I'm sure you've probably worked yourself over into a nervous wreck with looking up what could go wrong with such a surgery, but rest assured, the doctor is where he is because he is a highly trained neurosurgeon. They wouldn't have let him into the operating room, much less handed him the scalpel if he hadn't earned his doctorate in medicine and further doctorates in that field.

It's perfectly natural to be nervous before surgery of any kind, but know that you are in good hands. I hope you have a reasonably speedy recovery, and that all goes well. I'll keep you in my thoughts and prayers.