to two groups, namely, an observation group (n = 71) treated with bridging therapy and a control group (n = 67) treated with intravenous thrombolysis alone. The following indexes were recorded and compared between the two groups: treatment efficacy, National Institutes of Health Stroke Scale (NIHSS) score, activities of daily living, incidence rates of vascular recanalization, intracranial hemorrhage and reembolization after treatment, levels of inflammatory factors before and after treatment, levels of prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen (FIB) before and 1 week after treatment, and modified Rankin Scale scores 1, 3, and 6 months after treatment.

Results

Compared with the control group, the therapeutic efficacy, neurological function, activities of daily living, and vascular recanalization were markedly better in the observation group (P > 0.05). In addition, the incidence of intracranial hemorrhage and reembolization was statistically lower in the observation group (P < 0.05). No marked difference was found between the two groups in terms of pretreatment serum inflammatory factors and coagulation function (P > 0.05), while the above indicators improved statistically after treatment in both groups, with comparatively more obvious improvement in the observation group. It was also observed that, compared with the control group, the modified Rankin Scale score in the observation group was significantly better at 3 and 6 months after treatment (P < 0.05).

Conclusion

Bridging therapy can improve the vascular recanalization rate among patients suffering from acute cerebral infarction, reduce the incidence of intracranial hemorrhage and reembolization, and improve the prognosis and neurological function of patients, which is worthy of clinical application.

Predictors of malignant middle cerebral artery infarction after endovascular thrombectomy: results of DIRECT-MT trial

OBJECTIVES

Predictors of malignant middle cerebral artery infarction (mMCAi) in patients after intravenous thrombolysis were well documented, but the risk factors of mMCAi after endovascular thrombectomy (EVT) were not fully explored. Therefore, the present study aimed to investigate the predictors of mMCAi after EVT in stroke patients.

METHODS

This was a secondary analysis of the DIRECT-MT trial. Patients who underwent EVT for the occlusions of MCA and/or intracranial internal carotid artery were analyzed. Primary outcome was the occurrence of mMCAi after EVT. Demographic, clinical, imaging, and treatment data were recorded, and multivariate logistic regression analysis was used to identify independent predictors. All of the candidate predictors were included, and forward elimination was applied to establish the most effective predictive model. Predictive ability and calibration of the model were assessed using the area under the receiver operating characteristic curve (AUC) and Hosmer-Lemeshow test, respectively.

RESULTS

Of 559 enrolled patients, 74 (13.2%) patients developed mMCAi. Predictors of mMCAi included unsuccessful reperfusion, higher serum glucose, lower Alberta Stroke Project Early Computed Tomography Change Score (ASPECTS), higher clot burden score (CBS), lower collateral score, and higher pass number of thrombectomy device. AUC of predictive model integrating all independent variables was 0.836. The Hosmer-Lemeshow test showed appropriate calibration (p = 0.859).

CONCLUSIONS

Reperfusion, serum glucose, ASPECTS, CBS, collateral, and pass number of thrombectomy device were associated with the occurrence of mMCAi in stroke patients after EVT, while alteplase treatment was not. Our findings might facilitate the early identification and management of stroke patients at a high risk of mMCAi.

KEY POINTS

• A total of 13.2% of stroke patients with large vessel occlusion of anterior circulation developed mMCAi after EVT. • The occurrence of mMCAi had a definite negative impact on the outcome for stroke patients. • Reperfusion, serum glucose, ASPECTS, CBS, collateral score, and the pass number of thrombectomy device were associated with the occurrence of mMCAi after EVT in stroke patients.

Abnormal neurological pupil index is associated with malignant cerebral edema after mechanical thrombectomy in large vessel occlusion patients

BACKGROUND AND OBJECTIVES

Malignant cerebral edema (MCE) is a feared complication in patients suffering from large vessel occlusion. Variables associated with the development of MCE have not been clearly elucidated. Use of pupillometry and the neurological pupil index (NPi) as an objective measure in patients undergoing mechanical thrombectomy (MT) has not been explored. We aim to evaluate variables significantly associated with MCE in patients that undergo MT and hypothesize that abnormal NPi is associated with MCE in this population.

METHODS

A retrospective analysis of patients with acute ischemic stroke who had undergone MT at our institution between 2017 and 2020 was performed. Baseline and outcome variables were collected, including NPi values from pupillometry readings of patients within 72 h after the MT. Patients were divided into two groups: MCE versus non-MCE group. A univariate and multivariate analysis was performed.

RESULTS

Of 284 acute ischemic stroke patients, 64 (22.5%) developed MCE. Mean admission glucose (137 vs. 173; p < 0.0001), NIHSS on admission (17 vs. 24; p < 0.01), infarct core volume (27.9 vs. 17.9 mL; p = 0.0036), TICI score (p = 0.001), and number of passes (2.9 vs. 1.8; p < 0.0001) were significantly different between the groups. Pupillometry data was present for 64 patients (22.5%). Upon multivariate analysis, abnormal ipsilateral NPi (OR 21.80 95% CI 3.32-286.4; p = 0.007) and hemorrhagic conversion were independently associated with MCE.

CONCLUSION

Abnormal NPi and hemorrhagic conversion are significantly associated with MCE in patients following MT. Further investigation is warranted to better define an association between NPi and patient outcomes in this patient population.