Volume Analysis of Preadipocyte Injection for Vocal Cord Medialization

Objective: To compare the volume retention of injected preadipocytes with that of standard fat injection in a paralyzed rabbit true vocal cord. Study Design: Prospective analysis with blinded data collection. Methods: Thirteen New Zealand white rabbits were divided into two groups. Group 1 consisted of seven animals undergoing left-side vocal cord paralysis by resection of a 1-cm segment of the left-side recurrent laryngeal nerve and abdominal fat harvest for isolation of preadipocytes. Preadipocytes were cultured under sterile conditions in cell culture media. Animals in group 2 also underwent left-side vocal cord paralysis without fat harvest. After 10 to 14 days, in a second procedure, group 1 underwent injection of 0.1 mL cultured autologous preadipocytes, and group 2 underwent routine injection of 0.1 mL abdominal fat harvested during the same procedure. At 6 and 12 months, volumetric analysis was performed. Results: Volume analysis at 6 months showed a mean volume of 0.029 mL retained fat in group 2 representing a retention of approximately 29% (SD = 0.023) of the original injected volume. Retention in group 1 animals approximated 0.002 mL (SD = 0.0024) or 2% of the injected volume. Analysis at 12 months showed a mean volume of 0.008 mL (SD = 0.0078) in group 2 and of 0.002 mL (SD = 0.0015) in group 1. Group 2 showed significantly higher volumes of the injected fat at 6 and 12 months (P <.033). Conclusion: Volumes obtained with standard fat injection were superior to those obtained with preadipocyte injection at both 6 and 12 months.