Predicting Endovascular Treatment Outcomes in Acute Vertebrobasilar Artery Occlusion: A Model to Aid Patient Selection from the ASIAN KR Registry

Nomogram model of functional outcome for endovascular treatment in patients with acute basilar artery occlusion

Background and purpose

The efficacy and safety of endovascular treatment (EVT) in acute basilar artery occlusion (ABAO) has been confirmed by four randomized clinical trials. Nevertheless, the predictors of a 90-day favorable outcome after EVT have not been elucidated. We attempted to establish a nomogram for the prediction of a 90-day favorable outcome in ABAO patients with EVT.

Methods

Clinical data of ABAO patients with EVT were obtained from two nationwide clinical trial registries in China. Factors associated with a 90-day favorable outcome were screened by multivariable step-wise regression on the basis of univariable analysis. A nomogram was established to predict 90-day favorable outcome after EVT.

Results

The proportion of ABAO patients with a favorable outcome was 41.53% (157/378). Seven variables, including baseline National Institutes of Health Stroke Scale (NIHSS) <20 [odds ratio (OR): 8.330; P-value < 0.0001], posterior circulation Alberta Stroke Program Early CT (pc-ASPECT) score ≥7 (OR: 1.948; P-value = 0.0296), Pons-Midbrain Index (PMI) score < 2 (OR: 2.108; P-value = 0.0128), Posterior Circulation Collateral Score (PC-CS) ≥5 (OR: 3.288; P-value < 0.0001), local anesthesia (OR: 0.389; P-value = 0.0017), time from onset to recanalization (OTR) <330 min (OR: 2.594; P-value = 0.0013), and no occurrence of early neurological deterioration (END; OR: 0.039; P-value < 0.0001) were included into the nomogram, with C-index values of 0.8730 and 0.8857 in the training and the internal validation set, respectively.

Conclusions

The proposed nomogram provided a reliable prognostic scale, which can be employed in clinical settings for the selection and clinical management of ABAO patients.

Registration

https://www.clinicaltrials.gov, identifier: NCT03370939.

Incidence and predictors of futile recanalisation after endovascular therapy in acute vertebrobasilar artery occlusion patients: insight from the ANGEL-ACT registry

OBJECTIVES

To identify the occurrence rate and predictors of futile recanalisation after endovascular therapy (EVT) for acute vertebrobasilar artery occlusion (VBAO).

METHODS

Participants of the Endovascular Treatment Key Technique and Emergency Workflow Improvement of Acute Ischaemic Stroke (ANGEL-ACT) registry were selected for the analysis. Futile recanalisation was defined as patients did not achieve a 90-day good outcome (modified Rankin Scale ≤3) despite successful recanalisation (modified Treatment in Cerebral Ischaemia Scale ≥2b) after the procedure. Multivariable logistic regression analysis was conducted to find independent predictors of futile recanalisation in VBAO patients undergoing EVT.

RESULTS

Three hundred and fifteen patients with VBAO who achieved successful recanalisation after EVT were included in current analysis, of whom, 155 (49.2%) suffered futile recanalisation, and 160 achieved effective recanalisation. After the multivariable analysis, we found admission National Institutes of Health Stroke Scale (NIHSS) ≥19 (OR 4.81, 95% CI 2.76 to 8.39, p<0.001), platelet-lymphocyte ratio (PLR) ≥162.2 (OR 1.93, 95% CI 1.14 to 3.27, p=0.001), onset-to-puncture time (OTP) ≥334 min (OR 2.15, 95% CI 1.25 to 3.68, p=0.005) and use of general anesthesia (GA) (OR 1.87, 95% CI 1.09 to 3.22, p=0.024) were associated with futile recanalisation.

CONCLUSIONS

Futile recanalisation after EVT occurred 49.2% of VBAO patients in the ANGEL-ACT registry. NIHSS≥19, PLR≥162.2, OTP≥334 min and use of GA were independent predictors of futile recanalisation.

Good collaterals and better outcomes after EVT for basilar artery occlusion: A systematic review and meta-analysis

BACKGROUND

Stroke caused by acute basilar artery occlusion (BAO) is devastating with high dependency and mortality. Recent trials have demonstrated the efficacy of endovascular treatment (EVT) for acute BAO, while pretreatment collaterals may be a valuable prognostic indicator for post-EVT outcomes.

