Intracochlear fibrosis and the foreign body response to cochlear implant biomaterials

OBJECTIVE: To report current knowledge on the topic of intracochlear fibrosis and the foreign body response following cochlear implantation (CI). METHODS: A literature search was performed in PubMed to identify peer‐reviewed articles. Search components included “cochlear implant,” “Foreign body response (FBR),” and “fibrosis.” Original studies and review articles relevant to the topic were included. RESULTS: Ninety peer‐reviewed articles describing the foreign body response or intracochlear fibrosis following CI were included. CONCLUSIONS: Intracochlear fibrosis following CI represents a significant limiting factor for the success of CI users. Several strategies have been employed to mitigate the foreign body response within the cochlea including drug delivery systems and modifications in surgical technique and electrode design. A better understanding of the FBR has the potential to improve CI outcomes and the next generation of cochlear prostheses.