This is my take on it. Surgery is for mechanical problems. Surgery is NOT FOR PAIN. In fact, most of the time, after surgery you're left with the SAME pain or worse. So if you're looking for pain relief, surgery is not the way to go. You will still need pain medications. Plus, there is the "domino effect." The levels above and below the surgery site will fail because they've had to take on more of the load. So you end up having to have more surgery later on. The doctors don't tell you this.

The only reason I'd have MORE surgery is if I was in danger of permanent nerve damage or if my spinal canal was being impinged. Otherwise I'd opt for physical therapy, or in your wife's case the SCS or the pump.
Unfortunately, I had the SCS for 6 months, but because I'm thin the darn "generator" tried to work itself out of me, so the whole ball of wax had to be removed! So if your wife is skinny, tell her to beware! She might have the same trouble I did!

Plus the pain pump is even bigger than the SCS so i couldn't have that
If I was your wife, I'd get at LEAST 2 other opinions from different Neurosurgeons on what she should do. I wouldn't just take this one doctors opinion. This is too serious an operation to just depend on HIM.
Best of luck and I hope everything turns out ok. God bless. Hugs, lee