Spine: Thoracic Outlet Syndrome Flashcards
what is thoracic outlet syndrome?
group of clin syndromes caused by congenital/acquired compression of NV structures in thoracic outlet
how does thoracic outlet syndrome present?
comp of brachial plexus -> neuro sx (neurogenic thoracic outlet syndrome)
comp of subclavian vein -> swelling, decreased venous return, esp during and after strenuous UL exercise (venous thoracic outlet syndrome)
comp of subclavian artery -> ischaemic pain, paraesthesia, pallor, cold limb (arterial thoracic outlet syndrome)
what is the most common form of thoracic outlet syndrome?
neurogenic TOS
90-95% cases
what is the rarest form of thoracic outlet syndrome?
arterial TOS
<3% of cases
what are causes of thoracic outlet syndrome?
comp between anterior and middle scalene - most common cause
compression by cervical rib - 2nd most common cause
what is a cervical rib?
extra rib off the 7th vertebra
normal anatomical variant - in 0.5% of the population
how do cervical ribs often present?
bilaterally
more common in females
ix of thoracic outlet syndrome?
cxr - rule out bone cause (e.g. cervical rib)
USS/CT/MRI/angiography to detect vascular TOS
common sites of compression in thoracic outlet syndrome?
scalene triangle - between anterior and medius
costoclavicular space - between clavicle and 1st rib
rectopectoralis minor space - between pec minor and coracoid process
what is the scalene triangle?
first rib and anterior and middle scalene muscles
subclavian arteries, br of brachial plexus pass through borders of this triangle
subclavian vein passes anterior to it
how is imaging in TOS performed?
pt arm both abducted and adducted
mx of TOS?
arterial - surgical intervention
venous - depends on extent of thrombosis (may include anticoagulation, thrombolysis, surg decompression)
