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

The aim of this systematic review was to summarize the results of scientific publications on the clinical effectiveness of the cochlear implant (CI) procedure in adults. The members of the Working Group first examined existing research evidence from the national and international literature and main international guidelines. They considered as universally accepted the usefulness/effectiveness of unilateral cochlear implantation in severelyprofoundly adult patients. Accordingly, they focused their attention on the systematic reviews addressing clinical effectiveness and cost/efficacy of CI procedures, with particular regard to the most controversial issues for which international consensus is still lacking. The following aspects were evaluated: monolateral CI in advanced-age adult patients; bilateral (simultaneous/sequential) CI vs. unilateral CI and vs. bimodal stimulation; benefits derived from the monolateral CI procedure in adult patients with prelingual deafness. With regard to CI in elderly patients, the selected studies document an improvement of the quality of life and perceptive abilities after CI, even if the benefits were found to be inferior in patients over 70 years at the time of surgery. Thus, from the results of the studies included in the review, advanced age is not a contraindication for the CI procedure. With respect to unilateral CI, bilateral CI offers advantages in hearing in noise, in sound localization and less during hearing in a silent environment. However, high interindividual variability is reported in terms of benefits from the second implant. With regard to CI in prelingually deaf adults, the selected studies document benefits deriving from the CI procedure in terms of improvement of perceptive abilities and in the quality of life after CI, as well as subjectively perceived benefits. However, there is high interindividual variability and the study sample is limited.