I had surgery at Barrow for a 2.5 cm AN that had a very large (5 cm) cystic component. Dr. Spetzler (neurosurgeon) and Dr. Daspit (otologist) performed my surgery using the retrosigmoid approach. They used this approach in an attempt to preserve my hearing, which was perfect vefore the surgery. Because I was diagnosed with NF2, and taught middle school band, I decided to go to Barrow over House Ear Institute, because they at least offered me a chance at saving some hearing. Unfortunately, my hearing was lost as a result of the surgery. They left a significant portion of the tumor behind in an attempt to save my hearing. I have since gone to House to have the remainder of the tumor removed and follow my tumor growth on the other side.
My feeling is that the doctors and facilities at Barrow are excellent. They removed a large portion of what they described as a life-threatening tumor, leaving me with no facial problems or other side effects other than hearing loss. Also, the neurosurgeon at House said that Dr. Spetzler left the remaining portion of the tumor in such a way as to facilitate the easy identification of the facial nerve. Given my personal situation, I wouldn't change anything that I have done, including choosing Barrow for my initial treatment.
You ask about positive outcomes, and I have concluded that this is relative to each situation. My personal situation and goals are different than many on this board. My highest priority is facial nerve function, followed by my wish to get an Auditory Brainstem Implant; a device for patients with NF2 that can provide some sound sensations. Others have different goals.
I am very sorry that your daughter and your family have to deal with this. If I can be of any help, please feel free to contact me.