A double aortic arch is a congenital anomaly in which the ascending aorta that arises from the heart splits into two branches that completely encircle the trachea and the esophagus, eventually joining to form a descending aorta. Patients may be discovered incidentally, while difficulties in swallowing, dyspnea, stridor, and wheezing are main symptoms, usually appearing in the first years of life. Imaging studies, in the form of computed tomography angiography or magnetic resonance imaging, are necessary to make the diagnosis.
A double aortic arch (DAA) is a congenital anomaly that belongs to the group of "vascular rings", ie. abnormalities of the aortic arch that result in complete encircling of the trachea and the esophagus by blood vessels arising from the heart    . Vascular rings comprise approximately 1-2% of all congenital abnormalities of the heart and aorta , making them a rare occurrence in clinical practice. A DAA is distinguished by the division of the ascending aorta into two separate branches (one going anteriorly to the trachea and the esophagus, while the other going posteriorly) and then rejoining to form the descending aorta   . Signs and symptoms stem from compression of the trachea or the esophagus, and their onset is most commonly reported in infancy and early childhood . Dysphagia, together with feeding difficulties, is the main gastrointestinal symptom   . Conversely, stridor, dyspnea, wheezing and breathing difficulties are notable signs related to the respiratory tract  . Recurrent respiratory infections are also reported in a number of cases . On the other hand, asymptomatic patients in whom the diagnosis was discovered incidentally have been documented, the reason being atresia of one of the two encircling branches of the aorta that put less pressure on the trachea and esophagus  .The presence of additional cardiac anomalies (any forms of cyanotic congenital heart disease) that manifest with severe respiratory insufficiency and cyanosis may delay the diagnosis of a DAA .
The physician's role in raising clinical suspicion toward a congenital anomaly of the heart is crucial for diagnosing a double aortic arch. For this reason, a detailed history obtained from the patient (or the parent in the case of young children and infants) must cover the course and progression of symptoms. Because the DAA produces no murmurs, cardiac auscultation does not reveal any pathological findings, but the potential coexistence of a congenital heart disease illustrates the importance of a properly conducted physical examination. Imaging studies, however, are the cornerstone in detecting a double aortic arch. Plain radiography (showing tracheal deviation) or even transthoracic ultrasonography are of limited use in the assessment of vascular rings  , thus more advanced techniques, such as computed tomography (CT) and magnetic resonance imaging (MRI), need to be employed  . CT angiography is recommended as the gold-standard procedure in order to make a definite diagnosis, which can clearly visualize the two vessels and their structure . In the majority of cases, the posterior arch is dominant (approximately 75% of cases)  , and it is not uncommon for the less dominant arch to exhibit signs of atresia .