Global hearing health care: new findings and perspectives.

In 2015, approximately half a billion people had disabling hearing loss, about 6·8% of the world's population. These numbers are substantially higher than estimates published before 2013, and point to the growing importance of hearing loss and global hearing health care. In this Review, we describe the burden of hearing loss and offer our and others' recommendations for halting and then reversing the continuing increases in this burden. Low-cost possibilities exist for prevention of hearing loss, as do unprecedented opportunities to reduce the generally high treatment costs. These possibilities and opportunities could and should be exploited. Additionally, a comprehensive worldwide initiative like VISION 2020 but for hearing could provide a focus for support and also enable and facilitate the increased efforts that are needed to reduce the burden. Success would produce major personal and societal gains, including gains that would help to fulfil the "healthy lives" and "disability inclusive" goals in the UN's new 2030 Agenda for Sustainable Development.

Self-reported symptoms and patient experience: A British Acoustic Neuroma Association survey.

OBJECTIVE: To assess patient-reported outcomes and experience of vestibular schwannoma (VS) management. STUDY DESIGN: Survey of members of the British Acoustic Neuroma Association (BANA). METHODS: Members of the BANA were invited to complete an online survey. Questions were divided into five areas: Demographic details; symptoms at diagnosis; level of information received; treatment after-effects; and overall experience of diagnosis and/or treatment. DEMOGRAPHICS: 598 (58%) BANA members completed the survey. 77.1% of respondents were aged between 41 and 70 years. Symptoms at diagnosis: hearing loss (84%), unilateral tinnitus (40%) and imbalance (51%) were commonest. Isolated tinnitus and imbalance occurred in 2% and 6%, respectively. Information received: 39% stated they were given 'just the right amount of information about all management options', and 32% 'not enough information'. Treatment after-effects: Overall quality of life was classified as 'a lot better' (11%), 'a little better' (7%), 'unchanged' (25%), 'a little worse' (38%) and 'a lot worse' (19%). 61% respondents continued in the same job. Return to social life, hobbies and sports was impaired in 65%. Overall experience: Experience of treatment was graded as 'much better than expected' (20%), 'a little better' (15%), 'about the same' (27%), 'a little worse' (22%) and 'much worse' (16%). CONCLUSION: Quality of life measures are important in assessing VS management outcomes, and will increasingly inform clinical decision-making. Further examination of how patients with VS perceive their disease, cope with illness and use social support networks may also help to inform future practice and the creation of decision analytical models.

Comparison of the benefits of cochlear implantation versus contra-lateral routing of signal hearing aids in adult patients with single-sided deafness: study protocol for a prospective within-subject longitudinal trial.

BACKGROUND: Individuals with a unilateral severe-to-profound hearing loss, or single-sided deafness, report difficulty with listening in many everyday situations despite having access to well-preserved acoustic hearing in one ear. The standard of care for single-sided deafness available on the UK National Health Service is a contra-lateral routing of signals hearing aid which transfers sounds from the impaired ear to the non-impaired ear. This hearing aid has been found to improve speech understanding in noise when the signal-to-noise ratio is more favourable at the impaired ear than the non-impaired ear. However, the indiscriminate routing of signals to a single ear can have detrimental effects when interfering sounds are located on the side of the impaired ear. Recent published evidence has suggested that cochlear implantation in individuals with a single-sided deafness can restore access to the binaural cues which underpin the ability to localise sounds and segregate speech from other interfering sounds. METHODS/DESIGN: The current trial was designed to assess the efficacy of cochlear implantation compared to a contra-lateral routing of signals hearing aid in restoring binaural hearing in adults with acquired single-sided deafness. Patients are assessed at baseline and after receiving a contra-lateral routing of signals hearing aid. A cochlear implant is then provided to those patients who do not receive sufficient benefit from the hearing aid. This within-subject longitudinal design reflects the expected care pathway should cochlear implantation be provided for single-sided deafness on the UK National Health Service. The primary endpoints are measures of binaural hearing at baseline, after provision of a contra-lateral routing of signals hearing aid, and after cochlear implantation. Binaural hearing is assessed in terms of the accuracy with which sounds are localised and speech is perceived in background noise. The trial is also designed to measure the impact of the interventions on hearing- and health-related quality of life. DISCUSSION: This multi-centre trial was designed to provide evidence for the efficacy of cochlear implantation compared to the contra-lateral routing of signals. A purpose-built sound presentation system and established measurement techniques will provide reliable and precise measures of binaural hearing. TRIAL REGISTRATION: Current Controlled Trials http://www.controlled-trials.com/ISRCTN33301739 (05/JUL/2013).

