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

Abstract

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.

Polydimethylsiloxane in the Human Vocal Fold: Description of Partial Explantation

“…There was good development of scarring in the neighboring tissue after this 7‐year interval. This corroborates the results obtained by Caballero et al 5 in rabbit larynges. In that study, polydimethylsiloxane as compared with Teflon injection in rabbits showed a number of inflammatory fibrous reactions.…”

“…In that study, polydimethylsiloxane as compared with Teflon injection in rabbits showed a number of inflammatory fibrous reactions. Because of this fibrous reaction on the one hand and the particle volume of 200 μm on the other, which hinders phagocytosis, the increased stability and biocompatibility of polydimethylsiloxane were assumed 5 . In contrast, the present study shows no inflammatory cells such as macrophages or giant cells.…”

A pilot study of macrophage responses to silk fibroin particles

“…Monocytes/macrophages serve as an effective study system, due to their active roles in the processes of inflammation and wound healing 19. A variety of investigations have focused on the interactions between biomaterial particles and macrophages, and histological examinations have revealed that macrophages play a central role in the response to the particles 20–23. For this reason, many in vitro studies have aimed at simulating an in vivo response through the examination of macrophages.…”

“…19 A variety of investigations have focused on the interactions between biomaterial particles and macrophages, and histological examinations have revealed that macrophages play a central role in the response to the particles. [20][21][22][23] For this reason, many in vitro studies have aimed at simulating an in vivo response through the examination of macrophages. More specifically, macrophage cells have been employed extensively for in vitro studies to evaluate the inflammatory responses triggered by various biomaterials.…”

Polydimethylsiloxane particles are not experimental in the human larynx

“…Caballero et al reported in their recent study 1 on the superior tissue compatibility of polydimethylsiloxane particles compared to polytetrafluoroethylene when injected in vivo into rabbit larynges. This well-designed study suggests that polydimethylsiloxane particles may become a preferred substance for injection laryngoplasty, for which the ideal material is not available yet.…”