LIS (Lateral Internal Sphincterotomy) is actually considered the gold standard surgery for treating Chronic Anal Fissures. As far as science knows, an acute fissure becomes chronic due to the injured muscle (internal sphincter) entering into a state of continuous spasms and contraction, creating an ischemia that doesn't allow enough blood to flow to the site, hence impeding healing.LIS weakens a tiny part of the internal sphincter muscle by cutting some of the fibers, lowering the internal sphincter tone, which finally allows healing.The thing is, an ischemic wound usually presents these features;

- Gangrenous and death tissue.

- Doesn't easily bleed.

- Has no evidences of healing.

...But a CAF's features actually don't match those criteria because;

- Non gangrenous but healthy tissue.

- Bleeds quite easily, for some patients even daily and even in moderate amount.

- Presents evidences of healing by showing overgrowth of healing tissue ( Sentinel Pile - Hypertrophic scar)

...So my question is, is it really the lack of blood flow to the site the culprit behind an anal fissure becoming chronic?LIS works very well but presents some serious risks as incontinence, especially in women.Shouldn't we be looking elsewhere to find the solution?As far as I can understand a Chronic Anal Fissure doesn't classify as an ischemic wound, so why is medicine treating it like one?

The reason the sound doesn't heal is that the anus clenches it, which cause the spasms, which actually works to lessen blood flow due to the clenched muscle.

AF that become chronic are chronic not usually because they simply don't heal, but because constant use of the site makes it easy to reinjure or traumatize the area further. The more injuries, the tighter the muscle contracts, the harder it is to heal.

Ointments like nifedipine or nitro relax the muscle to encourage blood flow. Botox forces the muscle to relax by paralyzing it. Depending on how severe the issue is depends whether that helps. Lis also works to alleviate pressure.

This doesn't fix all AF, but most.

It's just like if you have a cut on your finger at the knuckle. The more you move the knuckle, the more the wound reopens. If you stabilize the knuckle, it will aid in healing. If you stabilize the clenching anus, it will aid in healing. But it's two fold as you have to have nice soft poops too