INTRODUCTION: Complex perianal fistulas (CPF) are common among Crohn’s disease (CD) patients and are associated with substantial morbidity. The burden and management of CPF are poorly studied. Treatment options include a combination of medical and surgical interventions. However, across all options identified, a high proportion of patients experience treatment failure (lack of or inadequate response) and relapse (Table). Only 4 identified studies were conducted specifically in patients refractory to anti–tumor necrosis factor (TNF)–α agents—a population with high unmet needs (one study of perifistular injections of infliximab, and three studies of surgical interventions). Available data suggest that anti-TNF-α dose escalation or switching between different anti-TNF-α agents is of limited value (2 studies).
AIM: To systematically review the literature on epidemiology, global disease burden, and treatment outcomes for CPF in CD patients.
METHODS: PubMed, Embase, and Cochrane were searched for relevant articles published from 2000 forward; congress abstracts were searched from 2011 forward. CPFs were defined as fistulas with intersphincteric, transsphincteric, suprasphincteric, extrasphincteric, or horseshoe tracts.
RESULTS: 535 records were reviewed by 2 independent researchers, and 63 relevant articles and abstracts were selected for inclusion (including 3 epidemiology and 3 burden; the rest were treatment guidelines/patterns or treatment outcome studies). The estimated cumulative incidence of CPF in CD, based mostly on studies conducted in referral centres, ranges from 12%-14% (2 studies). CPF can result in significant morbidity and greatly diminished quality of life; up to 59% of patients (1 study) are at risk of fecal incontinence.
CONCLUSIONS: CPFs in CD pose substantial clinical burden. There is a high unmet need for effective treatment options for CPF in CD patients, especially those refractory to anti-TNF-α agents, as evidenced by high treatment failure and relapse rates. Keywords: Crohn’s disease, complex perianal fistulas, global disease burden, treatment failure.
