The Use of Adipose-Derived Stem Cells for the Treatment of Complex Postoperative Enterocutaneous Fistulas: A Preliminary Case Series Study

<i>Background and Objectives</i>: Postoperative enterocutaneous fistulas, defined as abnormal communications between the intestinal lumen and the skin, represent one of the most challenging complications following abdominal surgery. Regenerative medicine, particularly through the use of adipose-derived mesenchymal stem cells (ADSCs), has recently emerged as a promising therapeutic option for chronic inflammatory and non-healing conditions. However, most studies have focused on complex perianal fistulas in Crohn's disease. This prospective, single-center observational study aimed to evaluate the feasibility, safety, and preliminary efficacy of autologous ADSC injection in patients with complex postoperative enterocutaneous fistulas. <i>Materials and Methods</i>: Six patients (four males and two females) with persistent postoperative enterocutaneous fistulas were enrolled. Autologous adipose tissue was harvested via lipoaspiration from the abdominal wall or flank and processed in a GMP-certified laboratory to obtain a suspension containing 5-10 million viable ADSCs in 3-5 mL of isotonic solution. ADSCs were injected directly into the fistulous tract under ultrasound guidance, following CT image review. Clinical and radiologic follow-up was performed to assess closure and output reduction. <i>Results</i>: Four of the six patients (66.7%) achieved complete fistula closure, with no residual output and radiologic confirmation of healing within 4-12 weeks. One patient (16.7%) demonstrated a significant reduction in fistula output (>80%), while another (16.7%) showed minimal improvement and subsequently required surgical repair at 6 weeks. No complications related to ADSC administration were observed. <i>Conclusions</i>: Autologous ADSC therapy appears to be a feasible, safe, and minimally invasive option for managing complex postoperative enterocutaneous fistulas. These encouraging preliminary results-showing complete closure in two-thirds of treated patients-support further investigation through larger, controlled trials to validate these findings and optimize treatment protocols.