I haven't done surgery for an anal fissure but I've done different RX salves--some work, some don't. Suffered hemorrhoids after my daughter's birth--had an internal one fixed when I had tubes tied, but even now, seven years after that (daughter born 9 years ago), I still suffer from external hemorrhoids (I had a colonoscopy this spring in which it showed that I still have minor internal hemorrhoids.). And occasionally, the fissure will break open. But not that often.
Lifestyle affects them; eat more fiber, take fish oil, drinks lots and lots of water. It's suspected my food allergies and intolerances play a role (I just found out about them last year), and there might possibly be some genetic problems; we're still exploring.
As someone who's had an internal hemorrhoid fixed; if you can live with them--the fissures--I'd suggest that. Surgery is by no way fun, nor does it guarantee that they won't come back. Sitz baths with cornstarch are a good way to bring relief and relieve the itch. Colonix by drnatura.com is a wonderful product; it offers a lot of fiber. I find that I don't have as many problems with bm straining if I take their fiber product regularly.