Abstract P517: The Effect of Unfavorable Vascular Anatomy on Mechanical Thrombectomy for Middle Cerebral Artery Occlusion Strokes Preliminary Evaluation of the AIM2 Score System

Abstract

Background: Time to reperfusion remains one of the strongest predictors of outcome in large vessel occlusion strokes (LVOS). Herein, we aim to assess the impact of unfavorable vascular anatomy on mechanical thrombectomy (MT) number of passes and procedural times. Methods: Retrospectively review of a prospective MT database spanning January-July 2018 including acute LVOS involving the middle cerebral artery-M1 segment and available baseline CT angiography. The AIM2 score (Table 1) was applied with patients categorized as favorable (AIM2: 0-2) versus unfavorable (AIM2: >=3) anatomy. The primary outcome was the rate of <3 device passes. Secondary outcomes included procedural times and the rates of successful reperfusion (mTICI2b-3) and 90-day mRS 0-2. Safety measures included rates of sICH and 90-day mortality. Results: Patients with unfavorable anatomy (n=15) were significantly younger (52±19, p=0.02) and had lower rates of hypertension (46% vs 80%, p=0.01) and smoking (0% vs 39%, p<0.001) versus those with favorable anatomy (n=50). Successful reperfusion with <3 passes was more often achieved with AIM2 scores 0-2 vs. ≥3 (84% vs 60%, p=0.04). There were no significant difference in other outcome measures (Table 2). Conclusions: The AIM2 score system represents a simple method for the systematically evaluation of vascular anatomy in MT and correlates significantly with increased number of MT passes.