LAUSR

Introduction: Stroke thrombectomy devices and the experience of neurointerventionists have improved significantly over the last few years making targeting distal occlusions such as of the M2 segment of the middle cerebral artery more feasible. We aimed to study the trend in the successful first pass (SFP) of M2 occlusions over time using the data from a contemporary multicenter registry. Methods: We reviewed the data from the Stroke Thrombectomy and Aneurysm Registry (STAR), which included data from 11 thrombectomy-capable stroke centers to identify stroke patients who underwent mechanical thrombectomy of M2 segment occlusion. SFP was defined by achieving modified Thrombolysis in Cerebral Infarction (mTICI) score≥2b with a single thrombectomy device pass. We analyzed the linear trendline of the rate of SFP over time. Then, we used a logistic regression model to assess predictors of SFP of M2 segment occlusion. Results: We included 401 patients who underwent stroke thrombectomy of M2 occlusion; median age was 71 (IQR 60-80), 212 (52.9%) were females, 174 (43.4%) were white, National Institute of Health stroke scale (NIHSS) was 14 (IQR 8-19), Alberta Stroke Program Early CT (ASPECT) score on presentation was 9 (IQR 7-10) and onset wot groin time was 287 (IQR 181-454). SFP was achieved in 118 (29.4%) patients (linear trendline over time is in Figure 1). Presenting after 2014 was an independent predictor of SFP (OR 1.9, 95% CI 1.1-3.2, P=0.019) after controlling for age, sex, NIHSS on presentation, intravenous alteplase (IV-tPA), and onset to groin time. Conclusion: SFP rate of M2 segment occlusion has increased after 2014 likely secondary the improvement in stroke thrombectomy devices and neurointerventionists experience.