LAUSR

Background The effects of secondary collateral compensation on outcomes remain unclear in patients with acute basilar artery occlusion (BAO) after endovascular treatment (EVT). This study aimed to evaluate the benefits of the anastomosis between the posterior inferior cerebellar artery (PICA) and the superior cerebellar artery (SCA) in BAO after EVT. Methods This cohort study was conducted using data from the Endovascular Treatment for Acute Basilar Artery Occlusion Study Registry. Patients with acute BAO and treated with EVT were included. The primary outcome was a modified Rankin Scale score of 0–2 at 90 days. Safety outcomes included symptomatic intracerebral hemorrhage (SICH) and 90-day mortality. Results Of the 646 patients included in the study, 196 (30.3%) patients had a PICA–SCA anastomosis. The PICA–SCA anastomosis was significantly associated with independent functional outcome at 90 days (67/196 (34.2%) vs 109/450 (24.2%), adjusted OR (aOR) 1.80 (95% CI 1.13 to 2.86), p=0.01) and was significantly associated with a decreased rate of SICH (40/442 (9.0%) vs 5/193 (2.6%), aOR 0.29 (95% CI 0.11 to 0.76), p=0.01). No significant difference was found between PICA–SCA anastomosis and 90-day mortality (219/450 (48.7%) vs 80/196 (40.8%), aOR 0.72 (95% CI 0.48 to 1.08), p=0.11). Subgroup analysis showed that the association between independent functional outcome and PICA–SCA anastomosis was strongest in patients with middle BAO (27/77 (35.1%) vs 22/118 (18.6%), aOR 2.64 (95% CI 1.13 to 6.15), p=0.03). Conclusions The PICA–SCA anastomosis is significantly associated with better functional outcomes in patients with acute BAO after EVT, especially in those with middle BAO.