A left superior vena cava is the result of the following embryological sequence:
The left anterior cardinal vein forms the left-sided vena cava. It drains into the coronary sinus. It is drained into by a communication from the distal part of the right anterior cardinal vein that forms the right brachiocephalic vein. The latter drains blood from the right side of the head and neck.
Last reviewed 01/2018