Abstract TP138: The Effect Of Dominant Division Catheterization In Mechanical Thrombectomy On First Pass Effect And Clinical Outcome

Abstract

Introduction: The middle cerebral artery (MCA M1 segment) bifurcates into anterior and posterior divisions (M2 segments) in 78% of the population. When feasible, preferential catheterization of the dominant division is performed during endovascular thrombectomy (EVT) in patients with acute ischemic strokes (AIS). Our aim was to evaluate the association of dominant division catheterization in EVT with first pass effect and clinical outcome. Methods: Retrospective chart review of AIS patients presenting to our comprehensive stroke center with AIS secondary to MCA M1 and/or internal carotid artery (ICA) terminus occlusions who underwent standardized EVT defined as proximal flow arrest, distal aspiration, and stent retriever. Patients receiving intra-arterial thrombolytics and/or non-thrombolytics were excluded. Digital subtraction angiographic images were reviewed to determine if dominant M2 branch catheterization was performed on first pass. Modified Thrombolysis in Cerebral Infarction (mTICI) score and 90-day modified Rankin score (mRS) were evaluated. TICI score of 2B or greater was considered successful recanalization. mRS ≤ 2 was considered good clinical outcome. Social science statistics software was used for data analysis. Results: From June 2019 to November 2021, 126 patients with MCA M1 and/or ICA terminus occlusions who underwent standardized EVT, 76 met the inclusion criteria. Fifty were excluded as they had codominant M2 branches. Mean age was 72 (95% CI 68.69, 75.31) and median NIHSS was 18 (95% CI 16.16, 18.72). Thirty-eight percent (n=34) of subjects were male. Fifty-seven subjects underwent dominant division catheterization during first pass. First pass recanalization was significantly associated with catheterization of dominant branch (Fisher value: 0.0002). Catheterization of dominant branch during first pass was not associated with total number of passes (Fisher value: 0.17). Administration of IV thrombolytics prior to procedure (n=19) was not significantly associated with pre-procedure recanalization (Fisher value: 0.38). Conclusion: Our study suggests that catheterization of dominant branch during thrombectomy is associated with higher rates of first-pass successful recanalization.