Superolateral boundary of axillary dissection is
Lateral group of axillary nodes are present along axillary vein. Axillary dissection is the removal of fat, fascia, nodes in the axilla. Usually level 1 and level 2 nodes are removed. Nodes below the axillary vein are usually removed. so the superolateral boundary of axillary dissection is axillary vein. Dissection is done through an individual crease transverse inciaion in the axilla. Reference :SRB's Manual of Surgery, 6th Edition, page no = 543, 529.
Clavipectoral fascia
Branchial plexus
Axillary aery
Axillary vein
Endocrinology and breast