Predictor of the first–pass effect in mechanical thrombectomy

Abstract

  The benefits of the first‒pass effect (FPE) are significant, as it enables complete recanalization with a single thrombectomy device pass. We investigated the factors that may predict the FPE by retrospectively analyzing the cases of intracranial thrombectomy in which a stent retriever or aspiration catheter was used as the first device at our facility since 2015. We investigated four groups: the FPE group (n＝35, 26.1%), the modified FPE group, the multiple passes/Thrombolysis in Cerebral Infarction grade (TICI) ＜ 2b group, and the TICI ＜ 2b group. Of the 144 cases, 134 occurred during the study period. The percentages of cardiogenic embolism were 38.9% in the TICI ＜ 2b group and significantly higher at approx. 70% in the other three groups (p＝0.02). The rate of lesions suggesting a single‒vessel occlusion (i.e., non‒terminus of the internal carotid artery [ICA], ICA/first segment [M1] of the middle cerebral artery [MCA], or M1/basilar artery [BA]) was high in the FPE and modified FPE groups at 71.4% and 65.2%, showing a significant difference between these two groups and the other groups (p＝0.03). After the adjustment for confounders, the independent predictor of FPE was ICA/M1/BA occlusion with an odds ratio of 2.37 (95% confidence interval 1.02‒5.49, p＝0.045). Our results demonstrated that ICA/M1/BA occlusion was an independent factor that increased the FPE.