Anorectal fistulas in Crohn's disease

Anorectal fistulas don't follow the same rules as idiopathic anorectal fist ulas do. Their cause and treatment is completely different. Almost 40 % of all patients suffering from Crohn's disease show anorectal manifestations. In 10-15 % of the cases the anorectal manifestation is the first sign of Cr ohn's disease at all. 30 % of all Fistulas heal at least for a while sponta neously The diagnostic procedures include nowadays anal endosonography and MRI as most sensitive ones and should be added for every work-up of anorect al Crohn. We differ a conservative from a radical therapy. To our opinion e very therapy should be adopted to the individual needs of each patient. The most important principle in anorectal Crohn's disease is laying open of th e fistula tract and excision of all the diseased tissue. This should be fol lowed either by a drainage seton or by a definitive plastic closure of the fistula (mucosa-muscle flap). For a mucosa-muscle-flap there is only in oth erwise disease-free patients and there only for high transsphincteric fistu las an indication. In our own series we treated of 69 patients 59 with a dr ainage seton and 10 with a mucose-muscle flap. Recurrence occurred in 6/59 respectively 2/10 of the treated patients. Anovaginal fistulas should due t o the high recurrence rate of surgically closed fistulas (>50 %) only be op erated if there are serious symptoms such as recurrent vaginal infection, v aginal flatus and permanent vaginal defecations.