This patient's presentation is consistent with a patent ductus arteriosus (PDA). The 6th branchial (aortic) arch gives rise to the ductus arteriosus as well as both the left and right pulmonary arteries.
Additional structures derived from the 6th branchial arch include the intrinsic muscles of the larynx (except cricothyroid), upper esophageal musculature, cricoid cartilage, vagus nerve, and the recurrent laryngeal nerve. Of note, the artery of arch 6 is obliterated during development, while the left side of arch 6 persists as the ductus arteriosus. Normally, the ductus arteriosus closes down soon after birth, resulting in the residual ligamentum arteriosum. Risk factors for development of PDA include prematurity and TORCH infection, among others. Indomethacin is utilized to close a PDA; while prostaglandin E2 (PGE2) can be given to maintain PDA patency in patients requiring persistence of the left-to-right shunt for oxygenation (Tetralogy of Fallot, Transposition of Great Vessels).
Saenz et al. reviews congenital heart disease in infants/newborns. VSD, ASD, AV canal, pulmonary stenosis, PDA, aortic stenosis, and coarctation of the aorta are all acyanotic lesions. Congestive heart failure is the primary manifestation of these acyanotic lesions. Observations or findings suggestive of a congenital heart defect include feeding difficulties, tachypnea, subcostal recession, and growth impairment.
Weisz et al. conducted a meta-analysis assessing the efficacy of PDA ligation in pre-term infants less than 32 weeks. Surgical ligation of the PDA was associated with decreased mortality; however, infants who undergo this procedure are at elevated risk of subsequent neurodevelopmental impairment.
Illustration A summarizes the derivatives of the 6 branchial arches. Illustration B depicts the branchial arches, clefts (grooves), and pouches. Illustration C shows a patent ductus arteriosus (PDA). Illustration D demonstrates the treatment algorithm for management of PDA in a newborn.
Answer 1: The 1st branchial cleft gives rise to the epithelial lining of the external auditory meatus.
Answer 2: The 4th branchial arch develops into the cricothyroid muscle as well as the majority of the muscles of the soft palate, thyroid cartilage, vagus nerve, superior laryngeal nerve, as well as the subclavian artery and aortic arch.
Answer 3: The 4th branchial pouch yields the superior parathyroids.
Answer 5: The 6th branchial pouch does not exist, there are only 1-4 pouches.
Saenz RB, Beebe DK, Triplett LC. Caring for infants with congenital heart disease and their families. Am Fam Physician. 1999 Apr 1;59(7):1857-68.
PMID:10208705 (Link to Abstract)
Weisz DE, More K, McNamara PJ, Shah PS. PDA ligation and health outcomes: a meta-analysis. Pediatrics. 2014 Apr;133(4):e1024-46.
PMID:24639268 (Link to Abstract)