Impact of Cervical Vertebral Artery Tortuosity on the Outcome After Mechanical Thrombectomy for Basilar Artery Occlusion

BACKGROUND: Vascular tortuosity affects the outcomes of mechanical thrombectomy (MT). We classified vertebral artery (VA) tortuosity into 3 types and investigated the effect of VA tortuosity on the outcomes in patients with basilar artery occlusion. METHODS: We retrospectively included patients who underwent MT for basilar artery occlusion between January 2012 and May 2022. Clinical and procedure-related factors were obtained. VA tortuosity was classified into 3 types: type I: nontortuous VA; type II: S-shaped vessel or a VA with a single acute angulation (<90 degrees); and type III: coiled vessel, kinked vessel, or a VA with acute angulation in >1 location. The 3-month modified Rankin scale, procedural outcomes, and post-MT intracranial hemorrhage were assessed. RESULTS: A total of 106 patients with basilar artery occlusion were included. Age, baseline stroke severity, and 3-month modified Rankin scale score were significantly different according to VA tortuosity (P = 0.003, P = 0.002, and P <0.001, respectively). A multivariable analysis demonstrated that the VA tortuosity was a predictor for the achievement of modified Rankin scale score of 0 to 3 (type I: reference; type II: odds ratio [OR] = 0.26, 95% CI = 0.07-0.95, P = 0.041; type III: OR = 0.12, 95% CI = 0.02-0.82, P = 0.031). Moreover, type III was associated with less successful recanalization (type I: reference; type III: OR = 0.12, 95% CI = 0.02-0.84, P = 0.032) and had a potential trend for post-MT intracranial hemorrhage (type I: reference; type III: OR = 3.09, 95% CI = 0.83-11.56, P = 0.094). CONCLUSION: We classified VA tortuosity into 3 types and showed the association between VA tortuosity and stroke outcomes after MT for basilar artery occlusion. Particularly, the mechanisms of poor outcomes in highly tortuous VA might be associated with baseline stroke severity, recanalization failure, and post-MT intracranial hemorrhage.