To evaluate the safety and efficacy of autologous adipose-derived stem cells (ADSCs) in the treatment of complex anal fistulas.

Twenty-three patients whose age ranged from 12 to 51 years old with complex anal fistula were treated with ADSCs in Colorectal Disease Center of Affiliated Nanjing Hospital of Nanjing University of Chinese Medicine from January 2018 to October 2018. They included 11 patients with Crohn′s disease anal fistulas(CDAF) and 12 patients with cryptoglandular anal fistulas (CPAF). And their clinical data during the follow-up period of 3~12 months were collected. The closure of fistulas were evaluated by clinical evaluation and MRI scan. And the time of complete epithelialization of fistulas were also counted. It shouldn′t be forgotten that Perianal Disease Activity Index (PDAI) should be recorded for patients with CDAF before and after treatment. In addition, anal incontinence score(Wexner score), visual analogue scale score, quality of life score(SF-36) and adverse events were recorded.

The total healing rate of fistulas was 69.57%(16/23). The healing rate of CDAF was 90.91% (10/11) and CPAF was 50%(6/12). The average external closure time of 16 patients with fistulas healing was (17.06±4.54) days, of which (17.90±4.53) days was CDAF and (15.67±4.59) days was CPAF. The quality of life score and visual analogue scale come back to preoperative levels in 7 days postoperation, while the anal incontinence score unchanged or decreased. The PDAI of patients with CDAF was (8.55+ 1.37) points before treatment, and (1.27+ 1.10) points 90 days after treatment (t=12.033, P<0.05). No adverse events associated with ADSCs injection were observed in the study.

ADSCs is a safe and effective treatment for complex anal fistula, especially for CDAF. It can protect the anal function of patients, relieve pain and improve the quality of life during perioperative period.