IV Thrombolysis in Basilar Artery Occlusion: Outcomes and Comparison With Endovascular Thrombectomy.

Background And Objectives: Recanalization is considered a prerequisite for favorable outcome in basilar artery occlusion (BAO). Intravenous thrombolysis (IVT) has been successfully used for eligible patients with BAO well beyond the 4.5-hour time window but has been largely underrepresented in the best medical management arms in recent randomized controlled trials of recanalization therapy in BAO. We aimed to analyze the outcomes of patients with BAO treated with IVT only and to compare IVT with endovascular thrombectomy (EVT).

Methods: This observational single-center, retrospective cohort study included consecutive patients with BAO treated with IVT and/or EVT up to 48 hours of symptom onset during 1995-2022. The primary outcome was favorable functional outcome (modified Rankin Scale 0-3) at 3 months collected by a stroke physician by phone. In the first part, we described the outcomes and factors associated with functional outcome in the IVT-only cohort during 1995-2022. In the second part, we used doubly robust inverse probability-weighted regression adjustment models to compare functional outcome of patients treated with IVT vs EVT+/-IVT during 2010-2022.

Results: In the whole cohort of 376 patients with acute BAO treated with recanalization therapy, 245 (65.2%) received only IVT. In the IVT-only cohort, most patients had moderate-to-severe clinical presentation (median NIH Stroke Scale 18) but no extensive early ischemic changes in the posterior circulation on admission. Half of them had onset-to-treatment time over 6 hours. 46.5% of the IVT-treated patients achieved 3-month favorable functional outcome, whereas mortality was 35.9%. sICH occurred in 11.1%. In a multivariable analysis, younger age, milder symptom severity, and less baseline ischemic changes predicted favorable functional outcome. In the 2010-2022 cohort, when compared with patients treated with EVT+/-IVT (n = 121), the IVT-only cohort (n = 122) had higher odds for favorable functional outcome (IVT 58.2% vs EVT 43.0% (aOR 2.82 [95% CI 1.31-6.05]).

Discussion: IVT alone produced outcomes comparable with those in recent trials of endovascular BAO recanalization. Furthermore, in head-to-head comparison in our cohort, the IVT-only approach was more often associated with favorable outcome than EVT+/-IVT. Thus, it should not be overlooked as the first-line recanalization therapy in acute BAO, even in longer time windows.

Classification Of Evidence: This study provides Class IV evidence that tPA is as effective as thrombectomy for basilar artery thrombosis.