Emmanuel A. M. Mylanus

Consensus statements on the BAHA system: where do we stand at present?

After more than 25 years of clinical experience, the BAHA (bone-anchored hearing aid) system is a well-established treatment for hearing-impaired patients with conductive or mixed hearing loss. Owing to its success, the use of the BAHA system has spread and the indications for application have gradually become broader. New indications, as well as clinical applications, were discussed during scientific roundtable meetings in 2004 by experts in the field, and the outcomes of these discussions are presented in the form of statements. The issues that were discussed concerned BAHA surgery, the fitting range of the BAHA system, the BAHA system compared to conventional devices, bilateral application, the BAHA system in children, the BAHA system in patients with single-sided deafness, and, finally, the BAHA system in patients with unilateral conductive hearing loss.

Cochlear implantation and quality of life in postlingually deaf adults: long-term follow-up.

Objective To investigate long-term quality of life (QoL) in postlingually deaf adults after entering the cochlear implantation (CI) program. Study Design and Setting Follow-up study from 1998 onwards in tertiary university medical center. Long-term CI users, patients who have not received a CI, and relatively short-term CI users were re-evaluated six years after initial data collection in 1998 by using three questionnaires (NCIQ, HUI3, and SF36) and speech perception tests. Results and Conclusions In general, the beneficial effect of CI remained stable during long-term follow-up, though scores on the questionnaires decreased slightly. Outcomes before and after cochlear implantation were significantly different. The group without a CI demonstrated slightly decreasing trends in outcomes. Long-term speech perception performance improved in time. Significance This is the first study to investigate long-term follow-up of CI patients, in all aspects of QoL combined with speech perception performance, in comparison with postlingually deaf adults without CI.

Clinical outcome of the simplified surgical technique for BAHA implantation.

Objective: To evaluate the clinical outcome of a simplified surgical technique for BAHA implantation, in terms of implant failure and its causes. Design: Retrospective analysis. Methods: Analysis of a consecutive cohort of 142 patients (150 loaded implants) fitted with the BAHA implant between January 1, 1997, and December 31, 1999. The simplified surgical Nijmegen technique comprises a longitudinal postauricular incision, extensive subcutaneous tissue reduction, and removal of the periosteum. Clinical outcomes were the rate of implant failures, its causes for this, and skin reactions around the percutaneous implants classified according to Holgers. Clinical results were compared with other BAHA series. Results: Mean follow-up was 5.6 ± 2.7 years (range, 0-10.5 yr). Holgers grade 2 or more severe skin reactions were seen in 6.5% of the 1,038 follow-up visits. Extrusion of the implants occurred as a result of failed osseointegration (n = 3), trauma (n = 5), infection (n = 1), and (other) medical reasons (n = 5 explanations). Total extrusion rate was 9.3%. Only 3% (1 and 3) were due to failed osseointegration or infection around the percutaneous implant. Conclusion: The modified Nijmegen surgical technique is a simple straightforward surgical procedure without the use of a pedicled skin flap. Surgery takes approximately 20 minutes. Meticulous performance of the procedure is considered important to achieve optimal results in the long-term. Particularly the soft tissue reduction has to be done with great care. In terms of the low rates of implant failure and adverse tissue reactions, the Nijmegen surgical technique proved to be a good alternative to other techniques.

Cochlear implantation in 53 patients with otosclerosis: demographics, computed tomographic scanning, surgery, and complications.

Objectives: To collect data from a large number of cochlear implant recipients with otosclerosis and to make an assessment of these patients’ clinical characteristics, computed tomographic scans, surgical findings, and complications, and to quantify the occurrence of postoperative facial nerve stimulation. Study Design: Retrospective multicenter study. Patients: Fifty-three patients with otosclerosis from four cochlear implant centers in the United Kingdom and The Netherlands were reviewed. Sixty surgical procedures were performed in these patients: 57 devices were placed in 56 ears. Results: The computed tomographic imaging demonstrated retrofenestral (cochlear) otosclerotic lesions in the majority of patients. Although not statistically significant, the extent of otosclerotic lesions on the computed tomographic scan as categorized in three types tends to be greater in patients with rapidly progressive hearing loss, in patients in whom there is surgically problematic insertion of the electrode array, and in patients with facial nerve stimulation. In four patients, revision surgery had to be performed. Twenty of 53 (38%) patients experienced facial nerve stimulation at various periods postoperatively. Conclusion: Cochlear implant surgery in patients with otosclerosis can be challenging, with a relatively high number of partial insertions and misplacements of the electrode array demanding revision surgery. A very high proportion of patients experienced facial nerve stimulation mainly caused by the distal electrodes. This must be discussed with patients preoperatively.

