Thoracic Outlet Syndrome


Review Sections

Thoracic Outlet Syndrome Icon    Thoracic Outlet Syndrome

Thoracic outlet syndrome (TOS) results from compression of the neurovascular structures as they pass through the thoracic outlet, primarily the interscalene triangle, the costo-clavicular space and the subpectoral tunnel. Some authors also include the area anterior to the humeral head, passageway for the median nerve roots and the axilla (1).

Thoracic outlet syndrome (TOS) is a highly controversial diagnosis. Experts strongly disagree on the pathophysiology, diagnosis and treatment. Plewa and Delinger estimate over 95% of patients with TOS have compression of the brachial plexus which cannot be objectively tested by any specific test (2). The form of TOS which seems to be most commonly mentioned is caused by the presence of a cervical rib although the incidence is estimated at one per million (3).

Thoracic outlet syndrome is primarily an exclusion diagnosis most often based on patient history and careful examination (4).

(1) Vanti C, Natalini L, Romeo A, Tosarelli D, Pillastrini P. Conservative treatment of thoracic outlet syndrome. A review of the literature. Eura Medicophys 2007 Mar;43(1):55-70.
(2) 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.
(3) Urschel JD, Hameed SM, Grewal RP. Neurogenic thoracic outlet syndromes. Postgrad Med J 1994 Nov;70(829):785-9.
(4) Watson LA, Pizzari T, Balster S. Thoracic outlet syndrome part 1: clinical manifestations, differentiation and treatment pathways. Man Ther 2009 Dec;14(6):586-95.

Clinical Reviews

Thoracic Outlet Syndrome: Prevention

Risk factors and prevention strategies for thoracic outlet syndrome (TOS) are very difficult to access for a number of reasons. Since its introduction as a diagnostic term in 1956 the diagnosis itself has remained controversial with some doubting the clinical entity even exists. Thoracic outlet syndrome has become an umbrella diagnosis that includes scalenus anticus syndrome, cervical rib syndrome, costo-clavicular syndrome and hyperabduction syndrome, to name just a few.

Thoracic Outlet Syndrome: Diagnosis

Thoracic outlet syndrome is the center of a raging controversy in the healthcare field. Vanti et al stated “Thoracic outlet syndrome (TOS) has been one of the most debated clinical topics over the last 120 years”. Some experts feel it is over-diagnosed while others think it is under-diagnosed. The fact that 120 TOS surgeries were performed at the Mayo Clinic over a 34 year period while in less than half of that time a single Colorado thoracic surgeon performed 1400 TOS surgeries is indicative of the controversy relating to TOS.

Thoracic Outlet Syndrome: Therapy

As discussed in the thoracic outlet syndrome (TOS) prevention and diagnosis monographs, TOS is a very controversial topic in the medical literature. Disagreements over methods to arrive at a diagnosis, whether it is under-diagnosed or over-diagnosed or even exists at all have resulted in a gross lack of evidence related to treatment. A recent Cochrane Review could only locate 1 randomized clinical trial (RCT) on treatment.

Medical Subject Heading (MeSH) Information

MeSH Term: Thoracic Outlet Syndrome

Scope Note: A neurovascular syndrome associated with compression of the BRACHIAL PLEXUS; SUBCLAVIAN ARTERY; and SUBCLAVIAN VEIN at the superior thoracic outlet. This may result from a variety of anomalies such as a CERVICAL RIB, anomalous fascial bands, and abnormalities of the origin or insertion of the anterior or medial scalene muscles. Clinical features may include pain in the shoulder and neck region which radiates into the arm, PARESIS or PARALYSIS of brachial plexus innervated muscles, PARESTHESIA, loss of sensation, reduction of arterial pulses in the affected extremity, ISCHEMIA, and EDEMA. (Adams et al., Principles of Neurology, 6th ed, pp214-5).

MeSH Synonyms:
  • Thoracic Outlet Syndrome
  • Outlet Syndrome, Thoracic
  • Outlet Syndromes, Thoracic
  • Syndrome, Thoracic Outlet
  • Syndromes, Thoracic Outlet
  • Thoracic Outlet Syndromes
  • Neurovascular Syndrome, Thoracic Outlet
  • Thoracic Outlet Neurovascular Syndrome
  • Aperture Syndrome, Thoracic Outlet
  • Superior Thoracic Aperture Syndrome
  • Costoclavicular Syndrome
  • Costoclavicular Syndromes
  • Syndrome, Costoclavicular
  • Syndromes, Costoclavicular
  • Neurogenic Thoracic Outlet Syndrome
  • Thoracic Outlet Syndrome, Neurogenic
  • Scalenus Anticus Syndrome
  • Syndrome, Scalenus Anticus
  • Thoracic Outlet Nerve Compression Syndrome
  • Nerve Compression Syndrome, Thoracic Outlet
  • Venous Thoracic Outlet Syndrome
  • Arterial Thoracic Outlet Syndrome
  • Neurologic Syndrome, Thoracic Outlet
  • Thoracic Outlet Neurologic Syndrome
Applicable MeSH Subheadings:
  • analysis
  • anatomy and histology
  • blood
  • classification
  • complications
  • congenital
  • diagnosis
  • diagnostic imaging
  • drug therapy
  • economics
  • embryology
  • enzymology
  • epidemiology
  • ethnology
  • etiology
  • genetics
  • history
  • immunology
  • metabolism
  • mortality
  • nursing
  • organization and administration
  • pathology
  • physiology
  • physiopathology
  • prevention and control
  • psychology
  • radiotherapy
  • rehabilitation
  • statistics and numerical data
  • surgery
  • therapy
  • veterinary
See Related MeSH Terms:

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