Try not to worry, I know it's easier said than done, but you really have no other option. Stressing out will do nothing beneficial for you.

I had brain surgery without an issue, also a pre-operation and several follow up cerebral angiograms, I have one scheduled this month.

I always request pediatric needles, cameras, etc. and I tell every staff member that I have CRPS. I write CRPS/RSD on my limb to remind the staff they must be careful moving me.

That said, in my experience no one seemed particularly interested in my CRPS spread fears. I sincerely wish we had our own lobbying group.