Cind,
I'm sorry you have this, but congratulations to your doctor(s) for a proper diagnosis...Thoracic Outlet Syndrome is pretty rare and so often mis-diagnosed.
Intensive physical therapy usually works...surgery would be the last resort in most cases.
With moderator's permission to post, here is a link to MEDLINE's website (the National Institutes of Health) and the page on TOS with info from the Cleveland Clinic and others. The board no longer makes links clickable, so you'll have to copy and paste it into your address bar:
http://search.nlm.nih.gov/medlineplus/query?DISAMBIGUATION=true&FUNCTION=searc h&SERVER2=server2&SERVER1=server1&PARAME TER=thoracic+outlet+syndrome&x=14&y=14
Good luck,
zuzu xx