Undetectable circulating tumor DNA confirms the inability of pseudomyxoma peritonei to systemic dissemination.

The study of circulating tumor DNA (ctDNA) plays a pivotal role in advancing precision oncology, providing valuable information for individualized patient care and contributing to the ongoing effort to improve cancer diagnosis, treatment, and management. However, its applicability in pseudomyxoma peritonei (PMP) remains unexplored. In this multicenter retrospective study involving 21 PMP patients, we investigated ctDNA presence in peripheral blood using three distinct methodologies. Despite mucinous tumor tissues exhibiting KRAS and GNAS mutations, ctDNA for these mutations was undetectable in blood samples. In this pilot study, circulating tumor DNA was not detected in blood when the tumor harbored mutations of known significance. In the future, a study with a larger sample size is needed to confirm these findings and to determine whether ctDNA could identify patients at risk for early recurrence and/or systemic metastases.

Therapeutic effect of adipose-derived mesenchymal stem cells in a porcine model of abdominal sepsis.

BACKGROUND: The term sepsis refers to a complex and heterogeneous syndrome. Although great progress has been made in improving the diagnosis and treatment of this condition, it continues to have a huge impact on morbidity and mortality worldwide. Mesenchymal stem cells are a population of multipotent cells that have immunomodulatory properties, anti-apoptotic effects, and antimicrobial activity. We studied these capacities in a porcine model of peritoneal sepsis. METHODS: We infused human adipose-derived mesenchymal stem cells (ADSCs) into a porcine model of peritoneal sepsis. Twenty piglets were treated with antibiotics alone (control group) or antibiotics plus peritoneal infusion of ADSCs at a concentration of 2 × 106 cells/kg or 4 × 106 cells/kg (low- and high-dose experimental groups, respectively). The animals were evaluated at different time points to determine their clinical status, biochemical and hematologic parameters, presence of inflammatory cytokines and chemokines in blood and peritoneal fluid, and finally by histologic analysis of the organs of the peritoneal cavity. RESULTS: One day after sepsis induction, all animals presented peritonitis with bacterial infection as well as elevated C-reactive protein, haptoglobin, IL-1Ra, IL-6, and IL-1b. Xenogeneic ADSC infusion did not elicit an immune response, and peritoneal administration of the treatment was safe and feasible. One day after infusion, the two experimental groups showed a superior physical condition (e.g., mobility, feeding) and a significant increase of IL-10 and TGF-ß in blood and a decrease of IL-1Ra, IL-1b, and IL-6. After 7 days, all animals treated with ADSCs had better results concerning blood biomarkers, and histopathological analysis revealed a lower degree of inflammatory cell infiltration of the organs of the peritoneal cavity. CONCLUSIONS: Intraperitoneal administration of ADSCs as an adjuvant therapy for sepsis improves the outcome and diminishes the effects of peritonitis and associated organ damage by regulating the immune system and reducing intra-abdominal adhesions in a clinically relevant porcine model of abdominal sepsis.

Toxicity study in a pig model of intraperitoneal collagenase as an "enzymatic scalpel" directed to break stroma in order to generate a new perspective for peritoneal carcinomatosis approach: an experimental research.

BACKGROUND: This study aimed to measure the toxicity resulting from collagenase administration to the peritoneal cavity in a pig model as a preliminary step to break down the stroma surrounding tumors. METHODS: Eight pigs were treated with 2 different collagenase concentrations previously tested in rats by our group. Time and temperature were controlled using a peritoneal lavage system (PRS System, Combat Medical Ltd.) identical to that used in human surgeries through hyperthermic intraperitoneal chemotherapy (HIPEC); 2 additional pigs were treated with peritoneal lavage only. Samples of blood and peritoneal fluid were collected pre-treatment, immediately after treatment, and 24 h postoperatively. In addition, histological studies and blood collagenase levels were measured. RESULTS: No complications were observed during the surgeries. Intraoperative images evidenced the release of peritoneal tissue during collagenase treatment. After surgery, the animals showed no signs of pain. Diet and mobility were normal at 4 h postoperatively, and there were no significant differences in hematologic or biochemical parameters. Quantification of MMP1 and MMP2 in all samples as measured by absorbance showed no differences in blood collagenase levels between pre-treatment, post-treatment, and 24 h postoperatively. None of the animals treated with collagenase showed peritoneal adhesions during the second surgery. Histologically, peritoneal organs and serous structures did not show any microscopic alterations associated with collagenase treatment in any group. CONCLUSION: Lavage of the peritoneal cavity with doses of up to 100,000 collagen digestion units/animal for 30 min is safe and removes connective tissue from the peritoneal cavity.

