Polydimethylsiloxane versus polytetrafluoroethylene for vocal fold medialization: Histologic evaluation in a rabbit model

The objective is to study the tissue reaction of the paralyzed vocal cord in response to the injection of particulate plastics in a rabbit model. Forty‐five New Zealand rabbits with surgical vocal‐fold paralysis were used in the study. Histologic reactions of the larynx and the regional lymph nodes were analyzed by a single blinded pathologist at 6 weeks and 6 months after a vocal‐cord injection of Teflon or of silicone elastomer. Macroscopic studies of the liver, lungs, spleen, kidney, and brain were performed. The histological study showed a greater proportion of chronic granulomatous inflammation in animals injected with silicone than in those injected with Teflon. The immunohistochemical study showed a higher degree of phagocytosis of Teflon particles than of the silicone particles. The silicone group presented a more severe fibrous reaction than the Teflon group, but the difference was not significant. No migration particles were found. It is concluded that silicone, having a greater viscosity than Teflon because of the size of its particles, induces more fibrosis and a larger proportion of foreign giant cells in the host. Due to this histological reaction, silicone particles present greater anchorage and stability. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 67B: 666–674, 2003