"Migrant" Ductal Tissue in the Aortic Arch: A Substrate for Prostaglandin-Responsive Coarctation

Neonatal aortic arch obstruction is typically related to ductal insertion and usually improves with prostaglandin E₁ (PGE₁). However, functional constriction caused by ectopic ductal tissue at atypical arch locations is rare and may mimic fixed coarctation.

A one-day-old neonate with suspected coarctation was found to have a right aortic arch with transverse arch hypoplasia, an aberrant left subclavian artery arising from a Kommerell diverticulum, and a large patent ductus arteriosus. Withdrawal of PGE₁ led to progressive distal arch constriction with left ventricular dysfunction, which reversed after reinstitution of PGE₁. Further imaging clarified the anatomy, and surgical excision of the transverse arch segment demonstrated ductal tissue on histopathology.

This case illustrates a rare mechanism of prostaglandin-responsive arch obstruction caused by ectopic ductal tissue, highlighting the importance of dynamic prostaglandin testing and multimodality imaging in differentiating functional from fixed neonatal arch obstruction.

We report, for the first time, a neonate with PGE₁-responsive coarctation of the transverse aortic arch resulting from ectopic ductal tissue, anatomically separate from the native ductus arteriosus, confirmed on histopathology.