The "right answer" is the one that makes sense to you after you ask the physician "why?" as a followup question to his answer. Most doctors who know what they are doing and are good at what they do can explain things to their patients so that it is easily understandable. So use commonsense, if it makes sense to you then that is the "right answer." If not, then continue with followup questions until it does make sense to you. If it never gets to that point, then it is the "wrong answer" for you.
Obviously the more AN cases that are done, the more experience the doctor has and that is probably THE most important thing of all. Commonsense will tell you that a neurosurgeon who does hundreds of cases a year will be much more adept then one who does only a few. And since ANs are supposed to be rare, that makes the number of cases done even more important. I chose not to have the first neurosurgeon I consulted treat me because when I asked him how many cases he did annually, he never gave me an answer. He played around his iPhone scrolling the screen apparently looking for cases he had done but he never did give me any answer. Then I remembered the answers he had given me to my questions and then I went to get second opinions and compared the answers. It would be in your best interest to see several doctors and get several opinions. Then evaluate the answers you were given and the one who gave you the most logical and commonsense answers is the one who would most likely be your best bet. One thing to keep in mind, however, is not to fall for the mistaken belief that there is only one way to perform a procedure. Doctors come from all different walks of life, have different training, have different levels of medical knowledge (as in postgraduate education), etc. so just because one doctor says one thing and another says something different, neither one is wrong because they are speaking from their own personal experience. This is only confusing if you have the mindset that there is only one answer for everything. In the real world, this is often not the case. You need to decide which opinion makes better sense to you and always use commonsense when possible; you will be surprise how good that often works. Although my background is dentistry, what I have said applies to medicine as well.