Case Report: An unusual case of a transposition of the great arteries with a double aortic arch: a highly complex fetal diagnosis with an unpredictable outcome

Abstract

Published data estimate the prevalence of the vascular ring at approximately 7 per 10,000 live births. The association of a double aortic arch with a D-transposition of the great arteries has been rarely described in the literature. In this study, we report the prenatal diagnosis of a 28-year-old woman. A fetal echocardiography at a gestational age of 24 weeks + 6 days showed a D-transposition of the great arteries and a double aortic arch with a ventricular septal defect and pulmonary stenosis. On the first night after birth, the baby experienced an increase in lactate levels, with the rate of oxygen saturation consistently below 80%. A few hours after birth, the patient underwent a Rashkind procedure. An echocardiography, CT chest x-ray, and CT angiogram confirmed a diagnosis with a severe reduction of the tracheal lumen (>85%) and bronchomalacia. Then, the patient underwent posterior tracheopexy and aortopexy and later an arterial switch operation, ventricular septal defect closure, and resection of a part of the infundibular septum, accepting the risk of potential neoaortic obstruction. The literature has reported only two cases of patients with a fetal echocardiogram diagnosis. Therefore, our patient is only the third one with a fetal diagnosis and the second one with a complex intracardiac anatomy, characterized not only by a ventricular septal defect but also by two separate components of the obstruction (a bicuspid valve and a dysplastic valve with a posterior deviation of the infundibular septum). In conclusion, a D-transposition of the great arteries with a double aortic arch remains an extremely unusual association. The clinical outcome of these patients presents a high degree of variability and is entirely unpredictable in prenatal life. Our greatest aim as fetal and perinatal cardiologists is to improve the management and outcome of these patients through a fetal diagnosis, recognizing types of congenital heart disease in newborns who require early neonatal invasive procedures.

Keywords: double aortic arch; fetal diagnosis; fetal echocardiography; transposition of the great arteries; vascular ring.

Figure 1

A D-TGA with a DAA. Image (A–D) The red blood vessel is the aorta with a double aortic arch; the blue one is the pulmonary artery. (A) A view from above; (B) a view from below; (C) a view from the right side; and (D) a view from the left side. (E–G) A CT scan 3D rendering of the double aortic arch in the transposition of the great arteries and the relationship with the trachea. (E) An anterior view; (F) a view from the right side; and (G) a posteroleft view. Ant, anterior; Post, posterior; R, right; L, left; Ao, aorta; LPA, left pulmonary artery; LPDA, left patent ductus arteriosus; Tr, trachea.

Figure 2

Images taken from a fetal transthoracic echocardiogram. (A) A cross-sectional view at the level of the aortic arch, with a color Doppler, where it is possible to observe the complete vascular ring surrounding the trachea, consisting of a double aortic arch. (B) A cross-sectional view at the level of the epiaortic vessels, with a color Doppler, showing the four epiaortic vessels originating separately (two on the right and two on the left). Ant, anterior; LAA, left aortic arch; LCA, Left carotid artery; LSA, left subclavian artery; Post, posterior; RCA, right carotid artery; RSA, right subclavian artery; T, trachea.

Figure 3

Images taken from a fetal transthoracic echocardiogram. (A) A long-axis view, with a color Doppler, where it is possible to observe the D-transposition with the anterior aorta and posterior pulmonary artery; the ventricular septal defect, with a dysplastic pulmonary valve. (B) An off-axis view at the level of the aortic arch, with a color Doppler, showing the anterior aorta with its complete vascular ring surrounding the trachea, consisting of a double aortic arch, and the posterior pulmonary artery. Ant, anterior; LAA, left aortic arch; LV, left ventricle; Post, posterior; RV, right ventricle; T, trachea.

Figure 4

(A,B) A preoperative transthoracic echocardiogram: a parasternal long-axis view and five-chamber view with and without a color Doppler, highlighting the posterior deviation of the infundibular septum causing subvalvular and valvar pulmonary obstruction and the restrictive interventricular septal defect. Images (C,D), A postoperative transthoracic echocardiogram: a parasternal long-axis view without and with a color Doppler, showing an excellent surgical outcome after an arterial switch operation, closure of the interventricular defect, and resection of the infundibular septum. AO, aorta; Inf Sept, infundibular septum; LV, left ventricle; PA, pulmonary artery.