Introduction Manual aspiration thrombectomy (MAT) and stent retriever mediated aspiration thrombectomy (SMAT) are well described reperfusion strategies for large vessel occlusions. This study aims to identify predictors of successful crossover to SMAT after failed first pass MAT.

Methods Prospectively collected data for patients with acute large vessel occlusions undergoing thrombectomy over a 23 month period at a comprehensive stroke center were reviewed. The primary outcome was successful removal of the index clot with resultant Thrombolysis in Cerebral Infarction 2b or greater reperfusion at any point after a failed initial MAT attempt, and multivariate logistic regression analyses were performed to determine predictors of successful crossover to SMAT.

Results Of 433 large vessel thrombectomies, 319 underwent first pass MAT, and 113 patients required a repeated pass for the index thrombus. Second pass MAT was performed in 77% of cases and was successful in 54%; second pass SMAT was performed in 23% of cases and was successful in 73% (P=0.11). Third pass MAT was employed in 45% of cases and was successful in 43% while SMAT was performed in 55% of cases and was successful in 77% (P=0.03). Overall, 12% of patients undergoing MAT on the first pass crossed over to successful SMAT. Predictors of successful crossover were internal carotid artery (ICA) location and higher presenting National Institutes of Health Stroke Scale (NIHSS) score.

Conclusion After failed first pass MAT, subsequent passes with SMAT had higher rates of successful index clot removal; patients with a higher initial NIHSS score and ICA clot location should be considered for early crossover or even initial SMAT for their clots.