Systematic review of the literature on the clinical effectiveness of the cochlear implant procedure in paediatric patients

The aim of this systematic review of the literature was to summarize the results of scientific publications on the clinical effectiveness of the cochlear implant (CI) procedure in children. The members of the Working Group first examined existing national and international literature and the principal international guidelines on the procedure. They considered as universally-accepted the usefulness/effectiveness of unilateral cochlear implantation in severely-profoundly deaf children. Accordingly, they focused attention on systematic reviews addressing clinical effectiveness and cost/efficacy of the CI procedure, with particular regard to the most controversial issues for which international consensus is lacking. The following aspects were evaluated: post-CI outcomes linked to precocity of CI; bilateral (simultaneous/sequential) CI vs. unilateral CI and vs. bimodal stimulation; benefits derived from CI in deaf children with associated disabilities. With regard to the outcomes after implantation linked to precocity of intervention, there are few studies comparing post-CI outcomes in children implanted within the first year of life with those of children implanted in the second year. The selected studies suggest that children implanted within the first year of life present hearing and communicative outcomes that are better than those of children implanted after 12 months of age. Concerning children implanted after the first year of life, all studies confirm an advantage with respect to implant precocity, and many document an advantage in children who received cochlear implants under 18 months of age compared to those implanted at a later stage. With regard to bilateral CI, the studies demonstrate that compared to unilateral CI, bilateral CI offers advantages in terms of hearing in noise, sound localization and during hearing in a silent environment. There is, however, a wide range of variability. The studies also document the advantages after sequential bilateral CI. In these cases, a short interval between interventions, precocity of the first CI and precocity of the second CI are considered positive prognostic factors. In deaf children with associated disabilities, the studies analyzed evidence that the CI procedure is also suitable for children with disabilities associated with deafness, and that even these children may benefit from the procedure, even if these may be slower and inferior to those in children with isolated deafness, especially in terms of high communicative and perceptive skills.