Thoracic Outlet Syndrome in Emergency Medicine Workup

Updated: Aug 09, 2017
  • Author: Andrew K Chang, MD, MS; Chief Editor: Erik D Schraga, MD  more...
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Workup

Laboratory Studies

With the rare exception of a vascular cause, the vast majority of ED presentations of thoracic outlet syndrome are not emergent. Screening tests may be appropriate if indicated and to rule out other causes. Once the clinical diagnosis is made, most of the imaging studies and other tests should be reserved for the outpatient setting.

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Imaging Studies

The noninvasive imaging modality of choice in evaluating patients with suspected thoracic outlet syndrome is magnetic resonance imaging (MRI). However, computed tomography (CT) plays an important role as well, especially in delineating bone anatomy. [4]

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Radiography

Cervical radiography may demonstrate a skeletal abnormality [5]

Chest radiography findings may include the following:

  • Cervical or first rib: This is usually associated with the arterial form of TOS but also can be a predisposition to developing the neurologic form following neck trauma.
  • Clavicle deformity
  • Pulmonary disease
  • Pancoast tumor
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Ultrasonography

Color flow duplex scanning for suspected vascular thoracic outlet syndrome (TOS)

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Arteriography

Indications for arteriography include the following:

  • Evidence of peripheral emboli in the upper extremity
  • Suspected subclavian stenosis or aneurysm (eg, bruit or abnormal supraclavicular pulsation)
  • Blood pressure differential greater than 20 mm Hg
  • Obliteration of radial pulse during EAST
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Venography

Indications for venography include the following:

  • Persistent or intermittent edema of the hand or arm
  • Peripheral unilateral cyanosis
  • Prominent venous pattern over the arm, shoulder, or chest
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Other Tests

The following special studies are generally appropriate in the outpatient setting; they should be arranged by the primary care physician once the patient has been discharged from the ED:

  • Nerve conduction evaluation via root stimulation and F wave is the best direct approach to evaluation of neurologic TOS.
  • Electromyography (EMG) is unreliable and does not provide objective evidence of TOS.
  • Cervical myelogram, CT scan, or MRI may be appropriate for patients suspected of having cervical disk disease or spinal cord disease.
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