This will almost certainly be screaming and fainting. The thrashing will make it more difficult for Oro to make clean incisions. I have seen quite a few surgeries (on cats and dogs admittedly) and being awake through it is
not pleasant. Those are
minor surgeries compared to what Hazou will endure. Many vets will do a neuter on the kitchen table with a scalpel and towel.
Before widespread anesthesia there was an
extreme focus on speed in surgical procedures because shock would literally kill the patients. Read about
Robert Liston, the only surgeon who ever managed a 300% fatality rate for a single procedure.
This is accomplished by Tsunade and Naruto looming over him. If we can't get them to stand guard we
should not go ahead with this idea.