There are many venous anomalies that can occur in the chest. The one that is relatively common and can involve CVL placement is a left SVC. Most often a left SVC is present along with a right SCV, as shown in the diagram. There may or may not be a left BCV connecting the two.

A CVL from the left side that has entered a left SVC will stay on the left, near the aorta. The commonest form of a left SVC drains into the coronary sinus, but most CVLs are not long enough to make the turn into this vessel.