During an emergency thoracotomy, the incision is made > 1cm lateral to the sternal margin. This will preserve which of the following structures?

In case of anterolateral thoracotomy, which is usually a transverse or a veical incision staing from fouh intercostal space, incision is made lateral to sternal in order to avoid injury to the adjacent vessels which include internal mammary aery. Superficial epigastric aery is the terminal branch of internal mammary aery and hence not at a risk in emergency thoracotomy. Intercostal vessels lie parallel to rib margin and hence not injured near sternal margin. Ref: General Thoracic Surgery, Volume 1 edited by Thomas W. Shields, Joseph LoCicero, Carolyn E. Reed, Richard H. Feins, Volume 1, Page 394