This clinical trial was to determine the safety and feasibility of expanded allogeneic adipose‐derived stem cells to treat Crohn’s‐related rectovaginal fistula (CRRVF). Sixty percent of the nonexcluded patients achieved a complete healing. This is a safe and feasible therapy for treating CRRVF, and the healing success rate appears promising.

Tracheal fistulas represent a challenging management problem. The standard treatment in most cases is based on surgical procedures. Various endoscopic treatment modalities have been proposed in patients at high surgical risk but the results are often unsatisfactory. The fistulas frequently recur with additional complications and sometimes death. The case history is reported of a patient with a tracheomediastinal fistula resulting from laser treatment of tracheal cancer. The fistula was treated by bronchoscopic injection of autologous adipose-derived stem cells (ASC) suspended in fibrin glue. The patient's stem cells were isolated from lipoaspirate according to a standardised procedure. No complications due to treatment with ASC occurred during the follow-up period and no fistularelated symptoms were detected. Postoperative bronchoscopic examination of the wall and base of the fistula revealed re-epithelialisation and neovascularisation that led to successful closure. To our knowledge, this is the first report of treatment of tracheal fistula by autologous cell therapy. Further studies are needed to confirm whether this new method should become routine practice.Acquired fistulas of the tracheobronchial airway are associated with serious management problems, with high rates of morbidity and mortality. The standard treatment varies with the type of fistula. 1The therapeutic approach is individualised and is based on surgical closure or endoscopic techniques. However, many patients die from haemorrhage resulting from progression of the fistula into the blood vessels.3-5 Using our clinical experience with adipose-derived stem cells (ASC), 6 we attempted to develop a new treatment for tracheomediastinal fistula. CASE REPORTA 67-year-old man with non-small cell lung cancer (T4N2Mx) located in the trachea and upper right lobe was treated initially with radio-chemotherapy and laser irradiation delivered locally through a rigid bronchoscope. During control bronchoscopy performed 2 years after the first treatment, the cancer was found to have reappeared near the carina. The relapse was treated with an Nd-YAG laser (total energy 8450 J over 40 min), applied as three procedures, and chemotherapy. Immediately after this second therapeutic intervention the lasertreated area (anterior tracheal wall) developed progressive necrosis that resulted in a tracheomediastinal fistula. 7 The diameter of the entrance to the fistula was 10 mm ( fig 1A) and the bronchoscope was able to pass into the mediastinum. Mediastinal tissue and anthracotic lymph nodes were visible. In addition, the right pulmonary artery and the superior vena cava were visible through the thin transparent walls of the fistula. A chest radiograph and CT scan indicated a pretracheal air cavity in the medial mediastinum (fig 1B), communicating through the fistula with the tracheal lumen.Open surgery was not considered because of the high risk to the patient of surgery in the previously irradiated field. We did consider closing the fistula with a stent or by appl...

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.

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Therapeutic options for recto-vaginal fistula in the setting of Crohn's disease are limited and many data are available in the literature. The manuscript describes the history of a patient who has been the pioneer of our Clinical Trials in treating this disease in fistulizing Crohn's disease environment. We believe it is the first time that a patient with this disease has been treated by adipose-derived stem cells in allogeneic form. The conclusion of our study with Mary is that the use of mesenchymal stem cells derived from adipose tissue is secure, either in autologous or allogeneic form. Furthermore, we have proved that if we use multi-dose and multiple applications on a patient, it does not produce any adverse effect, which confirms us the safety of using these cells in patients at least in the fistulizing Crohn's disease environment.

Biosutures are a comfortable way of stem cell delivery to the surgical field without modification of the operative protocol. ASCs suppress the local acute inflammatory reaction (increased macrophage migration and decreased neutrophil infiltration) in the tracheal anastomosis and cause an early switch from acute to chronic inflammation.

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.

AIMTo establish a rat model of anal sphincter injury and test different systems to provide stem cells to injured area.METHODSAdipose-derived stem cells (ASCs) were isolated from BDIX rats and were transfected with green fluorescent protein (GFP) for cell tracking. Biosutures (sutures covered with ASCs) were prepared with 1.5 x 106 GFP-ASCs, and solutions of 106 GFP-ASCs in normal saline were prepared for injection. Anorectal normal anatomy was studied on Wistar and BDIX female rats. Then, we designed an anal sphincter injury model consisting of a 1-cm extra-mucosal miotomy beginning at the anal verge in the anterior middle line. The sphincter lesion was confirmed with conventional histology (hematoxylin and eosin) and immunofluorescence with 4', 6-diamidino-2-phenylindole (commonly known as DAPI), GFP and α-actin. Functional effect was assessed with basal anal manometry, prior to and after injury. After sphincter damage, 36 BDIX rats were randomized to three groups for: (1) Cell injection without repair; (2) biosuture repair; and (3) conventional suture repair and cell injection. Functional and safety studies were conducted on all the animals. Rats were sacrificed after 1, 4 or 7 d. Then, histological and immunofluorescence studies were performed on the surgical area.RESULTSWith the described protocol, biosutures had been covered with at least 820000-860000 ASCs, with 100% viability. Our studies demonstrated that some ASCs remained adhered after suture passage through the muscle. Morphological assessment showed that the rat anal anatomy is comparable with human anatomy; two sphincters are present, but the external sphincter is poorly developed. Anal sphincter pressure data showed spontaneous, consistent, rhythmic anal contractions, taking the form of “plateaus” with multiple twitches (peaks) in each pressure wave. These basal contractions were very heterogeneous; their frequency was 0.91-4.17 per min (mean 1.6980, SD 0.57698), their mean duration was 26.67 s and mean number of peaks was 12.53. Our morphological assessment revealed that with the aforementioned surgical procedure, both sphincters were completely sectioned. In manometry, the described activity disappeared and was replaced by a gentle oscillation of basal line, without a recognizable pattern. Surprisingly, these findings appeared irrespective of injury repair or not. ASCs survived in this potentially septic area for 7 d, at least. We were able to identify them in 84% of animals, mainly in the muscular section area or in the tissue between the muscular endings. ASCs formed a kind of “conglomerate” in rats treated with injections, while in the biosuture group, they wrapped the suture. ASCs were also able to migrate to the damaged zone. No relevant adverse events or mortality could be related to the stem cells in our study. We also did not find unexpected tissue growths.CONCLUSIONThe proposed procedure produces a consistent sphincter lesion. Biosutures and injections are suitable for cell delivery. ASCs survive and are completely safe in this clinical s...