Exposure of left subclan aery by supraclavicular approach does not require cutting of ?
Scalenus medius lies posterior to the subclan aery and thus need not be divided to expose the aery. Whereas, sternocleidomastoid & scalenus anterior lie anteriorly and omohyoid lies superiorly and thus are cut during exposure of the subclan aery.
Sternocleidomastoid
Scalenus anterior
Scalenus medius
Omohyoid