Stem cell therapy in anal fistula:a mini review

When an abscess is drained, either spontaneously or surgically , the pathway to the infection remains and is lined with epithelial tissue and leads to the formation of anal fistulas. The treatment of fistulas remains a serious challenge for colorectal surgeons with varying degrees of success because extensive surgery to complete control complex fistulas results in fecal incontinence. One of the most recent non-surgical methods is cell therapy, clinical trials for which are ongoing in the third phase. In this method, stem cells with different sources are used to control inflammation and replace the lost tissue in the fistula tract. Therefore, the purpose of this narrative review is to review cell therapy in treatment of anal fistulas along with its weaknesses and strengths. Finally this review of existing studies for anal fistulas suggests that until now, only two sources of stem cells , in both allogeneic and autologous forms, have been used in clinical trials for treatment of anal fistulas: adipose tissue and bone marrow (mainly adipose tissue) and except for the two Phase III clinical trials in 2012 and 2016, all clinical trials in this field were conducted in phase one and two with the aim of determining the safety and efficacy of these cells.