Captive igs who live that long get top-notch care from their owners. These igs often last to 25 years. This iguana will easily survive the tail-tip removal, if x-rays show it's necessary.
X-rays are needed to find whether there is major damage to the thick portion of the tail. If bones are broken the tail might be splinted by an expert. Tail tip removal is short and seemingly causes little pain, so this doesn't add age-related risk.
I would go to a vet and find out what repairs need to be done, if any. A good vet will want x-rays and a blood test.