Introduction
The left brachiocephalic vein usually courses obliquely downward,
passing anterior to the aortic arch and its own brachiocephalic
branches. It joins the right brachiocephalic vein to form superior caval
vein. Rarely, the left brachiocephalic vein takes an anomalous course.
It extends lateral to the aortic arch, enters the gap between the
extrapericardial aorta and the right pulmonary artery, and crosses the
mediastinum posterior to the ascending aorta and anterior to trachea. It
then joins the superior caval vein between the azygous vein and superior
cavoatrial junction.1-5 This pattern is usually
described as the retroaortic left brachiocephalic vein (Figures
1A-1F).1-6
It is a rare anomaly, first described by Kerschner in
1888.7 The first angiographic description was provided
by Roberts and associates in 1951, with Cloez and associates recognizing
it echocardiographically in 1982. Webb and associates described computed
tomographic findings, again in 1982, while Fujimoto and associates
showed magnetic resonance findings in 1992.1,8-10 In
1992, Takada and associates described a double circumaortic left
brachiocephalic vein.11
As far as we are aware, around 250 cases have now been reported since
1980.1-80 When found in isolation, the anomalous
course is of no clinical importance. Recognition of in the setting of
associated lesions, in contrast, is important. This is because it can be
mistaken for a persistent left superior caval vein, or a vertical vein
in the setting of totally anomalous pulmonary venous connection. In this
review, we evaluated all clinical, as well as necropsy, studies
describing this venous anomaly with and without coexisting congenital
heart diseases. We have emphasized its potential implications for the
cardiac surgeon.