Fixation of cochlear implants: an evidence-based review of literature.

Hypothesis: There are numerous cochlear implant fixation techniques to prevent soft tissue complications related to device migration. The literature does not provide sufficient evidence to determine the most suitable fixation method.

Background: Cochlear implants (CI) are becoming a routine treatment for patients with severe to profound deafness. Steadily growing numbers of implant centres and surgeons worldwide are inevitably leading to higher rates of complications, including device migration. It is currently unknown whether this can be prevented by proper implant fixation during surgery. The low prevalence of this complication makes it challenging to interpret publications regarding CI fixation techniques.

Methods: An exhaustive literature review reveals a variety of different fixation techniques. Most authors advocate the creation of a bony well for the CI receiver/stimulator (R/S); however, an increasing number of surgeons no longer secure implants at all. Here we give an overview of all published fixation methods, with special attention to the evidence-based quality and descriptions of the advantages and drawbacks of each.

Conclusions: Literature review reveals an absence of level I evidence-based publications addressing device migration. Existing publications report on too few cases to draw a conclusion on whether surgical fixation prevents implant migration. To have statistical power, studies of alternative or new fixation methods should include high numbers of implantations in each study arm and the studies should be longitudinal and prospective. In default of other evidence, it seems fair to define good practice as the creation of at least a bony well and/or (bony) sutures.