Unusual case of innominate artery compression syndrome in a 6-year-old symptomatic child

We present a case of a 6-year-old male child who presented to the paediatric department with history of stridor. The child was afebrile and his mother also complained about intermittent episodes of choking on lumpy food.

Baseline blood tests were normal and the chest radiograph (Fig.1) demonstrated normal appearances. Narrowing of the lower trachea was identified on micro laryngoscopy and bronchoscopy and the child was referred to Radiology to rule out the possibility of a vascular ring. On contrast-enhanced CT scan of chest, the brachiocephalic artery was noted to originate on the left side of the trachea and traversing anteriorly to it. Just above the carina, there was a definite compression over the trachea resulting in approximately 70% luminal stenosis.

Among the congenital vascular rings causing airway obstruction, brachiocephalic/ innominate artery compression syndrome is a rare cause [3].Double aortic arch is the most common symptomatic vascular ring. Right aortic arch and aberrant left pulmonary artery are less common symptomatic causes. The most frequently observed vascular ring; the aberrant right subclavian artery is not usually symptomatic [3]. 

Innominate artery compression syndrome is also recognised as “anomalous innominate artery syndrome”. It was first documented by Gross and Neuhauser in 1948 [1] and is comprised of a triad of clinical symptoms such as cough, stridor and occasional apnoea.

Computerised tomography of thorax with intravenous contrast administration is one of the most important diagnostic tools to confirm symptomatic congenital vascular rings, as was demonstrated in our case. We conducted the study following our trust protocol which is as follows: Kv: 100, mA: 40-160 with thin section (1.25 mm) reconstruction and non-ionic low-osmolar intravenous contrast through a power injector at speed of 2ml/sec. It confirmed a clearly anomalous vascular anatomy. There was a single left sided aortic arch. The brachiocephalic artery appeared slightly bulky and it originated to the left of the aorta (Fig.2, Fig.3). At the level of the thoracic inlet it traversed anterior to the trachea causing compression of tracheal airway by approximately 70%(Fig.4, Fig.5, Fig.6). The anatomy of the other major neck vessels was normal and no other obvious congenital abnormality was detected.

The findings were conveyed to the paediatric ear nose and throat team and a referral letter was sent to the regional paediatric cardiothoracic team. 

The child is currently on conservative management and awaiting his appointment with the cardiothoracic surgeon. In the regional multidisciplinary team meeting, the small thoracic cavity was thought to be contributing to the tracheal compression, given the age of this child, severity of symptoms is expected to reduce with age as little evidence of symptomatic case over 2 years of age seen in the literature[2].

Radiological findings of innominate artery compression can be subtle and should be looked for in children presenting with respiratory distress. Detailed clinical workup and radiological investigation such as contrast-enhanced CT thorax and dynamic airway assessment by fluoroscopy are crucial to the diagnosis [4].