I have sleep apnea and I use a CPAP. During the diagnosis, there were tests but nothing that would/could finger a physical culprit that could be fixed via surg

I have sleep apnea and I use a CPAP. During the diagnosis, there were tests but nothing that would/could finger a physical culprit that could be fixed via surgery. My question is, what tools are there to narrow, to a certainty, what would need to be done via surgery? In all my research I have found none. Maybe I missed them. If I did not, then it amounts to a guess by a surgeon. And that's what worries me and has fed a lot of the horror stories I've read about.