Rationale: Recently, two prospective multicenter RCT reported a potential beneficial effect of endovascular thrombectomy (EVT) in patients with an acute symptomatic basilar artery occlusion (BAO). However, the high rate of crossover in BEST study and the long-term of recruitment in BASICS study influenced the validity of the results.

Objective: To assess the outcomes and prognostic factors of recanalization therapy in patients with BAO, caused by a CTA/MRA/DSA confirmed occlusion of the basilar artery.

Study design: This is a prospective observational study. Study population: Patients with acute ischemic stroke and a confirmed basilar artery occlusion by CTA/MRA/DSA.

Main study parameters/outcomes: Favorable outcome at day 90 defined as a modified Rankin Score (mRS - functional scale) of 0-3. The estimate will be adjusted for the known prognostic variables age, time from onset to treatment, stroke severity (NIHSS), PC ASPECT and collateral flow and adjusted and unadjusted estimates with corresponding 95% confidence intervals will be reported.

Acute basilar artery thrombosis is associated with a poor prognosis. Prevalence of basilar artery occlusion are not known in Vietnam.Various treatments were tried in groups of patients with acute ischemic stroke due to basilar artery occlusion, but evidence based was not cleared previous studies. Therefore, we conduct this study to evaluate the efficacy and safety of recanalization therapies, which included intravenous thrombosis alone, endovascular alone, or bridging IVT and endovascular, in basilar artery occlusion stroke patients.

Inclusion Criteria:

• Symptoms and signs compatible with ischemia in the basilar artery territory.
• Basilar artery occlusion (BAO) confirmed by CTA or MRA or DSA.
• Age 18 years or older
• Patients were treated with one of these among therapies IVT alone, bridging IVT and thrombectomy or thrombectomy alone..

Exclusion Criteria:

• Patients did not agree to enroll.

Imaging exclusion criteria:

• High-density lesion consistent with hemorrhage of any degree
• Significant cerebellar mass effect or acute hydrocephalus

All patients who were acute ischemic stroke due to basilar artery occlusion admitted People 115 Hospital and treated recanalisation therapies : intravenous tPA, bridging tPA and thrombectomy or thrombectomy alone.