Impact of vertebral artery tortuosity on mechanical thrombectomy for basilar artery occlusion – A tertiary center experience

Tortuosity in anterior circulation has been associated with the outcomes of mechanical thrombectomy (MT). We classified vertebral artery (VA) tortuosity and investigated the effect of VA tortuosity on the outcomes of basilar artery occlusion (BAO) after MT. We enrolled patients who underwent MT for BAO. VA tortuosity was classified into three-types; Type-I: non-tortuous, Type-II: S-shape or VA with acute angulation (<90°), and Type-III: coiled, kinked, or VA with multiple acute angulations. The 3-month modified Rankin Scale (mRS), successful recanalization, and post-MT hemorrhagic transformation (HT) were assessed. A total of 106 patients were included. Age, baseline stroke severity, and the 3-month mRS score were significantly different according to the VA tortuosity (P=0.003, P=0.002, and P<0.001, respectively). A multivariable analysis demonstrated that VA tortuosity was a predictor for mRS score 0-3 (Type-I: reference; Type- II: 0.26 [0.07–0.95], P=0.041; Type-III: 0.12 [0.02–0.82], P=0.031). Moreover, Type-III was associated with less successful recanalization (Type-I: reference; Type-III: 0.12 [0.02–0.84], P=0.032) and was a potential factor for post-MT HT (Type-I: reference; Type-III: 3.09 [0.83– 11.56], P=0.094). VA tortuosity was significantly associated with the stroke outcome after MT for BAO. Initial stroke severity and successful recanalization might affect the stroke outcome.