Abstract 068: Basilar artery bifurcation anatomy as a determinant of recanalization and stroke outcome

Introduction Background: Thrombectomy improves outcomes in patients with basilar artery (BA) occlusion [1,2]. We hypothesized that the anatomic configuration of the BA bifurcation, classified as T‐ or Y‐shaped, may impact the outcome. Specifically, we expected that a T‐shaped BA would involve more deep penetrating arteries of the midbrain and thalamus, leading to greater disability or death [3,4]. Methods In this 2‐center retrospective cohort study over seven years, we included patients with stroke due to distal BA occlusion and performed blinded classification of their BA anatomy as either T‐ or Y‐shaped [Figure 1]. The primary outcomes were favorable functional status at 90 days (modified Rankin Scale 0 – 2) and successful reperfusion (TICI scores 2B or 3). Results 70 patients (mean age 66 years, 36% women) were included. 38 had T‐ and 32 had Y‐shaped bifurcations. Baseline characteristics were similar for both groups, including demographics, treatment time, baseline NIHSS, THRIVE score, posterior circulation collateral score, and presence of tandem occlusion. Comparing the T‐ to the Y‐ shape, there was no difference in the likelihood of successful reperfusion (1.09 [0.52–2.27], p=1.00) nor 90‐day favorable mRS (0‐2) score (RR: 0.68 [0.37–1.27]; p=0.18). Similarly, mortality at 30 and 90 days were not significantly affected by the type of bifurcation. Conclusion The configuration of the basilar artery does not significantly impact reperfusion success or stroke outcome.