Should we appeal surgery denial?

My 62 yo husband has been having tingling numbness in his thumbs for over a year. In the past two months it has started in his forearms. He is 6 mos post retirement and we have an active life enjoying hiking, kayaking, 4 wheeling and canyoneering. He went to a Chiropractor for 8 weeks. Testing shows strength and reflexes as normal. No positioning seems to increase or decrease his symptoms. EMG shows mild carpal tunnel possibility. The neurosurgeon thought he had carpal tunnel until he looked at the MRI. The MRI shows severe spinal stenosis with a 4-5 mm space. Boney growths coming in from both the front and back with the greatest growth in back. Surgery was scheduled for a rear laminectomy and mini fusion of C3 and 4. WPS insurance company has denied authorization because he lacks symptoms. Our surgeon had said if we lead non-active lives or if my husband were older he would just watch it, but he feels strongly that trauma (even a fall which is not that unusual) could cause irreparable damage.
After reading about spinal stenosis I see that it can affect his bladder. He has had bladder urgency for more than a year but no difficulty with walking or lower body symptoms. His prostate is not enlarged. Also the tingling is now in his forearms. These last two symptoms were not included in the surgeons notes and I'm not sure if they would be relevant in pursuing an appeal. With the problems sometimes associated post surgery, is it something we want to move forward with any sooner than necessary? We are nervous now about doing some of the activities we enjoy. I think because my husband is so active and strong that many of the symptoms haven't shown themselves as they would if he lost his strength. But recovery should be easier if he is healthy.