Intraperitoneal collagenase as a novel therapeutic approach in an experimental model of colorectal peritoneal carcinomatosis.

The usefulness of local collagenase in therapeutic approaches to solid tumors has been tested recently. In this study, we evaluate the safety and efficacy of intraperitoneal collagenase associated or not to mitomycin for treatment of colorectal peritoneal metastases in an experimental rat model. Using a fixed-dose procedure, we found that a dose of collagenase of 37 IU/mL administered for 15 min with a hyperthermia pump at 37.5 °C, both in isolation or associated to sequential treatment with intraperitoneal mitomycin, led to a macroscopic decrease in tumor volume as evaluated by the modified peritoneal cancer index (mPCI). Concerning the safety of the procedure, the animals showed no physiological or behavioral disorders during 8 weeks of follow-up. Local treatment for peritoneal metastases of colorectal origin with intraperitoneal collagenase has proved safe and effective in an experimental murine model. Therefore, the stroma-first approach by enzymatic breakdown of collagen from the tumor's extracellular matrix provides a new therapeutic target for colorectal peritoneal metastases.

Mesenchymal stem cells in perianal Crohn's disease.

The use of mesenchymal stem cells has resulted in a breakthrough for the treatment of complex perianal fistulas in Crohn's disease. This novel treatment is associated with a minimally invasive surgical technique that can be well defined. However, our previous experience has taught us that neglecting any of the critical steps in the operation can result in frequent treatment failure. We have put together a comprehensive guide, a stepwise algorithm, for our minimally invasive approach to identify common pitfalls and reduce treatment failures. Using data we have collected over the past 15 years from drug development, execution of clinical trials, and enacting an advanced educational training program, we spelt out each stage of the minimally invasive surgical intervention for stem cell delivery for perianal Crohn's disease. In this article, we provide 21 tips for a correct approach during the five major phases of the surgical procedure. To optimize the efficacy of mesenchymal stem cells for perianal Crohn's disease, a standardized minimally invasive technique including a reliable and reproducible series of key steps should be utilized.

A First Step to a Biomarker of Curative Surgery in Colorectal Cancer by Liquid Biopsy of Methylated Septin 9 Gene.

OBJECTIVES: To confirm that patients affected by colorectal cancer have the V2 region of Septin 9 (SEPT9) gene hypermethylated in the circulating free DNA from a peripheral blood sample before surgery and to determine if this hypermethylated DNA disappears from the patients after complete resection of the tumour. METHODS: Plasma from 10 patients with colorectal cancer was collected preoperative and three months after surgery. The analysis of the methylation status of the promoter region of the SEPT9 gene was performed using a 7500 Fast Real-Time PCR System. RESULTS: Hypermethylation of SEPT9 gene was detected in 8 out of 10 preoperative samples (one negative result was probed to be a Lynch syndrome) and in 4 out of 10 postoperative samples matching with the cases of recurrence or persistence of disease. This means that, in this sample, the preoperative sensitivity and specificity of the test were 88.9% and 100%, respectively, and there is 100% correlation between the positive results of the SEPT9 test and a recurrence/persistence of the disease in patients after surgical resection. CONCLUSIONS: Our study shows that circulating hypermethylated SEPT9 is a specific colorectal cancer biomarker. This hypermethylated SEPT9 DNA disappears around three months after surgery and that circulating hypermethylated SEPT9 may be the first noninvasive marker for postsurgical diagnosis; this conclusion must be confirmed with a more significant number of patients.

Stem Cell Therapy: A Compassionate Use Program in Perianal Fistula.

