Exposure of left subclan aery by supraclavicular approach does not require cutting of
Scalenus medius is located posterior to the subclan aery. Hence there is no need to cut this to expose the subclan aery. Ref - Bdc 6th e Vol 3 pg165,166 , pubmed.com
Sternocleidomastoid
Scalenus anterior
Scalenus medius
Omohyoid
Head and neck