Bridging or Direct Thrombectomy in Posterior Circulation Large-Vessel Occlusion Stroke: Analysis of Binational Registries and Meta-Analysis

BACKGROUND AND OBJECTIVES: The role of IV thrombolysis before endovascular thrombectomy (bridging thrombectomy, BT) in posterior circulation large-vessel occlusion stroke remains uncertain. This study evaluated the effectiveness and safety of BT compared with direct thrombectomy (DT) using data from 2 nationwide registries and an updated meta-analysis. METHODS: Patients from collaborative registries in Taiwan and South Korea who underwent thrombectomy for vertebral, basilar, and posterior cerebral artery occlusions were included. This observational study included hospital-based registry data with standardized collection of treatments and outcomes. Propensity score matching was applied to adjust for baseline differences between BT and DT groups. Outcomes included 90-day modified Rankin Scale (mRS) score, mortality, successful reperfusion, and symptomatic intracranial hemorrhage (sICH). We also performed a systematic review and meta-analysis of observational studies comparing BT vs DT in posterior circulation large-vessel occlusion stroke. RESULTS: Among the combined 9,942 patients, 873 (median age 71, 32% female) who underwent thrombectomy for posterior circulation stroke were analyzed. Of them, 281 received BT and 592 received DT. BT was associated with a lower 90-day mRS score (median 3 vs 4; adjusted odds ratio [OR] 1.44 per 1-point improvement, 95% CI 1.09-1.91) and lower mortality (17.4% vs 26.9%; adjusted OR 0.51, 95% CI 0.33-0.81). The proportions of successful reperfusion (79.3% vs 81.1%) and sICH (2.5% vs 2.9%) were comparable. In propensity score-matched cohorts (n = 205 each), BT remained associated with better functional outcomes (OR 1.44, 95% CI 1.00-2.07) and reduced mortality (matched OR 0.45, 95% CI 0.26-0.78). The meta-analysis, which included 39 studies and 7,288 patients, confirmed that BT was associated with higher odds of achieving 90-day mRS score 0-2 (OR 1.57, 95% CI 1.28-1.94), 90-day mRS score 0-3 (OR 1.33, 95% CI 1.05-1.68), and lower mortality (OR 0.77, 95% CI 0.61-0.97), without an increased risk of sICH (OR 1.01, 95% CI 0.71-1.44). DISCUSSION: BT was associated with better 90-day functional outcomes and lower mortality, without increasing hemorrhagic risk in posterior circulation large-vessel occlusion stroke. These findings support the use of BT in eligible patients, pending further validation from randomized trials. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that in patients with posterior circulation stroke undergoing thrombectomy, previous IV thrombolysis is associated with better 90-day functional outcomes and lower mortality without increasing hemorrhagic risk.