Abstract
OBJECTIVES: A higher reperfusion grade after endovascular thrombectomy (EVT) is associated with a good prognosis. However, the effect of the number of retrievals has not yet been investigated in vertebrobasilar occlusion (VBAO). Therefore, the aim of this study was to investigate whether to continue retrieval after early modified thrombolysis in cerebral infarction (mTICI) 2b to achieve a better reperfusion grade. METHODS: We retrospectively analyzed the data of patients who underwent EVT caused by VBAO in a multicenter registry dataset. Patients who underwent successful reperfusion were included (mTICI 2b/3). Regression models were used to analyze the correlation of different reperfusion grades stratified by the number of retrieval attempts with clinical prognosis and hemorrhage transition. RESULTS: We included 432 patients: 34.5% (n = 149) had a final mTICI score of 2b and 65.5% (n = 283) had a final mTICI score of 3. Patients who obtained a mTICI of 3 after the first pass had significantly increased odds of having a good prognosis. As the number of passes increases, the chances of obtaining a good prognosis decreases. After three or more passes, the odds of achieving functional independence and favorable outcomes were comparable to those of the first mTICI 2b, regardless of the 90-day (OR 1.132 95% CI 0.367-3.487 p = 0.829; OR 1.070 95% CI 0.375-3.047 p = 0.900) or 1-year follow-up (OR 1.217 95% CI 0.407-3.637 p = 0.725; OR 1.068 95% CI 0.359-3.173 p = 0.906). INTERPRETATION: Within two retrieval attempts, mTICI 3 was better than the first retrieval to mTICI 2b. After early mTICI 2b, each retrieval should be undertaken with caution to pursue a higher reperfusion grade.