Basilar artery and posterior circulation collaterals score on digital subtraction angiography predicts prognosis for acute basilar artery occlusion treated with endovascular thrombectomy

Background and purpose The prognosis of acute basilar artery occlusion (BAO) is poor, carrying a high risk of disability and mortality if left untreated. Several radiological scores may predict the clinical outcome of acute BAO treated with endovascular thrombectomy (EVT). This study aims to assess the prognostic value of a novel radiological score, the Basilar Artery and Posterior Circulation Collaterals (BAPCOR) score. Methods A retrospective analysis was performed on consecutive acute BAO patients treated with EVT. The BAPCOR score, a 15-point digital subtraction angiography (DSA)-based grading system, was used to assess thrombus burden and posterior circulation collateral status. Successful recanalization was defined as a modified thrombolysis in cerebral infarction (mTICI) score 2b-3, and a good outcome was defined by a modified Rankin Scale (mRS) score of ≤ 2 at 3 months. Receiver operating characteristic (ROC) curve determined the area under the curve (AUC) and the optimum cutoff value. Multivariate regression analysis was used to identify predictors of clinical outcome. Results Among the enrolled patients, 85.1% (40/47) achieved successful recanalization (mTICI, 2b-3) and 34.0% (16/47) had a good outcome (mRS score 0–2). The ROC analysis indicated that the AUC of the BAPCOR score was 0.868 (95%CI: 0.753–0.983). A cut-off value of predicting poor outcome was set at 8.5, with sensitivity of 0.688 and specificity of 0.935. Correlation analysis showed a moderate negative correlation between BAPCOR and mRS. Conclusion The BAPCOR scoring system is associated with outcomes in acute BAO patients treated with EVT with superiority in reflecting thrombus burden and collateral status.