Abstract P519: Higher Number of Thrombectomy Passes Significantly Increases Risk of Mass Effect, Poor Functional Outcome, and Mortality

Abstract

Background: Endovascular treatment (EVT) is a widely proven method to treat patients diagnosed with intracranial large vessel occlusion (LVO). Through this method of treatment, it has been hypothesized that a lower number of thrombectomy passes is an indicator of higher rates of modified Thrombolysis in Cerebral Infarction 2b-3 (mTICI) and favorable outcomes defined as modified Rankin Scale 0-2 (mRS). Methods: Through the utilization of a prospectively collected endovascular database between 2012-2020, variables such as demographics, co-morbid conditions, intracerebral hemorrhage, mass effect, mortality rate, and good/poor outcomes in regard to mTICI score and mRS assessment at discharge were examined. The outcomes between patients receiving EVT who were treated with < 3 thrombectomy passes or ≥ 3 passes were compared. Results: Out of 454 patients treated with mechanical thrombectomy of qualifying intracranial internal carotid artery or middle cerebral artery occlusion, site of occlusion (internal carotid artery, M1 and M2), a total of 372 (81.9%) were treated with < 3 thrombectomy passes (average age 70.34 ± 13.75 years, 46.0% women), and 82 (18.1%) were treated with ≥ 3 thrombectomy passes (average age 70.30 ± 13.72 years, 48.8% women). Significantly higher rates of mass effect (p=0.043), mRS score 3-6 (p=0.029), and mortality (p=0.025) were noted in patients treated with ≥ 3 thrombectomy passes. Further analysis revealed that patients presenting 6-24 hours from symptom onset had significantly lessened chance of effective recanalization (TICI 2B-3; p=0.021). Conclusion: A higher number of thrombectomy passes, characterized as ≥ 3 passes in this study, was associated with significantly worsened patient outcome in regard to functional outcome, and mortality. Further research is required to determine whether the number of thrombectomy passes is an accurate indicator of treatment outcome and whether delayed presentation time increases risk of poor outcome.