Abstract WMP7: Clinical Outcome After Multiple Retrieval Attempts in Endovascular Treatment for Acute Ischemic Stroke

Abstract

Introduction: Dedicated analyses scrutinizing the deteriorating benefit of multiple endovascular thrombectomy attempts are lacking. Here, we present insights into choosing the optimal number of retrieval attempts (RA) based on multicentric data of the German Stroke Registry (GSR). Materials & Methods: In this retrospective multicenter (n=17) study, 2611 patients of the GSR were included. In 1244 patients with complete datasets, clinical outcome was correlated with the number of retrieval attempts. The framework of generalized linear mixed-effects models was used, and the primary clinical outcome was modified Rankin scale (mRS) at 90 days <= 2. The main co-factor of interest was the number of successful RA while the model was also adjusted for confounders such as age, sex, admission NIHSS, ASPECTS, intravenous thrombolysis (IVT), type of anesthesia, time from groin puncture to final angiographic series, and reperfusion (thrombolysis in cerebral infarction [TICI]) score. Results: Age (ß=0.94, p<0.001), admission NIHSS (ß=0.89, p<0.001) and general anesthesia (ß=0.62, p=0.0063) showed significant negative-, while ASPECT-score (ß=1.19, p=8.6x10 -5 ) and IVT (ß=1.34, p=0.044) showed positive association with mRS2 after adjusting for all covariates. Compared to the reference group of 0 successful RA, successful reperfusion after one RA showed the strongest trend (ß=3.14, p=0.096) toward functional independence. Similarly, the estimated effect of 2nd to 5th RAs stayed positive but non-significant. Six or more RAs had a negative effect (ß =0.55, p=0.45) on functional independence. Conclusion: There is decreasing clinical benefit of every retrieval attempt in EVT. However, successful reperfusion achieved after up to 5 retrieval attempts seems to be beneficial compared to failure of reperfusion.