Internal Carotid Artery and the Proximal M1 Segment Are Optimal Targets for Mechanical Thrombectomy

Hypoperfusion Intensity Ratio as an Indirect Imaging Surrogate in Patients With Anterior Circulation Large-Vessel Occlusion and Association of Baseline Characteristics With Poor Collateral Status

BACKGROUND

Collateral status (CS) plays a crucial role in infarct growth rate, risk of postthrombectomy hemorrhage, and overall clinical outcomes in patients with acute ischemic stroke (AIS) secondary to anterior circulation large-vessel occlusions (LVOs). Hypoperfusion intensity ratio has been previously validated as an indirect noninvasive pretreatment imaging biomarker of CS. In addition to imaging, derangements in admission laboratory findings can also influence outcomes in patients with AIS-LVO. Therefore, our study aims to assess the relationship between admission laboratory findings, baseline characteristics, and CS, as assessed by hypoperfusion intensity ratio in patients with AIS-LVO.

METHODS AND RESULTS

In this retrospective study, consecutive patients presenting with AIS secondary to anterior circulation LVO who underwent pretreatment computed tomography perfusion were included. The computed tomography perfusion data processed by RAPID (Ischema View, Menlo Park, CA) generated the hypoperfusion intensity ratio. Binary logistic regression models were used to assess the relationship between patients' baseline characteristics, admission laboratory findings, and poor CS. A total of 221 consecutive patients with AIS-LVO between January 2017 and September 2022 were included in our study (mean±SD age, 67.0±15.8 years; 119 men [53.8%]). Multivariable logistic regression showed that patients with AIS caused by cardioembolic and cryptogenic causes (adjusted odds ratio [OR], 2.67; 95% CI, 1.20-5.97; P=0.016), those who presented with admission National Institutes of Health Stroke Scale score ≥12 (adjusted OR, 3.12; 95% CI, 1.61-6.04; P=0.001), and male patients (adjusted OR, 2.06; 95% CI, 1.13-3.77; P=0.018) were associated with poor CS.

CONCLUSIONS

Stroke caused by cardioembolic or cryptogenic causes, admission National Institutes of Health Stroke Scale score of ≥12, and male sex were associated with poor CS, as defined by hypoperfusion intensity ratio in the patients with AIS-LVO.

Relative Cerebral Blood Flow as an Indirect Imaging Surrogate in Patients With Anterior Circulation Large Vessel Occlusion and Association of Baseline Characteristics With Poor Collateral Status

BACKGROUND

In acute ischemic stroke (AIS), collateral status (CS) is an important predictor of favorable outcomes in patients with AIS. Among quantitative cerebral perfusion parameters, relative cerebral blood flow (rCBF) is considered an accurate perfusion-based indicator of CS. This study investigated the relationship between admission laboratory values, baseline characteristics, and CS as assessed by rCBF in patients with AIS-large vessel occlusion.

METHODS AND RESULTS

In this retrospective multicenter study, consecutive patients presenting with AIS secondary to anterior circulation large vessel occlusion who underwent pretreatment computed tomography perfusion were included. The computed tomography perfusion data processed by RAPID (IschemaView, Menlo Park, CA) generated the rCBF. Binary logistic regression models assessed the relationship between patients' baseline characteristics, admission laboratory values, and poor CS. The primary outcome measure was the presence of poor CS, which was defined as rCBF <38% at a lesion size ≥27 mL. Between January 2017 and September 2022, there were 221 consecutive patients with AIS-large vessel occlusion included in our study (mean age 67.0±15.8 years, 119 men [53.8%]). Logistic regression showed that male sex (odds ratio [OR], 2.98 [1.59-5.59]; P=0.001), chronic kidney disease (OR, 5.18 [2.44-11.0]; P<0.001), admission National Institutes of Health Stroke Scale score ≥12 (OR, 5.17 [2.36-11.36]; P<0.001), and systolic blood pressure <140 (OR, 2.00 [1.07-3.76]; P=0.030) were associated with poor CS.

CONCLUSIONS

Higher stroke severity on admission with National Institutes of Health Stroke Scale score ≥12, systolic blood pressure <140, chronic kidney disease, and male sex are statistically significantly associated with poor CS in patients with AIS due to anterior circulation large vessel occlusion as defined by rCBF <38%.

