[Perianal fistulas in Crohn's disease--biologicals and surgery: is it worthwhile?].

Perianal fistulas and abscesses are a common manifestation in Crohn's disease (CD), seen in about 30 - 40 % of the patients. Often they are combined with CD of the anal canal and occur as a complex system of fistulas. The evaluation of these fistulas can be done with endoscopic ultrasound or magnetic resonance imaging, the conceptual accuracy of both methods is high. There are accepted therapeutic concepts for surgery and for the conventional drug therapy according to the classification of the fistulas. In contrast, the therapeutic regimens for a complex perianal fistulising CD are not convincing, especially not for maintainance therapy. However, several studies about therapy with anti-TNF-alpha antibodies have shown good results while long-time results with other recent anti-TNF-alpha antibodies apart from infliximab are still lacking. In this review article we analyse the current literature and develop a stage-adapted therapy for the use of biologicals and surgery in fistulising perianal CD.