Autologous Adipose-derived Stem Cells (ASCs) for the Treatment of Perianal Fistula in Crohn Disease: A Pilot Study

Crohn's disease is an immunologically mediated inflammatory bowel disease with a reported incidence of 4.0-7.0, 7.1, and 1.34 per 100,000 persons in Europe, the U.S., and Korea, respectively. Uncontrolled chronic inflammation finally causes various complications in intestine such as bowel obstruction, fistulas, abscesses, and anal fissures. The incidence of perianal fistula was reported in 13%- 39% of patients with Crohn's disease. Medical treatment for Crohn's fistulae initially focused on surgical intervention accompanied by symptomatic treatment with antibiotics and immunosuppressants. The most serious problem after surgical intervention is the relatively high incidence of postoperative anal incontinence caused by sphincter injury during the procedure. Conversely, available pharmacological therapies for Crohn's fistulae based on biologic agents such as infliximab do not generally reach ideal goal of treatment (e.g., complete closure of the fistula). A high recurrence rate after treatment with infliximab has also been reported, even after long-term maintenance therapy, which suggests that infliximab monotherapy does not provide adequate healing. The ACCENT II study demonstraded a complete fistula healing in 25% of patients. To reach a better clinical outcome, combination treatment with infliximab and surgical intervention is highly recommended for management of Crohn's fistulae. Nonetheless, even this strategy does not result in a satisfactory healing for many patients. The ideal therapeutic goal of treatment is not only complete closure of the fistula without recurrence but also preservation of anal sphincter function. Unfortunately, currently available medical or surgical treatment is not likely to offer a cure for perianal fistulae and, as noted above, recurrence is frequently reported. Together with active research in the field of bone marrow-derived mesenchymal stem cells (BM-MSCs) and hematopoietic stem cells, autologous or allogenic adipose tissue-deriv