Treatment of Vesicovaginal Fistulas With Autologous Cell Injections—A Randomized Study in an Animal Model

Purpose: To evaluate the effect of autologous satellite cell and smooth muscle cell transplantation on vesicovaginal fistulas in a randomized controlled study by comparing the proportion of fistula closure and tissue composition between the 2 groups. Materials and Methods: Eight pigs underwent surgery to establish an experimental induced fistula. One pig was excluded due to insufficient weight gain. Seven pigs were randomized to receive either an injection of satellite cells and smooth muscle cells or no treatment. Cells were isolated from abdominal skeletal muscle and bladder smooth muscle, cultured in vitro, and marked with bromodeoxyuridine. Cell purity, growth kinetics, and differentiation potential were determined. Cells were injected around the fistula using a cystoscope. Five weeks after the injection of cells, the fistula area was examined macroscopically and histologically. Results: The isolated satellite cell population consisted of 76.6% neural cell adhesion molecule positive cell and the smooth muscle cell population of 88.6% a-smooth muscle actin positive cells. All pigs had a persisting fistula before treatment. One of the 4 vesicovaginal fistulas was closed 5 weeks after injection of satellite cells and smooth muscle cells compared to none in the control group. No histological differences in the tissue composition between the 2 groups were observed and no bromodeoxyuridine-labeled cells were detected around the fistula tissue in the histological examination. Conclusion: We established an animal model with a persisting clinical and histological confirmed vesicovaginal fistula. The study indicated that there might be an effect on vesicovaginal fistula closure using an injection of satellite cells/smooth muscle cells and alginate gel.