My insurance would only cover part of my surgery, and both the insurance company and my doctor asked me to do the seep study. I too, use a cpap machine and have been sleeeping a lot better and no longer am fatigued. Just like bobrocky I use the nose pillows mask which isn't tight or uncomfortable like the full mask. I agree with many above that to be safe you should tell your surgeon. I didn't have to use my mask after the surgery, but it was important for them to know I might need it in case I had difficultly on the day of the surgery. Good luck, and I hope you can have the surgery soon, as I know it is hard to wait once you have made a decision.