What are the symptoms and treatment options for thoracic outlet syndrome?

Thoracic Outlet Syndrome: Symptoms and Treatment

Symptoms of Thoracic Outlet Syndrome

Thoracic outlet syndrome (TOS) presents with varying symptoms depending on which structures are compressed, including upper extremity pain, numbness, tingling, weakness, swelling, discoloration, heaviness of the arm, claudication, coldness, pallor, and decreased pulses. 1

TOS can be classified into three distinct types based on the compressed structures:

1. Neurogenic TOS (95% of cases):

   • Arm pain and paresthesias
   • Weakness and muscle wasting in the hand
   • Symptoms exacerbated by shoulder or neck movement 2

2. Venous TOS (4-5% of cases):

   • Arm swelling
   • Discoloration of the hand
   • Visible collateral veins 3

3. Arterial TOS (1% of cases):

   • Pallor
   • Arm claudication
   • Cool extremity
   • Acute limb-threatening ischemia in severe cases 4

Physical examination findings include:

• Diminished radial pulse with provocative maneuvers
• Muscle imbalances and postural abnormalities
• Positive results on tests such as Adson's Test, Wright's Test, and Eden's Test (multiple tests should be performed due to insufficient sensitivity of individual tests)
• A systolic blood pressure difference of more than 25 mmHg between arms is considered significant 1

Diagnosis

Diagnosis is confirmed through:

• Catheter venography
• CT venography (CTV)
• MRI/MRV
• Duplex ultrasound

A dedicated MRI of the brachial plexus is the recommended imaging modality, which should include:

• High-resolution T1-weighted and T2-weighted sequences in sagittal and axial planes
• Evaluation in both neutral and arms-abducted positions to demonstrate dynamic compression 1

Treatment Approach

First-Line Treatment: Conservative Management

Conservative management is the first-line approach for TOS, including:

• Targeted physical therapy focusing on:
  • Latissimus dorsi stretching and release
  • Postural correction
  • Strengthening of antagonist muscles
  • Activity modification 1
• Anti-inflammatory medication
• Weight loss when appropriate
• Botulinum toxin injections in selected cases 5

Surgical Management

Surgical intervention is indicated for:

• Vascular TOS (arterial or venous)
• True neurogenic TOS
• Cases of nonspecific TOS that fail conservative therapy 6

Surgical decompression typically includes:

• First rib resection
• Scalenectomy
• Cervical rib resection (if present)
• Resection of the subclavius muscle and costoclavicular ligament 1

For venous TOS with thrombosis, a multimodal approach is recommended:

1. Catheter-directed thrombolysis for acute thrombosis
2. Immediate anticoagulation therapy
3. Surgical decompression typically within 4-6 weeks after initial thrombolysis 1

For arterial TOS with thrombosis:

1. Emergency catheter-directed thrombolysis for limb-threatening ischemia
2. Surgical decompression
3. Possible subclavian artery reconstruction 4

Post-Surgical Rehabilitation

Post-surgical rehabilitation is critical for long-term success:

• Passive and assisted mobilization of the shoulder starting immediately post-surgery
• Resistance strength training starting at 8 weeks postoperatively 1, 5

Important Considerations and Pitfalls

1. Delayed diagnosis beyond 14 days can significantly worsen outcomes 1

2. Potential surgical complications include:

   • Injury to subclavian vessels
   • Brachial plexus injury
   • Hemothorax
   • Pneumothorax 5

3. Avoid stent placement before surgical decompression as it can lead to stent fracture or thrombosis 1

4. Relying solely on axial imaging slices can lead to misrepresentation of stenosis severity 1

5. Inadequate surgical decompression may lead to persistent symptoms and need for reintervention 1

6. TOS is not a diagnosis of exclusion - there should be evidence for a physical anomaly that can be corrected 5