Bilateral cochlear implantation in children and the impact of the inter-implant interval

Objectives/hypothesis: To determine the effectiveness of simultaneous versus sequential bilateral cochlear implantation on postoperative outcomes in children with bilateral deafness and to evaluate the impact of the inter-implant interval and age at second implantation on postoperative outcomes in children who already received their first cochlear implant.

Data sources: PubMed, Embase, and Web of Science.

Review methods: All studies comparing the effects of simultaneous with sequential bilateral cochlear implantation on postoperative outcomes and those evaluating the impact of the inter-implant interval and age at second implantation were retrieved.

Results: Four studies compared the effects of simultaneous with sequential bilateral cochlear implantation. All studies lacked randomization. Of these, three reported better speech perception and expressive language development at one year of bilateral experience for simultaneous cochlear implantation. Of the nineteen publications on the impact of the inter-implant interval on postoperative outcomes, the risk of bias was low-moderate for seven studies which were derived from five different study populations. In two of these populations no impact of the inter-implant interval was found, while in three a longer inter-implant interval was associated with poorer speech and language development.

Conclusion: Observational studies suggest that simultaneous implantation in children may be associated with improved speech and language development, and that a prolonged inter-implant interval between both implantations may have a negative impact on these postoperative outcomes. Randomized trials are, however, needed to demonstrate whether simultaneous implantation indeed is superior to sequential bilateral implantation in children with bilateral deafness.

Level of evidence: NA.