Hi! Sorry to just now be responding - I had a baby on Sunday!
You probably know quite a bit about Dr. Thompson already since you saw him.
I'm happy to answer your questions about my experiences -

how did he diagnose your arterial TOS? What diagnostic tests did he use?
I had an MRA where I moved my arms in various positions. This clearly showed the aneurysm I had in my right subclavian artery (with my blood flow pretty much being shut off on my right side when I lifted my arms above my head). I also had a chest x-ray that showed my pronounced extra rib on the right side and a much smaller (non-problematic) extra rib on the left.

What were your symptoms? I didn't have many symptoms actually, but he thought it needed to be repaired because of the aneurysm. I did realize after the surgery that it was causing me more muscular/postural problems than I realized with the things I had been doing to compensate for the uneven anatomy.

Also -- how are you doing post-surgery?? I'm over a year out now, and I'm doing really well. The month or so after surgery was rough, but I know it was worth it. I was also in PT for several months which was helpful. I'm relieved to have the surgery behind me and not have to worry about the
aneurysm any more.

I wish you all the best moving forward!