Anomalous subaortic course of brachiocephalic vein: Evaluation on multidetector computed tomography angiography

Aim To evaluate the morphology and associated cardiovascular abnormalities in patients with an anomalous subaortic course of brachiocephalic vein on multidetector computed tomography (CT) angiography. Material and Methods A retrospective study was performed at a tertiary referral institute to identify patients with subaortic brachiocephalic vein on multidetector CT (MDCT) angiography using dual source CT scanner between January 2014 and July 2021. The morphology of the subaortic brachiocephalic vein along with the cardiovascular anatomy and associated anomalies were evaluated. Results Out of 4349 patients who had undergone MDCT angiography for evaluation of congenital heart diseases, we identified 126 (2.9%) patients with subaortic brachiocephalic vein. The subaortic brachiocephalic vein was left-sided in 125 patients while a right-sided subaortic brachiocephalic vein was identified in a patient with left isomerism. Common cardiovascular associations included tetralogy of Fallot (109/126; 88.1%), double outlet right ventricle (8/126; 6.3%) and common arterial trunk (5/126; 3.9%). The presence of a right aortic arch was seen in 78/126 (62%) patients. Some degree of right ventricular outflow obstruction was present in 119/126 (94.4%) patients; pulmonary stenosis was seen in 78 (62%) patients while pulmonary atresia was seen in 41 (32.5%) patients. Conclusion A subaortic brachiocephalic vein can coexist with various complex congenital heart diseases, most commonly tetralogy of Fallot and commonly associated with right aortic arch and pulmonary stenosis/atresia. It is important to identify this anomalous course of brachiocephalic vein before performing surgical procedures or venous catheterization to avoid potential complications.