Thoracic outlet syndrome is a condition whereby symptoms are produced from compression of nerves or blood vessels, or both, because of an inadequate passageway through an area between the base of the neck and the armpit (the thoracic outlet). The thoracic outlet is surrounded by muscle, bone, and other tissues. Any condition that results in enlargement or movement of the tissues of or near the thoracic outlet can cause the thoracic outlet syndrome. These conditions include an extra rib from the neck at birth, development of fibrous bands, muscle enlargement, injuries, weight gain, or in rare cases tumours at the top of the lung. Often no specific cause is found.
Symptoms include neck, shoulder and arm pain, numbness or impaired circulation to the extremities (causing discoloration). Often symptoms are most noticeable when the arm is positioned above the shoulder or extended (reaching for a shelf or hanging washing. Patients can have a wide spectrum of symptoms from mild and intermittent, to severe and constant. Pains can extend to the fingers and hands, causing weakness.
The diagnosis of thoracic outlet syndrome is suggested by the symptoms and supported by clinical examination. Further supportive testing can include electrical tests, duplex ultrasound and magnetic resonance imaging (MRI).
Treatment of the thoracic outlet syndrome can usually be successful with physiotherapy. Treatments include a variety of exercises that effectively stretch open the tissues of the thoracic outlet.
Some patients with severe, resistant symptoms can require surgical operations to open the thoracic outlet. The thoracic outlet is approached through an incision 10-15cm long either above the collar bone or just below the armpit depending on the cause of compression symptoms. These procedures include division of extra fibrous or muscular bands and/or removal (resection) of the first rib in order to spare injury to the affected nerve and blood vessels from ongoing compression.