I can only speak for myself, of course - but I would suggest exploring every other avenue prior to surgery. Doctors in the U.S. do 6X as many spinal fusions as those in Europe. My first surgeon looked at my MRIs for 15 seconds and said, "You need a 3 level fusion." He didn't spend ANY time considering my symptoms, prior therapies, my discogram results or other treatments.
I've had 10 different steroid injections, with varying success. Add to that PT, TENS, chiro visits, etc. It wasn't until I had exhausted virtually every alternative that I agreed to surgery.
My personal view is to get SEVERAL opinions. Take the time to do so, it IS worth it. I had a much more minor surgery, a laminoforamenotomy, and it GREATLY helped. Not to say you should rule surgery out, but - even if you LIKE your current doctor, or trust his judgment, it cannot hurt to get another set of professional eyes on your lab work.
YOU are the one that has to live with the results. Best of luck to you.
Jim