AIMS

To systematically review and synthesize evidence on the associations between pretreatment collateral status and outcomes after EVT in acute BAO.

METHODS

We retrieved relevant full-text articles published in English since 1 January 2010, reporting associations between pretreatment collateral status and outcomes after EVT for BAO, by searching MEDLINE and Embase. The primary outcome was favorable or good 90-day functional outcome (modified Rankin Scale [mRS] 0-2 or 0-3); secondary outcomes included successful recanalization, symptomatic intracranial hemorrhage, final infarct volume, and 90-day mortality. Risk ratios (RRs) with 95% confidence intervals (CIs) for good versus poor collaterals on the outcomes were synthesized using random-effects models. Subgroup and sensitivity analyses were conducted for the primary outcome.

RESULTS

Overall, 29 primary studies (2995 participants) were included in qualitative review, among which 16 studies (1447 participants) were meta-analyzed. With different imaging modalities and methods to grade the collateral status, good collaterals were found in 33-85% of patients in the individual primary studies (I2 = 95.2%, p < 0.001), with a pooled proportion of 51% (95% CI: 40-62%) across all studies. Good pretreatment collaterals were associated with a doubled rate of favorable/good 90-day functional outcome (RR = 2.03, 95% CI: 1.63-2.51, p < 0.001), a higher rate of successful recanalization (RR = 1.23, 95% CI: 1.04-1.45, p = 0.015), and reduced 90-day mortality (RR = 0.59, 95% CI: 0.43-0.81, p = 0.001) after EVT for BAO. None of the primary studies reported the associations of good collaterals with the other secondary outcomes. Subgroup analyses revealed possibly more prominent protective effect of good pretreatment collaterals over the primary outcome, in studies with longer time windows in patient eligibility criteria for EVT (p = 0.028 for between-subgroup heterogeneity).

CONCLUSIONS

In patients with BAO receiving EVT, good pretreatment collateral status was associated with a higher chance of favorable 90-day functional outcome, despite the various methods in grading the collateral circulation. Efforts are needed for more standardized collateral assessment in BAO, for more reliable and generalizable investigations of its clinical implications.

Branch-site occlusion sign predicts the embolic origin of acute ischemic stroke: a meta-analysis

Objective

The study aimed to investigate whether branch-site occlusion (BSO) sign could predict the etiology of acute intracranial large artery occlusion (ILVO) and the stentriever (SR) response.

Methods

We systematically reviewed studies that evaluated the predictive role of BSO for the etiology of ILVO-AIS or EVT outcome between 1 January 2000 and 31 August 2022 from PubMed, Embase, and Web of Science.

Results

The sensitivity and specificity of BSO sign predicting etiology of ILVO-AIS were 0.87 (95% CI 0.81-0.91) and 0.64 (95% CI 0.33-0.87), respectively. The sensitivity and specificity of BSO sign predicting stentriever response were 0.84 (95% CI 0.63-0.94) and 0.61 (95% CI 0.18-0.92), respectively.

Conclusion

The BSO sign could be a valid and precise imaging marker to predict embolism caused ILVO-AIS and recanalization success by SR without rescue therapy.

What Is the Evidence for Endovascular Thrombectomy in Posterior Circulation Stroke?

Posterior circulation infarcts comprise approximately 25% of ischemic strokes but are less often treated with recanalization therapy and have longer treatment delays compared with anterior circulation strokes. Among posterior circulation strokes, basilar artery occlusion is associated with the most severe deficits and the worst prognosis. Endovascular thrombectomy is a standard of care for patients with anterior circulation large vessel occlusion, but not until recently were the first randomized controlled trials on endovascular thrombectomy in basilar artery occlusion published. Two of the trials were neutral, whereas two others showed better functional outcome after thrombectomy up to 24 hours of symptom onset compared with best medical treatment, which in most cases had low rates of intravenous thrombolysis. According to observational data, thrombectomy seems to be safe also in isolated posterior cerebral artery occlusions and might be an option for selected patients, even if its outcome benefit is yet to be demonstrated.

Is improved access to magnetic resonance imaging imperative for optimal ischemic stroke care?

