First off, I agree entirely that this would be very interesting if it were available.
Having now experienced the ACGME case log, however, there are a few difficulties.
First off, things are easily miscategorized. Secondly, you only get credit for “index” cases so if you do a tumor+fusion or something, only one of those will end up getting credit. Next, residents and residency programs have vastly different expectations when it comes to completing the ACGME case log. One of our chiefs looks to have 300 fewer cases than the other - not because they operate less but because they forget to log cases.
Lastly, the usual caveat applies: just because you log the aneurysm doesn’t mean you clipped it. Or even dissected the fissure. Nonetheless, I think this data would be interesting ... but it certainly isn’t in obvious public domain.