ABSTRACT
AIM: To report our experience in a compassionate use program for complex perianal fistula. METHODS: Under controlled circumstances and approved by European and Spanish laws, a compassionate use program allows the use of stem cell therapy for patients with nonhealing diseases, mostly complex fistula-in-ano, who do not meet criteria to be included in a clinical trial. Candidates had previously undergone multiple surgical interventions that had failed. The intervention consisted of surgery (with closure of the internal opening or a surgical flap performance), followed by stem cell injection. Three types of cells were used for implant: stromal vascular fraction, autologous expanded adipose-derived, or allogenic adipose-derived stem cells. Healing was evaluated at 6th month follow-up. Outcome was classified as partial response or healing. Relapse was evaluated 1 year later. Maximum follow-up period was 48 months. RESULTS: 45 patients (24 male) were included; the mean age was 45 years, which ranged from 24 to 69 years. Since some of them received repeated doses, 52 cases were considered (42 fistula-in-ano, 7 rectovaginal fistulas, 1 urethrorectal fistula, 1 sacral fistula, and 1 hidradenitis suppurativa). Regarding fistula-in-ano, there were 18 Crohn's-associated and 24 cryptoglandular. 49 cases (94.2%) showed partial response starting 6.5 weeks of follow-up. 24 cases (46.2%) healed in a mean time of 5.5 months. A year later, all patients cured remained healed. No adverse effects related to stem cell therapy were reported. CONCLUSION: Stem cells are safe and useful for treating anal fistulae. Healing can be achieved in severe cases.
ABSTRACT
Anal fistula is a challenging condition both for surgeons and patients. Recurrent fistula, Crohn's disease, or autoimmune disorders add further complexity to this situation. Numerous clinical trials have now demonstrated that cell-based therapy appears to be a good complement to fistulous surgery. As in any new treatment, especially that involving living cells, appropriate application is paramount to achieve optimal outcomes. As stem cell-based treatments are gaining a strong foothold in fistula management worldwide, we herein aim to share our mesenchymal stem cell surgical protocol. With the goal of optimizing results of this emerging therapy, we have improved and refined our protocol over the past 17 years of working with stem cells in clinical trials. The protocol consists of nine reproducible steps for mesenchymal stem cell application inside the fistulous tract, and has proven to be safe and effective in several studies, including international phase III clinical trials.
Subject(s)
Adipose Tissue/cytology , Digestive System Surgical Procedures/methods , Mesenchymal Stem Cell Transplantation/methods , Mesenchymal Stem Cells , Rectal Fistula/therapy , HumansABSTRACT
BACKGROUND: Autologous adipose-derived stem cells may represent a novel approach for the management of complex fistula-in-ano. After successful phase I and II clinical trials, a phase III trial was performed to investigate the safety and efficacy. DESIGN: In this multicenter, randomized, single-blind, add-on clinical trial, 200 adult patients from 19 centers were randomly assigned to receive 20 million stem cells (group A, 64 patients), 20 million adipose-derived stem cells plus fibrin glue (group B, 60 patients), or fibrin glue (group C, 59 patients) after closure of the internal opening. Fistula healing was defined as reepithelization of the external opening and absence of collection >2 cm by MRI. If the fistula had not healed at 12 weeks, a second dose (40 million stem cells in groups A and B) was administered. Patients were evaluated at 24 to 26 weeks (primary end point) and at 1 year (long-term follow-up). RESULTS: All results are according to the "blinded evaluator" assessment. After 24 to 26 weeks, the healing rate was 39.1%, 43.3%, 37.3% in groups A, B, and C (p = 0.79). At 1 year, the healing rates were 57.1%, 52.4%, and 37.3 % (p = 0.13). On analysis of the subpopulation treated at the technique's pioneer center, healing rates were 54.55%, 83.33%, and 18.18%, at 24 to 26 weeks (p < 0.001). No SAEs were reported. CONCLUSIONS: In treatment of complex fistula-in-ano, a dose of 20 or 60 million adipose-derived stem cells alone or in combination with fibrin glue was considered a safe treatment, achieving healing rates of approximately 40% at 6 months and of more than 50% at 1-year follow-up. It was equivalent to fibrin glue alone. No statistically significant differences were found when the 3 groups where compared. CLINICAL TRIALS REGISTRATION: www.clinicaltrials.gov, identifier NCT00475410; Sponsor, Cellerix SA.
