Development and Prevention of Biofilm on Cochlear Implants: A Systematic Review

Background and Objectives: Biofilm formation on cochlear implants (CIs) poses a major problem for surgeons, leading to a high incidence of explantation and revision surgery. Therefore, developing appropriate and cost-effective biofilm detection and prevention techniques is of the essence. In this systematic review, we sought to investigate the development of biofilm formation on CIs. We also elaborated on experimental preventative biofilm measures. Materials and Methods: We conducted a systematic search of both in vitro and in vivo literature published in PubMed, Scopus, and ScienceDirect, until 15 June 2024, for published studies evaluating the biofilm formation and strategies for inhibiting biofilm formation on CIs. Depending on the type of the included study, we assessed quality with the modified Consolidated Standards of Reporting Trials tool, the Joanna Briggs Institute Case Reports Critical Appraisal Tool, a modified Delphi technique, and the ROBINS-I tool. We synthesized the available information on biofilm formation on CIs and the infection prevention capacity of the included antibiofilm agents. Results: A total of 26 studies were included in this systematic review. Biofilms in CIs are usually localized in their recesses such as their removable magnet pocket as opposed to their smooth surfaces. S. aureus and P. aeruginosa are the most commonly isolated microorganisms, and they tend to be strong biofilm producers. The optimal treatment strategy for a biofilm-infected CI is explantation. Most of the examined biofilm prevention methods in CIs present sufficient antibiofilm activity. Conclusions: Biofilm formation in CIs is considered one of the most dreadful complications. There have been no specific guidelines for the treatment of those cases, with removal and/or replacement of the CI being the treatment of choice. Various experimental prevention methods provide promising antibiofilm activity both in vivo and in vitro.