Neuroimaging, including CT and MRI, is integral to ischemic stroke (IS) treatment, management, and prevention. However, the use of MRI for IS patients is limited despite its potential to provide high-quality images that yield definitive information related to the management of IS. MRI is beneficial when the information provided by CT is insufficient for decisions related to the diagnosis, etiology, or treatment of IS. In the emergency setting, MRI can improve the diagnostic accuracy of CT-negative acute ischemic strokes (AIS) and ensure a better selection of patients for reperfusion therapies with thrombolysis and/or thrombectomy. Moreover, MR imaging may help avoid hospital admissions for patients with stroke mimics, facilitate earlier discharge, and reduce overall hospital costs. MRI in the in-patient setting can help determine stroke etiology to aid in stroke prevention management upon discharge. Furthermore, early access to MRI in IS out-patients can aid in diagnosing, risk stratifying, and determining optimal management strategies for patients with a TIA or a minor stroke. Recent technological advances, particularly low-to-mid-field MR scanners, can improve access to MRI. These MR scanners provide faster protocols, cost-effectiveness, smaller footprints, safety, and lower power requirements. In conclusion, MRI use for IS treatment, management, and prevention is imperative and justifiable, and the latest technological advancements in MR scanners hold the potential to enhance access.

Collateral Status and Outcomes after Thrombectomy

Endovascular treatment (EVT) using novel mechanical thrombectomy devices has been the gold standard for patients with acute ischemic stroke caused by large vessel occlusion. Selection criteria of randomized control trials commonly include baseline infarct volume with or without penumbra evaluation. Although the collateral status has been studied and is known to modify imaging results and clinical course, it has not been commonly used for trials. Many post hoc studies, however, revealed that collateral status can help predict infarct growth, recanalization success, decreased hemorrhagic transformation after EVT, and extension of the therapeutic time window for revascularization. Here, we systematically review the recent literature and summarized the outcomes of EVT according to the collateral status of patients with acute ischemic stroke caused by large vessel occlusion. The studies reviewed indicate that pretreatment collateral circulation is associated with both clinical and imaging outcomes after EVT in patients with acute ischemic stroke due to large vessel occlusion although most patients were already selected by other imaging or clinical criteria. However, treatment decisions using information on patients' collateral status have not progressed in clinical practice. Further randomized trials are needed to evaluate the risks and benefits of EVT in consideration of collateral status.

Endovascular treatment for acute basilar artery occlusion due to different stroke etiologies of large artery atherosclerosis and cardioembolism

Introduction

Stroke etiology may affect the prognosis of acute basilar artery occlusion (BAO). This study aimed to estimate the efficacy and safety of endovascular treatment (EVT) in BAO strokes due to the underlying stroke etiologies of large artery atherosclerosis (LAA) and cardioembolism (CE).

Patients and methods

Patients with LAA and CE subtypes from the registry EVT for Acute Basilar Artery Occlusion Study (BASILAR) were selected for this analysis. We estimated the EVT treatment effect relative to standard medical treatment (SMT) in these patients by using a propensity score approach with inverse probability of treatment weighted estimation. Outcomes included 90-day favorable functional outcomes (modified Rankin scale (mRS) 0-3), functional independence (mRS 0-2), all-cause mortality, and symptomatic intracranial hemorrhage (sICH).

Results

A total of 744 patients were included in the final analysis. After weighting with inverse probability of treatment estimation, the patients who, based on their characteristics, were treated with EVT rather than SMT, demonstrated higher rates of favorable functional outcomes in both the LAA (29.2% vs 11.7%, adjusted OR with 95% CI: 4.34 [2.15-8.78], p < 0.001) and the CE subtype (36.0% vs 8.1%, adjusted OR with 95% CI: 9.14 [1.96-42.55], p = 0.005). A similar finding was also observed for functional independence. EVT patients also demonstrated lower rates of mortality than SMT. Among EVT patients, no significant difference was observed in mortality or sICH between LAA and CE groups, but LAA patients had lower rates of favorable functional outcome and functional independence (29.2% vs 37% and 24.2% vs 32.9%, respectively), where the latter remained significant after adjustment for imbalances in baseline data (p = 0.04).

