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Thoracic Outlet Syndrome in Emergency Medicine

  • Author: Andrew K Chang, MD; Chief Editor: Erik D Schraga, MD  more...
Updated: Mar 04, 2014


Thoracic outlet syndrome (TOS) is a broad term that refers to compression of the neurovascular structures in the area just above the first rib and behind the clavicle that results in upper extremity symptoms. It represents a constellation of symptoms. The cause, diagnosis, and treatment are controversial. The brachial plexus (95%), subclavian vein (4%), and subclavian artery (1%) are affected such that TOS is usually classified into neurogenic, venous, and arterial forms.[1] Most presentations to the emergency department (ED) are nonemergent and require only symptomatic treatment and referral.



The brachial plexus trunks and subclavian vessels are subject to compression or irritation as they course through 3 narrow passageways from the base of the neck toward the axilla and the proximal arm. The most important of these passageways is the interscalene triangle, which is also the most proximal. This triangle is bordered by the anterior scalene muscle anteriorly, the middle scalene muscle posteriorly, and the medial surface of the first rib inferiorly. This area may be small at rest and may become even smaller with certain provocative maneuvers. Anomalous structures, such as fibrous bands, cervical ribs, and anomalous muscles, may constrict this triangle further. Repetitive trauma to the plexus elements, particularly the lower trunk and C8-T1 spinal nerves, is thought to play an important role in the pathogenesis of thoracic outlet syndrome (TOS).

The second passageway is the costoclavicular triangle, which is bordered anteriorly by the middle third of the clavicle, posteromedially by the first rib, and posterolaterally by the upper border of the scapula.

The last passageway is the subcoracoid space beneath the coracoid process just deep to the pectoralis minor tendon.




United States

Because no objective confirmatory test is available for thoracic outlet syndrome (TOS), there is much disagreement with regards to its true incidence, with reported figures ranging from 3-80 cases per 1000 people.


Neurologic TOS is generally neither progressive nor likely to resolve spontaneously.

Arterial or venous TOS usually results in a good outcome with adequate treatment.


Neurologic complications include chronic pain.

Arterial complications include thrombosis, thromboembolism, acute ischemia, and poststenotic aneurysm formation.

Venous thrombosis may develop.


Overall, the entity is approximately 3 times more common in women than in men. However, the sex ratio varies depending on the type of thoracic outlet syndrome (TOS) (eg, neurologic, venous, arterial), as follows:

  • Neurologic - Female-to-male ratio approximately 3.5:1
  • Venous - More common in males than in females
  • Arterial - No gender predilection


The onset of symptoms usually occurs in persons aged 20-50 years.

Contributor Information and Disclosures

Andrew K Chang, MD Associate Professor, Department of Emergency Medicine, Albert Einstein College of Medicine, Montefiore Medical Center

Andrew K Chang, MD is a member of the following medical societies: American Academy of Emergency Medicine, American Academy of Neurology, American College of Emergency Physicians, Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.


J Stephen Bohan, MD, FACP, FACEP Director, Observation Medicine, Clinical Director, Department of Emergency Medicine, Harvard Medical School, Brigham and Women's Hospital

J Stephen Bohan, MD, FACP, FACEP is a member of the following medical societies: American College of Emergency Physicians, American College of Physicians, Royal Society of Medicine

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

David Eitel, MD, MBA Associate Professor, Department of Emergency Medicine, York Hospital; Physician Advisor for Case Management, Wellspan Health System, York

David Eitel, MD, MBA is a member of the following medical societies: American College of Emergency Physicians, American Society of Pediatric Nephrology, Society for Academic Emergency Medicine, Society of Critical Care Medicine

Disclosure: Nothing to disclose.

Chief Editor

Erik D Schraga, MD Staff Physician, Department of Emergency Medicine, Mills-Peninsula Emergency Medical Associates

Disclosure: Nothing to disclose.

Additional Contributors

Richard S Krause, MD Senior Clinical Faculty/Clinical Assistant Professor, Department of Emergency Medicine, University of Buffalo State University of New York School of Medicine and Biomedical Sciences

Richard S Krause, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Emergency Medicine, American College of Emergency Physicians, Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

  1. Fugate MW, Rotellini-Coltvet L, Freischlag JA. Current management of thoracic outlet syndrome. Curr Treat Options Cardiovasc Med. 2009 Apr. 11(2):176-83. [Medline].

  2. Sanders RJ, Hammond SL, Rao NM. Diagnosis of thoracic outlet syndrome. J Vasc Surg. 2007 Sep. 46(3):601-4. [Medline].

  3. Demondion X, Herbinet P, Van Sint Jan S, Boutry N, Chantelot C, Cotten A. Imaging assessment of thoracic outlet syndrome. Radiographics. 2006 Nov-Dec. 26(6):1735-50. [Medline].

  4. Huang JH, Zager EL. Thoracic outlet syndrome. Neurosurgery. 2004 Oct. 55(4):897-902; discussion 902-3. [Medline].

  5. Barkhordarian S. First rib resection in thoracic outlet syndrome. J Hand Surg [Am]. 2007 Apr. 32(4):565-70. [Medline].

  6. Franklin GM, Fulton-Kehoe D, Bradley C, Smith-Weller T. Outcome of surgery for thoracic outlet syndrome in Washington state workers' compensation. Neurology. 2000 Mar 28. 54(6):1252-7. [Medline].

  7. Povlsen B, Belzberg A, Hansson T, Dorsi M. Treatment for thoracic outlet syndrome. Cochrane Database Syst Rev. 2010. (1):CD007218. [Medline].

  8. Aufderheide TP. Peripheral arteriovascular disease. Emerg Med: Concepts and Clinical Practice. 1998. 2:1844-7.

  9. Brooke BS, Freischlag JA. Contemporary management of thoracic outlet syndrome. Curr Opin Cardiol. 2010 Nov. 25(6):535-40. [Medline].

  10. Hood DB, Kuehne J, Yellin AE, Weaver FA. Vascular complications of thoracic outlet syndrome. Am Surg. 1997 Oct. 63(10):913-7. [Medline].

  11. Oates SD, Daley RA. Thoracic outlet syndrome. Hand Clin. 1996 Nov. 12(4):705-18. [Medline].

  12. Plewa MC, Delinger M. The false-positive rate of thoracic outlet syndrome shoulder maneuvers in healthy subjects. Acad Emerg Med. 1998 Apr. 5(4):337-42. [Medline].

  13. Sanders RJ, Hammond SL, Rao NM. Thoracic outlet syndrome: a review. Neurologist. 2008 Nov. 14(6):365-73. [Medline].

  14. Weber RJ, Lebduskin S. Rehabilitation issues in plexopathies. Phys Med Rehabil. 1988. 996-8.

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