Downsizing of voice prosthesis diameter in patients with laryngectomy: an in vitro study

In patients with laryngectomy, voice prostheses inserted into a tracheoesophageal fistula (TEF) are widely used for vocal rehabilitation. Gradual dilation of the TEF may cause bothersome leakage around voice prostheses. Prosthesis-related weight and mechanical trauma possibly exacerbate TEF dilation. If prosthesis size were to be decreased, with a concomitant decrease in prosthesis weight and diameter, dilation of the TEF would probably lessen. We performed in vitro tests to study the effects on aerodynamic prosthesis function when the prosthesis size-in particular, the inner diameter-was decreased. The effects on airflow and pressure were specifically studied in the airflow range of patients with laryngectomy. A 1-mm decrease of the regular inner prosthesis diameter from 5 mm to 4 mm showed no significant aerodynamic consequences at the average laryngectomized airflow point. Also, such a 1-mm decrease in diameter involved a prosthesis weight reduction of 18%. In view of these findings, downsizing the standard prosthetic diameter should be considered in future voice prosthesis development.