Cardiothoracic Surgery: Neurogenic Thoracic Outlet Syndrome

Thoracic Outlet Syndrome (TOS)

Definition

Anatomy

Types

Neurogenic Thoracic Outlet Syndrome
- Compression of the Brachial Plexus
- Most Common Type (95%)
Venous Thoracic Outlet Syndrome (Paget-von Schroetter Syndrome)
- Compression of the Subclavian Vein
- Accounts for 3% of TOS
- *See Vascular: Venous Thoracic Outlet Syndrome
Arterial Thoracic Outlet Syndrome
- Compression of the Subclavian Artery
- Least Common Type (1%)
- Strongest Indication for Surgical Intervention
- *See Vascular: Arterial Thoracic Outlet Syndrome

Basics

Cause: Compression of the Brachial Plexus
Etiology: Neck Trauma or Repetitive Strain Injury (RSI)
Most Common Nerve Involved: Ulnar (C8-T1; Wrist Flexion & Intrinsic Hand Muscles)

Presentation

Arm Pain
Arm Paresthesia
Arm Weakness
Atrophy of Hypothenar & Interosseous Muscles
Neck Pain
Occipital Headache
Pseudoangina – Atypical Anterior Chest Wall Pain that Simulates Angina Pectoris

Diagnosis

Can Be a Clinical Diagnosis
Other Supportive Tests:
- MRI
- Electromyography
- Ulnar Nerve Conduction Velocity (UNCV)
Compression Maneuvers for TOS: (Poor Accuracy)
- Adson’s Test: Symptoms Reproduced by Ipsilateral Head Turn
- Costoclavicular Maneuver (Military Brace): Symptoms Reproduced by Passive Shoulder Depression & Retraction
- Wright Test (Halsted Maneuver/Hyperabduction Maneuver): Symptoms Reproduced by Shoulder Abduction > 90 Degrees

Grading of Compression (Based on Nerve Conduction Velocity)

Treatment

Primary Treatment: Physical Therapy
- Goal is to Reduce the Stress on Anatomical Compression Sites
- Most Patients with Slight-Mild Grade Show Significant Improvement
- Most Patients with Moderate-Severe Grade Fail to Show Significant Improvement
If Physical Therapy Fails: Surgical Decompression
- Surgery: First Rib Resection & Anterior Scalene Division