Long term problems could be caused by scar tissue regrowth & adhesions, or possibly if the surgeon was not an expert at that kind of surgery.
Other post op causes could have played a part in the continued pain.

The surgery might have fixed the clot issue but you might still have symptoms of TOS that the surgery could not address.

Have you had a comprehensive evaluation by an expert/skilled/advanced PT or chiropractor?
You might have some improvements if you try those.
Also adding posture, stretching & whole body awareness regimen is a good move to make. Some use portions of yoga, tai chi, Alexander technique.

lots of saved info here-
http://neurotalk.psychcentral.com/thread84.html


I don't know the time frame for wc claims , but you do need to think of your future {jobs & life} and if it was work caused - you should seek a good wc atty {consult and interview some} to see if you have a claim.

unfortunately many will shine you on just to get you to sign with them, and they will not do the best for you, many just want to get the % of $$ you might get.
So be skeptical while interviewing and check them out as best you can before choosing one.