Importance of Occlusion Site for Thrombectomy Technique in Stroke: Comparison Between Aspiration and Stent Retriever

BACKGROUND AND PURPOSE

Thrombectomy with stent retriever and direct aspiration are equally effective in the endovascular treatment of anterior circulation acute ischemic stroke. We report efficacy and safety of initial treatment technique per occlusion segment.

METHODS

For this study, we analyzed data from the MR CLEAN Registry, a prospective, observational study in all centers that perform endovascular therapy in the Netherlands. We used ordinal logistic regression analysis to compare clinical and technical results of first line direct aspiration treatment with that of stent retriever thrombectomy stratified for occlusion segment. Primary outcome measure was functional outcome at 3 months. Secondary outcome measures included reperfusion grade expressed as the extended Thrombolysis in Cerebral Infarction score, periprocedural complication risk, time to reperfusion, and mortality.

RESULTS

Of the 2282 included patients, 1658 (73%) were initially treated with stent retriever and 624 (27%) with aspiration. Four hundred sixty-two patients had an occlusion of the intracranial part of the carotid artery, 1349 of the proximal middle cerebral artery, and 471 of the distal parts of the middle cerebral artery. There was no difference in functional outcome between aspiration and stent retriever thrombectomy (odds ratio, 1.0 [95% CI, 0.9-1.2]) in any of the occlusion segments (P value for interaction=0.2). Reperfusion rate was higher in the aspiration group (odds ratio, 1.4 [95% CI, 1.1-1.6]) and did not differ between occlusion segments (P value for interaction=0.6). Procedure times were shorter in the aspiration group (minutes 50 versus 65 minutes; P<0.0001). There was no difference in periprocedural complications or mortality.

CONCLUSIONS

In unselected patients with anterior circulation infarcts, we observed equal functional outcome of aspiration and stent retriever thrombectomy in all occlusion segments. When aspiration was the first line treatment modality, reperfusion rates were higher and procedure times shorter in all occlusion segments.

Is Endovascular Treatment Still Good for Ischemic Stroke in Real World?: A Meta-Analysis of Randomized Control Trial and Observational Study in the Last Decade

BACKGROUND AND PURPOSE

Although endovascular treatment (EVT) for acute ischemic stroke is classified as I evidence, outcomes after EVT in real-world practice appear to be less superior than those in randomized clinical trials (RCTs). Additionally, the effect of EVT is unclear compared with medical treatment (MT) for patients with mild symptoms defined by National Institutes of Health Stroke Scale score <6 or with severe symptoms defined by Alberta Stroke Program Early CT Score <6.

METHODS

Literatures were searched in big databases and major meetings from December 6, 2009, to December 6, 2019, including RCTs and observational studies comparing EVT against MT for patients with acute ischemic stroke. Observational studies were precategorized into 3 groups based on imaging data on admission: mild stroke group with National Institutes of Health Stroke Scale score <6, severe stroke group with Alberta Stroke Program Early CT Score <6 or ischemic core ≥50 mL, and normal stroke group for all others. Outcome was measured as modified Rankin Scale score of 0 to 2, mortality at 90 days, and symptomatic intracranial hemorrhage (sICH) at 24 hours.

RESULTS

Fifteen RCTs (n=3694) and 37 observational studies (n=9090) were included. EVT was associated with higher modified Rankin Scale 0 to 2 rate and lower mortality in RCTs and normal stroke group, whereas EVT was associated with higher sICH rate in normal stroke group, and no difference of sICH rate appeared between EVT and MT in RCTs. In severe stroke group, EVT was associated with higher modified Rankin Scale 0 to 2 rate and lower mortality, whereas no difference of sICH rate was found. In mild stroke group, there was no difference in modified Rankin Scale 0 to 2 rate between EVT and MT, whereas EVT was associated with higher mortality and sICH rate.

CONCLUSIONS

Evidence from RCTs and observational studies supports the use of EVT as the first-line choice for eligible patients corresponding to the latest guideline. For patients with Alberta Stroke Program Early CT Score <6, EVT showed superiority over MT, also in line with the guidelines. On the contrary to the guideline, our data do not support EVT for patients with National Institutes of Health Stroke Scale score <6.