In a Subclan aery block at the outer border of 1st rib, all of the following aeries help in maintaining the circulation to upper limb except
Subscapular aery
Superior thoracic
Thyrocervical trunk
Suprascapular aery
In distal subclan & proximal axillary aery block aerial anastomosis exists between 1st pa of SCA&3RD pa OF axillary aery Ref: Gray's 40e/p447-451
General anatomy