Correlation of Symptoms with Bronchoscopic Findings in Children with a Prenatal Diagnosis of a Right Aortic Arch and Left Arterial Duct

Abstract

A right aortic arch (RAA) with a left arterial duct (LAD) together encircle the trachea and have the potential to cause tracheobronchial compression and published guidelines recommend bronchoscopy in symptomatic patients. The aim of the study was to describe the incidence of tracheal compression in a cohort of prenatally diagnosed RAA and LAD. Retrospective review of clinical course and imaging of prenatal cases of RAA and LAD assessed with flexible bronchoscopy over an 11-year period. 34 cases of prenatally diagnosed RAA with LAD underwent bronchoscopy at median age of 9 months (range 0.4-123) of whom 11 had respiratory symptoms and 23 were asymptomatic. In the neonatal period, three cases demonstrated respiratory symptoms. An aberrant left subclavian artery (ALSA) was identified in 29 cases. Pulsatile tracheal compression was identified in 32/34 (94%) cases and two cases showed normal tracheal appearances. Significant tracheal compression (> 70% occlusion) was present in 25/34 (74%) cases of which 16 were asymptomatic. Significant carinal compression (> 70% occlusion) was identified in 14/34 (42%) cases, an ALSA was observed in 13/14. Surgical relief of a vascular ring has been performed in 27 (79%) cases at a median age of 15 months (range 0.6-128 months). At surgery, a fibrous remnant of an atretic left aortic arch was identified in 11/27 (41%) cases. Significant tracheal compression may be present in infants even without symptoms. If early relief of airway compression is to be achieved to promote normal development of tracheal cartilage, early bronchoscopy should be considered.

Prenatal diagnosis and clinical implications of an apparently isolated right aortic arch

“…Monitoring and assessment of children with an RAA and left arterial duct/ligament is variable, and our current practice provides a more consistent approach to this cohort. The recent meta‐analysis suggests monitoring until 2 years of age, but subsequent evidence has shown that symptoms do not correlate with tracheal compression, and further examples of this were seen in this current cohort. Stridor may not be apparent in infancy because of low air flow rates, and there may be insufficient muscle power to generate clear obstructive symptoms.…”

“…Once the lumen of the arterial duct obliterates, it remains as the arterial ligament and thus the left limb persists of the “ring” and continues to maintain the encirclement of the trachea and esophagus such that an anatomical ring is present as the right pulmonary artery passes anterior to the trachea. Classical teaching reports that an aberrant left subclavian artery is required to create a vascular ring; however, our studies of the RAA population have provided further insights such as tracheal compression in the absence of an aberrant left subclavian artery . Thus, patients with an RAA and left arterial duct/ligament should be considered to have an anatomical vascular ring.…”

“…Patients with airways or feeding symptoms suggestive of a vascular ring were investigated with bronchoscopy and MRI or CT scan. From 2014, all infants with RAA and left arterial duct, including those that were asymptomatic, were offered bronchoscopy and CT or MRI scan because of the poor correlation of symptoms with airway compression, and follow‐up included a multidisciplinary approach including airway specialists . The degree of airway compression was classified according to the Myer classification .…”

“…From 2014, all infants with RAA and left arterial duct, including those that were asymptomatic, were offered bronchoscopy and CT or MRI scan because of the poor correlation of symptoms with airway compression, and follow-up included a multidisciplinary approach including airway specialists. 14 The degree of airway compression was classified according to the Myer classification. 15 Postnatal cross-sectional imaging was used to correlate vascular anatomy relative to the airway.…”

EDUCATIONAL SERIES IN CONGENITAL HEART DISEASE: Prenatal diagnosis of congenital heart disease

“…Vascular rings are a heterogenous group of congenital anomalies caused by several morphological mechanisms that can result in oesophageal, or more commonly, symptoms of tracheobronchial compression ( 51 , 52 ). Greater than 60% of children referred for vascular ring surgery present with significant stridor; however, recent evidence may suggest that asymptomatic compression can occur during the first two years of life when the delicate cartilaginous rings of the airway are developing ( 51 , 53 ). Although associated morbidity and mortality following surgical resection of a vascular ring is low ( 54 ), some children have persistent symptoms of airway compression postoperatively ( 52 ), thus hypothesising that this may be related to a delay in repair and irreversible damage to the airways.…”