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Thoracic Outlet Syndrome

From WikiSM

Other Names

  • Neurogenic thoracic outlet syndrome (nTOS)
  • Arterial thoracic outlet syndrome (aTOS)
  • Venous thoracic outlet syndrome (vTOS)
  • Vascular thoracic outlet syndrome

Background

  • This page refers to thoracic outlet syndrome, a constellation of compressive problems that occur at the thoracic outlet

History

  • First recognized in the 19th century (need citation)

Epidemiology

  • Incidence difficult to discern with articles reporting incidence from 3-80/1000 [1]
  • Neurogenic thoracic outlet account for around 90% of cases [2]
  • Another study estimates 95% neurogenic, 4% venous and 1% arterial[3]

Introduction

Thoracic outlet and relevant anatomy[4]
Overview of the structures of the thoracic outlet. There several important features in the thoracic outlet at the base of the neck: the scalene triangle, the costoclavicular space, and the subcoracoid (pectoralis minor) space. The scalene triangle is bounded by the anterior middle scalene muscles, as well as the 1st rib. Through this space passes the brachial plexus, which is composed of five nerve roots (C5, C6, C7, C8, and T1), as well as the brachial artery. The subclavian vein passes through the costoclavicular space, anterior to the anterior scalene muscle[5]

General

  • TOS is a disorder that results in compression of neurovascular bundle exiting the thoracic outlet
  • Symptoms in the shoulder/upper extremity include pain, numbness, tingling, weakness, pallor, muscle atrophy
  • Etiology is varied and can be neurogenic, venous, arterial or a combination of them
  • Diagnosis requires a high index of suspicion
  • Conservative management can be considered in some patients, but surgical intervention is definitive

Pathophysiology

  • Usually grouped into congenital, traumatic or functionally acquired
    • Congenital - Presence of cervical rib, anomalous first rib, elongated transverse process
      • Muscular anomalies (scalenus anticus anomolies)
      • Fibrous anomalies (transversocostal, costocostal, etc.) are most common
    • Traumatic - whip-lash injuries and falls
      • Does not have to happen acutely and can progress over time after old injury
    • Functional acquired related to vigorous or repetitive activity related to sports or work
      • Typically overhead athletes or occupations with head or shoulders flexed anteriorly such as secretaries, computer operators, etc.

Anatomy: Interscalene Triangle

Anatomy: Costoclavicular Space

  • Borders
    • Anterior: subclavius muscle
    • Inferoposterior: first rib and anterior scalene muscle
    • Superior: clavicle
  • Contents
    • Brachial plexus
    • Subclavian artery
    • Subclavian vein

Anatomy: Subcoracoid Space

Risk Factors

  • Females more likely than males to be diagnosed with TOS
  • Most common ages diagnosed are between ages 20-50

Differential Diagnosis

Clinical Features

Demonstration of the elevated arm stress test[6]
Demonstration of Adsons Test[7]

History

  • Patients typically report (needs to be updated)

Physical Exam: Physical Exam Neck

  • Need to examine entire cervical spine and upper extremity
  • Inspect head and neck posture, looking for muscle atrophy
  • Observe skin color, temperature, hair distribution
  • Blood pressure can differ between arms
  • Shoulder and chest may have edema, pallor, visible collateral veins, bluish discoloration
  • Arterial TOS can have supraclavicular fullness or anuerismal pulsations
  • Motor strength of digits 1-3 is typically preserved

Slemonosky Triad

  • Tenderness in the supraclavicular area
  • Weakness of the 4th and 5th digits
  • Hand paleness and/or paresthesias with elevation of the hands

Special Tests

Evaluation

MRI identifies left subclavian vein stenosis (white arrow) after ipsilateral arm abduction[8]
a Standard radiography showing a cervical rib on the right (arrow). b Color Doppler US examination, performed with lowered arms, shows a regular diameter (12 mm) and a regular flow-C of the right subclavian artery. d Color Doppler US examination with raised arms shows artifacts due to turbulent flux. E: Duplex Doppler US shows increase in peak speed (105 cm/s)[9]

Radiographs

Ultrasound

  • Ultrasound maintains high sensitivity and specificity and is noninvasive and inexpensive (need citation)
    • Can also assess dynamic blood flow during compression maneuvers such as hyperabduction

MRI

  • Should be obtained on cervical spine or brachial plexus for neurogenic TOS
    • Indications: usually profound weakness, failure to improve with conservative management

EMG/NCS

  • Nerve conduction studies sometimes performed and are frequently normal

Other

  • Prior gold standard arteriography and venography for vascular TOS (catheter-based)
    • Uncommonly used in modern medicine
  • Injection into the scalenes rarely used but can be helpful for diagnostic purposes in some cases [10]

Classification

  • Neurogenic thoracic outlet syndrome
  • Venous thoracic outlet syndrome
  • Arterial thoracic outlet syndrome

