Examination of Biofilm Related Material Deterioration on 20 PROVOX®2 Voice Prostheses by Scanning Electron Microscopy

Backround: Mechanical impairment of valve function by biofilms is considered to cause loss of function of voice prostheses in laryngectomized patients. Material deterioration and infiltrative growth of Candida associated biofilms have already been observed on Groningen Buttons. Goal of the Study was the examination of biofilm formation and material damages on PROVOX (R) 2 voice prostheses. Methods: 20 PROVOX (R) 2 voice prostheses were withdrawn from 17 laryngectomized patients Clue to aspiration (mean in-vivo time: 118 d, median 98 d). Microbial spectrum, colonization patterns and morphologies of prosthesis damage were assessed using standard microbiologic procedures and scanning electron microscopy. Results: Biofilm with various growth patterns predominantly adhered to the esophageal parts of the prostheses. Microbiologic findings showed Candida species as main colonisers on esophageal surfaces. Different morphologies of surface alteration and material infiltration of the polymer material were identified on 8 prostheses with 35 d of in-vivo time minimum. Conclusion: Valve dysfunction of PROVOX (R) 2 voice prostheses can be attributed to biofilm formation on esophageal surfaces and edges of the valve flap and seating. The identified morphologies of material damage and invasive growth indicate towards lytic processes of the polymer material due to Candida associated biofilms.