Abstract WMP40: Accuracy of Extracranial Vertebral Artery Hemodynamic Parameters in the Evaluation of Intracranial Vertebral Artery Steno-Occlusive Disease

Abstract

Objectives: To explore the accuracy of the hemodynamic parameters of the extracranial segment of vertebral artery (EVA) for evaluating the intracranial segment steno-occlusive disease. Methods: A total of 275 consecutive patients who were diagnosed as posterior circulation ischemic stroke with unilateral intracranial VA (IVA) stenosis or occlusion in our hospital from January 2015 to December 2017 were enrolled. All patients were examined by neck vascular ultrasound, CT angiography (CTA) and / or digital subtraction angiography (DSA) within one week. According to the results of DSA or CTA,the patients were divided into mild,moderate,severe stenosis and occlusion groups. The peak systolic velocity (PSV), end diastolic velocity (EDV), resistance index (RI value) of the EVA (V2 segment) were recorded and analyzed. The area under the receiver operating characteristic curve (AUC) of the PSV, EDV, RI values were calculated. The sensitivity, specificity, and accuracy of the above hemodynamic parameters were compared. Results: With the severity of the IVA stenosis, the PSV and EDV of the V2 segment were gradually decreased, and the RI value was gradually increased ( P <0.001). The AUC of the PSV, EDV, and RI values were gradually decreased when compared the occlusion before PICA(posterior inferior cerebellar artery),occlusion after PICA and severe stenosis. When EDV≤0 cm/s or RI value≥1.00, the accuracy of IVA occlusion before PICA was the highest (97.8%), with a specificity 98.7% and a sensitivity 91.9%. When EDV≤10cm/s, the accuracy of occlusion after PICA was 89.1%, with a sensitivity 91.2%, a specificity 87.9%. The accuracy of PSV≤39cm/s and RI value≥0.76 was less than that of EDV (86.2% , 84.7%).The accuracy for IVA severe stenosis were less than 85%. Conclusion: The ultrasonic hemodynamic parameters of the EVA can accurately diagnose the occlusion of the IVA and distinguish the occlusion site, but the diagnostic accuracy of the severe stenosis is relatively low.