title: Improving the outcome of fistulising Crohn's disease.
abstract: Fistulas are a frequent manifestation of Crohn's disease (CD) and can result in considerable morbidity. Approximately 35% of all patients with CD will experience one fistula episode during their disease course of which 54% is perianal. The major symptoms of patients with perianal fistulas are constant anal pain, the formation of painful swellings around the anus and continuous discharge of pus and/or blood from the external fistula opening. The exact aetiology of perianal fistulas in CD patients remains unclear, but it is thought that a penetrating ulcer in the rectal mucosa caused by active CD forms an abnormal passage between the epithelial lining of the rectum and the perianal skin. Genetic, microbiological and immunological factors seem to play important roles in this process. Although the incidence of perianal fistulas in patients with CD is quite high, an effective treatment is not yet discovered. In this review all available medical and surgical therapies are discussed and new treatment options and research targets will be highlighted.
authors.affiliation: Dept. of Gastroenterology and Hepatology (C4-14), Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands. Electronic address: i.molendijk@lumc.nl.
authors.forename: Ilse
authors.initials: I
authors.lastname: Molendijk
authors.affiliation: Dept. of Surgery (K6), Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands. Electronic address: k.c.m.j.peeters@lumc.nl.
authors.forename: Koen C M J
authors.initials: KC
authors.lastname: Peeters
authors.affiliation: Dept. of Surgery, Groene Hart Hospital, P.O. Box 1098, 2800 BB Gouda, The Netherlands. Electronic address: coen.baeten@ghz.nl.
authors.forename: Coen I M
authors.initials: CI
authors.lastname: Baeten
authors.affiliation: Dept. of Gastroenterology and Hepatology (C4-14), Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands. Electronic address: r.a.veenendaal@lumc.nl.
authors.forename: Roeland A
authors.initials: RA
authors.lastname: Veenendaal
authors.affiliation: Dept. of Gastroenterology and Hepatology (C4-14), Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands. Electronic address: ae.meulen@lumc.nl.
authors.forename: Andrea E
authors.initials: AE
authors.lastname: van der Meulen-de Jong
mesh_terms: D003424:Crohn Disease / Q000175:diagnosis / Q000628:therapy*; D013505:Digestive System Surgical Procedures / Q000379:methods*; D004322:Drainage / Q000379:methods*; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use*; D012003:Rectal Fistula / Q000175:diagnosis / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D007155:Immunologic Factors
keywords: Classical treatment; Crohn's disease; Perianal fistulas; Potential future therapies; Research targets