Surgical findings and auditory performance after cochlear implant revision surgery.

The objective of this study was to review cochlear reimplantation outcomes in the tertiary hospital and analyze whether facts such as type of failure, surgical findings, or etiology of deafness have an influence. A retrospective study including 38 patients who underwent cochlear implant revision surgery in a tertiary center is performed. Auditory outcomes (pure tone audiometry, % disyllabic words) along with etiology of deafness, type of complication, issues with insertion, and cochlear findings are included. Complication rate is 2.7 %. Technical failure rate is 57.9 % (50 % hard failure and 50 % soft failure), and medical failure (device infection or extrusion, migration, wound, or flap complication) is seen in 42.1 % of the cases. Management of cochlear implant complications and revision surgery is increasing due to a growing number of implantees. Cases that require explantation and reimplantation of the cochlear implant are safe procedures, where the depth of insertion and speech perception results are equal or higher in most cases. Nevertheless, there must be an increasing effort on using minimally traumatic electrode arrays and surgical techniques to improve currently obtained results.

Auditory brainstem implants: past, present and future prospects.

The purpose of the auditory brainstem implant (ABI) is to directly stimulate the cochlear nucleus complex and offer restoration of hearing in patients suffering from profound retrocochlear sensorineural hearing loss. Electrical stimulation of the auditory pathway via an ABI has been proven to be a safe and effective procedure. The function of current ABIs is similar to that of cochlear implants in terms of device hardware with the exception of the electrode array and the sound-signal processing mechanism. The main limitation of ABI is that electrical stimulation is performed on the surface of the cochlear nuclei, thereby making impractical the selective activation of deeper layers by corresponding optimal frequencies. In this article, we review the anatomical, and experimental basis of ABIs and the indications, and surgical technique for their implantation. To the best of our knowledge, we describe the first pathology images of the cochlear nucleus in a patient who had received an ABI.

Traditional and emerging indications in cochlear and auditory brainstem implants.

Electrical stimulation of the auditory pathway via a cochlear or an auditory brainstem implant has been proved to an effective and safe procedure in the treatment of many patients suffering from a profound sensorineural hearing loss of cochlear and retrocochlear origin. In this paper we will present the impact of experience, technical advances in the design of auditory implants, and improvements in stimulation strategies in traditional criteria for implantation. Besides current indications for cochlear and auditory brainstem implants, we will review a continuously expanding group of potential candidates, namely emerging indications. This review will be exemplified with data from the University of Navarra Cochlear Implant Program, currently accounting for more than 500 patients implanted.

[Cochlear implants in post-lingual persons: results during the first five years of the clinical course]. / Implantes cocleares en personas postlinguales: resultados durante los primeros cinco años de evolución.

Abundant literature is available on the results of cochlear implants in postlingual persons. Nevertheless, there are few long-term studies with a follow-up of more than 1 year. We present the outcomes of 37 postlingual patients with a 5-year follow-up period. We examined the modifications that occurred with changes in coding strategy (MPEAK-SPEAK). After activation, the coding strategy was SPEAK in 10 patients. MPEAK in 20: 7 other SPEAK had changed from MPEAK. Significant improvement (p < 0.01) was observed in all the tests in the first 6 months. Subsequent assessments revealed a constant improvement in all tests. The results were statistically significant (p < 0.05) for vowels, consonants and bisyllables. Performance with the SPEAK strategy was better than with MPEAK. These results were statistically significant for consonants (p < 0.05), monosyllables (p < 0.05) and bisyllables (p < 0.01). We concluded that the results of postlingual patients after cochlear implantation showed clear benefits of these devices in profound bilateral deafness, better results with the SPEAK coding strategy than with MPEAK and constant improvement in results, even after the first year of surgery.