Vertebrobasilar system variations; Analysis with multi-detector CT angiography

Abstract

Objective: The vertebrobasilar system provides vascular nutrition to the posterior part of the brain, medulla spinalis, medulla oblongata, and cerebellum. Anatomical variations in these vascular structures increase the incidence of thrombus and aneurysms in patients. This study examines the presence of anatomical anomalies in the vertebrobasilar system. Material and Methods: Retrospective CT angiogram images of 93 adult cases over 18 years of age who were examined for any reason in KSU, Training and Research Hospital Radiology Unit. Results: Vertebral artery hypoplasia was observed in 15% of the cases. Left dominance was observed in 64.2% of the cases, right dominance in 28.6%, and co-dominance in 7.2%. Vertebral artery duplication was not observed. Vertebral artery fenestration was observed in 2.1% of cases. Vertebral artery of flexible origin was detected in 7.5%. In 57% of cases with a variable origin, the vertebral artery originated as the second branch of the subclavian artery. The right vertebral artery originating from the brachiocephalic artery was seen in 14.2%, the left vertebral artery originating from the arcus aorta was seen in 14.2%, and the left aberrant vertebral artery was seen in 14.2%. Fenestration of the basilar artery was observed in 2.1%, and hypoplasia of the basilar artery in 1.1%. Fetal type PCA variation was observed in 35.4% of cases, bilateral fetal PCA in 3.2%, right fetal PCA in 17.2%, and left fetal PCA in 15%. PCA duplication was observed in 3.2%, SCA duplication in 16.1%, unpaired single SCA in 2.1%, and SCA fenestration in 1.1%. An unpaired single AICA was observed in 15%, duplication of AICA in 2.1%, hypoplastic AICA in 6.4%, and AICA originating from SCA in 1.1%. An unpaired single PICA was observed in 12.9%, hypoplastic PICA in 2.1%, basilar artery originating PICA in 9.6%, AICA originating PICA in 4.3%, and PICA duplication in 1.1%. Conclusion: This study provides a detailed analysis of anatomical variations in the vertebrobasilar system using multi-detector CT angiography. The findings highlight the prevalence and diversity of these variations, such as vertebral artery hypoplasia, dominance patterns, fenestrations, and origin variations. These variations have significant clinical implications, particularly in the context of interventional and surgical procedures, as well as in the diagnosis and management of cerebrovascular diseases. Recognizing and understanding these anatomical differences can aid clinicians in planning more effective treatment strategies, potentially reducing the risk of complications associated with thrombus and aneurysm formation. Further research with larger and more diverse populations is recommended to validate these findings and to explore the impact of these variations on clinical outcomes. Ultimately, this study contributes to the existing body of knowledge and underscores the importance of personalized approaches in the management of vertebrobasilar system anomalies.