I wish I had an answer to why I had scar tissue issues with one surgery and not the other. Human anatomy is so complicated.

I had scalenectomies because in my case, my surgeon did not find the need for rib removal as he was interested in removing the compression that led to a fall out in my subclavian artery where the pulse becomes zero. ( Did I forget to mention that I had bilateral arterial TOS). Once he achieved the blood flow, he felt that it did not warrant rib removal because of all the complications and risks involved.

But that does not mean scalenectomy is a fit for everyone, some people need the ribs removed, as it does create so much extra space. Everyone's case is different, and it justifies whatever is best for them.

Some people are fine without surgery as well, just have to put those exercises in your daily routine and that's enough for them to live with some limitations but not affecting their quality of life immensely.

My surgeon told me that once you have TOS you have some percentage of it all your life, you cannot be a hundred percent perfect and you just have to accept that. Don't do anything that builds those pects and scalenes in the gym.