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.