Symptoms occurring due to compression of structures like
Brachial plexus (95% of cases)
Subclavian vein (4% of cases)
Subclavian artery (1% of cases)
Caused by narrowing of the anatomical opening called “thoracic inlet”, “thoracic outlet” or “superior thoracic aperture”, which is a hole surrounded by
Clavicula
The first rib
Scalenus anterior
Scalenus medius
If the thoracic outlet becomes narrower some or all of the neurovascular structures may be compressed
Etiology
Trauma
Collarbone fracture
Hypertrophy of scalenus muscles
Pancoast tumor
Congenital cervical (extra) rib
Clinical features
Neurogenic thoracic outlet syndrome
Due to compression of brachial plexus
Pain, anaesthesia, paraesthesia in neck and arm
Often in areas innervated by ulnar nerve
Venous thoracic outlet syndrome
Due to compression of subclavian vein
Swelling
Venous distension
Venous thrombosis
Arterial thoracic outlet syndrome
Due to compression of subclavian artery
4 Ps
Pulselessness (in the hand)
Pain
Pallor
Paraesthesia
Treatment
Physical therapy
In mild cases, can be enough
Thoracic outlet decompression surgery
Transaxillary resection of extra rib or first rib
Angioplasty, if vessels are affected
Cervical rib
Some people have a congenital extra rib before the first rib called the cervical rib
The first rib starts at Th1
The cervical rib starts at C7
This cervical rib compresses the thoracic outlet, causing TOS
The treatment is surgical resection of the cervical rib
