Multidedector computerized tomography evaluation of arcus aorta branchi̇ng pattern variations and vertebral artery dominance-hypoplasia frequency

Purpose: Anatomic variants and branching patterns of the aortic arch are often seen as a random finding during routine computed tomography (CT) scanning. These variations may be important or cause symptoms such as dysphagia when performing endovascular interventions or head and neck surgery. This study analyzed the common anatomic variations in aortic arch branches in patients with multislice computed tomography imaging technique, the prevalence of variations in the aortic arch branches in the Turkish population. It aimed to identify and evaluate relationships between gender, branching variants, and asymmetric VAs. In addition, we aimed to determine the relative frequency of vertebral artery dominance-hypoplasia in Turkish society. Material and method: Between August 2009 and 2019, 1003 men, 1034 women, totally 2037 cases were evaluated with thoracic computed tomography angiography (CTA) for various indications. 2-dimensional multiplanar reformats, 3-dimensional images were created with MIP and volume rendering methods. Aortic arc branching variations were assigned letters and numbers according to the classification of Wang et al. Prevalence of aortic arch branching variations It was aimed to investigate the prevalence of hypoplasia and domination over the V1 segments of the vertebral arteries and their relationship with each other. Findings: Our study is important that it constitutes the largest series created in our country with 2037 cases. The classical branching pattern known as normal is in our study classified as type A was observed in 1562 cases (76.7%). Different kinds of variations were observed in the remaining 475 patients (24.3%) in aortic arch branching. The most common variation was the variation that we classified as type B1, which was named as bovine aortic arc, which ACCS received from TB originated in 315 cases (15.5%). The second row is the variation in which the left vertebral artery we detected in 97 cases (4.7%) originated directly from the aortic arch between ACCS and ASS and classified as type C1. 29 aberrant right subclavian artery in 7 cases (1.4%) 0.35) right aortic arch, double aortic arch in 4 cases (0.2%), and situs inversus totalis in 1 case. In addition, aortic coarctation was observed in 5 cases. In our study, vertebral artery dominance (VAD) was detected in 512 cases (25.3%), in 204 of these cases (10.1%), right VAD and in 308 (15.2%) left VAD. In our study, vertebral artery hypoplasia (VAH) was observed in 405 cases (19.8%), in 246 (12%) of them, right VAH and in 159 (7.8%) of left VAH. Conclusion: The prevalence of aortic arch branching variations is high and varies geographically.Vascular surgeons, interventional radiologists, head and neck surgeons should be aware of these anomalies before the planned surgery or interventional radiological procedure, since these variations, generally which are clinically insignificant, are particularly important in patients who scheduled for head and neck surgery or interventional radiological procedures. Vascular variations which are detected incidentally during routine CT scans should always be reported. Our findings showed that MSCT, which is a fast and safe diagnostic method in the evaluation of aortic arch variants and branches, produces reliable results due to the contribution of multiplanar reformate reconstruction images. According to our findings, the incidence of aortic arch branching variations in women appears to be significantly increased compared to men. Variations in which the left vertebral artery arises directly from the aortic arch were strongly associated with right VAD and left VAH.Our study also provided simple information about prevalance and relative frequency of vertebral artery dominance and hypoplasia among the Turkish population