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.

Bisphosphonate-related osteonecrosis. Application of adipose-derived stem cells in an experimental murine model.

BACKGROUND: Bisphosphonate-related osteonecrosis of the jaw is a pathological condition without effective established treatment and preventive strategies. The aim of this study was to analyse the effect of adipose-derived stem cells (ASC) in an experimental murine model of osteonecrosis. MATERIAL AND METHODS: 38 Wistar rats were injected intraperitoneally with zoledronic acid. After treatment, upper jaw molars were extracted. The animals were randomly assigned to one of two groups. In the control group, saline solution was applied over the alveolar sockets after the tooth extractions. In the treatment group, ASCs were applied instead of saline solution. The control and treatment groups were subdivided based on the time of euthanasia. A clinical and histological analysis was performed. RESULTS: The presence of osteonecrosis in alveolar bone was observed in a similar distribution in both groups. In the ASC-treated group, new bone formation was greater than in controls. CONCLUSION: In this study, application of ASCs showed greater new bone formation in an osteonecrosis-like murine model. Previous inhibited post-extraction bone remodelling could be reactivated, and these findings appeared to be secondary to implantation of ASCs.

A Step-By-Step Surgical Protocol for the Treatment of Perianal Fistula with Adipose-Derived Mesenchymal Stem Cells.

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.

Uso de células troncales derivadas de lipoaspirado en un modelo experimental animal de rotura de manguito rotador / Use of adipose-derived stem cells in an experimental rotator cuff fracture animal model

Objetivo. La reparación del manguito rotador tiene una alta tasa de fracaso. Se investiga si la aplicación de células troncales derivadas de lipoaspirado mejorará la resistencia de la reparación y recreará la entesis original. Material y métodos. Estudio experimental en 44 ratas BDIX con sección y reparación con sutura del tendón supraespinoso y asignación aleatoria a uno de 3 grupos: grupo A, nada (control); grupo B, aplicación local de vehículo de fibrina; y grupo C, aplicación de 2 x 106 células troncales derivadas de lipoaspirado. Se realiza estudio mecánico en célula de carga y estudio histológico en hematoxilina-eosina. Resultados. En el estudio mecánico no hubo diferencias entre grupos. La carga hasta el fracaso aumentó de los grupos de 4-8 semanas. En el estudio histológico se observó la unión hueso-tendón mediante un tejido fibrovascular desorganizado. En el grupo C se observó un aumento de células plasmáticas a las 4 y 8 semanas. Conclusión. La utilización de células troncales derivadas de lipoaspirado no recrea la organización celular de la entesis ni mejoran las propiedades biomecánicas de la misma. Son necesarios más estudios para investigar técnicas que mejoren la cicatrización del tendón (AU)

Aim. Rotator cuff repairs have shown a high level of re-ruptures. We hypothesized that the use of adipose-derived stem cells (ASC) could improve the biomechanical and histological properties of the repair. Material and methods. Controlled experimental study conducted on 44 BDIX rats with section and repair of the supraspinatus tendon and randomization to one of three groups: group A, no intervention (control); group B, local applications of a fibrin sealant; and group C, application of the fibrin sealant with 2 x 106 ASC. At 4 and 8 weeks a biomechanical and histological analysis was performed. Results. There were no differences in load-to-failure at 4 and 8 weeks between groups. The load-to-failure did increase between week 4 and week 8. Histologically the tendon-to bone union showed a disorganized fibrovascular tissue. Group C showed a different inflammatory pattern, with less presence of neutrophils and more presence of plasma cells. Conclusion. The use of ASC does not improve the biomechanical or histological properties of the repair site. More studies are needed to improve techniques that enhance the healing site of the repair (AU)

Potential of mesenchymal stem cell in stabilization of abdominal aortic aneurysm sac.

