Acute Basilar Artery Occlusion: Does Recanalization Improve Clinical Outcome? A Critically Appraised Topic

Background: Acute basilar artery occlusion (BAO) is a devastating, life-threatening condition that accounts for approximately 1% of all strokes. Currently, there is no consensus on the best treatment strategy for patients with BAO. Whereas endovascular reperfusion therapy is proven to improve outcomes in anterior circulation stroke, its benefit in acute BAO has not been confirmed in randomized controlled trials. Objective: To critically assess the current evidence regarding recanalization in acute BAO, and to discuss the outcomes of different treatment strategies in the management of acute BAO. Materials and Methods: The objective was addressed through the development of a critically appraised topic that included a clinical scenario, structured question, literature search strategy, critical appraisal, assessment of results, evidence summary, commentary, and bottom-line conclusions. Participants included consultant and resident neurologists, and content experts in the field of vascular and hospital neurology. Results: A recent meta-analysis was selected for critical appraisal to assess the recanalization hypothesis in acute BAO. The authors performed a systematic literature search through August 2013 and pooled in the analysis of 45 studies and 2056 patients. The overall recanalization rate was 75% in this meta-analysis. The authors concluded that recanalization was associated with a 1.5-fold reduction in the risk of death or dependency, and a 2-fold reduction in the risk of mortality. Subgroup analysis comparing different modes of intervention revealed data that favor endovascular intervention over intravenous thrombolysis (IVT). However, the authors were not able to obtain a statistically valid direct comparison of the 2 therapies as their meta-analysis included observational studies. Subgroup analysis on the treatment window revealed that onset-to-treatment time of <12 hours was associated with a higher recanalization rate (81%) and a lower intracranial hemorrhage rate (10%) compared with onset-to-treatment time >12 hours. Conclusions: IVT is the standard of care for BAO patients presenting within 4.5 hours of symptom onset, whereas recanalization is associated with better outcomes regardless of how recanalization is achieved. Randomized controlled trials comparing IVT plus endovascular treatment versus IVT in the treatment of acute BAO are needed to provide evidence-based management guidance.