Aw Motherluch - I'm so sorry you are suffering.
I had a fistula that formed as a complication of an LIS I had in May. Mine wasn't anterior - it was off to the side, where the incision had been made (the incision healed the wrong way and formed a fistula). Anyway, while I was preparing for my fistulotomy, I did a lot of reading on the subject, and from what I understand, a lot depends on what kind of fistula you have. If it's a low, superficial fistula, that doesn't involve the sphincter muscle, then a fistulotomy is the standard surgerical intervention. If, however, the fistula is 'high' -- the internal opening is higher up in the anal canal -- then it likely tracts through muscle. In those cases, a seton is used to avoid incontinence. A seton may be a way to fix it, since there are actually two kinds of setons. A draining seton just keeps the fistula open so that it doesn't form an abscess; but a cutting seton actually cuts through the sphincter muscle (like a wire cheese cutter), very slowly so that the muscle heals and continence is preserved. From what I've read, this process can take a few months, but it should actually heal the fistula.
I understand your frustration! Fistulas are no fun at all. I think it's a great idea to get as many opinions as you can and see the top specialists. Have you ruled out IBD as a cause of your fistula? I'm pretty sure that would make a big difference to how the fistula would be treated.
I really hope you find a great doctor and that you feel better very soon!