BACKGROUND: In their origin, abdominal aortic aneurysms (AAAs) are related to an inflammatory reaction within the aortic wall, which can lead to weakness and degeneration of this structure. One of the most widely accepted treatment modalities for AAAs is the placement of stent grafts. Nevertheless, in some patients blood re-enters the aneurysm sac, creating so-called leaks, which constitute a renewed risk of rupture and death.This study explores the possibility of filling aneurysm sacs treated by endovascular aneurysm repair with adipose tissue-derived mesenchymal stem cells (ASCs) in a porcine model. METHODS: We developed a porcine model using 22 animals by creating an artificial AAA made with a Dacron patch. AAAs were then treated with a coated stent that isolated the aneurysm sac, after which we introduced allogeneic ASC into the sac. Animals were followed-up for up to 3 mo. The experiment consisted of the aforementioned surgical procedure performed first, followed by computed tomography and echo-Doppler imaging during the follow-up, and finally, after sacrificing the animals, histologic analysis of tissue samples from the site of cell implantation by a blinded observer and the detection of implanted cells by immunofluorescence detection of the Y chromosome. RESULTS: Our findings demonstrate the survival of ASCs over the 3 mo after implantation and histologic changes associated with this treatment. Treated animals had less acute and chronic inflammation throughout the study period, and we observed increasing fibrosis of the aneurysm sac, no accumulation of calcium, and a regeneration of elastic fibers in the artery. CONCLUSIONS: The combination of endovascular aneurysm repair and cell therapy on AAAs has promising results for the stabilization of the sac, resulting in the generation of living tissue that can secure the stent graft and even showing some signs of wall regeneration. The therapeutic value of such cell-based therapy will require further investigation.

[Use of adipose-derived stem cells in an experimental rotator cuff fracture animal model]. / Uso de células troncales derivadas de lipoaspirado en un modelo experimental animal de rotura de manguito rotador.

AIM: Rotator cuff repairs have shown a high level of re-ruptures. We hypothesized that the use of adipose-derived stem cells (ASC) could improve the biomechanical and histological properties of the repair. MATERIAL AND METHODS: Controlled experimental study conducted on 44 BDIX rats with section and repair of the supraspinatus tendon and randomization to one of three groups: group A, no intervention (control); group B, local applications of a fibrin sealant; and group C, application of the fibrin sealant with 2 x 10(6) ASC. At 4 and 8 weeks a biomechanical and histological analysis was performed. RESULTS: There were no differences in load-to-failure at 4 and 8 weeks between groups. The load-to-failure did increase between week 4 and week 8. Histologically the tendon-to bone union showed a disorganized fibrovascular tissue. Group C showed a different inflammatory pattern, with less presence of neutrophils and more presence of plasma cells. CONCLUSION: The use of ASC does not improve the biomechanical or histological properties of the repair site. More studies are needed to improve techniques that enhance the healing site of the repair.

Uso de plasma rico en plaquetas para cicatrización de úlceras crónicas de miembros inferiores / Use of Platelet-Rich Plasma in the Healing of Chronic Ulcers of the Lower Extremity

INTRODUCCIÓN Y OBJETIVOS: El plasma rico en factores plaquetarios (PRP) ha sido utilizado como terapia adyuvante en el tratamiento de úlceras crónicas de miembros inferiores (UCMI), con resultados particularmente esperanzadores en las úlceras neuropáticas. Sin embargo, su uso en úlceras venosas e hipertensivas ha sido menos estudiado. Nuestro objetivo es valorar la seguridad y factibilidad del uso del PRP en UCMI y estimar sus beneficios en la cicatrización dirigida. MATERIAL Y MÉTODOS: Se trata de un estudio prospectivo. Fueron seleccionados 11 pacientes con úlceras en miembros inferiores de más de 6 semanas de evolución, de etiología no isquémica. Se administró PRP en inyección subcutánea perilesional y aplicación tópica, en 4 sesiones separadas por una semana. Se suministraron cuestionarios de calidad de vida (SF-12), se registró el dolor (escala visual analógica) y el perímetro de la úlcera antes y después de su aplicación. RESULTADOS: Hubo predominancia de mujeres (8/11 = 73%) y de úlceras venosas (7/11 = 64%) sobre las hipertensivas (4/11 = 36%). La mediana de edad fue de 79 años y el tiempo medio de evolución de la úlcera de 17 meses (6-108 meses). Se evidenció una disminución estadísticamente significativa del dolor (p < 0,05) y mejoría mental y física de la calidad de vida (p < 0,05). Se evidenció una reducción media en el área de las úlceras del 60%, con 5 cicatrizaciones completas. No se registraron eventos adversos. CONCLUSIÓN: La aplicación local de PRP en úlceras crónicas de miembros inferiores representa una herramienta válida, de uso práctico en la cicatrización dirigida, que puede mejorar la calidad de vida de estos pacientes, siendo particularmente útil en el control del dolor local

