Since you have cervical ribs I think it is a given that rib resection at a minimum is necessary, I have searched high and low and there are no gold standard imaging tests. The surgeons often find stuff that don't show up in imaging which is why I recommend utilizing an experienced vascular surgeon over a neuro or thoracic surgeon. I had several MRIs and angiograms and nothing fully predicted what my surgeon found inside...and each side was different.

I recommended consulting numerous surgeons (between 2-5). I consulted 5, 4 of which were vascular surgeons. The 5th was a neurosurgeon who had done surgery on my C-Spine and he referred me to a vascular guy.

I would let the surgeons explain to you why they choose a supraclavicular vs transaxillary approach. Some even use both (transaxillary for the ribs and supraclavicular for the scalanes). I believe surgeon skill and experience is much more important than their approach of preference.