Hey, ya I went to the doc at Center for Colorectal Health in Beverly Hills. It was years ago, I can't recall the exact name of the doc but it was something strange (to me anyhow) and that sounds about right. Definitely H-something.
Anyhow to be honest, I had a problem with the fissure healing but not staying healed too. After this length of time, I'd think something more aggressive than just nitro might be in order. Why not give Botox a shot earlier and see if it helps? If you've been using nitro for a while and keep retearing, it sounds like it probably won't help in the long run.
I can't say much about whether a fissurectomy is warranted, as I didn't have one myself -- sorry... I think in most cases LIS is the primary procedure and fissurectomy is secondary. That is, LIS is the one that actually gets at the root of the problem, and fissurectomy is to help LIS do its job. AFAIK whether a fissurectomy is warranted is usually determined by how the fissure looks, i.e., whether it the edges look like they're scarred real badly or not.
Honestly I think I'd be more interested in curing the fistula than the fissure at this point. IIRC fistulas almost never resolve on their own, and you definitely don't want that to get worse. If memory serves, it's actually tougher to fix than a fissure. There are some some anecdotal reports that antibiotics like metronizadole can help "cure" or at least prevent the worsening of small fistulas, but generally speaking, the only way to treat them is through surgery. I kind of wonder why the docs are advising against surgery for either the fistula or the fissure, but if they gave specific reasons, then they may know better.