Conclusions

In acute BAO strokes, both LAA and CE patients who, based on their characteristics, were treated with EVT rather than SMT, demonstrated better outcomes. Among EVT patients, LAA and CE subtypes displayed important baseline and treatment differences, and LAA patients were less likely to achieve functional independence at 3 months, but mortality and sICH were similar between LAA or CE subtypes. These results need to be confirmed in future clinical trials.

Etiology-Related Outcome of Endovascular Therapy in Posterior Circulation Stroke Compared to Anterior Circulation Stroke

Background and Purpose

We investigated the impact of stroke etiology on the endovascular treatment (EVT) procedure and clinical outcome of posterior circulation stroke (PCS) patients with EVT compared to anterior circulation stroke (ACS) patients.

Methods

We retrospectively analyzed ischemic stroke patients who underwent EVT between January 2012 and December 2020. Enrolled ACS and PCS patients were compared according to etiologies (intracranial arterial steno-occlusion [ICAS-O], artery-to-artery embolic occlusion [AT-O], and cardioembolic occlusion [CA-O]). EVT procedure and favorable clinical outcomes at 3 months (modified Rankin Scale 0–2) were compared between the ACS and PCS groups for each etiology.

Results

We included 419 patients (ACS, 346; PCS, 73) including 88 ICAS-O (ACS, 67; PCS, 21), 66 AT-O (ACS, 50; PCS, 16), and 265 CA-O (ACS, 229; PCS, 36) patients in the study. The onset-to-recanalization time was longer in the PCS group than in the ACS group (median 628.0 minutes vs. 421.0 minutes, P=0.01). In CA-O patients, the door-to-puncture time was longer, whereas the puncture-to-recanalization time was shorter in the PCS group than in the ACS group. The proportions of successful recanalization and favorable clinical outcomes were similar between the ACS and PCS groups for all three etiologies. Low baseline National Institutes of Health Stroke Scale (NIHSS) scores and absence of intracerebral hemorrhage at follow-up imaging were associated with favorable clinical outcomes in both groups, whereas successful recanalization (odds ratio, 11.74; 95% confidence interval, 2.60 to 52.94; P=0.001) was only associated in the ACS group.

Conclusions

The proportions of successful recanalization and favorable clinical outcomes were similar among all three etiologies between PCS and ACS patients who underwent EVT. Initial baseline NIHSS score and absence of hemorrhagic transformation were related to favorable outcomes in the PCS and ACS groups, whereas successful recanalization was related to favorable outcomes only in the ACS group.

Endovascular Treatment for Posterior Circulation Stroke: Ways to Maximize Therapeutic Efficacy

The efficacy of endovascular treatment (EVT) in patients with posterior circulation stroke has not been proven. Two recent randomized controlled trials failed to show improved functional outcomes after EVT for posterior circulation stroke (PC-EVT). However, promising results for two additional randomized controlled trials have also been presented at a recent conference. Studies have shown that patients undergoing PC-EVT had a higher rate of futile recanalization than those undergoing EVT for anterior circulation stroke. These findings call for further identification of prognostic factors beyond recanalization. The significance of baseline clinical severity, infarct volume, collaterals, time metrics, core-penumbra mismatch, and methods to accurately measure these parameters are discussed. Furthermore, their interplay on EVT outcomes and the potential to individualize patient selection for PC-EVT are reviewed. We also discuss technical considerations for improving the treatment efficacy of PC-EVT.

Endovascular thrombectomy versus standard medical treatment for stroke patients with acute basilar artery occlusion: a systematic review and meta-analysis

BACKGROUND

Whether endovascular thrombectomy (EVT) is superior to standard medical treatment (SMT) for stroke patients with acute basilar artery occlusion (BAO) is uncertain. This systematic review and meta-analysis aimed to compare the safety and efficacy of EVT with SMT for treating BAO patients.

METHODS

Papers were retrieved from PubMed, Embase, and the Cochrane Library databases. The primary outcome of this meta-analysis was favorable functional outcomes at 3 months (defined as a modified Rankin Scale (mRS) score of ≤3). A random effect model was used to calculate risk ratios (RR) with 95% confidence intervals (CIs) per outcome.

