Lholl, I am surprised they'd say "guaranteed." I had a hemangioma also and I believe they start in generally the same place (geniculate ganglion area where there are a lot of blood vessels), and mine also extended into the IAC. (I had terrible dizziness, unusual for a hemangioma.) The worst quote I heard for facial function was 50% chance of severing the nerve in surgery.
Obviously I defer to your doctors on your specific anatomy and situation. But generally:
The advice for hemangiomas used to be that facial-nerve damage was so likely in surgery that it was better to do nothing -- the heman itself would destroy the facial nerve, too, but it would take longer for nature to do it. Kind of "enjoy your facial function while it lasts." Then get a nerve graft after your function declines to Grade III.
But those poor odds for surgery was when they thought they had to take out 100% of it or it would grow right back.
House has a new study -- I don't think it's even been published yet -- in which they watched patients where a bit was left behind to save the facial nerve, and it found that these do not grow back in decades (and counting). So now they advise being less aggressive in removal -- leave a little behind, but get most of it out and also remove the bone around it so it has plenty of room in there if it *were* to grow back at all. {Also, once there is room to breathe in there, radiation would be an option if it acted up again. Which, again, they show zero patients with regrowth; the only patient who had some growth had declined to have it (or let's say the bulk of it) removed.}
Their study also shows great results with facial nerve function after surgery for those who go in with great function. Basically, patients came out with what they went in with or better.
IMO, and I did a lot of research over a year, this study is a game-changer for hemangiomas. To me, in my decision-making (and I had early facial symptoms, so that prodded me forward), it seemed to me that it no longer seems as wise to just wait and let nature do its destructive work -- if you have Grade I or II now, you have very good odds of preserving that (in the right surgical hands).
Thus, if you are not interested in consulting with House, I would strongly suggest you ask your own doctors if they are familiar with this NEW (very new) study from House of 19 patients*, and if not, if they can get their hands on it, and see if that impacts what they tell you. I would discuss very carefully with them what they think your odds are in surgery and in "letting nature take its course." Have they treated hemans before? Even an experienced skull-base surgeon has probably seen very few of them, and I think they need to do some research on your behalf.
(19 is a lot for a hemangioma study, as you'll soon find if you're researching! They are rare in the literature. Though it may not be published yet, it was presented at the facial nerve symposium in Rome earlier this year so may be available to them.)
Meanwhile, if you opt to W&W, I would be alert to any facial twitching, dry eye or "big eye" appearing in photographs (eye on the affected side looking larger or "more wide open" than the other).
