Hi tenai .....
You may already know my story, but here it is again, if you do not.
I had retrosigmoid approach surgery for my 2.6 cm AN eight years ago. I was told it was removed "in toto." Initial post-op MRIs showed "scar tissue," which, like yours took a growth spurt. It was removed a second time via translab approach five years ago. (Different doctors, different medical facilities, different states.) So far my follow-up MRIs have been stable. I had no radiation at any time due to massive doses of radium to my head as a kid.
Dr. Schwartz explained that on second surgeries they want a clean plane to approach the tumor, hence translab for me the second time. I had no fat graft the first time, but did the second time.
1) The second surgery was about the same length of time as the first, around five hours.
2) It was more difficult to remove because of the surrounding scar tissue.
3) Yes, they drilled a different hole.
4) Fat graft was done.
Much depends upon which direction/location of the regrowth as to the neurosurgeon's choice for approach, I would think.
Many thoughts and prayers for right answers from experts in the field!
Clarice