Bone-anchored hearing aid in unilateral inner ear deafness: a study of 20 patients.

Objective: To evaluate the benefit of a bone-anchored hearing aid (BAHA) contralateral routing of sound (CROS) in 20 patients with unilateral inner ear deafness. Subjects: 21 patients were recruited; 15 had undergone acoustic neuroma surgery and 6 patients had unilateral profound hearing loss due to other causes; 1 patient was excluded. Only patients with thresholds of better than 25 dB HL (500–2000 Hz) and an air-bone gap of less than 10 dB in the best ear were included. Methods: Evaluation involved audiometric measurements before intervention, when fitted with a conventional CROS and after implementation and quantification of the patients’ subjective benefit with a hearing aid-specific instrument: the Abbreviated Profile of Hearing Aid Benefit (APHAB). Results: Lateralization scores were not significantly different from chance (50%) in any of the three conditions. Measurements of speech perception in noise showed an increase in the signal to noise ratio (S/N ratio) with the conventional CROS (p = 0.001) and with the BAHA CROS compared to the unaided condition when speech was presented at the front with noise on the poor hearing side. On the other hand, a lower S/N ratio was seen with the BAHA CROS (p = 0.003) compared to the unaided situation when noise was presented at the front with speech on the poor hearing side. The patient outcome measure (APHAB) showed improvement, particularly with the BAHA CROS. Conclusions: The poor sound localization results illustrate the inability of patients with unilateral inner ear deafness to localize sounds. The speech-in-noise measurements reflect the benefit of a BAHA CROS in lifting the head shadow while avoiding some of the disadvantages of a conventional CROS. The benefit of the BAHA CROS was most clearly reflected in the patients’ opinion measured with the APHAB.

The effectiveness of bilateral cochlear implants for severe-to-profound deafness in children: a systematic review.

Objective: To assess the clinical effectiveness of bilateral cochlear implantation compared with unilateral cochlear implantation alone or with a contralateral hearing aid (bimodal stimulation), in children with severe-to-profound hearing loss. Recently, the National Institute for Health and Clinical Excellence (NICE) in the U.K. has conducted a systematic review on cochlear implantation. We decided to update the pediatric part of the NICE review. Data Sources: The electronic databases MEDLINE and Embase were searched for European, North American, and Australasian studies published between October 2006 and June 2009. Reference lists of the included articles were also searched for relevant articles. Study Selection: Studies were included if they comprised data on comparisons between bilateral cochlear implantation and unilateral cochlear implantation and/or bilateral cochlear implantation and bimodal stimulation, in children with severe-to-profound sensorineural hearing loss. The following outcome measures were analyzed: audiological, speech perception, speech production, functional capacities, health-related quality of life, and/or educational outcomes. Data Extraction: Characteristics of the participants, interventions, outcomes, and methodological comments were entered into data extraction forms and the level of evidence was assessed. Data Synthesis: Results were standardized for each outcome measure by calculating a standardized mean difference (effect size). Conclusion: Effect sizes could not be pooled because of the heterogeneity of the studies. Therefore, we presented the results qualitatively. Although the level of evidence was low, the advantages of bilateral cochlear implants corresponded with the primary benefits of bilateral hearing, that is, improved speech perception in quiet and noise. Localization results were less consistent. No data on audiologic, speech production, or educational outcomes were available.

European multi-centre study of the Nucleus Hybrid L24 cochlear implant

Abstract Objectives: To investigate the preservation of residual hearing in subjects who received the Nucleus Hybrid L24 cochlear implant. To investigate the performance benefits up to one year post-implantation in terms of speech recognition, sound quality, and quality of life. Design: Prospective, with sequential enrolment and within-subject comparisons. Post-operative performance using a Freedom Hybrid sound processor was compared with that of pre-operative hearing aids. Study sample: Sixty-six adult hearing-impaired subjects with bilateral severe-to-profound high frequency hearing loss. Results: Group median increase in air-conduction thresholds in the implanted ear for test frequencies 125–1000 Hz was < 15 dB across the population; both immediately and one year post-operatively. Eighty-eight percent of subjects used the Hybrid processor at one year post-op. Sixty-five percent of subjects had significant gain in speech recognition in quiet, and 73% in noise (≥ 20 percentage points/2 dB SNR). Mean SSQ subscale scores were significantly improved (+ 1.2, + 1.3, + 1.8 points, p < 0.001), as was mean HUI3 score (+ 0.117, p < 0.01). Combining residual hearing with CI gave 22−26 %age points mean benefit in speech recognition scores over CI alone (p < 0.01). Conclusions: Useful residual hearing was conserved in 88% of subjects. Speech perception was significantly improved over preoperative hearing aids, as was sound quality and quality of life.

