UNIQUE ANOMALOUS LEFT BRACHIOCEPHALIC VEIN IN A CHILD WITH
TETRALOGY OF FALLOT
A three-month-old child presented with complaints of recurrent cyanotic
spells and failure to thrive. Trans-thoracic echocardiography showed a
subaortic ventricular septal defect (VSD) with aortic-overriding and
pulmonary atresia suggestive of tetralogy of Fallot (TOF) morphology.
Computed tomography angiography was performed for further evaluation and
confirmed a subaortic VSD (Figures A & B, black star) ,
aortic-overriding and right ventricular infundibular stenosis(Figure B, black arrow) with hypoplastic confluent branch
pulmonary arteries, suggestive of Tetralogy of Fallot (TOF) morphology.
Additionally, an anomalous course of the left brachiocephalic vein
(LBCV) was noted. The LBCV was seen coursing inferiorly in the
mediastinum, posterior and lateral to the distal aortic arch and then
the proximal descending aorta (Figure C) before splitting into
two branches – a smaller superior branch at T6-T7 vertebral level(Figure D, black asterisk) and a larger inferior branch at
T7-T8 vertebral level (Figure E, black asterisk). These two
branches then crossed the midline behind the oesophagus and further
united to re-form the LBCV, which then coursed superiorly in the right
para-tracheal region to join the right brachiocephalic vein (Figure F,
dotted arrows) to form the right superior vena cava (SVC), giving a
‘double garland appearance’ (Figure G). In addition, the
azygous vein was seen draining into the inferior branch of the LBCV(Figures F and G, white arrow) rather than its usual drainage
into the SVC.
Exact delineation of systemic venous anatomy is crucial for
interventional and surgical procedures requiring systemic venous access,
such as BD Glenn shunt. In addition, central venous catheterization is
imperative before cardiac surgical procedures. If unknown, inadvertent
injury of the anomalous systemic vein can lead to mediastinal
haemorrhage. In addition, various surgical shunt procedures for
structural heart diseases are based on the systemic venous system.
The ‘U-shaped’ or ‘garland’ configuration of the retroesophageal course
of LBCV is a rare variant with limited case reports in literature.
However, a ‘double garland’ appearance with splitting of the LBCV is
unique and, to the best of our knowledge, has not been reported
previously.