Generally, scalenectomy only is indicated for some cases of NTOS by mostly neurosurgeons and proteges of Dr. Sanders (Annest, Avery).

VTOS treatment by vascular and cardiothoracic surgeons usually requires cervical and/or first rib resection in addition to scalenectomy/scalenotomy.

You costoclavicular space may still be compressed due to the rib and scar tissue could have built up on the brachical plexus.

Who was your original surgeon? I second the recommendation to consult with Dr. Dean Donahue.