RESULTS

Five articles, including two randomized controlled trials (RCTs) and four observational cohort studies, comprising 1484 patients (1024 in the EVT group and 460 in the SMT group), were included in the meta-analysis. The pooled results demonstrated no significant differences between the EVT and SMT groups in achieving favorable functional outcomes at 3 months (RR=1.63, 95% CI 0.90, 2.96; p=0.11). However, patients in the EVT group had higher rates for symptomatic intracerebral hemorrhage (RR=6.22, 95% CI 2.06 to 18.76; p=0.001) but lower mortality at 3 months (RR=0.72, 95% CI 0.56 to 0.91; p=0.007) than patients in the SMT group.

CONCLUSION

Among patients with BAO, EVT and SMT did not differ significantly in achieving favorable functional outcomes at 3 months, but BAO patients treated with EVT might have lower mortality at 3 months. RCTs are warranted to further assess the efficacy and safety of EVT for BAO patients.

A Case Series and Literature Review of Vertebral Artery Stump Syndrome

Purpose

Stump syndrome refers to cerebral ischaemic symptoms caused by an embolus from a previously occluded ipsilateral artery that occludes a down-stream artery. It can be divided into two types: carotid stump syndrome and vertebral artery stump syndrome (VASS). At present, there is limited clinical experience with VASS. We aimed to propose a more precise diagnostic standard for VASS, and to share our experience with handling this condition.

Materials and Methods

We retrospectively collected data of patients who were treated with endovascular thrombectomy in the stroke centre of the First Hospital of Jilin University from January 2016 to March 2020. After screening patients with posterior-circulation acute ischaemic stroke, we selected patients who had an acute occlusion of an intracranial artery in the context of a previously occluded ipsilateral vertebral artery origin, as confirmed by digital subtraction angiography.

Results

Eleven patients met our inclusion criteria. Nine patients achieved recanalization of both extracranial and intracranial occluded arteries, one patient had modified thrombolysis in cerebral infarction grade 3, and eight patients had grade 2b. Residual stenosis of recanalized intracranial arteries was less than 30% in all cases, while three patients had embolism of distal arteries. No dissection or subarachnoid haemorrhage occurred. Two patients didn't reach vascular recanalization. Among the nine patients with recanalized artery, four had a 90-day modified Rankin Scale score ≤ 3 (favourable outcome), and four patients died; As for the two non-recanalized patients, one had a mRS score of 5 and one died.

Conclusion

VASS is a clinical syndrome caused by embolic occlusion of a distal intracranial artery occluded ipsilateral extracranial vertebral artery. Antegrade blood flow from the collateral vessels, distal embolic occlusion and mild or no residual stenosis of the occluded intracranial artery after recanalization are notable features of this clinical event. Endovascular thrombectomy may be effective for treating VASS.

Predictive value of DWI posterior-circulation lesion volume for 90-day clinical outcome after endovascular treatment of acute basilar artery occlusion: a retrospective single-center study

PURPOSE

The relationship between posterior-circulation lesion volume (PCLV) and clinical outcomes is poorly investigated. We aimed to analyze, in patients with acute basilar artery occlusion (ABAO), if pre-endovascular treatment (EVT) PCLV was a predictor of outcomes.

METHODS

We analyzed consecutive MRI selected, endovascularly treated ABAO patients. Baseline PCLV was measured in milliliters on apparent diffusion-coefficient map reconstruction. Univariable and multivariable logistic models were used to test if PCLV was a predictor of 90-day outcomes. After the received operating characteristic (ROC) analysis, the optimal cut-off was determined to evaluate the prognostic value of PCLV.

RESULTS

A total of 110 ABAO patients were included. The median PCLV was 4.4 ml (interquartile range, 1.3-21.2 ml). Successful reperfusion was achieved in 81.8% of cases after EVT. At 90 days, 31.8% of patients had a modified Rankin scale ≤ 2, and the mortality rate was 40.9%. PCLV was an independent predictor of functional independence and mortality (odds ratio [OR]:0.57, 95% confidence interval [CI], 0.34-0.93 and 1.84, 95% CI, 1.23-2.76, respectively). The ROC analysis showed that a baseline PCLV ≤ 8.7 ml was the optimal cut-off to predict the 90-day functional independence (area under the curve [AUC] = 0.68, 95% CI, 0.57-0.79, sensitivity 88.6%, and specificity 49.3%). In addition, a PCLV ≥ 9.1 ml was the optimal cut-off for the prediction of 90-day mortality (AUC = 0.71, 95% CI, 0.61-0.82, sensitivity 80%, and specificity 60%).

