Thoracic outlet syndrome is a broad term encapsulating three distinct, but interrelated conditions.

These conditions include:

• Arterial compression
• Venous compression
• Neurogenic compression

Underlying triggers / causes:

• Neurogenic TOS– hyperextension neck trauma, for example whiplash, or repetitive stress injury
• Venous TOS– repetitive arm activities (throwing, swimming, arms overhead) in patients with congenital anomalies of costoclavicular space
• Arterial TOS– congenital anomalies of costoclavicular space – patients may have an extra “cervical” rib, or may have an unusual 1^st rib, muscle strap or insertion, or deformed clavicle. This can lead to subclavian artery injury (aneurysm or stenosis).

ANATOMY – slightly different for each condition – Three Spaces

1) scalene triangle

• most common site of brachial plexus compression by cervical anomalous first ribs

2) costoclavicular space, between the first rib and clavicle

• site of subclavian vein compression.

3) Pectoralis minor space

• space between the PM muscle and ribs of the chest wall -> axillary compression syndrome

It is very important for Dr Morrisroe to have a good understanding of your symptoms and how they affect your life. She will spend time speaking with you, and undertaking examinations to ensure that your history and physical examination are focused and thorough.

In the event that you have thoracic outlet syndrome, unless there are acute arterial or venous pathology, the first line therapy is usually focused physiotherapy. Following physiotherapy, you may be offered a botox injection of your scalene muscle. Response to a relatively low-risk botox injection can be a good indicator of response to surgery.