Thoracic Outlet Syndrome

Thoracic outlet syndrome (TOS) describes a variety of symptoms caused by the compression of the brachial nerve plexus or subclavian vessels (artery and/or vein) at the thoracic outlet.

Three types depending on the primary structure subjected to compression:

  1. Arterial TOS (subclavian artery)
  2. Venous TOS (subclavian vein)
  3. Neurogenic TOS (brachial plexus nerve roots)

These may occur separately or together.

In the majority of cases, symptoms are neurological with pain and weakness resulting from C8 or T1 root compression.

Less commonly are the thoracic outlet syndromes affecting the blood vessels. These lesions typically gives rise to recognized symptoms eg. thrombosis (clot) of subclavian vein and aneurysms (ballooning) of the subclavian artery complicated by thromboembolism.

The thoracic outlet is already a crowded space however, there are other factors that may worsen this situation. Some patients have anatomical variations in their muscles, ligments and bones. These are quite common eg. complete and incomplete cervical ribs, rudimentary or abnormal 1st ribs. Anatomic factors merely lower the threshold for development for symptoms.

Activities involving sustained or repeated elevation of the arm or vigorous turning of the head may place additional tension on the scalene muscles thereby potentiating any positional compression of these vital structures.

Our practice specialises in arterial and venous thoracic outlet syndrome. We provide a careful and detailed approach to help manage this condition.