Abstract WMP65: Association Of Pre-mechanical Thrombectomy Collateral Scores With Functional Outcome In Short Versus Extended Window For Thrombectomy

Abstract

Introduction: We aim to determine the association of pre-mechanical-thrombectomy (MT) collateral scores in the short (<6 hours from onset) versus extended (6-24 hours from onset) window for MT with a good functional outcome. Methods: We performed a retrospective chart review of patients who underwent MT for anterior circulation large vessel occlusion at a comprehensive stroke center from 7/2014 to 12/2020. A board-certified neuroradiologist, who was blinded to the clinical outcomes, used collateral grading scales of Miteff (ordinal), Mass (ordinal), and modified-Tan (dichotomous) to designate collateral scores on the pre-MT CT Angiogram. The patients were divided into short (<6 hours from onset) versus extended (6-24 hours from onset) groups depending on their timing of presentation to the emergency department. A binary logistic regression analysis was performed, controlling for age, sex, NIHSS, ASPECTS≥6, TICI score≥2b, recanalization time, mean arterial pressure, blood glucose, location of the occlusion, atrial fibrillation, LDL, hemoglobin-A1C, and administration of intravenous-alteplase, with the pre-MT collateral grading scores as predictors. The primary outcome was a good functional outcome (3-month mRS≤2). Results: 220 patients met the inclusion criteria.162 patients presented in the short window for MT. The pre-MT scales of Mass (OR, 0.35; 95%CI, 0.16-0.78; P 0.01) and modified-Tan (OR, 0.35; 95%CI, 0.16-0.78; P 0.01) were associated with a good functional outcome, unlike the Miteff scale (OR, 0.46; 95% CI, 0.18-1.18; P 0.103). 58 patients met our inclusion criteria for patients who presented in the extended window for MT. The pre-MT scales of Mass (OR, 0.75; 95% CI, 0.23-2.48; P 0.63), Miteff scale (OR, 0.78; 95%CI, 0.17-3.64; P 0.746) and modified-Tan (OR, 1.14; 95%CI, 0.1-12.98; P 0.918) were not associated with a good functional outcome. Conclusions: Our study demonstrates that good collateral grades on Mass and modified-Tan scales are associated with a good functional outcome for patients who present to the ED in the short window for MT. We did not find an association of any pre-MT collateral scores with a good functional outcome for patients presenting in the extended window for MT.