CASE 8080 Published on 31.01.2010
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The Right-sided cervical aortic arch : A Rare Vascular Anomaly

Section

Paediatric radiology

Case Type

Clinical Cases

Authors

Moumou H, Chat L, Dafiri R.
Department of Radiology, Children’s Hospital, Rabat, Morroco.

Connected authors
moumou houda MOROCCO
Patient

10 years, male

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Clinical History
A 10-year-old boy presented with a pulsatile swelling in the right supraclavicular region, which had gradually increased in size.
Imaging Findings
On closer questioning, he noted minimal solid dysphagia. On clinical examination, normal blood pressure was noted and all peripheral pulses were palpable. Chest auscultation revealed a few basal crackles and a faint grade 2 left parasternal systolic murmur was audible in cardiovascular auscultation. A barium oesophagogram realized and revealed a smooth round posterior indentation on the upper oesophagus by the retroesophageal segment of the aortic arch (Fig. 1). Echocardiography showed normal intracardiac anatomy and demonstrated a trace aortic insufficiency. The transverse arch was badly visualized. In complement, a cervical Doppler ultrasound examination was realised which revealed a cervical aortic arch (Fig. 2). With this complex vascular anomaly, a cardiac magnetic resonance imaging was requested. This revealed a right-sided circumflex retroesophageal arch aortic which passed into the neck up to the C5-C6 level. The ordering of the aortic arch branches was defined as left common carotid, right common carotid, right vertebral, right subclavian, and left subclavian arteries from proximal to distal (Fig. 3, 4 et 5). No brachiocephalic trunk was present. The transverse arch measures 15 mm and ascending and descending aortas measuring 15,55 mm and 15,46 mm, respectively. The right vertebral artery, the third branch, originated directly off the aortic arch just proximal to the right common carotid artery. The origin of the left vertebral artery was the left common carotid artery. The left subclavian artery, the last branch, originated at the junction between the distal arch and the left descending thoracic aorta but it was not aneurysmal.
Discussion
Aortic arch anomalies are reported to occur in 0,5-3% of patients [1]. Among them, CAA is a developmental entity in which the aortic arch is cranial to its usual position. It is a rare congenital anomaly with a prevalence of less than 1/10 000 live births [2]. Since its first description by Reid in 1914 very few cases of cervical aortic arch have been reported [3].
The mechanism of development of an aortic anomaly is explained by the hypothetical double aortic arch system. During embryonic development, there are five or six pairs of aortic arches that connect the truncus arteriosus with the paired dorsal aortae. The normal arch is formed through progressive involution of segments of the third and fourth arches and the dorsal aorta, with migration of the arch from the cervical to the thoracic region [4]. There are three major theories explaining the development of the cervical aortic arch: Persistence of the second or third branchial arch combined with the resorption of the fourth arch, which normally forms the aortic arch [5, 6]; failure of the normal fourth arch to descend into the neck; and fusion of the third and fourth arches and failure to descend into the neck [7]. Often, there are associated developmental changes including abnormal laterality and branching [8].
CAA is usually present between the ages of 20 and 40 and has an equal sex distribution except when associated with aneurysm formation, which occurs in approximately 20% of patients, predominantly women [9]. Though often isolated, it may be associated with certain congenital aortic or cardiac anomalies, including aortic aneurysm, pseudocoarctation, ventricular septal defect, double outlet right ventricle, aortic stenosis, tricuspid atresia, atrial septal defect and sinus of valsalva aneurysm [10, 11].
CAA is often asymptomatic or presents as a pulsatile swelling in the neck or supraclavicular region as was seen in our case. It may also be associated with symptoms related to compression of the trachea or oesophagus, such as dyspnea or dysphagia, or recurrent respiratory infections [12]. So, though rare, CAA should be considered in the differential diagnosis of a pulsatile neck mass with the potential for being mistaken for a carotid aneurysm noted.
Indirect evidence of vascular anomalies of the aortic arch and its branches may be obtained with barium swallow, oesophagogastroscopy, and bronchoscopy showing indentation of the oesophagus or compression of the upper airways [13]. Echocardiography, computed tomography and cardiac catheterization are important diagnostic tools, but magnetic resonance angiography is particularly useful in accurately defining the complex anatomy without invasive procedures or exposure to radiation [14, 15]. The distinct advantages of magnetic resonance angiography over other imaging modalities are the ability to image in different planes, larger field of view and excellent spatial and contrast resolution.
In summary, we could successfully demonstrate the cervical location of the aortic arch and its branching pattern using contrast-enhanced MR angiography. We considered that MR angiography was suitable for evaluating congenital anomaly of the thoracic aorta.
Differential Diagnosis List
Right-sided cervical aortic arch
Final Diagnosis
Right-sided cervical aortic arch
Case information
URL: https://www.eurorad.org/case/8080
DOI: 10.1594/EURORAD/CASE.8080
ISSN: 1563-4086
Figure 1

Lateral view of barium esophagogram

Lateral view of barium esophagogram
It revealed a smooth round posterior indentation on the upper oesophagus by the retroesophageal segment of the aortic arch.
Figure 2

Cervical doppler ultrasound

Cervical doppler ultrasound
Cervical doppler ultrasound
The right common carotid and vertebral arteries emerging from the cervical arch aortic. Note their close proximity.
Figure 3

Sagittal view of MR angiography

Sagittal view of MR angiography
Shows the cervical aortic arch with the origin of the right common carotid and vertebral arteries.
Figure 4

Volume rendering of magnetic resonance angiography in left anterolateral view

Volume rendering of magnetic resonance angiography in left anterolateral view
The first vessel originating from the cervical aortic arch is the left common carotid artery. The second is the right common carotid artery.
Figure 5

Volume rendering of magnetic resonance angiography in posterior view

Volume rendering of magnetic resonance angiography in posterior view
The circumflex course of the arch and the origin of right subclavian and left subclavian arteries.