Unique anomalous left brachiocephalic vein in a child with tetralogy of fallot

A 3-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 (Figure 1A & B, black star), aortic-overriding and right ventricular infundibular stenosis (Figure 1B, black arrow) with hypoplastic confluent branch pulmonary arteries, suggestive of 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 1C) before splitting into two branches – a smaller superior branch at T6-T7 vertebral level (Figure 1D, black asterisk) and a larger inferior branch at T7-T8 vertebral level (Figure 1E, black asterisk). These two branches then crossed the midline behind the esophagus 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 1F, dotted arrows) to form the right superior vena cava (SVC), giving a 'double garland appearance' (Figure 1G). In addition, the azygous vein was seen draining into the inferior branch of the LBCV (Figure 1F 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.1 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. Saurabh Deshpande: Conceptualization; Writing—original draft; Writing—review and editing. Pratyaksha Rana: Conceptualization; Writing—original draft; Writing—review and editing. Megha M Sheth: Supervision. Hit Jivani: Writing—review and editing. T M Harishkar: Writing—review and editing. The authors declare no conflict of interest. Yes, the data that support the findings of this study are available on request from the corresponding author. According to our institutional ethics committee policy (U.N. Mehta Institute of Cardiology and Research Centre, Ahmedabad), ethical clearance is not required for a case report/image correspondence. Deidentified image data of the patient was used in retrospective manner from the radiological archive of the department. Hence, consent was not obtained/applicable. No animals or humans were used nor harmed for this research manuscript.