CONCLUSIONS

Pre-treatment PCLV was an independent predictor of 90-day outcomes in ABAO. A PCLV ≤ 8.7 and ≥ 9.1 ml may identify patients with a higher possibility to achieve independence and a higher risk of death at 90 days, respectively.

Predictors of Early Neurological Deterioration in Stroke Due to Vertebrobasilar Occlusion

Background and Aims: This study explores the predictors of early neurological deterioration (END) in patients with vertebrobasilar occlusion (VBO) in both primary endovascular therapy (EVT) and medical management (MM) groups. Methods: Patients diagnosed with VBO from 2010 to 2018 were included. Comparative and multivariate analyses were used to identify predictors of all-cause END in the EVT group, and END due to ischemia progression (END-IP) in the MM group. Results: In 174 patients with VBO, 43 had END. In the primary EVT group (N = 66), 17 all-cause END occurred. Distal basilar occlusion (odds ratio (OR), 14.5 [95% confidence interval (CI), 1.4-154.4]) and reperfusion failure (eTICI < 2b67 (OR, 5.0 [95% CI, 1.3-19.9]) were predictive of END in multivariable analysis. In the MM group (N=108), 17 END-IP occurred. Higher systolic blood pressure (SBP) at presentation (per 10 mmHg increase, OR, 1.5 [95% CI, 1.1-2.0]), stroke onset-to-door time <24 h (OR, 5.3 [95% CI, 1.1-2.0]), near-total occlusions (OR, 4.9 [95% CI, 1.2-19.6]), lower posterior circulation-Alberta Stroke Program Early CT scores (OR, 1.6 [95% CI, 1.0-2.5]), and lower BATMAN collateral scores (OR, 1.6 [95% CI, 1.1-2.2]) were predictive of END-IP. Conclusions: In patients with stroke due to VBO, potential predictors of END can be identified. In the primary EVT group, failure to achieve reperfusion and distal basilar occlusion were associated with all-cause END. In the MM group, higher SBP at presentation, onset-to-door time less than 24 h, incomplete occlusions, larger infarct cores, and poorer collaterals were associated with END-IP.

Factors Contributing to an Efficacious Endovascular Treatment for Acute Ischemic Stroke in Asian Population

Although randomized control trials about endovascular treatment (EVT) of emergent large vessel occlusion (LVO) have demonstrated the success of mechanical thrombectomy as the choice of treatment, a wide range of caveats remain unaddressed. Asian patients were rarely included in the trials, thereby raising the question of whether the treatment could be generalized. In addition, there remains a concern on the feasibility of the method with respect to its application against intracranial atherosclerosis (ICAS)-related LVO, frequently observed in the Asian population. It is important to include evidence on ICAS LVO from Asian countries in the future for a comprehensive understanding of LVO etiology. Besides the issues with EVT, prognostic concerns in diabetes patients, acute kidney injury following EVT, neuroprotective management against reperfusion injury, and other peri-EVT issues should be considered in clinical practice. In the current article, we present an in-depth review of the literature that revises information pertaining to such concerns.

Etiological Approach to Understanding Recanalization Failure in Intracranial Large Vessel Occlusion and Thrombectomy: Close to Embolism but Distant From Atherosclerosis

Introduction: In patients with intracranial large vessel occlusion (LVO) who undergo endovascular treatment (EVT), recanalization failure may be related to intracranial atherosclerotic stenosis (ICAS). We evaluated whether the risk factors of recanalization failure could possibly be a marker of ICAS among various types of LVO.

Methods: From a multicenter registry, patients with middle cerebral artery M1 segment occlusions who underwent thrombectomy within 24 h were included. Based on the on-procedure and post-procedure angiographic findings, patients were classified into embolic, ICAS-related, tandem occlusion, and recanalization failure groups. Recanalization failure was defined if the occluded vessel could not be recanalized by stent retrieval, contact aspiration, or local lytics treatment. Risk factors, imaging markers, and EVT methods were compared between groups.

