It is certainly not unheard of in some of the sexually explicit procedures for the practitioner to be motivated by their fetishistic drive to do the procedure; that is, they may get off on cutting you.
Now, there's nothing wrong with someone being aroused by the thought of a procedure. When it becomes a problem is when it starts clouding judgment; you don't want to be in a position where the cutter is motivated primarily by their own sexual drives (rather than by a desire to help you achieve your personal goals).
Almost universally, a good way to identify a responsible cutter is that they'll go to great lengths to ensure that you're ready for your procedure, that you're mentally stable and able to handle it, and they'll even try and talk you out of it often to gauge your drives.
The most obvious way to identify a fetishistic practitioner is if they make "scene details" (i.e. what you're wearing or not wearing, doing the procedure while you're in restraints, etc.) a priority, you can bet that is where their head is at. Unless that's what you're LOOKING FOR (and I'm not saying there's anything wrong with this happening as long as it's consensual), avoid these practitioners.