Abstract 48: Outcomes And Risk Of Hemorrhagic Transformation Following Mechanical Thrombectomy In Primary Distal Posterior Cerebral Artery Occlusions-subgroup Analysis From STAR

Abstract

Background: While mechanical thrombectomy (MT) has become the standard of care for acute stroke patients presenting with large vessel occlusion (LVO) and salvageable brain tissue, limited data is currently available regarding the benefits of MT in patents with medium vessel occlusions (MeVO) especially in the posterior circulation (P2 occlusions). Methods: We used the Stroke Thrombectomy and Aneurysm registry (STAR) which included data from 35 stroke centers in North America, Europe, Asia, and South America. We included patients who presented with MeVO in the M2, M3 or P2 segments and underwent MT. We used a Generalized Linear Model to assess the relationship between location of occlusion and outcomes. Results: 9812 patients were included in STAR at the time of this analysis; 43 underwent MT for P2 occlusion, 130 underwent MT for M3 occlusion; and 1273 underwent MT for M2 occlusion. There was no difference in age, sex, race, rate of IV-tPA and stroke severity between patients in all 3 groups (Table 1). There was a trend toward lower rate of atrial fibrillation in patients with P2 and M3 occlusions. Patients with P2 occlusions were less likely to achieve successful recanalization (modified treatment in cerebral infarction score≥2b); intraarterial thrombolysis was used less in P2 occlusions (4.7% compared to 16.2% in M3 occlusions and 10.1% in M2 occlusions). However, there was no difference in the rate of successful first pass. On multivariable analysis, P2 occlusions were not associated with hemorrhagic transformation (OR 2.0, 95% CI 0.7-5.7, P 0.186), 90-day mortality (OR 0.5, 95% CI 0.2-1.4, P 0.183), or 90-day favorable outcome (OR 2.0, 95% CI 0.9-4.4, P 0.084). Conclusions: In this multicenter study, there was no significant difference in safety and efficacy of MT in patients with MeVOs in posterior circulation (P2 occlusions) compared to M2 and M3 occlusions. Improved techniques for successful recanalization are needed for posterior circulation MeVOs.