Microbial colonization of Provox voice prosthesis in the Indian scenario

Tracheoesophageal speech using the voice prosthesis is considered to be the "gold standard" with success rates as high as 90%. Despite significant developments, majority eventually develop dysfunction due to microbial deterioration. We did a pilot study of 58 laryngectomy patients who developed prosthesis dysfunction.

A total of 58 laryngectomy patients who had their dysfunctional prosthesis removed were included in this study. Dysfunctional prostheses were removed and examined. Esophageal and tracheal flanges were examined separately. After obtaining pure fungal and bacterial cultures, the yeast strains were identified. Bacteria were identified with the light microscope and gram staining. We analyzed prosthesis lifespan and probable factors affecting it.

Central leak was found in 43% cases while in 57% peri-prosthetic leakage was the most common reason for prosthesis replacement. Microbial analysis revealed a combination of yeast and bacteria in approximately 55% culture samples. Out of these, almost 90% had the presence of single yeast species with bacteria. Pure fungal culture was identified in rest of the 45% cultures while none detected pure bacterial forms. Candida tropicalis was the solitary yeast in 81% while Candida albicans was seen in 10% as the solitary yeast. Bacterial isolates revealed Klebsiella pneumonia in 19%, Escherichia coli in 8% while Staphylococcus aureus was grown in 1% cultures. The consumption of curd (P = 0.036, 95% confidence intervals [CI]: 2.292-64.285) to have a significant correlation of the mean prosthesis lifespan. Consumption of curd (P = 0.001, 95% CI: 0.564-2.008) and history of prior radiotherapy (P = 0.015, 95% CI: 0.104-0.909) had a significant bearing on the Provox prosthesis lifespan.

Candida is the most common organism grown on voice prosthesis in Indian scenario. Consumption of curd and history of prior radiotherapy significantly affect Provox prosthesis lifespan.