GENERAL FEATURES OF TOS

The thoracic outlet is an area of the body located within the lower part of the neck, beginning just above and behind the clavicle and overlying the first rib, and extending to the upper part of the arm.

Thoracic Outlet Syndrome (TOS) is a general term used to describe conditions caused by compression of the major nerves and/or blood vessels in this area.

There are three principal types of thoracic outlet syndrome:

  • Neurogenic TOS
    • Caused by compression of the brachial plexus nerves that serve the entire arm and hand
    • Patients with neurogenic TOS often have gradual development of symptoms that include pain, numbness, and tingling in the arm or hand, particularly with activity or in elevated positions of the arm, which can progress to become disabling
    • 85-95% of all patients with TOS are affected by neurogenic TOS
  • Venous TOS
    • Caused by compression of the axillary and/or subclavian veins, the main veins serving the arm
    • Patients with venous TOS may have the abrupt development of vascular symptoms requiring urgent evaluation and treatment
  • Arterial TOS
    • Caused by compression of the axillary and/or subclavian arteries, the main arteries serving the arm
    • Like patients with venous TOS, individuals may have the abrupt development of vascular symptoms requiring urgent evaluation and treatment

All three types of TOS are considered rare conditions. The diagnosis of neurogenic TOS is difficult and often elusive, and may involve extensive testing, multiple specialist evaluations, and prolonged attempts at various forms of management. The diagnosis of the venous and arterial forms of TOS may appear to be relatively straightforward to vascular specialists, but in some cases the signs and symptoms of these conditions can present a confusing picture.

Treatment for TOS may include either non-surgical management or surgery. Optimal treatment for all three forms of TOS requires the experience and expertise of health care professionals knowledgeable about these conditions, and a great deal of patience.

We invite you to explore our site to find out more about TOS, to learn more about the Washington University Center for Thoracic Outlet Syndrome at Barnes-Jewish Hospital, to read some of the feature stories about our patients, and to see whether we might be able to help you or someone you know.