Predictors of Unfavorable Outcome After Endovascular Thrombectomy for Acute Basilar Artery Occlusion with Mild...

Unfavorable outcome is not uncommon after endovascular thrombectomy (EVT) in patients with acute basilar artery occlusion (BAO) presenting with mild symptoms, but predictors remain unclear. This study aimed to identify clinical and imaging predictors of unfavorable outcome in patients with BAO and mild symptoms.

We retrospectively analyzed 71 patients with acute BAO and baseline NIHSS ≤ 10 who underwent EVT. Patients were classified by 90-day modified Rankin Scale (mRS) scores into favorable (0-2) and unfavorable (3-6) outcome groups. Clinical and imaging variables, including perfusion parameters, were compared. Independent predictors for unfavorable outcome were assessed using multivariable logistic regression. Subgroup analyses were performed according to onset-to-puncture time (early ≤ 6 h vs. late > 6 h) and door-to-puncture time (immediate ≤ 120 min vs. delayed > 120 min).

Of 71 patients, 25 (35.2%) had unfavorable outcomes. These patients were older, had higher admission NIHSS score, and more frequently showed pons-midbrain-thalamus (PMT) hypoperfusion (Tmax > 6 s). Multivariable analysis identified PMT hypoperfusion as an independent predictor of unfavorable outcome (adjusted OR, 3.93; 95% CI, 1.02-15.23; P = 0.047). Stratified analysis showed PMT hypoperfusion was strongly associated with unfavorable outcome in patients treated in the late time window (aOR, 14.90; 95% CI, 1.35-163.75; P = 0.028) and delayed EVT (aOR, 16.12; 95% CI, 1.16-230.70; P = 0.038), but not in the early or immediate treatment.

In BAO with mild symptoms, perfusion imaging may predict the outcome. PMT hypoperfusion independently predicted unfavorable outcome, particularly in patients treated in the late window or with delayed EVT.