I think the surgery is described somewhere on a website I'm sure, but can't recall which one.

Part depends on if he is going in thru armpit {axilla\axillary} or collarbone {supra clavicular} area - probably spelled these wrong
and part depends on what exactly the dr finds when in there, I guess it's quite common for things to be laid out with some minor variances.
rib resection, scalenectomy, scar tissue removal.

images of BP surgeries-
http://images.google.com/images?hl=e...h+Images&gbv=2
http://www.medigraphics.com/ma_april01.html