- See: Vascular Problems of the Upper Extremity:
- Discussion:
- thoracic outlet space is created by the clavicle, first rib, subclavius muscle, costoclavicular ligament, and anterior scalene muscle;
- most often affects subclavian artery, vein, and lower trunk (C8 & T1) of brachial plexus;
- both the subclavian artery and the brachial plexus traverse between the anterior and middle scalene muscles;
- most symptoms arise from neural compression;
- compression may occur at the junction of the lower trunk and 1st rib;
- in some cases, thoracic outlet syndrome will be accentuated by recurrent anterior shoulder instability, and may be the cause of the "dead arm syndrome;"
- diff dx:
- Axillopectoral Muscle:
- Symptomatic Axillopectoral Muscle in a Swimmer: A Case Report Am J Sports Med June 2013 41 1400-1403; published online before print April 30, 2013,
- Exam:
- neuro exam:
- compression of the inferior trunk (C8, T1) is seen most often;
- anterior division of inferior cord forms medial cord which gives rise to the median & ulnar nerves;
- sensory changes in the ring and little finger;
- intrinsic weakness;
- can mimic symptoms of cubital tunnel syndrome;
- upper extremity edema: may indicate effort thrombosis of axillary vein;
- extinction of pulses:
- radial pulse obliteration is not by itself specific, but loss of pulse with reproduction of symptoms is a positive test;
- decreases interscalene space by tensing anterior and middle scalenes;
- arm of the affected side placed on the sitting patients thigh with forearm supinated;
- turn head to the affected side;
- extend neck and hold breath;
- positive test is obliteration of the radial pulse;
- hyperabduction maneuver:
- tests for compression against axillary pulley which consists of pectoralis minor tendon, coracoid, and humeral head;
- components of axillary vessels and plexus bent 90 deg at the junction of the glenoid and humeral head;
- place extremity in full abduction and reach back as far possible;
- creation of a bruit in the supraclavicular area is further evidence;
- alternatively, the patient turns head toward side of compression, inhales, raises arm, and patient shrugs shoulders;
- "at attention" test:
- narrows the costoclavicular space between the clavicle & 1st rib;
- pt thrust shoulders down and back as when stading at attention or carrying a backpack
- positive test is radial pulse obliteration;
- Radiographs:
- evaluate for cervical ribs;
- CXR to rule out pancoast tumor;
- Surgical Management:
- first rib resection;
- references:
- The results of supraclavicular brachial plexus neurolysis (without first rib resection) in management of post-traumatic "thoracic outlet syndrome"
- Arterial complications of the thoracic outlet syndrome: fifty-five operative cases.
- Thoracic outlet syndrome surgery causing severe brachial plexopathy.
- Surgery for thoracic outlet syndrome may be hazardous to your health.
- First Rib Resection in Thoracic Outlet Syndrome.
Evaluation of patients with thoracic outlet syndrome.
The relationship between dead arm syndrome and thoracic outlet syndrome.
A rare cause of thoracic outlet syndrome
Arterial and Venous Injuries in Athletes. Findings and Their Effect on Diagnosis and Treatment