Abstract WP21: Primary Thrombectomy Within 3 Hours of Onset in Acute Ischemic Stroke From Large Artery Occlusion (PAST3-LAO)- A Pilot Study

Abstract

Background: Based on recent trials, AIS due to large artery occlusion (LAO) is resistant to IV thrombolysis and adjunctive stent retriever thrombectomy (SRT) is associated with better recanalization rates and outcomes.Despite the benefit with endovascular therapy 39% to 68% of patients were either disabled or dead.Thrombectomy in AIS with LAO within 3 hours (IV t-PA window) is performed as secondary therapy after IV thrombolysis, which may be associated with delay in enrollment and recanalization. Objective: Primary objective is to evaluate the safety, feasibility and recanalization rate of primary SRT (without IV tPA) within 3 hours in AIS with NIHSS >10 from LAO.Secondary objective is to determine the functional outcome in 30-days and 90-days. Methods: Based on institutionally approved protocol patients with LAO with LCB within 3 hours were offered primary SRT alone as an alternative to IV rtPA, after informed consent.Consecutive patients who underwent primary SRT for LAO within 3 hours from 2012 to 2014 were enrolled.Outcomes were measured using modified Rankin Scale. Results: 18 patients with LAO; mean age 62.8±15.3 years and mean NIHSS 16±5; chose primary SRT after informed consent.Thrombectomy was performed using new generation stent-retriever device in addition to small intra-arterial rtPA (2-10 mg).Number of passes was 1.6±0.9.Near complete (TICI2b in 1) and complete (TICI3 in 17) recanalization was observed in all (100%) patients.Mean time to recanalization from symptoms onset was 188.5±82.7 and from groin puncture was 64.61±40.14 minutes.Immediate post-thrombectomy, 24 hour and 30 day NIHSS score was 4.4±3.7, 1.9±3.2 and 0.3±0.9 respectively.There was no procedure related complication.Asymptomatic perfusion related hemorrhage developed in 6 patients (33%).30 days good outcome was observed in all cases (mRS0= 38.9%, mRS1=44.4%, mRS2=16.7%). 90 days good outcome was observed as follows (mRS0= 50.0%, mRS1=44.4%, mRS2=5.6%). Conclusion: Our pilot study demonstrates that primary SRT in AIS due LAO occlusion with LCB is not only safe and feasible, but associated with complete recanalization and good functional outcome.Larger randomized controlled studies are needed.