Abstract WMP4: Analysis of Outcomes From the Endovascular Treatment of Posterior Circulation Strokes in the Modern Era of Stent Retriever Thrombectomy

Background: Evidence for endovascular treatment of anterior circulation strokes is well developed. However, patients with posterior circulation strokes have been excluded from recent randomized endovascular stroke trials. Objective: To evaluate outcomes of posterior circulation strokes treated with modern endovascular therapy since the FDA approval of stent retrievers, and to identify predictors of clinical outcomes and complications in this specific population of stroke patients. Methods: We performed a multicenter retrospective analysis of consecutive patients with posterior circulation strokes who underwent thrombectomy with stent retrievers or primary aspiration thrombectomy (including the ADAPT approach). We correlated favorable clinical outcomes with demographic, clinical and technical characteristics. Results: A total of 84 patients were included in this study (mean age, 63.5 years; mean admission NIHSS score, 19.2). Favorable clinical outcome at 3 months, defined as mRS score 0-2 was achieved in 34 (40%) patients. NIHSS score < 20, the use of conscious sedation rather than general anesthesia and successful recanalization (TICI 2b/3) were significant predictors of favorable clinical outcome at 90 days. The use of baseline advanced imaging (CT perfusion, multi-phase CTA or MRI) for patient selection was not associated with improved outcomes. In patients with the time of symptom onset to femoral puncture < 6 hours, mRS 0-2 at 3 months was achieved in 51.2% of cases. Treatment initiated beyond the 6-hour window resulted in 30.2% rate of mRS 0-2 at 3 months. Conclusions: Severity of admission NIHSS score, recanalization success and the type of anesthesia strongly correlate with clinical outcomes in endovascular therapy of posterior circulation strokes. The highest rate of long-term favorable outcomes was achieved in patients whose thrombectomy was initiated within the first 6 hours of stroke onset. However, even when started beyond the 6 hours window, endovascular treatment of posterior circulation strokes is feasible.