The goal of this clinical trial is to learn if human placenta mesenchymal stem cells (MSC)-derived exosomes work to treat complex perianal fistula in adults without Crohn's disease. The safety of this treatment will also be learned. The main questions it aims to answer are:
* Does treatment with MSC-derived exosomes lower the number of fistula recurrences in participants? * Is treatment with MSC-derived exosomes safe? We will compare treatment with MSC-derived exosomes to the routine treatment which is fistulotomy (surgery to close the fistula) alone to see if MSC-derived exosomes work better to treat complex fistula.
Participants will:
* Undergo fistulotomy plus MSC-derived exosome injections or fistulotomy alone. * Visit the clinic the week after surgery and then every 4 weeks for checkups and tests
participants with complex perianal fistula
provided written informed consent
participants with any inflammatory bowel diseases
pregnant or lactating participants
participants with contraindications for surgery
participants with hepatitis