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What is the optimal maintenance treatment for perianal Crohn's disease?

F istulizing Crohn’s disease (CD) is one of the more dreaded complications for patients with this disease. If not treated aggressively from the onset, it can frequently lead to incontinence and even proctectomy. The initial management of fistulizing CD will be covered in another chapter. This chapter will focus primarily on how to maintain fistula closure. However, it would be remiss not to stress that good long-term treatment outcomes depend heavily on the adequacy of the initial treatment strategy. Studies have demonstrated that failure to fully recognize and treat all of the active perianal process (i.e., abscess and secondary fistulas branches) can result in a simple fistula becoming a complex fistula and/or an abscesses.1 Once a fistula becomes complex, the chance for complete closure of the fistula is dramatically reduced.1–3 At that point, the goal becomes primarily one of symptom control (i.e., cessation of drainage), and not complete closure or fibrosis of the tract. Previously, antibiotics including ciprofloxacin or metronidazole and immunomodulators including azathioprine (AZA) or 6-mercaptopurine (6-MP) were the primary treatment for fistulizing CD. The focus of the reports using these medications was on the acute treatment of active fistulas. Improvement in fistula drainage utilizing these medications was found to be 50% for both antibiotics and immunomodulators.4,5 Recently, with the introduction of antitumor necrosis factor-alpha antibodies such as infliximab (IFX), the endpoints of clinical trials for fistulizing CD has shifted not only from fistula “improvement” to complete cessation of fistula drainage, but also from the acute management of an active fistula to maintenance therapy.