Impact on the trachea in children with prenatally diagnosed vascular
ring formed by a right aortic arch
Abstract
Objective: There has been a rise in the prenatal detection of
right sided aortic arch (RAA). When associated with a left-sided
arterial duct (LD), this forms a vascular ring encircling the trachea.
Infants may have symptoms or signs suggestive of trache-oesophageal
compression but many are asymptomatic. The objective of this study was
to investigate the relationship between symptoms and severity of
tracheo-bronchial compression assessed by bronchoscopy.
Methods: Retrospective review of all cases of prenatally
diagnosed RAA-LD in the absence of associated congenital heart disease
at Evelina London Children’s Hospital and Kings College Hospital over a
4-year period between April 2015-2019. Clinical records, fetal
echocardiograms and free-breathing flexible bronchoscopy (FB) data were
reviewed. Results: 112 cases of isolated RAA-LD were identified
of whom 82 cases (73%) underwent FB. FB was performed median age of 11
months (range 1-36 months), no complications occurred. Aberrant left
subclavian artery (ALSA) was present in 86% (96/112) and mirror image
branching (MIB) in 13% (15/112). 34/112 (30%) reported symptoms during
follow up. 36/77 (47%) with ALSA who underwent FB showed
moderate-severe compression mostly at distal tracheal and carinal level
of whom 38% had parent-reported symptoms. Moderate-severe compression
was seen in 3/5 (60%) with MIB mostly at mid tracheal level of whom 3
were symptomatic but only 2 with compression. In total 36% (18/50) of
investigated asymptomatic patients showed moderate to severe
compression. Respiratory symptoms were poorly predictive of
moderate-severe compression (positive predictive value 66%).
Conclusion: The absence of symptoms did not exclude significant
tracheal compression. The anatomical effect of the vascular ring is
underappreciated when symptoms alone are used as a marker of tracheal
compression.