Perianal Crohn's disease: a review

Perianal involvement in Crohn's disease (CD), which encompasses fistulas, ulcers, abscesses, strictures and cancer, can lead to significant impairment in quality of life. The objective of this article is to review the major perianal complications of CD and the current medical and surgical modalities used to treat them. Antibiotics are commonly used despite a lack of controlled trials to validate their use and should be used as a bridge to maintenance therapy. The anti-metabolites azathioprine and 6-MP have shown a positive response in terms of fistula closure, although these data are mostly from trials looking at this as a secondary endpoint. Infliximab is an effective agent for induction and maintenance of treatment of fistulizing CD. Further studies to evaluate the use of subcutaneous anti-tumor necrosis factors are needed to convincingly prove their efficacy for perianal fistulizing disease. In CD, clinicians should avoid surgery as a first-line approach for skin tags, hemorrhoids or fissures in the setting of proctitis. Surgery, particularly lateral internal sphincterotomy, in combination with medical therapy is associated with higher fissure healing rates in the absence of proctitis. Fistulotomy is curative for most simple low perianal fistulae, but complex fistulas often require sphincter-sparing surgical procedures. Less invasive approaches such as a chemical sphincterotomy should be used first, with therapy escalated only if this fails.