Comparison of autologous platelet rich plasma (PRP) and stem cell activity in the recovery of vocal cord mucosal damage on an experimental model

Objective: The aim of this study was to histopathologically compare the efficacy of PRP (platelet-rich plasma) and adipose-derived stem cell (ADSC) applications on the healing process following vocal cord injury in a rabbit model. Materials and Methods: In the study, a total of 10 "New Zealand rabbits" were used, consisting of 3 females and 7 males. The study groups were determined as the control group (Group 1), the scar group (Group 2), the ADSC group (Group 3), and the PRP group (Group 4). Four vocal cords that underwent no intervention were used as the control group. In the PRP group, the left vocal cords of the subjects were injured to a depth of 2 mm using 2 mm microcup forceps. PRP was obtained from the blood taken from the marginal ear vein of the rabbit intraoperatively via centrifugation. The PRP solution was applied to the left vocal cords of the subjects, while the right vocal cords were similarly injured but received no treatment. In the stem cell group, the vocal cords of the subjects were injured to a depth of 2 mm using 2 mm microcup forceps. The stem cells enzymatically extracted from the adipose tissue in the interscapular region of the rabbit were applied intraoperatively to the left vocal cords of the subjects. The right vocal cords were similarly injured but received no treatment. The right vocal cords of all subjects were designated as the scar group. After one month, the subjects were sacrificed, and their vocal cords were dissected via total laryngectomy and examined immunohistochemically. The parameters to be compared in the histopathological evaluation were determined as Type 1 collagen density, lamina propria (LP) thickness, epithelial thickness, TGF Beta 1 density, elastic fiber density, and gland density. Results: The results obtained from the groups receiving PRP and ADSC injections contain findings indicating that both treatments have a positive effect on the healing of vocal cord scars. However, since neither the PRP nor ADSC group demonstrated xi superiority over the other, it would be appropriate to consider variables such as cost, patient preference, and ease of material acquisition when selecting a treatment method. Given that adipose tissue harvesting is more invasive than PRP, the process of obtaining stem cells for immunohistochemical analysis is lengthy, and PRP preparation is a rapid and well-studied method, it was concluded that these two treatments could be applied in a stepwise approach for the treatment of vocal cord scars. Statistical analyses revealed that the "scar" group showed significant differences compared to other groups. Additionally, the absence of a significant difference between the PRP and ADSC groups suggests that these two treatment approaches have similar efficacy. Conclusion: The results obtained from the groups receiving PRP and ADSC injections contain findings indicating that both treatments have a positive effect on the healing of vocal cord scars. However, since neither the PRP nor ADSC group demonstrated superiority over the other, it would be appropriate to consider variables such as cost, patient preference, and ease of material acquisition when selecting a treatment method. Given that adipose tissue harvesting is more invasive than PRP, the process of obtaining stem cells for immunohistochemical analysis is lengthy, and PRP preparation is a rapid and well-studied method, it was concluded that these two treatments could be applied in a stepwise approach for the treatment of vocal cord scars. Statistical analyses revealed that the "scar" group showed significant differences compared to other groups. Additionally, the absence of a significant difference between the PRP and ADSC groups suggests that these two treatment approaches have similar efficacy.may be more practical as a first-line treatment in cases of acute injury. Keywords: Vocal fold, PRP injection, stem cell, animal model