Cell therapy and vocal fold scarring

Vocal fold microstructure is complex and can be affected by laryngeal microsurgery, inducing scarring that prevents mechanical uncoupling of epithelium and muscle, leading to vibration disorder and disabling dysphonia. Treatment options presently are few, and often without efficacy for vibration, having only an impact on volume to reduce glottal closure defect. The present review of the literature had two aims: (i) to report the current state of the literature on cell therapy in vocal fold scarring; and (ii) to analyze the therapeutic interest of the adipose-derived stromal vascular fraction in the existing therapeutic armamentarium. A PubMed® search conducted in September 2016 retrieved English or French-language original articles on the use of stem cells to treat vocal fold scarring. Twenty-seven articles published between 2003 and 2016 met the study selection criteria. Mesenchymal stem cells were most widely used, mainly derived from bone marrow or adipose tissue. Four studies were performed in vitro on fibroblasts, and 18 in vivo on animals. End-points comprised: (i) scar analysis (macro- and micro-scopic morphology, viscoelastic properties, extracellular matrix, fibroblasts); and (ii) assessment of stem cell survival and differentiation. The studies testified to the benefit of mesenchymal stem cells, and especially those of adipose derivation. The stromal vascular fraction exhibits properties that might improve results by facilitating production logistics.