It sounds as if your surgeon is inexperienced with the neurogenic components of TOS (there seem to be only a handful of true TOS experts scattered across the country). Since you initially had some relief, I don't think he damaged your brachial plexus. However, scarring/adhesions of the brachial plexus and possibly the scalene remnants could have developed and be contributing to your issues.

This is a good site for educating yourself regarding TOS: http://surgerydept.wustl.edu/TOS_For_Patients.aspx

Thread: Scar Tissue and Adhesions Post-Surgery