Collateral Scores and Outcomes after Endovascular Treatment for Basilar Artery Occlusion.

BACKGROUND: Basilar artery occlusion (BAO) is a rare stroke subtype with high mortality rates. Best BAO reperfusion strategy is still controversial. OBJECTIVE: We aim to describe outcomes of BAO patients submitted to mechanical thrombectomy (MT) in a comprehensive stroke center in Brazil and analyze which previous published computed tomography angiography (CTA) collateral score better predict functional outcomes. METHODS: Retrospective analysis of consecutive BAO patients. CTA was used to evaluate the posterior circulation collateral score (PC-CS), the basilar artery on CTA score, and for the presence of posterior communicating arteries. A favorable outcome was defined as modified Rankin Score ≤3 at 90-days. After univariate analyses, multivariate logistic regression was used to identify if any collateral score independently predicts favorable outcomes. RESULTS: Between January 2011 and April 2017, 27 (85% male) BAO patients with median NIHSS 26 (IQR 15-32) were identified. Twenty-five (93%) patients were treated with MT devices, and only 2 (7%) patients were treated with angioplasty and stenting. Successful recanalization rate was 85%, and only 1 (3.7%) patient had symptomatic hemorrhagic transformation. Favorable outcomes were reached in 10 (37%) patients. In univariate analysis, female sex, NIHSS, Glasgow coma scale, mild-to-moderate symptoms on admission, onset-to-groin time, and PC-CS predicted favorable outcomes. In multivariate analysis, PC-CS (OR 1.69; 95% CI 1.10-2.60; p = 0.016) and NIHSS (OR 0.84; 95% CI 0.77-0.93; p = 0.001) remained the only independent predictors of favorable outcomes. The PC-CS AUC was 0.80 (95% CI 0.62-0.98; p = 0.012). CONCLUSIONS: MT is a promising strategy for BAO treatment. Among collateral scores, PC-CS was the only independent predictor of favorable outcomes in the present study.

Thrombectomy for M2 occlusions and the role of the dominant branch.

INTRODUCTION: The benefits of thrombectomy for occlusion of M2 segments remain controversial. The aim of this study is to assess thrombectomy's efficacy and safety in patients with M2 segment occlusion and associations between occlusion sites and anatomic variations of M1 division. MATERIALS AND METHODS: A prospective series of 30 patients with acute ischemic stroke (AIS) resulting from M2 segment occlusion of the middle cerebral artery (MCA) who underwent thrombectomy was analyzed. The primary endpoint was assessed by the Extended Treatment in Cerebral Infarction scale (eTICI). The secondary endpoints were the incidence of symptomatic hemorrhagic transformation (sICH), mortality and good functional outcome at three months. RESULTS: The mean patient age was 69.2 years. The mean National Institutes Health Stroke Scale score (NIHSS) upon hospital admission was 16. The recanalization rates were eTICI 2b/3 in 90% and 2c/3 in 60% of the patients. Total recanalization of the M2 branch was achieved in 53% of patients. sICH incidence was 6.6%, the mortality rate was 30%, and a good functional outcome (mRS ≤2) was observed in 50% of the patients. Twenty-seven patients (90%) had a dominant M2 branch and all were occluded. Regarding the site of M2 occlusions, 74% of patients had proximal M2 occlusions. CONCLUSIONS: Thrombectomy appears to be a safe and effective method for the treatment of acute M2 segment occlusions of the MCA. Most of the cases had a dominant M2 branch, and all of them were occluded. Larger studies are needed to verify the benefits of thrombectomy for different settings of M2 occlusions.