Intended Thrombectomy for Basilar Artery Occlusion with Mild Deficits: Evidence from a Multicenter Prospective...

Background The role of endovascular thrombectomy (EVT) in basilar artery occlusion (BAO) with mild deficits (National Institutes of Health Stroke Scale [NIHSS] score < 10) remains uncertain. Purpose To compare the outcomes of EVT combined with best medical management (BMM) versus BMM alone in individuals with BAO and mild deficits. Materials and Methods Consecutive eligible patients treated at eight stroke centers between September 2023 and March 2025 were enrolled in a prospective registry. The primary outcome was 90-day functional independence (modified Rankin Scale [mRS] score of 0-2). Secondary outcomes were 90-day excellent outcome (mRS score of 0-1), death, and early neurologic deterioration (END), defined as a four-point or greater increase in NIHSS score within 72 hours. Primary analyses followed an intention-to-treat-like framework with inverse probability weighting (IPW). As-treated and per-protocol sensitivity analyses were used to assess the robustness of the results and the impact of treatment crossover (EVT after END). Results Among 401 participants (mean age, 64.9 years ± 8.9 [SD]; 278 male participants), the median onset-to-arterial-puncture time in the EVT group was 402 minutes (IQR, 271-583 minutes). After multivariable adjustment in the IPW-adjusted data, EVT was associated with higher odds of functional independence (odds ratio [OR], 1.55 [95% CI: 1.17, 2.06]) and excellent outcome (OR, 1.48 [95% CI: 1.09, 2.03]) and lower odds of death (OR, 0.65 [95% CI: 0.45, 0.77]) and END (OR, 0.35 [95% CI: 0.20, 0.61]). Subgroup analyses demonstrated EVT-related functional benefit in participants with NIHSS scores of 6-9 but not in those with NIHSS scores of 0-5 (P for interaction = .02 for functional independence); however, in participants with NIHSS scores of 0-5, EVT was associated with lower odds of END and death. Sensitivity analyses accounting for treatment crossover showed attenuated functional advantage for EVT. Conclusion In participants with BAO and mild deficits, EVT plus BMM was associated with better outcomes than BMM alone; however, functional benefit was observed in those with NIHSS scores of 6-9 but not those with NIHSS scores of 0-5. Chinese Clinical Trial Registry no. ChiCTR2300075711 © RSNA, 2026 Supplemental material is available for this article.