3-Vessel-Trachea View demonstrating a tortuous Ductus Arteriosus and a
persistent Left Superior Vena Cava (LSVC).
The Ductus Arteriosus is a blood vessel segment that
connects the main pulmonary trunk to the proximal descending aorta. It plays a
vital role in fetal circulation as it allows the majority of the deoxygenated
blood coming from the right ventricle to bypass the fetal lungs and join the
thoracic aorta. 50% of the blood flowing through the thoracic aorta returns to
the placenta (via the umbilical arteries) where oxygenation occurs.
A tortuous Ductus Arteriosus, with an S-configuration,
toward the end of gestation (late third trimester) is considered a normal
finding with no clinical implications, as Ductus Arteriosus aneurysms resolve
spontaneously in postnatal life. Nonetheless, a small group of infants develop
complications such as thrombo-embolism, and compression of nearby thoracic
structures. Postnatal evaluation is therefore recommended in this group.
Abuhamad, A.Z., Chaoui, R. (2016). A practical guide to fetal
echocardiography: Normal and abnormal hearts (3rd ed.). Philadelphia, PA:
Ganesan, S., Hutchinson, D.P., Sampson, A.J. (2015). Prenatal
diagnosis of ductus arteriosus aneurysm. Ultrasound, 23(4), 251-253.