Pathohistological Study of the Larynx with Silicone for 18 Years after Thyroplasty Type I

Thyroplasty type I is one of various surgical treatments for glottic insufficiency following unilateral recurrent nerve paralysis. However, the choice of materials for the prosthesis inserted into the thyroid cartilage is controversial with regard to stability and safety. We experienced a case of laryngeal palsy caused by syringomyelobulbia. Thyroplasty type I was performed with a silicone block 18 years ago to prevent aspiration pneumonia, but in accordance with progress of the laryngeal palsy, the patient developed severe pneumonia. We performed a total laryngectomy for the improvement of his dysphagia, and conducted a histopathological study of the larynx with the silicone prosthesis. We found slight fibrinogenesis around the silicone block, however, foreign body giant cells, inflammatory cells, or absorption of silicone were not observed. We tentatively concluded that these findings show the stability and safety of silicone as a prosthesis for thyroplasty type I.