Autologous adipose-derived stem cells for the treatment of Crohn’s fistula-in-ano: an open-label, controlled trial

BACKGROUND: Crohn’s fistula-in-ano is a refractory disease in colorectal and anal surgery. Although autologous adipose-derived stem cell (ADSC) has been used in the treatment of Crohn’s fistula-in-ano because of its convenience, non-incision of normal tissue, good tolerance, repeatability, quick recovery, less pain, less damage to anal function, and high quality of life during the perioperative period, there are no reports of its use in China. This is the first clinical trial in China on the treatment of Crohn’s fistula-in-ano with ADSC to evaluate its efficacy and safety. METHODS: A total of 22 patients with Crohn’s fistula-in-ano were enrolled in this study from January 2018 to October 2018 in the Colorectal Disease Center of Nanjing Hospital of Chinese Medicine Affiliated to Nanjing University of Chinese Medicine. Patients were divided (1:1) into an observation group (ADSC) and a control group (incision-thread-drawing procedure). Primary efficacy endpoint evaluated at months 3, 6, and 12 was the closure of fistulas (closure of all treated fistulas at baseline, confirmed by doctor’s clinical assessment and magnetic resonance imaging or transrectal ultrasonography). The patients additionally completed some scoring scales at each follow-up including simplified Crohn’s Disease Activity Index (CDAI), Perianal Disease Activity Index (PDAI), Inflammatory Bowel Disease Questionnaire (IBDQ), pain scores with visual analog score (VAS), and Wexner score. The data of inflammatory indexes were also collected. RESULTS: The healing rates of the observation group and the control group at months 3, 6, and 12 were as follows: 10/11(90.9%) vs 5/11(45.5%), 8/11(72.7%) vs 6/11(54.5%), and 7/11(63.6%) vs 6/11(54.5%), respectively. There was no statistical difference between the two groups. In addition, the improvement in simplified CDAI, PDAI, IBDQ, VAS, and Wexner score of the observation group were better than that of the control group at each follow-up. The inflammatory indexes decreased in both the observation group and the control group at 3 months follow-up. And there were no significant differences in the changes of inflammatory indexes between two groups at month 3 compared with the baseline. Safety was maintained throughout month 12, and adverse events occurred in 63.6% of patients in the observation group and 100% patients in the control group. And no adverse event associated with ADSC injection was observed in the study. CONCLUSION: ADSC is a feasible and effective treatment for Crohn’s fistula-in-ano, compared with traditional incision and thread-drawing. It can protect anal function of patients, relieve pain, allow quick recovery, be well-tolerated, and improve the quality of life during perioperative period. TRIAL REGISTRATION: China Clinical Trials Registry, No. ChiCTR1800014599. Registered 23 January 2018.