Injectable collagen in vocal and laryngeal insufficiency

Rehabilitation if the voice and the larynx by means of endoscopic injection, proposed already in 1911, continues to present a problem regarding the choice of substance to inject. Autologous products are rapidly absorbed; synthetic products provoke inflammatory, foreign-body type reactions leading to rejection. Teflon figures among those products most used since 1962. The importance of the inflammatory reactions it produces locally has brought us to confine its indication to vocal fold paralysis secondary to a broncho-pulmonary tumor, when life expectancy is therefore low. That is why injectable collagen appeared to us as being a useful solution when it was proposed by Ford in 1984 (Ford et al, 1984). This concerns highly purified collagen, of bovine origin. Its antigenicity is adequately reduced without destruction of the essential structural components. We have investigated its possible applications: glottic gaping, difficulties in swallowing after partial and reconstructive surgery of the larynx, velo-pharyngeal insufficiency, enlarge tracheo-esophageal fistula for a vocal prosthesis.
Whit a view to judging innocuity, integration with the host tissue and stability of the results, we have carried out a microscopic, optical and electronic study in the dog. We have also reported on human laryngeal autopsy specimens examined at different delays after injection. Before giving an account of this work, our first concern is to recall the anatomy and physiology of the organs treated and also some pathologies affecting them where collagen can be used. This first part formulates a critical review of the various therapies available in the past. The various types of collagen used are presented.
Careful study of the literature has provided us with assurance of the local and humoral immunity tolerance. We have also reviewed the other works that have dealt with the use of collagen for rehabilitation of the voice and larynx