INTRODUCTION AND OBJECTIVES: Platelet-rich plasma (PRP) is used as an adjuvant in the treatment of chronic ulcers of the lower extremity and has shown particularly promising results in the case of neuropathic ulcers. There has been less research, however, into its use in venous and hypertensive ulcers. Our aim was to assess the safety and feasibility of using PRP in the treatment of chronic ulcers of the lower extremity and to evaluate its potential benefits in directed healing. MATERIAL AND METHODS: We prospectively selected 11 patients with nonischemic ulcers of the lower extremity that had been present for at least 6 weeks. PRP was injected subcutaneously into the perilesional tissue and applied topically in 4 sessions held at 1-week intervals. We assessed quality of life (SF-12 questionnaire), pain (visual analog scale), and the circumference of the ulcer before and after treatment. RESULTS: There was a predominance of women (8/11, 73%), and venous ulcers (7/11, 64%) were more common than hypertensive ulcers (4/11, 36%). The median age of the patients was 79 years and the median time since onset of the ulcer was 17 months (range, 6-108 months). We observed a significant reduction in pain (P < 0.05) and a significant improvement in the physical and mental components of the SF-12 (P < 0.05). The mean reduction in ulcer size was 60%, and complete healing was achieved in 5 cases. No adverse effects were observed. CONCLUSION: The local application of PRP is a valuable and practical procedure that promotes the healing of chronic ulcers of the lower extremity; it can improve patient quality of life and is particularly effective in local pain relief

Use of platelet-rich plasma in the healing of chronic ulcers of the lower extremity.

INTRODUCTION AND OBJECTIVES: Platelet-rich plasma (PRP) is used as an adjuvant in the treatment of chronic ulcers of the lower extremity and has shown particularly promising results in the case of neuropathic ulcers. There has been less research, however, into its use in venous and hypertensive ulcers. Our aim was to assess the safety and feasibility of using PRP in the treatment of chronic ulcers of the lower extremity and to evaluate its potential benefits in directed healing. MATERIAL AND METHODS: We prospectively selected 11 patients with nonischemic ulcers of the lower extremity that had been present for at least 6 weeks. PRP was injected subcutaneously into the perilesional tissue and applied topically in 4 sessions held at 1-week intervals. We assessed quality of life (SF-12 questionnaire), pain (visual analog scale), and the circumference of the ulcer before and after treatment. RESULTS: There was a predominance of women (8/11, 73%), and venous ulcers (7/11, 64%) were more common than hypertensive ulcers (4/11, 36%). The median age of the patients was 79 years and the median time since onset of the ulcer was 17 months (range, 6-108 months). We observed a significant reduction in pain (P<.05) and a significant improvement in the physical and mental components of the SF-12 (P<.05). The mean reduction in ulcer size was 60%, and complete healing was achieved in 5 cases. No adverse effects were observed. CONCLUSION: The local application of PRP is a valuable and practical procedure that promotes the healing of chronic ulcers of the lower extremity; it can improve patient quality of life and is particularly effective in local pain relief.

Autologous expanded adipose-derived stem cells for the treatment of complex cryptoglandular perianal fistulas: a phase III randomized clinical trial (FATT 1: fistula Advanced Therapy Trial 1) and long-term evaluation.

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.

Adipose-derived stem cells in Crohn's rectovaginal fistula.

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.

A new bronchoscopic treatment of tracheomediastinal fistula using autologous adipose-derived stem cells.

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 standard-ised procedure. No complications due to treatment with ASC occurred during the follow-up period and no fistula-related 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.