Thoracic outlet compression syndrome
- Describes a collection of upper limb neurological and vascular symptoms
- Arise from proximal compression of neurovascular structures
- Usually affects middle aged women
- Male : female ratio is 1:3
- 10% have bilateral symptoms
Pathophysiology
- Compression can result from a bone, muscle or fibromuscular band
- Compressing lesion is usually congenital
- 30% of cases follow trauma (e.g. whiplash injury)
Clinical features
- Neurological features are more common than vascular
- Subclavian artery aneurysm and axillary vein thrombosis are uncommon
- Symptoms often worsened by carrying weights or lifting arms above head
- Differential diagnosis includes:
- Cervical spondylosis
- Distal nerve compression
- Pancoast's tumour
- Connective tissue disorders
- Vascular and venous embolic disease
- Diagnosis depends mainly on the history
- Signs are few but diagnosis may be confirmed with the
- Roos test - Reproduction of symptoms with arms flexed and abducted
- Subclavian compression tests (e.g. Adson's manoeuvre)
- Loss of radial pulse with head turned to opposite side and neck extended
Investigations
- The results of investigations are often normal
- A CXR may show a cervical rib
- Nerve conduction studies may be needed to exclude a distal nerve compression
- Arch aortogram may show a subclavian artery aneurysm
- Duplex scanning may show arterial or venous compression and the effect of position
Picture provided by Andrew McIrvine, Darent Valley Hospital, Dartford, United Kingdom
Treatment
- Symptoms may improve with physiotherapy
- If disabling symptoms need to consider surgical decompression
- Involves resection of most of first rib
- Can be achieved through either a supraclavicular or transaxillary approach
- 10% will develop a pneumothorax
Prognosis
- 80% report a symptomatic improvement
- More than 50% of patients are usually symptom free
- Failure to improve is often due to:
- A double crush compression syndrome
- Incomplete division of compressing structure
Bibliography
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