1169. Overdue Mechanical Thrombectomy: A Treatment for all Strokes

Authors: Karim Hafazalla; Elias Atallah, MD; Ahmad Sweid, MD; Omaditya Khanna, MD; Somnath Das, BS; Michael Baldassari, BA; Nohra Chalouhi, MD; Stavropoula Tjoumakaris, MD; Robert Rosenwasser; Pascal Jabbour, MD (Philadelphia, PA)

Introduction: Decisions on the use of mechanical thrombectomy(MT) beyond 8hrs from onset of stroke symptoms remains debatable. The adequate tools used for the triage of patients with acute ischemic stroke(AIS) symptoms has not been definitive yet. We studied the safety and the efficacy of delayed MT(>8hrs) with image-based selection criteria. Methods: Data of prospectively treated patients was retrospectively collected between 2010-2017. Data on intra-venous tissue plasminogen activator(IV-rtPA), National Institute Health Stroke Scale at admission, per-procedure complications, mortality, and clinical functional status evaluated with the modified Rankin Scale (mRS) at latest follow-up was gathered. The primary outcomes were: safety and the feasibility of delayed(>8hours) MT, functional independence on latest follow-up(mRS score < 2), functional improvement on latest follow-up defined as a de-escalation by one of the mRS score, and overall mortality with delayed MT. Multivariate effects logistic regressions were conducted for statistical analysis. Results: Of 234 patients (mean age 64.4years), 215 were included in statistical analysis: 137 who received MT <8hrs from onset of symptoms(OS), and 78 others who received MT beyond 8hours. 81/234(30.7%) patients had their MT with Second Generation Stent-Retrievers, 16/234(6.8%) patients received therapy with large-bore aspiration catheters, 135/234(70.5%) patients received a salvage thrombus aspiration after failed first-line stent-retrievers thrombectomy.The average time of revascularization was 92.2min(SD=97.10). 199/234(85.0%) had a mTICI of 2b or higher. MT beyond 8hrs was not a predictor of disability or functional deterioration, increased mortality, per-procedural complications, or successful vessel repermeabilization. However, delayed thrombectomy was linked to a higher length of post-procedural hospital stay. Conclusion: Patient selection for MT should not be primarily driven by time-based criteria. More objective dynamics such as image-based criteria should be further promoted as primary selection tools. Delayed MT after 8hours should be a safe and highly efficacious first-line modality of treatment for strokes of anterior and posterior circulation.