Diagnostic challenges and safety considerations in cochlear implantation under the age of 12 months

Aim: To review the current knowledge on cochlear implantation in infancy, regarding diagnostic, surgical and anesthetic challenges.

Study-design: Meta-analysis. EBM level: II.

Materials/methods: Literature-review from Medline and database sources. Related books were also included.

Study selection: Meta-analyses, prospective controlled studies, prospective/retrospective cohort studies, guidelines, review articles.

Data synthesis: The diagnosis of profound hearing loss in infancy, although challenging, can be confirmed with acceptable certainty when objective measures (ABR, ASSR, OAEs) and behavioural assessments are combined in experienced centres. Reliable assessment of the prelexical domains of infant development is also important and feasible using appropriate evaluation techniques. Overall, 125 implanted infants were identified in the present meta-analysis; no major anesthetic complication was reported. The rate of surgical complications was found to be 8.8% (3.2% major complications) quite similar to the respective percentages in older implanted children (major complications ranging from 2.3% to 4.1%).

Conclusion: Assessment of hearing in infancy is feasible with adequate reliability. If parental expectations are realistic and hearing aid trial unsuccessful, cochlear implantation can be performed in otherwise healthy infants, provided that the attending pediatric anesthesiologist is considerably experienced and appropriate facilities of pediatric perioperative care are readily available. A number of concerns, with regard to anatomic constraints, existing co-morbidities or additional disorders, tuning difficulties, and special phases of the developing child should be also taken into account. The present meta-analysis did not find an increased rate of anesthetic or surgical complications in infant implantees, although long-term follow-up and large numbers are lacking.