There are a myriad of sphincter saving techniques for trans-sphincteric fistulas. Perhaps a testament to the fact that there is no one size fits all and certainly no “perfect” technique. Clearly the decision making is crucial: case selection and managing patient expectations are paramount.

We all come across cases from time to time, with a large internal opening (IO) in an otherwise uncomplicated (Grade 3) fistula. Now the definition of "large" varies in the literature, but we all have a rough idea of what me mean by that (a little akin to “complicated” incisional hernia repair not having an agreed upon definition, but we all know it when we see it!). It doesn't necessarily have to be the cavitating Crohn's type huge IO but just one that is several mm even.

What are peoples’ thoughts about the best management of cases specifically with a large IO (in non-IBD cases)? An advancement flap in a very large IO risks anastomotic breakdown with ensuing continence/functional issues; FILAC is less good for these as is fibrin glue; the anal fistula plug is not great also. LIFT likely to fail if IO very large. Personally, I have no experience with OTSC which may be good, so I’m keen to hear people’s ideas. I suspect seton and wait, wait, wait! But what if it remains large? Then what?

Many thanks!