Every case is different.
My spine is fused L1-L3 with a TPS.
I had a flying accident, that shattered L2, fractured T4 & T5... and snapped some ribs.
Prior to surgery I was in pain but everything worked. After the 10hrs surgery I spent 2 weeks in HELL and another 4 weeks in hospital. I woke up and it was like the farker had been beating my thighs with a cricket bat, my right leg was paralysed and it felt like a bag of wood chips had been wrapped tightly around my knee down to my foot and retrograde ejac., muscle cramps, hernias, cattle prod like electric shocks in my legs.
4 years on and the only day I'm not in pain, is the day I spend in bed.
Have you tried external support, like a kidney belt? How old are you and which disc? Does he want to go in from the side or back?
I don't know how things would have turned out without the surgery, but I think I would have preferred to spend 6months in bed under traction.