Effect of endovascular treatment on patients with basilar artery occlusion presenting with different pathologic mechanisms: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to summarize the clinical outcomes of endovascular treatment in patients with basilar artery occlusion (BAO) with different pathologic mechanisms. METHODS: Two independent reviewers searched PubMed/MEDLINE, Embase and Cochrane Library database up to December 2022, patients with different BAO pathological mechanisms (BAO with in situ atherosclerosis vs. embolism alone without vertebral artery steno-occlusion vs. embolism from tandem vertebral artery steno-occlusion) were collected and analyzed. We calculated the odds ratios (ORs) and 95% confidence intervals (CIs) to assess the associations between clinical outcomes and BAO pathological mechanisms. RESULTS: A total of 1163 participants from 12 studies were identified. Compared with embolism alone, patients with in situ atherosclerotic BAO had a lower favorable outcome rate (modified Rankin score [mRS] 0-2: 34.5% vs. 41.2%; OR 0.83, 95% CI 0.70-0.98; P = 0.03) and moderate outcome rate (mRS 0-3: 45.8% vs. 55.4%; OR 0.65, 95% CI 0.47-0.90; P = 0.01) at 3 months and a higher risk of mortality (29.9% vs. 27.2%; OR 1.31, 95% CI 0.96-1.79, P = 0.09; adjusted OR 1.46, 95% CI 1.08-1.96). Tandem BAO had a comparable mortality risk to that of in situ atherosclerotic BAO (OR 1.37, 95% CI 0.84-2.22; P = 0.48) or embolism alone (OR 1.44, 95% CI 0.65-3.21; P = 0.43), and there were no significant differences in favorable or moderate outcomes between tandem BAO and each of the other two BAO mechanisms. CONCLUSION: Among BAO patients with endovascular treatment, embolism mechanism had better clinical outcomes than in situ atherosclerosis, and atherosclerotic mechanism was associated with a higher mortality at 3 months. RCTs are needed to further confirm clinical outcomes of BAO by different mechanisms.