Higher number of stent-retriever thrombectomy passes significantly increases risk of mass effect, poor functional outcome, and mortality

Introduction 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) reperfusion and favorable outcomes at 90-days 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 regarding mTICI score and mRS assessment at 90-days 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 (ICA) or middle cerebral artery occlusion, site of occlusion (ICA, ICA-T M1, and M2/M3), a total of 372 (81.9%) were treated with < 3 passes (average age 70.34 ± 13.75 years, 46.0% women), and 82 (18.1%) were treated with ≥3 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), mortality (p = 0.025), and poor reperfusion (p < 0.0001) were noted in patients treated with ≥3 passes. Conclusion A higher number of thrombectomy passes, characterized as ≥3 in this study, was associated with significantly worsened patient outcome regarding mRS and mortality. Further research is required to determine whether the number of thrombectomy passes is an accurate predictor of treatment outcome.