The Basilar Artery on Computed Tomography Angiography Prognostic Score for Basilar Artery Occlusion

Abstract

B asilar artery occlusion (BAO) comprises ≈1% of all strokes and is one of the most devastating neurological conditions associated with high risk of disability and mortality if recanalization does not occur. [1][2][3] Despite recent breakthroughs in the treatment of large vessel occlusion ischemic stroke, BAO patients were excluded from recent randomized controlled trials, 4-8 and the evidence for treatment is derived largely from small retrospective studies.9,10 The Australian Urokinase Stroke Trial is the only completed randomized trial, in which 16 patients were randomized, and a good outcome was observed in 4 of 8 patients who received intra-arterial urokinase compared with 1 of 8 patients in the control group, 11 with a significant association between successful recanalization and favorable outcome in pooled observational data.12 However, the largest prospective observational study in BAO patients showed similar outcomes Background and Purpose-Basilar artery occlusion is associated with high risk of disability and mortality. This study aimed to assess the prognostic value of a new radiological score: the Basilar Artery on Computed Tomography Angiography (BATMAN) score. Methods-A retrospective analysis of consecutive stroke patients with basilar artery occlusion diagnosed on computed tomographic angiography was performed. BATMAN score is a 10-point computed tomographic angiography-based grading system which incorporates thrombus burden and the presence of collaterals. Reliability was assessed with intraclass coefficient correlation. Good outcome was defined as modified Rankin Scale score of ≤3 at 3 months and successful reperfusion as thrombolysis in cerebral infarction 2b-3. BATMAN score was externally validated and compared with the Posterior Circulation Collateral score. Results-The derivation cohort included 83 patients with 41 in the validation cohort. In receiver operating characteristic (ROC) analysis, BATMAN score had an area under receiver operating characteristic curve of 0.81 (95% confidence interval [CI], 0.7-0.9) in derivation cohort and an area under receiver operating characteristic curve of 0.74 (95% CI, 0.6-0.9) in validation cohort. In logistic regression adjusted for age and clinical severity, BATMAN score of <7 was associated with poor outcome in derivation cohort (odds ratio, 5.5; 95% CI, 1.4-21; P=0.01), in validation cohort (odds ratio, 6.9; 95% CI, 1.4-33; P=0.01), and in endovascular patients, after adjustment for recanalization and time to treatment (odds ratio, 4.8; 95% CI, 1.2-18; P=0.01). BATMAN score of <7 was not associated with recanalization. Interrater agreement was substantial (intraclass coefficient correlation, 0.85; 95% CI, 0.8-0.9). BATMAN score had greater accuracy compared with Posterior Circulation Collateral score (P=0.04). Conclusions-The addition of collateral quality to clot burden in BATMAN score seems to improve prognostic accuracy in basilar artery occlusion patients.

Collateral Scores and Outcomes after Endovascular Treatment for Basilar Artery Occlusion

“…Our data are in agreement with PC-CS as a predictor of outcomes; however, the presence of both PCoAs was not related to favorable outcomes in our sample. In BAT-MAN cohort, all patients were treated with acute reperfusion therapies and outcomes were analyzed at 90 days, similarly to our protocol [12]. In that study, a better accuracy of the BATMAN score over PC-CS was suggested, which is in contrast to our results [12].…”

“…In BAT-MAN cohort, all patients were treated with acute reperfusion therapies and outcomes were analyzed at 90 days, similarly to our protocol [12]. In that study, a better accuracy of the BATMAN score over PC-CS was suggested, which is in contrast to our results [12]. However, intra-arterial urokinase infusion was allowed in BAT-MAN cohort, and some included patients were not submitted to EVT.…”

“…A total of 80 mL of contrast material (Omnipaque ® , 300 mg/mL, GE Healthcare AS, Oslo, Norway) was injected at a rate of 5 mL/s and followed by a 50-mL normal saline chase at a rate of 5 mL/s. CTA was used to identify BAO and also to evaluate recently published scores, named posterior circulation collateral score (PC-CS) [11] and basilar artery on CTA (BATMAN) score [12]. We also screened the presence of both posterior communicating arteries (PCoAs).…”

“…Collateral status is strongly recognized as one of the most important prognostic factors in anterior circulation large vessel occlusion strokes [10]. Recently, posterior circulation computed tomography angiography (CTA) collateral scores have been proposed and linked to outcomes in BAO [11,12]. We aim to describe outcomes of BAO patients that underwent EVT in a comprehensive stroke center in Brazil and to analyze which previous published CTA collateral score better predicts outcomes in these patients.…”

Neuroimaging Predictors of Clinical Outcome in Acute Basilar Artery Occlusion

“…In their multivariate analysis, an unfavorable BATMAN score (defined as <7) was independently associated with poor outcome (defined as an mRS of 4 or greater) in both derivation and validation cohorts. A BATMAN score of <7 had a sensitivity of 84% and specificity of 76% to predict a poor outcome (22). …”