Was your initial rib resection transaxillary or supraclavicular? Mine was transaxillary and my neurogenic (ulnar) symptoms returned after 9 months. I had a supraclavicular cleanup of scar tissue and to check for adhesions of scalene remnants (it was suspected but there were none in my case, just scar tissue on the brachial plexus). I am close to a year post supraclavicular procedures and TOS symptom free (my cervical spine is another story).

If your surgeon is telling you it's the end of the line I would seek additional opinions.