Case Report: Persistent fifth aortic arch with coarctation and fourth aortic arch interruption causing infant heart...

Persistent fifth aortic arch (PFAA) with concomitant interruption of the fourth aortic arch is an extremely rare congenital aortic arch malformation. Due to its unique anatomical configuration, variable hemodynamic presentations, and the potential for adequate fetal circulatory compensation in some cases, prenatal ultrasonographic diagnosis remains challenging. This condition is frequently misidentified as a normal variant or confused with other aortic arch anomalies. We report a male infant with unremarkable prenatal ultrasound who presented at 90 days of life with a 12-days history of worsening cough. Postnatal echocardiography confirmed the diagnosis of PFAA with coarctation and Type A interruption of the fourth aortic arch. Resection of the coarctation segment and reconstruction of the aortic arch using an autologous pericardial patch were performed, along with end-to-side anastomosis between the fourth arch and the descending aorta. One year postoperatively, echocardiography revealed unobstructed aortic arch flow without pressure gradient and recovery of left ventricular function. Through a systematic analysis of prenatal sonographic features, postnatal clinical progression, imaging evolution, and surgical outcomes, this case provides insights into prenatal recognition, postnatal management, and clinical decision-making for this rare aortic arch malformation.