Comments on: "Long-term efficacy of mesenchymal stem cell treatment for complex perianal fistulas: A systematic review and meta-analysis".

The meta-analysis by Wang et al. aimed to assess the long-term effects of mesenchymal stem cells on complex perianal fistula. The authors concluded that mesenchymal stem cell therapy has a long-term effect on the clinical response of complex perianal fistula and should be widely promoted not only in adults but also in infants and adolescents; however, more research on this topic is needed. We appreciate the authors' hard work, and we also agree with this argument. However, we have several concerns about the study. We think it is necessary to discuss the effect of anti-TNF and immunosuppressive therapy on the effcacy of mesenchymal stem cell treatment for perianal fistula in future trials, in order to optimize treatment strategies in perianal fistula patients and reduce the economic burden of patients. In the future, it will be interesting to assess the safety and feasibility of injection of fibrin glue combined with mesenchymal stem cells in perianal fistula.