Results: Among 326 patients, 214 were classified as embolism, 76 as ICAS, 16 as tandem, and 20 as recanalization failure. The group with recanalization failure showed higher scores on the National Institutes of Health Stroke Scale (NIHSS) (median, 16.0 vs. 14.5 vs. 14.0 vs. 17.0, p = 0.097), frequent atrial fibrillation (59.3 vs. 18.4 vs. 0 vs. 40.0% p < 0.001), and elevation in erythrocyte sedimentation rate (ESR) (14.5 ± 15.7 vs. 15.0 ± 14.1 vs. 21.2 ± 19.5 vs. 36.0 ± 32.9, p < 0.001) among the groups. The rate of computed tomography angiography-based truncal-type occlusion in recanalization failure group was not as high as that in the ICAS group (8.1 vs. 37.5 vs. 0 vs. 16.7%, p < 0.001). Balloon guide catheters (BGC) were less frequently utilized in the recanalization failure group as compared to their use in the other groups (72.0 vs. 72.4 vs. 62.5 vs. 30.0%, p = 0.001). In the multivariable analysis, initial higher NIHSS [odds ratio (OR), 1.11 95% confidence interval (CI), 1.01–1.22 p = 0.027], higher ESR (OR, 1.03 CI, 1.01–1.05 p = 0.006), and non-use of BGCs (OR, 3.41 CI, 1.14–10.17 p = 0.028) were associated with recanalization failure. In M1 occlusions, the predominant mechanism of recanalization failure was presumed to be embolic in 80% and due to ICAS in 20%.

Conclusion: The analysis of recanalization failures does not suggest an underlying predominant ICAS mechanism. Sufficient utilization of thrombectomy devices and procedures may improve the rates of recanalization.

A Meta-Analysis of Prognostic Factors in Patients with Posterior Circulation Stroke after Mechanical Thrombectomy

BACKGROUND

Posterior circulation stroke is characterized by poor prognosis because its optimal thrombolysis "time window" is always missed. After mechanical thrombectomy (MT), the recanalization rate of posterior circulation obstruction is significantly increased, but prognosis remains poor. To best manage patients, prognostic factors are needed to inform MT triaging after posterior circulation stroke.

METHODS

A systematic literature search was done for the period through April 2020. Studies included those with posterior circulation stroke cases that underwent MT. The primary outcome measure in this study was the modified Rankin Scale on day 90.

RESULTS

No outcome differences were found in gender, atrial fibrillation, smoking, and coronary artery disease (OR = 1.07, 95% CI: 0.90-1.28; OR = 1.02, 95% CI: 0.82-1.26; OR = 1.26, 95% CI: 0.94-1.68; and OR = 0.84, 95% CI: 0.58-1.22, respectively). Hypertension, diabetes mellitus, and previous stroke correlated with poorer prognosis (OR = 0.61, 95% CI: 0.48-0.77; OR = 0.60, 95% CI: 0.50-0.73; and OR = 0.74, 95% CI: 0.55-0.99, respectively). However, hyperlipidemia correlated with better prognosis (OR = 1.28, 95% CI: 1.04-1.58).

CONCLUSION

Our analysis indicates that hypertension, diabetes mellitus, or previous stroke correlate with poorer outcomes. Intriguingly, hyperlipidemia correlates with better prognosis. These factors may help inform triage decisions when considering MT for posterior circulation stroke patients. However, large, multicenter, randomized controlled trials are needed to validate these observations.

DWI cerebellar infarct volume as predictor of outcomes after endovascular treatment of acute basilar artery occlusion

BACKGROUND

Preprocedural predictors of outcome in patients with acute basilar artery occlusion (ABAO) who have undergone endovascular treatment (EVT) remain controversial. Our aim was to determine if pre-EVT diffusion-weighted imaging cerebellar infarct volume (CIV) is a predictor of 90-day outcomes.

METHODS

We analyzed consecutive MRI-selected endovascularly treated patients with ABAO within the first 24 hours after symptom onset. Successful reperfusion was defined as a modified Thrombolysis in Cerebral Infarction score of 2b-3. Using the initial MRI, baseline CIV was calculated in mL on an apparent diffusion coefficient map reconstruction (Olea Sphere software). CIV was analyzed in univariate and multivariable models as a predictor of 90-day functional independence (modified Rankin Scale (mRS) 0-2) and mortality. According to receiver operating characteristic (ROC) analysis, the optimal cut-off was determined by maximizing the Youden index to evaluate the prognostic value of CIV.

