Use of adipose tissue-derived stromal stem cells in treating fistula

1. A method of treating a fistula in a subject comprising injecting into the walls of the fistula tract at one or more sites a first composition comprising at least 10×10 6 adipose tissue-derived stromal stem cells.

2. The method of claim 1 , wherein the first composition comprises at least 20×10 6 adipose tissue derived stromal stem cells.

3. The method of claim 1 , wherein said adipose tissue-derived stromal stem cells were passaged at least four times.

4. The method of claim 1 , wherein the concentration of the adipose tissue-derived stromal stem cells in the first composition is at least 5×10 6 cells/mL.

5. The method of claim 1 , wherein the adipose tissue-derived stromal stem cells are allogeneic to the subject.

6. The method of claim 1 , wherein at least 50% of the cells in the population express the CD44 marker.

7. The method of claim 1 , wherein the fistula is selected from the group consisting of an anorectal fistula, enteroenteral fistula, enterocutaneous fistula, vesicovaginal fistula, fistula-in-ano, fecal fistula, arteriovenous fistula, biliary fistula, cervical fistula, craniosinus fistula, enterovaginal, gastric fistula, metroperitoneal fistula perilymph, pulmonary arteriovenous fistula, umbilical fistula, and tracheoesophageal fistula.

8. The method of claim 1 , further comprising administering a therapeutic agent to said subject.

9. The method of claim 8 , wherein said therapeutic agent is administered locally to the fistula.

10. The method of claim 8 , wherein said therapeutic agent is administered systemically to said subject.

11. The method of claim 8 , wherein said therapeutic agent is selected from the group consisting of an anti-inflammatory agent, an immunosuppressive agent, a biological agent, an antibiotic and an antidiarrheal agent.

12. The method of claim 1 , further comprising

(i) deep scraping of at least one fistula track

(ii) closing the internal hole of the scraped track with a suture

(iii) delivering a second composition comprising at least 10×10 6 adipose tissue-derived stromal stem cells to the closed sutured internal hole, wherein delivery of the first composition occurs before step (i), after step (iii), between step (i) and (ii), or between step (ii) and (iii).

13. The method of claim 12 , further comprising deep scraping of the fistula prior to delivering the first composition and filling said fistula with an adhesive before, during or after delivering the second composition.

14. The method of claim 13 , wherein the second composition is mixed with the adhesive before delivering the second composition.

15. The method of claim 13 , wherein said adhesive is a fibrin glue or gel.