Obviously, I can't begin to put myself in your shoes without actually damaging my spine and then hoping it heals up properly soon enough, but I would advise weighing the risk and the reward. If the doctors think it's a high probability of success and it'll vastly increase quality of life, it might be worth a small risk. If the probability of success isn't very big and the doctors are concerned that either you could die or that you're likely to end up worse of than when they started, then it might not be worth it, even if they could fully restore you, feeling, walking, functionality and all.