What is new in the treatment of perianal fistulae in Crohn's disease?

Perianal fistulae in Crohn's disease occur frequently and are the most difficult perianal manifestation of the disease to treat. The relation between the fistula and the sphincter apparatus and pelvic floor forms the basis for the surgical problems. Simple lower fistulae with regard to the anal sphincters can be treated as any other perianal fistula with a technique in which the fistulous tract is layed open with only a minor division of sphincter muscle. Complex high-situated fistulae require another treatment approach in order not to render the patient incontinent. Therefore, it is of prime importance to be informed about the nature of the fistula before operation. Magnetic resonance imaging seems to give all the information needed on complex fistulae that was not available previously. It allows a thorough surgical planning of the procedure in which all the fistulous tissue is removed with primary repair of the pelvic floor and sphincters if necessary. Our first results are promising.