Deterioration of the Provox silicone tracheoesophageal voice prosthesis: microbial aspects and structural changes.

Device life of tracheoesophageal voice prostheses is limited due to deterioration of the polymers. A group of 55 postlaryngectomy patients fitted with a Provox voice prosthesis have been studied prospectively during 6 months. Thirty-seven prostheses were replaced due to a dysfunctional valve mechanism. Although colonization with Candida species was highly associated with destruction of the silicone material, other upper respiratory tract commensals, e.g. Staphylococcus aureus, were also demonstrated. Electron microscopy of the contaminated devices showed colonization and disruption of the silicone material by penetrating yeast hyphae. During the study a remarkable increase of intratracheal phonatory pressures was assessed with progressive colonization of the prostheses.