The thoracic duct empties into the venous system, specifically at the point where the left internal jugular vein and the left subclavian meet.
The thoracic duct joins cervical lymphatics and drains into the superior aspect of the jugulosubclavian vein confluence behind the left sternocleidomastoid muscle. Care must be taken to avoid injury to these structures during surgery. A search for cervical, rudimentary, or broad first ribs should be done.
Thoracic outlet obstruction. Scalene triangle. Venous TOS occurs secondary to compression that occurs in the costoclavicular space. The borders of the costoclavicular space are the first rib, the costoclavicular ligament, the subclavius, and the anterior scalene muscle.