Answer E. Vascular Ring
Discussion
Congenital vascular rings result from abnormal development of the
aortic arch and its associated vessels during embryonic growth. Vascular
rings (VR) make up 1% of total congenital abnormalities of the heart
and vascular system. They can partially or completely encircle the
trachea and esophagus resulting in airway or GI manifestations. These
anomalies typically involve the aortic arch, the brachiocephalic
arteries, and the ductus arteriosus. VR can take several forms,
including double aortic arch (DAA), right aortic arch with left
ligamentum arteriosum, innominate artery compression, and pulmonary
artery sling. DAA is the most common form of vascular ring
malformations. It is a complete VR and occurs due to failure of
regression of one of the bilateral aortic arches during development.
There are multiple types of DAA including: dominant right arch with
small left arch, dominant left arch with small right arch, and balanced
aortic arches.
Symptoms and presentations associated with double aortic arch vary
based on the size of the ring formed by the vascular structures. Small
restrictive rings can present early with respiratory failure after
birth, apneic episodes, and cyanosis. Later presentations may include
noisy breathing, persistent cough, recurrent lower respiratory tract
infections, persistent dysphagia, failure to thrive, and exercise
intolerance.
Diagnosing vascular rings typically involves a combination of imaging modalities, including:
- Echocardiogram – can delineate the type of double aortic arch
- Chest x-ray – may show the loss of the aortic knob and the indentation of the trachea.
- Barium swallow study – shows an indentation of the esophagus. The
persistence of a bilateral indentation of esophagus on the frontal view
is suggestive of a double aortic arch.
- CT (with IV contrast) or MRI – helps to elucidate the anatomy
- Bronchoscopy – can be used to evaluate the airway anatomy, observe
the extent of compression or collapse, and rule out other anomalies
The treatment for vascular rings depends on the severity of symptoms
and the anatomy present. Conservative management includes nutritional
support and monitoring of respiratory symptoms. In symptomatic cases
with significant airway or esophageal compression, surgical intervention
is often required. Surgical procedures aim to divide or reposition the
abnormal vascular structures to relieve the compression on the trachea
and esophagus, thus improving respiratory and feeding functions.
The choice of surgical approach depends on the specific type and
anatomy of the vascular ring. The most common surgical approach involves
dividing and separating the abnormal vascular structure causing the
compression. For example, in a double aortic arch, one of the arches may
be divided so the trachea and esophagus regain their normal position.
The long-term prognosis for children who undergo surgical correction
of vascular rings is generally excellent. Once the compression is
relieved, most children experience significant improvement in their
respiratory and feeding symptoms. They can lead normal, healthy lives
without ongoing issues related to the vascular ring. Postoperative
complications after surgery are infrequent but can include feeding
intolerance, persistent coughing, stridor and wheezing. Phrenic nerve or
recurrent laryngeal nerve injuries during surgery can result in
diaphragm or vocal cord paralysis. The formation of an aorto-esophageal
fistula can also occur. Other complications include persistent noisy
breathing from tracheomalacia and/or bronchomalacia due to the presence
of the vascular ring during fetal development.
It is important to note that the prognosis varies depending on
several factors, including the type and complexity of the vascular ring,
the age at which surgery is performed, and any associated congenital
heart defects or other medical conditions. Close follow-up with
pediatric specialists is typically recommended to monitor the child's
progress and address any potential long-term issues.
References
-
Hanneman K, Newman B, Chan F. Congenital Variants and Anomalies of the Aortic Arch. Radiographics. 2017; 37:32-51.
- Kau T, Sinzig M, Gasser J, Lesnik G, Rabitsch E, Celedin S, Eicher W,
Illiasch H, Hausegger KA. Aortic development and anomalies. Semin
Intervent Radiol. 2007; 24:141-152.
-
Licari A, Manca E, Rispoli GA, Mannarino S, Pelizzo G, Marseglia GL.
Congenital Vascular Rings: A Clinical Challenge for the Pediatrician.
Pediatric Pulmonology. 2015; 50:511-524.
-
Priya S, Thomas R, Nagpal P, Sharma A, Steigner M. Congenital
anomalies of the aortic arch. Cardiovasc Diagn Ther. 2018; 8:S26-S44.