RESULTS

Of the 110 MRI-selected patients with ABAO, 64 (58.18%) had a cerebellar infarct. The median CIV was 9.6 mL (IQR 2.7-31.4). Successful reperfusion was achieved in 81.8% of the cases. At 90 days the proportion of patients with mRS ≤2 was 31.8% and the overall mortality rate was 40.9%. Baseline CIV was significantly associated with 90-day mRS 0-2 (p=0.008) in the univariate analysis and was an independent predictor of 90-day mortality (adjusted OR 1.79, 95% CI 1.25 to 2.54, p=0.001). The ROC analysis showed that a CIV ≥4.7 mL at the initial MRI was the optimal cut-off to discriminate patients with a higher risk of death at 90 days (area under the ROC curve (AUC)=0.74, 95% CI 0.61 to 0.87, sensitivity and specificity of 87.9% and 58.1%, respectively).

CONCLUSIONS

In our series of MRI-selected patients with ABAO, pre-EVT CIV was an independent predictor of 90-day mortality. The risk of death was increased for baseline CIV ≥4.7 mL.

Prediction of Infarct Growth and Neurological Deterioration in Patients with Vertebrobasilar Artery Occlusions

We aimed to identify predictors of infarct growth and neurological deterioration (ND) in vertebrobasilar occlusions (VBOs) with a focus on clinical-core mismatch. From 2010 to 2018, VBO patients were selected from a university hospital registry. In total, 138 VBO patients were included. In these patients, a posterior circulation Alberta Stroke Program Early CT score (PC-ASPECTS) less than 6 was associated with futile outcome. Within patients with feasible cores, a decrease in PC-ASPECTS score of 2 or more on follow-up imaging was classified as infarct growth and could be predicted by a National Institutes of Health Stroke Scale (NIHSS) mental status subset of 1 or higher (odds ratio (OR): 3.34, 95% confidence interval (CI) (1.19-9.38), p = 0.022). Among the 73 patients who did not undergo reperfusion therapy, 13 patients experienced ND (increase in discharge NIHSS score of 4 or more compared to the initial presentation). Incomplete occlusion (vs. complete occlusion, OR 6.17, 95% CI (1.11-34.25), p = 0.037), poorer collateral status (BATMAN score, OR: 1.91, 95% CI (1.17-3.48), p = 0.009), and larger infarct cores (PC-ASPECTS, OR: 1.96, 95% CI (1.11-3.48), p = 0.021) were predictive of ND. In patients with VBO, an initial PC-ASPECTS of 6 or more, but with a decrease in the mental status subset of 1 or more can predict infarct growth, and may be used as a criterion for clinical-core mismatch. ND in VBO patients presenting with milder symptoms can be predicted by incomplete occlusion, poor collaterals, and larger infarct cores.

Acute Kidney Injury after Endovascular Treatment in Patients with Acute Ischemic Stroke

Acute kidney injury (AKI) is often associated with the use of contrast agents. We evaluated the frequency of AKI, factors associated with AKI after endovascular treatment (EVT), and associations with AKI and clinical outcomes. We retrospectively analyzed consecutively enrolled patients with acute ischemic stroke who underwent EVT at three stroke centers in Korea. We compared the characteristics of patients with and without AKI and independent factors associated with AKI after EVT. We also investigated the effects of AKI on functional outcomes and mortality at 3 months. Of the 601 patients analyzed, 59 patients (9.8%) developed AKI and five patients (0.8%) started renal replacement therapy after EVT. In the multivariate analysis, diabetes mellitus (odds ratio (OR), 2.341; 95% CI, 1.283–4.269; p = 0.005), the contrast agent dose (OR, 1.107 per 10 mL; 95% CI, 1.032–1.187; p = 0.004), and unsuccessful reperfusion (OR, 1.909; 95% CI, 1.019–3.520; p = 0.040) were independently associated with AKI. The presence of AKI was associated with a poor functional outcome (OR, 5.145; 95% CI, 2.177–13.850; p < 0.001) and mortality (OR, 8.164; 95% CI, 4.046–16.709; p < 0.001) at 3 months. AKI may also affect the outcomes of ischemic stroke patients undergoing EVT. When implementing EVT, practitioners should be aware of these risk factors.