The thoracic outlet space is created by the clavicle, first rib, subclavius muscle, costoclavicular ligament, and anterior scalene muscle. It most often affects subclavian artery, vein, and the lower trunk (C8 & T1) of the brachial plexus. The neurological exam may reveal sensory changes in the ring and little finger and intrinsic weakness. Radiographs here show cervical ribs, but could also show a Pancoast tumor or even be normal. Leffert reviewed thoracic outlet syndrome and cautioned that surgery be reserved for intolerable symptoms as surgical complications can be significant.
Leffert, R. Thoracic outlet syndromes. Hand Clinic 1992; 8: 285 - 297
PMID:1613036 (Link to Abstract)