To compare the efficacy and safety of mechanical thrombectomy (MT) in patients with Vertebrobasilar Tandem Occlusion (VBTO) and Isolated Basilar Artery Occlusion (IBAO).

Posterior circulation strokes present significant treatment challenges due to their complex anatomy and variable collateral circulation. VBTO involves acute basilar artery (BA) occlusion alongside occlusion or severe stenosis of one or both vertebral arteries (VAs). Approximately 64% of patients with BA occlusion have significant VA stenosis or occlusion. MT is increasingly employed to treat AIS caused by posterior circulation occlusions. However, the comparative outcomes between VBTO and IBAO remain unclear.

PubMed, Embase, and Cochrane were searched from inception to September 2024. Risk Ratios (RR) were pooled with 95% Confidence Interval (CI) using the Random effects model in Review Manager version 5.4.1. Efficacy outcomes included 90-day functional independence (modified Rankin Scale (mRS) 0-2) and successful recanalization (Thrombolysis in cerebral infarction (TICI) 2b-3) while safety outcomes included symptomatic intracerebral hemorrhage (sICH) and 90-day mortality. Study quality was evaluated using the Newcastle-Ottawa Scale. Publication bias was assessed through funnel plot. Sensitivity analysis was conducted for heterogeneity.

Six cohort studies with a sample size of 647 were extracted and analyzed. MT in VBTO was found to have significantly increased the risk of sICH (RR=2.20; 95% CI: [1.09-4.46]; p= 0.03; I² =0%) compared to IBAO. There was no significant difference in terms of 90-day functional independence (mRS 0-2) (RR=1.25; 95% CI:[0.73-2.12]; p 0.42; I² =69%), successful recanalization (TICI 2b-3) (RR=0.96, 95% CI:[0.81-1.13]; p=0.60; I² =76%), and 90-day mortality (RR=1.28; 95% CI:[0.78-2.10]; p=0.33; I² =72%).

MT in patients with VBTO significantly increases the risk of sICH compared to IBAO. However, both groups showed comparable outcomes in terms of 90-day functional independence, successful recanalization, and 90-day mortality.