Persistent left SVC

Imaging description A persistent left superior vena cava (PLSVC) is present in 0.3% of a healthy population and approximately 4.4% of patients with congenital heart disease [1]. A left brachiocephalic vein is either very small or absent in 65% of patients with PLSVC [2]. In approximately 10% of cases with a PLSVC, the right SVC will be absent. The CT imaging of a PLSVC is the same in all cases [2, 3], but the presence of the left brachiocephalic vein and right SVC will be variable. A PLSVC is seen as a tubular structure running along the left side of the mediastinum from the region of the origin of the left brachiocephalic vein inferiorly. In approximately 90% of cases, the PLSVC will drain into the coronary sinus (Figures 58.1–58.3). In the other 10%, the PLSVC will drain into the left atrium (Figure 58.4). Absence of the left brachiocephalic vein results in the left upper body veins draining by way of the PLSVC.