I couldn't get the link to work.
Sorry to hear that you can't play guitar anymore. I've been playing for about 22 years myself, and i've had hand problems with carpal tunnel, and now the ganglion. It's very frustrating. I hope you're right about the scar tissue. If I can get rid of that, it would be a success.
Here's a couple of things that have helped my hands:
1. Chiropractic adjustments- I go to a chiro that is certified for extremity adjustments. He adjusts my neck, spine, elbows, and wrists. Sometimes the relief is instant, other times it takes a few more treatments or a little more time.
2. Hot water soaks- makes my wrist feel a little looser.
3. I try to keep massaging the cyst, to try to keep it somewhat pliable.
4. I do plenty of exercises and stretches. The more I let my wrist sit idle, the stiffer it was.
I don't know if any of those things will help you. I guess our sitiations are a little different from one another. I'll see what info I can dig up on volar ganglions, and arthroscopic procedures.