A case report of a Double Descending Dorsal Aorta in a complex congenital heart disease.

Background: Double dorsal aorta is a rare congenital embryological vascular anomaly resulting from incomplete regression and fusion of the dorsal aortae during embryogenesis. This anomaly could be associated with various other congenital heart defects (CHDs), including transposition of the great arteries, ventricular septal defect (VSD), persistent truncus arteriosus, tetralogy of Fallot (TOF), and Coarctation of the aorta (COA). Clinical presentation: This is a 9 year old girl with complex congenital heart disease and a double dorsal aorta who underwent a single ventricle palliation and this anomaly was detected during pre Fontan evaluation. She presented at age of 2 weeks with cyanosis, initial diagnosis was situs inversus, Dextrocarida, DORV with malposed great arteries, subpulmonary and valvular pulmonary stenosis, Patent ductal arteriosus and left superior vena cava. Patient was discussed with cardiothoracic team and Underwent left bidirectional Glenn at 10 months of age (2017) During pre-Fontan catheterization (June 2021) → incidental discovery of double descending (double dorsal) aorta, subsequently confirmed by CTA Fontan Completion: Deferred due to multiple severe comorbidities. Conclusion: Double dorsal aorta is an extremely rare embryologic vascular anomaly due to failure of fusion of the paired dorsal aortae. Although was asymptomatic, its identification is important in complex congenital heart disease because it may affect surgical planning and catheter based interventions. In this patient, the anomaly was detected incidentally during pre Fontan evaluation emphasizing the value of detailed preoperative imaging.