Endovascular Treatment in Subtypes of Posterior Large Vessel Occlusion: A Pooled Analysis From 2 Registries

BACKGROUND: Current evidence on differential outcomes of endovascular therapy for the different pathological subtypes of vertebrobasilar artery occlusion is still limited. The study aimed to compare characteristics and clinical outcomes among distinct pathological subtypes of vertebrobasilar artery occlusion undergoing endovascular therapy. METHODS: This was a posthoc pooled analysis of 1320 patients from the BASILAR (Endovascular Treatment for Acute Basilar Artery Occlusion Study; 2014–2019) and the PERSIST (Posterior Circulation Ischemic Stroke Registries; 2015–2018) registries. This analysis included adults (≥18 years) with moderate to severe vertebrobasilar artery occlusion who underwent endovascular therapy within 24 hours of their last known well. Patients were stratified by stroke mechanism: group 1 (embolism without vertebral stenosis), group 2 (tandem embolism from vertebral stenosis/occlusion), and group 3 (in situ atherosclerotic thrombosis). Baseline characteristics, procedural details, and clinical outcomes were compared across these 3 groups. The primary outcome was a favorable functional outcome, defined as a modified Rankin Scale score of 0 to 3 at 90 days. Baseline characteristics, procedural details, and clinical outcomes were compared across these 3 groups. Because the primary independent variable was categorical with no single referent category, all comparisons among the 3 groups were conducted as exploratory analyses. RESULTS: A total of 1067 patients were included (group 1, n=257 24.08%; group 2, n=176 16.49%; group 3, n=634 59.42%). The overall successful recanalization rate was 84.72% (904/1067), and the favorable functional outcome (90-day modified Rankin Scale score of 0–3) rate was 33.40% (275/1063). The procedure time in group 1 was significantly shorter than that in groups 2 and 3 (median time, 90 versus 135 and 110 minutes, P <0.001). There was no significant difference in the primary outcome of a favorable functional outcome among the 3 groups. After adjusting for potential confounders, group 1 exhibited a significantly higher proportion of patients achieving excellent outcomes at 90 days (modified Rankin Scale score, 0–1) compared with groups 2 and 3 (21.9% versu 17.1%, adjusted odds ratio, 0.57 95% CI, 0.32–0.99; 21.9% versus 16.5%, adjusted odds ratio, 0.59 95% CI, 0.37–0.95). No significant differences were observed in recanalization rates, favorable functional outcome, symptomatic intracranial hemorrhage, or mortality among the 3 groups. CONCLUSIONS: The outcome of endovascular therapy for vertebrobasilar artery occlusion may vary based on the stroke mechanism; patients with embolism without vertebral artery steno-occlusion may achieve excellent outcomes compared with other causes. REGISTRATION: URL: http://www.chictr.org.cn ; Unique identifier: CTR1800014759 and CTR2000033211.