Differences in aerodynamic characteristics of new and dysfunctional Provox (R) 2 voice prostheses in vivo

Tracheoesophageal voice prostheses need to be replaced due to increased airflow resistance or retrograde leakage of fluid into the trachea as a consequence of biofilm formation. Previous in vitro studies show a change of aerodynamic features of biofilm covered voice prostheses after removal of the prostheses out of the patient. To assess these changes in an in situ situation, aerodynamic characteristics were measured within 45 patients at the beginning and at the end of the wearing process of the Provox 2 voice prosthesis. As a consequence, the influence of biofilm formation on aerodynamic characteristics can be evaluated. In the majority of cases, leakage through the prosthesis was the reason for replacement. No differences were found in the total flow, volume range and intratracheal pressure (ITP) of the voice prostheses measured. The airflow resistance of biofilm covered prostheses was significantly reduced compared to new clean prostheses. However, no correlation was found between the extent of biofilm and the different aerodynamic features measured. Biofilm formation on the Provox 2 is responsible for both reduction in airflow resistance and leakage through the prosthesis by deterioration of the silicone rubber material

Effect of dairy products on the lifetime of Provox2 voice prostheses in vitro and in vivo

Background. Reduction of biofilm formation on tracheoesophageal voice prostheses by certain dairy products might extend their clinical lifetime. The purpose of this study was to determine the influence of certain dairy products on voice prosthetic biofilms and lifetimes in vitro and in vivo. Methods. The in vitro results were accomplished using an artificial throat. The lifetimes of Provox2 prostheses were evaluated in a patient group that daily consumed the evaluated products. Results. Buttermilk and Yakult Light fermented milk decreased the amount of bacteria on voice prostheses but stimulated yeast prevalence in vitro. Concurrently, lifetimes of voice prostheses in patients consuming buttermilk were not significantly different, whereas patients consuming Yakult Light fermented milk drink had a significantly (p <.01) increased prosthesis lifetime by a factor of 3.76. Conclusion. Yakult Light fermented milk drink reduced biofilm formation on Provox2 prostheses in vitro and in vivo and significantly increased prosthesis lifetime. In vivo, no significant effects were observed for patients consuming buttermilk. (c) 2005 Wiley Periodicals, Inc

Prevention of biofilm formation by dairy products and N-acetylcysteine on voice prostheses in an artificial throat

Objective - To evaluate the preventive effect of buttermilk, Yakult Light fermented milk drink and N-acetylcysteine on biofilm formation on voice prostheses in vitro. Material and Methods - Groningen button and Provox(R) 2 voice prostheses were inoculated with a mixture of bacteria and yeasts isolated from previously explanted Groningen button voice prostheses. After 5 h, separate throats were flushed with buttermilk, Yakult Light fermented milk drink, N-acetylcysteine or phosphate-buffered saline, which served as a control. After 7 days, the microflora on each voice prosthesis was determined. Results - On Groningen button voice prostheses, buttermilk, Yakult Light fermented milk drink and N-acetylcysteine all reduced the amount of both bacteria and yeasts. On Provox(R)2 voice prostheses, buttermilk, Yakult Light fermented milk drink and N-acetylcysteine reduced the amount of bacteria but, conversely, increased the amount of yeasts. Conclusion - These in vitro experiments demonstrate that biofilm formation on voice prostheses is reduced in an artificial throat by the use of buttermilk, Yakult Light fermented milk drink and N-acetylcysteine. However, the structural differences between the type of voice prostheses may influence the ultimate effects

Lactobacilli:Important in biofilm formation on voice prostheses

OBJECTIVE: We sought to identify bacterial strains responsible for biofilm formation on silicone rubber voice prostheses. STUDY DESIGN: We conducted an analysis of the bacterial population in biofilms on used silicone rubber voice prostheses by using new microbiological methods. METHODS: Two microbiological methods were used: polymerase chain reaction-denaturing gradient gel electrophoresis and fluorescence in situ hybridization. Twenty-six Provox2 and eight Groningen Ultra Low Resistance voice prostheses that were removed because of leakage through the prosthesis or because of increased airflow resistance were used in this study. RESULTS: The results showed that 33 of the 34 explanted voice prosthetic biofilms contained lactobacilli in close association with the Candida sp. present. CONCLUSION: Lactobacilli are general colonizers of tracheoesophaueal voice prostheses in vivo, growing intertwined with Candida. This knowledge may be important in the development of new pathways directed to prevent or to influence biofilm formation on tracheoesophageal voice prostheses and elongate their lifespan. (c) 2007 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved