A 20-year-old female presented with a pulsatile neck mass. On evaluation, she was found to have right cervical aortic arch, which is a rare anomaly. We highlight the conventional and Computed tomography angiography features of this vascular anomaly.
A 20-year-old female presented with a pulsatile mass in the right supraclavicular region. There was no history of trauma, prior catheterization, or similar complaints in the family. She denied any neurological symptoms, respiratory and swallowing difficulties. Examination of the neck revealed a pulsatile, non-tender, right supraclavicular mass, measuring around 3 × 4 cm. All the peripheral pulses were felt and no bruits were heard. Systemic examination was normal. The differential diagnosis include tortuous innominate artery, tortuous common carotid artery, aneurysm of innominate or common carotid artery, cervical aortic arch and thyrocervical trunk aneurysm.
Chest X-ray showed a widened upper mediastinum and absence of a normal aortic knob. Conventional and Computed tomography (CT) angiography [Figure 1] and [Figure 2] revealed right sided cervical aortic arch, reaching the upper margin of C7 vertebral body, and descending to the left of midline. Aortic arch is seen to cross the midline to the left at D3 vertebral level, passing posterior to and elevating the trachea and oesophagus. There was no brachiocephalic trunk [Videos 1 and 2]. The first branch of arch was the left common carotid artery arising at D2-3 vertebral level, crossing the midline, anterior to trachea. Second branch was a short right common carotid artery, dividing into external and internal carotid artery. Next branch was the right subclavian artery. The last branch was left subclavian artery, arising at D3 level on the left side, from a localized dilatation of aorta called Kommerell diverticulum. The descending aorta was normal. There were no associated cardiac anomalies.
Figure 1 (a-b): Contrast enhanced CT angiography showing cervical aortic arch and its branches. The first branch originating from the arch is the left common carotid artery (LCC), branching into left internal carotid (ICA) and external carotid arteries. The second branch is right common carotid artery (RCC). Next branch is the right subclavian artery. The last branch is left subclavian artery, arising from a localized dilatation of aorta called Kommerell diverticulum (KM). Right vertebral artery (VA) is arising directly from aorta
Figure 2 (a-c): Conventional angiography showing cervical aortic arch (CA) and its branches. The first branch originating from the arch is the left common carotid artery (LCC), branching into left internal carotid and external carotid arteries. The second branch is right common carotid artery (RCC). Next branch is the right subclavian artery. The last branch is left subclavian artery (LS), arising from a localized dilatation of aorta called Kommerell diverticulum (KM)
Cervical aortic arch is a rare vascular anomaly. The aortic arch extends high into the superior mediastinum, above the level of clavicle. A presumptive diagnosis of cervical aortic arch can be made by noting loss or decrease of femoral pulses during brief compression of the mass. It is difficult and inaccurate to establish a definitive diagnosis of pulsatile neck mass only by physical examination. Imaging modalities like X-ray, Doppler color flow imaging and angiography are useful for evaluation of such masses. A fairly consistent set of findings encountered in cervical aortic arch include-widening of superior mediastinum, absence of a normal aortic knob, cervical position of the apex of the aortic arch, separate origin of the carotid arteries with absence of a contralateral innominate artery, anomalous origin of contralateral subclavian artery from an aortic diverticulum and variable relationship of descending thoracic aorta to spine. Embryologically, this anomaly is due to regression of the fourth primitive aortic arch, with persistence of right third primitive aortic arch.  Kommerell diverticulum is the remnant of the left fourth aortic arch and gives rise to left subclavian artery. This is situated at the junction of right aortic arch and proximal descending thoracic aorta. Based on the configuration of the aorta, sequence of brachiocephalic branching and embryogenesis, cervical aortic arch can be classified into five types.  Our case, with contralateral descending aorta and presence of both common carotid arteries, was consistent with type B cervical aortic arch. In this subset, anatomic vascular ring is formed by aortic arch on the right, ligamentum arteriosum to the left, pulmonary artery anteriorly and retroesophageal segment of aorta posteriorly. Majority of the patients with cervical aortic arch are asymptomatic, whereas few present with pulsatile neck mass or symptoms due to compression of trachea and esophagus by a vascular ring. The recognized associations with cervical aortic arch are VSD, tetralogy of Fallot, pulmonary atresia with VSD, double-outlet right ventricle without pulmonary stenosis.  Rare associations include anomalous left brachiocephalic vein in subjects with chromosome 22q11.2 deletion.  Compressive symptoms need surgical intervention. In addition, they need regular follow-up as aneurysm of cervical arch requires surgical repair. Our patient is asymptomatic and is on regular follow-up. To conclude, cervical aortic arch should be considered in the differential diagnosis of pulsatile neck mass. Lack of awareness regarding this entity may lead to erroneous diagnosis and inappropriate treatment.
Nagashima M, Shikata F, Higaki T, Kawachi K. Cervical aortic arch and Kommerell's diverticulum associated with the anomalous subaortic left brachiocephalic vein in a patient with chromosome 22q11.2 deletion. Interact Cardiovasc Thorac Surg 2010;2:202-3.
Correspondence Address: Dattatreya P.V. Rao Department of Cardiology, Sri Jayadeva Institute of Cardiovascular Sciences and Research, Banneraghatta Road, 9th Block, Jayanagar, Bangalore, Karnataka India
Source of Support: None, Conflict of Interest: None