Management

Neurogenic TOS

  • Conservative management initially
    • Some controversy regarding appropriate management
  • Multi-modal approach[11]
    • Patient education (postural mechanics, weight control, relaxation techniques)
    • TOS-specific Physical Therapy (active stretching, targeted muscle strengthening, activity modification)
    • Pharmacologic therapy
  • Pharmacologic management often provides symptomatic relief
    • NSAIDs, oral steroids used for neuropathic pain
    • Muscle relaxants, anticonvulsants and antidepressants occasionally used as adjuvants
    • Injection of local anesthetic, steroids or botulism toxin into anterior scalene/pectoralis have been used
  • Surgical indications
    • Cases that fail conservative management for 4-6 months may be candidate for surgery if there is uncontrolled pain or progressive upper extremity weakness
  • Surgical technique
    • First rib resection to decompress brachial plexus and can be performed by vascular surgeons (mostly), neurosurgeons, orthopedic surgeons and plastic surgeons.
    • Transaxillary, supraclavicular, and infraclavicular approaches used, with each having positive results with no definitively superior technique [12]
    • Scalenectomy and debridement of any fibrous bands often done depending on anatomy and symptoms

Venous TOS

  • Acute
    • Acute (<6 weeks) treated with anticoagulation, thrombolysis (catheter-directed), decompression by first rib removal and or/scalenectomy and venoplasty
    • Anticoagulation normally given for additional 3-6 months until venous patency confirmed with follow up imaging
      • Reports greater than 90 percent clinical success and less invasive methods such as robotic and thoracoscopic assisted techniques becoming more popular [13]
  • Chronic (> 6 weeks) with evidence of stenosis or occlusion treated with surgical decompression with first rib removal and or/scalenectomy
    • Thombolysis may be performed with total occlusion
    • Venoplasty can be used for residual subclavian stenosis
    • Intermittent without evidence of obstruction or occlusion may have trial of conservative management including limiting provocative position
    • Many have surgical decompression without anticoagulation or venoplasty

Arterial TOS

  • Approached venous TOS and dependent on severity of complications
    • Asymptomatic patients without evidence of arterial degeneration may be managed nonsurgically with serial arterial ultrasound every 6 months
    • No definitive guidelines exist
  • Surgical Indications
    • Evidence of arterial complications such as intimal damage, mural thrombus, embolization, post-stenotic first rib or aneurysmal formation
  • Surgical technique
    • Decompression with resection of cervical or first ribs, fibrous bands, scalenectomy and any other associated anomalies
    • Debate whether scalenectomy alone is as effective as first rib resection
    • Next step is arterial resection of the source of arterial embolus such as subclavian artery aneurysm or luminal stenosis
    • Digital revasculatization is the last step with vascular reconstruction in the form of primary anastomosis, interposition graft or axillary-brachial bypass to improve outflow of the limb

Rehab and Return to Play

Rehabilitation

  • Needs to be updated

Rehab Program PDFs

Return to Play/ Work

  • Needs to be updated

Prognosis and Complications

Prognosis

  • Needs to be updated

Complications

  • Pneumothorax, wound infection, hematoma and hemothorax
  • Potential for arterial, venous or nerve root injuries (rare)

See Also

References

  1. ↑ Citisli V. Assessment of diagnosis and treatment of thoracic outlet syndrome, an important reason of pain in upper extremity, based on literature. J Pain Relief. 2015;04(02):1–7.
  2. ↑ Freischlag J, Orion K. Understanding thoracic outlet syndrome. Scientifica (Cairo). 2014;2014:1–6.
  3. ↑ Hangge, Patrick, et al. "Paget-Schroetter syndrome: treatment of venous thrombosis and outcomes." Cardiovascular diagnosis and therapy 7.Suppl 3 (2017): S285.
  4. ↑ Jones, Mark R., et al. "Thoracic outlet syndrome: a comprehensive review of pathophysiology, diagnosis, and treatment." Pain and therapy 8 (2019): 5-18.
  5. ↑ Ohman, J. Westley, and Robert W. Thompson. "Thoracic outlet syndrome in the overhead athlete: diagnosis and treatment recommendations." Current Reviews in Musculoskeletal Medicine 13 (2020): 457-471.
  6. ↑ Otoshi, Kenichi, et al. "The prevalence and characteristics of thoracic outlet syndrome in high school baseball players." Health 9.08 (2017): 1223.
  7. ↑ Image courtesy of learnmuscles.com, "Orthopedic Assessment of Thoracic Outlet Syndrome – Adson’s, Eden’s, Wright’s"
  8. ↑ Rizzo, Stefania, et al. "Diagnostic and Therapeutic Approach to Thoracic Outlet Syndrome." Tomography 10.9 (2024): 1365-1378.
  9. ↑ Farina, Renato, et al. "The role of ultrasound imaging in vascular compression syndromes." The Ultrasound Journal 13.1 (2021): 4.
  10. ↑ Narayanasamy N, Rastogi R. Thoracic outlet syndrome (TOS): an enigma in pain medicine. In: Kaye AD, Shah RV, editors. Case studies in pain management. Cambridge: Cambridge University Press; 2014. pp. 102–108.
  11. ↑ Kuhn JE, Lebus GF, Bible JE. Thoracic outlet syndrome. J Am Acad Orthop Surg. 2015;23(4):222–32.
  12. ↑ Povlsen B, Hansson T, Povlsen SD. Treatment for thoracic outlet syndrome. Cochrane Database Syst Rev. 2014.
  13. ↑ Jones, M.R., Prabhakar, A., Viswanath, O. et al. Pain Ther (2019) 8: 5
Created by:
John Kiel on 14 June 2019 08:33:10
Last edited:
5 December 2025 19:17:52
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