The prevention of vocal fold scarring using autologous adipose tissue-derived stromal cells

Prevention and treatment of vocal fold scarring and atrophy remain challenging. The aim of this study was to treat injured vocal folds using autologous adipose tissue-derived stromal cells (ADSCs) and evaluate the ability to prevent vocal fold scarring and atrophy by ADSCs in a canine animal model. Ten adult dogs were used for this experiment. ADSCs from the adipose tissue from the inguinal area were isolated and cultured in all dogs. Immediately after being mixed with atelocollagen, the ADSCs (1-3 x 10(6)) were injected into the right vocal fold of each animal, using a syringe with a 23-gauge needle. As a control, atelocollagen was injected into the left vocal fold of the same dog. The effects of the prevention of vocal fold scarring and atrophy were measured by morphological and histological assessment. At 8 weeks, there was a difference in granuloma and atrophic changes between the ADSC-injected and control sides in the majority of the dogs. This difference continued to be present at the 24 weeks' follow-up. On histopathologic examination, a large number of cells labeled with a fluorochrome were observed in ADSC-injected vocal folds 8 weeks after the initial treatment. This study demonstrates the multipotential ability of ADSCs in the regeneration of injured vocal folds. Injecting ADSCs into a damaged vocal fold appears to be useful in preventing vocal fold scarring and atrophy 24 weeks after initial damage.