The left retro-aortic brachiocephalic vein: morphologic data and diagnostic ultrasound in 27 cases

A left retro-aortic brachiocephalic vein is a rare anatomic entity. A retro spective study was made of 5218 congenital cardiopathies treated between 19 82 and 1998 in a medico-surgical department of paediatric cardiology. A lef t retro-aortic brachiocephalic vein was demonstrated in 27 patients, i.e. a n incidence of 0.5%, The chief cardiopathy in these patients was a tetralog y of Fallot in 25 cases (93%). Among these 25 cases of Fallot's tetralogy t he aortic arch was rightsided in 19 cases (70%). The paraclinical diagnosis of this anomaly was facilitated by ultrasonography, provided it was sought for. In this series 6 cases (22%) were discovered during surgery without p revious ultrasound diagnosis. The embryological origin of the left retro-ao rtic brachiocephalic v. differs from that of the venous trunk in its classi cal anatomic form. It derives from the inferior (but not superior) transver se plexuses, connecting the two anterior cardinal veins. One of the main co nsequences of this anomaly is its possible confusion with other vascular st ructures, particularly the right pulmonary artery. Such confusion may give rise to inappropriate surgical procedures. The differential diagnosis is fa cilitated by the use of the Doppler: the venous flow is biphasic and regula ted by respiration, whereas the Doppler recording from a pulmonary artery i s that of a characteristic systolic arterial flow.