Diagnosis of fetal ductus arteriosus aneurysm: importance of the three-vessel view.

OBJECTIVE

To present four cases of ductus arteriosus aneurysm (DAA) detected by fetal echocardiography and highlight the value of the three-vessel view in the diagnosis of DAA.

METHODS

In addition to the standard fetal echocardiographic views, we examined the three-vessel view in four cases of DAA. The three-vessel view was achieved by sliding the transducer cranially from the four-chamber plane toward the fetal upper mediastinum to demonstrate cross-sections of the main pulmonary artery, the ascending aorta and superior vena cava arranged in a straight line from the left anterior to the right posterior aspect of the mediastinum. DAA was diagnosed when there was a tortuous ductus arteriosus with a dilation that protruded leftward of the aortic arch.

CASE SERIES: In the first case, an insulin-dependent diabetic woman underwent fetal ultrasound examination at 36 weeks' gestation showing right-to-left cardiac disproportion and bidirectional flow in the aorta and main pulmonary artery (PA). The three-vessel view showed a dilated ductus arteriosus (DA) which was stenosed at its distal end. In the second case, a woman had fetal ultrasound scans at 38 and 39 weeks' gestation for suspected intrauterine growth restriction and oligohydramnios. The scans identified an abnormal aortic arch and the three-vessel view showed an elongated vascular structure at the distal end of the PA, which was the DAA. In the third case, a woman with a high-risk obstetric history had multiple scans showing an abnormal PA to aorta relationship, with an apparent 'kink' in the PA. The three-vessel view clarified that this was the DAA. In the fourth case, a woman was scanned because of a 3-kg weight gain in 1 week. The fetal ultrasound scan showed moderate polyhydramnios with normal fetal growth and normal intracardiac anatomy and flow, and the three-vessel view demonstrated a large DA. In each of these cases, the DAA appeared to have occurred in isolation with non-specific clinical findings.

CONCLUSION

We advocate the use of the three-vessel view, in conjunction with the standard echocardiography views currently employed, to assist in the diagnosis of DAA.