Assessment of more than 1,000 implanted percutaneous bone conduction devices: skin reactions and implant survival.

Objective This study assesses soft tissue reactions and implant stability of 1,132 percutaneous titanium implants (970 patients) for bone conduction devices (BCDs). In addition, it examines BCD usage and comparisons between different patient groups. Study Design Retrospective survey. Mean follow-up time of 4.6 years. Setting Tertiary care referral center. Patients The surveyed cohort was divided into 3 different age groups (children, adults, and the elderly). In addition, 4 groups with variable loading times (i.e., the time between placement of the implant and loading the BCD sound processor) were identified as well as a subgroup of patients with mental retardation. Main Outcome Measures Soft tissue reactions around the percutaneous implants as classified by the Holgers grading system, implant failure, and revision surgery rates. Results In 95.5% of the 7,415 observations of 1,132 implants, there were no adverse soft tissue reactions. Implant loss was 8.3%. Significantly more soft tissue reactions and implant failures were observed in children compared with adults and the elderly (p < 0.05). Implant survival was lower in patients with mental retardation compared with patients without mental retardation (p = 0.001). The loading time did not influence the occurrence of soft tissue reactions and implant survival rates. Conclusion Children and patients with mental retardation are the most vulnerable to soft tissue reactions and implant losses. Additional and more frequent care needs to be given during outpatient consultations. Because loading as early as 3 to 5 weeks did not negatively affect skin reactions or implant survival, full BCD installation can occur earlier without risk.

Sound localization ability of young children with bilateral cochlear implants.

Objective: To evaluate the benefit of bilateral cochlear implantation in young children. Study Design: Clinical trial comparing a group of bilaterally implanted children with a group of unilaterally implanted children. Setting: Tertiary referral center. Patients: Five bilaterally implanted children (mean age at testing, 3 yr 7 mo) were compared with 5 unilaterally implanted children (mean age at testing, 5 yr 3 mo). Meningitis was the cause of deafness in all of the children. Methods: Children were asked to localize a prerecorded melody band limited from 500 to 4,000 Hz presented from loudspeakers placed at either −90 or 90 degrees or −30 or 30 degrees azimuth. Their parents filled in the Speech, Spatial and Qualities of Hearing Scale (SSQ) and PedsQL questionnaires on hearing and health-related quality of life of their children. Results: The bilaterally implanted children had significantly better scores on the localization test than the children with unilateral cochlear implants. The scores of the children with bilateral cochlear implants were also significantly higher on the spatial domain of the SSQ, which concerns localization. No significant differences were found in the speech and quality of hearing domains and the total scores on the SSQ or the PedsQL between the two groups. Conclusion: Children with bilateral cochlear implantation already demonstrate an advantage over unilaterally implanted children at a young age.

Congenital malformation of the inner ear and paediatric cochlear implantation.

Objectives: To study the surgical aspects and performance outcome of cochlear implantation in children with malformed inner ears. Study Design: Clinical and audiometric evaluation in 13 patients. Methods: Patient data concerning surgery, postoperative follow-up, and pre- and postimplantation audiometry were obtained from the cochlear implant center’s database and evaluated. A review of the literature has been included. Setting: Tertiary referral center. Patients: The patients had a variety of inner ear malformations and profound hearing loss. One patient with recurrent meningitis had a severe cochlear malformation (common cavity). Results: Major complications did not occur. In one patient with an abnormal position of the cochlea and concurring middle ear disease, it was difficult to find the scala tympani during surgery. A cerebrospinal fluid gusher was encountered in two patients and an aberrant facial nerve in another, which did not lead to any complications. The patients with mild cochlear malformation such as an incomplete partition demonstrated a good performance in speech perception tests. Even the child with the common cavity deformity had some open-set speech perception 1 year after implantation. Conclusions: Viewing the patients from this study and patients from a review of the literature concerning cochlear implantation in children with malformed inner ears including severe cochlear malformations, the occurrence of an aberrant facial nerve was 17%, which increases to 27% if one reviews the surgical findings in children with severe malformed cochleae such as a common cavity or a severe cochlear hypoplasia. In the latter patients, results in speech perception vary. Although the result of cochlear implantation may be promising, as in our patient with a common cavity, during preoperative counseling the child’s parents must be informed that the result is uncertain.