Effect of ossicular prosthesis biofilms on middle ear scarring and hearing outcomes.

OBJECTIVES

Microbial biofilms have been associated with poor outcomes with a variety of biomedical implants; however, this relationship has not been established with ossicular chain reconstruction prostheses (ORPs). The purpose of this study was to determine if biofilms are present on ORPs in patients undergoing revision ossicular chain reconstruction and if their presence correlates with middle ear scarring or hearing outcomes.

STUDY DESIGN

Prospective and blinded.

SETTING

Tertiary referral center.

PATIENTS

Patients undergoing revision ossicular chain reconstruction with previous ORP placement were enrolled. INTERVENTION/MAIN OUTCOME MEASURE: Ossicular chain reconstruction prostheses associated with poor hearing and residual or recurrent disease were cultured and examined using scanning electron microscopy. Audiometric thresholds and middle ear scarring scores were recorded.

RESULTS

Twelve patients were included in the study. Of the prostheses, 25% were culture positive, and 67% had microscopic evidence of biofilm. No difference was found between the middle ear scarring scores (p = 0.31) and hearing outcomes (p = 0.11) of biofilm and nonbiofilm prostheses. There was no correlation between middle ear scarring and degree of conductive hearing loss (R2 = 0.04; p = 0.54).

CONCLUSION

Biofilms are commonly found on ORPs at the time of revision ossicular chain reconstruction. The interaction between biofilms and the host environment is complex. Many factors besides biofilms may impact middle ear scarring and hearing.