Elective computed tomography in an 85-year-old man (Figure a; mixed arterial/venous contrast phase) revealed an absent right superior vena cava (SVC; asterisk) and an isolated persistent left SVC ...

beneath the entrance of the superior vena cava. A few veins merge and drain into the IVC before it makes its way up to the heart: The left renal vein, the left adrenal vein, and left gonadal veins ...