Effect of collateral status on the outcomes of endovascular treatment of acute basilar artery occlusion due to large-artery atherosclerosis.

Objective: Authors of this study aimed to evaluate the effects of collateral status on the prognostic value of endovascular treatment (EVT) in patients with basilar artery occlusion (BAO) due to large-artery atherosclerosis (LAA).

Methods: The study included 312 patients from the BASILAR (Endovascular Treatment for Acute Basilar Artery Occlusion Study) registry who had undergone EVT for acute BAO due to LAA and whose composite collateral scores were available. The effects of collateral status on EVT were assessed based on the composite collateral score (0-2 vs 3-5). The primary outcome was a favorable outcome (modified Rankin Scale score of 0-3) at 90 days.

Results: The composite collateral score was 0-2 in 130 patients and 3-5 in 182. A good collateral status (composite collateral score 3-5) was associated with a favorable outcome (66/182 [36.3%] vs 31/130 [23.8%], adjusted odds ratio [aOR] 2.21, 95% CI 1.18-4.14, p = 0.014). A lower baseline National Institutes of Health Stroke Scale (NIHSS) score was an independent predictor of a favorable outcome in the poor collateral status group (aOR 0.91, 95% CI 0.87-0.96, p = 0.001). In the good collateral status group, there was a significant correlation between favorable outcomes and a younger age (aOR 0.96, 95% CI 0.92-0.99, p = 0.016), lower baseline NIHSS score (aOR 0.89, 95% CI 0.85-0.93, p < 0.001), lower proportion of diabetes mellitus (aOR 0.31, 95% CI 0.13-0.75, p = 0.009), and shorter procedure time (aOR 0.99, 95% CI 0.98-1.00, p = 0.003).

Conclusions: A good collateral status was a strong prognostic factor after EVT in patients with BAO underlying LAA. A shorter procedure time was associated with favorable outcomes in patients with a good collateral status.