Thoracic Outlet Syndrome in Emergency Medicine Guidelines

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

In 2016, the Society for Vascular Surgery published new reporting standards as listed here [2] :

Neurogenic TOS

Neurogenic TOS should be defined by the presence of three or more of the following four criteria.

1. Local Findings

  • a. History: Symptoms consistent with irritation or inflammation at the site of compression—scalene triangle—in the case of NTOS and pectoralis insertion site in the case of NPMS—along with symptoms due to referred pain in the areas near the thoracic outlet. Patients may complain of pain in the chest wall, axilla, upper back, shoulder, trapezius region, neck, or head (including headache).
  • b. Examination: Pain on palpation of the affected area as above

2. Peripheral Findings

  • a. History: Arm or hand symptoms consistent with central nerve compression. Such symptoms can include numbness, pain, paresthesias, vasomotor changes, and weakness (with muscle wasting in extreme cases).
    • i. These peripheral symptoms are often exacerbated by maneuvers that either narrow the thoracic outlet (lifting the arms overhead) or stretch the brachial plexus (dangling; often driving or walking/running).
  • b. Examination: Palpation of the affected area (scalene triangle or pectoralis minor insertion site) often reproduces the peripheral symptoms.
    • i. Peripheral symptoms are often produced or worsened by provocative maneuvers that are believed to narrow the scalene triangle (EAST) or to stretch the brachial plexus (ULTT).

3. Absence of other reasonably likely diagnoses (cervical disk disease, shoulder disease, carpal tunnel syndrome, chronic regional pain syndrome, brachial neuritis) that might explain the majority of symptoms

4. In those who undergo it, the response to a properly performed TEST INJECTION is positive.

Venous TOS (VTOS)

VTOS is defined as an abnormality of the subclavian vein caused by extrinsic compression at the costoclavicular junction (VTOS) or, rarely, the pectoralis minor space (VPMS).

In general, all three of the following criteria must be present in patients with this diagnosis, but even if the patient is asymptomatic, ultrasonic or venographic documentation of axillosubclavian thrombus in the absence of other factors is enough for the diagnosis to be made.

1. History

  • a. Arm swelling, usually with discoloration and heaviness
    • i. This can occur with the arms overhead only, suggesting nonthrombotic VTOS, or present as a fixed symptom, suggesting subclavian vein thrombosis.
  • b. Absence of inciting cause (indwelling catheter, malignant neoplasm)

2. Examination

  • a. Visible arm swelling at rest, although if the arm swelling is reported only with exertion or arms overhead, the arm may be normal at rest.
  • b. Arm discoloration
  • c. Shoulder, upper arm, or chest wall venous collaterals

3. Imaging

  • a. Documentation of venous compression at the costoclavicular junction by ultrasound, venography, or cross-sectional imaging
    • i. If the vein is occluded from mid upper arm to the innominate in the setting of appropriate symptoms (and no secondary cause is present), VTOS may be assumed to be present.
    • ii. If the vein is patent but abnormal, the location of the abnormality (costoclavicular junction or pectoralis minor space) should be documented.
    • iii. If the vein appears normal at rest, results of ultrasound or venography with the arm abducted >90 degrees should be reported.

Arterial TOS (ATOS)

ATOS is defined as an objective abnormality of the subclavian artery caused by extrinsic compression and subsequent damage at the scalene triangle. Such an abnormality can be symptomatic (ischemia or embolization) or asymptomatic (aneurysm, occlusion, or silent embolization). Loss of pulses or discoloration with provocative maneuvers in patients with NTOS does not mean that ATOS is present; documented injury to the subclavian artery or symptomatic arm ischemia with arms elevated must be present for this diagnosis to be made.

As many as possible of the following items should be documented during evaluation for ATOS.

1. History

  • a. Classic symptoms and signs of chronic or acute ischemia
    • i. Rest pain in the arm, hand, or fingers
    • ii. Paresthesias (numbness or tingling or falling asleep) in the arm and hand
    • iii. Ischemia of the arm and hand with extreme exertion or arms overhead
    • iv. Loss of dexterity in the hand, clumsiness of the arm
    • v. Coldness color changes, temperature sensitivity in the arm and hand, or other symptoms suggestive of Raynaud syndrome
  • b. Isolated finger pain or ulceration (suggestive of embolization)
  • c. A history of
    • i. Potential prior embolic events or arterial thrombosis
    • ii. Trauma to the shoulder and upper extremity
    • iii. Fractures of clavicle or first rib
  • d. Any known anatomic or genetic abnormalities (eg, a cervical rib)

2. Examination

  • a. Status of pulses in the arm (brachial, radial, ulnar) at rest
  • b. Pulse examination, symptoms, and ideally objective hemodynamic data with arms positioned to reproduce potentially ischemic symptoms c. Presence of hand or digit lesions consistent with arterial thrombosis or embolization
  • d. Neurologic examination
  • e. Presence of arm or hand weakness, atrophy, or paralysis
  • f. Presence of ulceration, gangrene, or tissue loss
  • g. Presence of vasospastic changes
  • h. Presence of discoloration
  • i. Presence of pulsatile mass at supraclavicular or infraclavicular fossa
  • j. Presence of bruit at supraclavicular or infraclavicular fossa

3. Results of imaging

  • a. Duplex ultrasound, including direct imaging of the subclavian and axillary arteries and outflow arteries of the arm
  • b. Hemodynamic testing including finger plethysmography (at rest, with provocative maneuvers, or after exercise if normal at rest and suspicion is high)
  • c. Arteriography, including digital subtraction imaging to the tips of the fingers
  • d. CT angiography or MR angiography

4. Imaging to evaluate the bony thoracic outlet (CT, MRI, chest radiography, or cervical spine films). The presence or absence of a cervical rib, elongated C7 transverse process, or anomalous first rib should be reported.

5. TOS disability scale