Unlocking the human inner ear for therapeutic intervention.

The human inner ear contains minute three-dimensional neurosensory structures that are deeply embedded within the skull base, rendering them relatively inaccessible to regenerative therapies for hearing loss. Here we provide a detailed characterisation of the functional architecture of the space that hosts the cell bodies of the auditory nerve to make them safely accessible for the first time for therapeutic intervention. We used synchrotron phase-contrast imaging which offers the required microscopic soft-tissue contrast definition while simultaneously displaying precise bony anatomic detail. Using volume-rendering software we constructed highly accurate 3-dimensional representations of the inner ear. The cell bodies are arranged in a bony helical canal that spirals from the base of the cochlea to its apex; the canal volume is 1.6 µL but with a diffusion potential of 15 µL. Modelling data from 10 temporal bones enabled definition of a safe trajectory for therapeutic access while preserving the cochlea's internal architecture. We validated the approach through surgical simulation, anatomical dissection and micro-radiographic analysis. These findings will facilitate future clinical trials of novel therapeutic interventions to restore hearing.

Development and validation of DeciBHAL-US: A novel microsimulation model of hearing loss across the lifespan in the United States.

BACKGROUND: Hearing loss affects over 50% of people in the US across their lifespan and there is a lack of decision modeling frameworks to inform optimal hearing healthcare delivery. Our objective was to develop and validate a microsimulation model of hearing loss across the lifespan in the US. METHODS: We collaborated with the Lancet Commission on Hearing Loss to outline model structure, identify input data sources, and calibrate/validate DeciBHAL-US (Decision model of the Burden of Hearing loss Across the Lifespan). We populated the model with literature-based estimates and validated the conceptual model with key informants. We validated key model endpoints to the published literature, including: 1) natural history of sensorineural hearing loss (SNHL), 2) natural history of conductive hearing loss (CHL), and 3) the hearing loss cascade of care. We reported the coefficient of variance root mean square error (CV-RMSE), considering values ≤15% to indicate adequate fit. FINDINGS: For SNHL prevalence, the CV-RMSE for model projected male and female age-specific prevalence compared to sex-adjusted National Health and Nutrition Examination Survey (NHANES) data was 4.9 and 5.7%, respectively. Incorporating literature-based age-related decline in SNHL, we validated mean four-frequency average hearing loss in the better ear (dB) among all persons to longitudinal data (CV-RMSE=11.3%). We validated the age-stratified prevalence of CHL to adjusted NHANES data (CV-RMSE=10.9%). We incorporated age- and severity-stratified time to first hearing aid (HA) use data and HA discontinuation data (adjusted for time-period of use) and validated to NHANES estimates on the prevalence of adult HA use (CV-RMSE=10.3%). INTERPRETATION: Our results indicate adequate model fit to internal and external validation data. Future incorporation of cost and severity-stratified utility data will allow for cost-effectiveness analysis of US hearing healthcare interventions across the lifespan. Further research might expand the modeling framework to international settings. FUNDING: This study was funded by the National Institute on Deafness and Other Communication Disorders and the National Institute on Aging (3UL1-TR002553-03S3 and F30 DC019846).

Effectiveness of computer-based auditory training for adult users of cochlear implants.

Cochlear implantation is effective at restoring partial hearing to profoundly deaf adults, but not all patients receive equal benefit. The present study evaluated the effectiveness of a computer-based self-administered training package that was designed to improve speech perception among adults who had used cochlear implants for more than three years. Eleven adults were asked to complete an hour of auditory training each day, five days a week, for a period of three weeks. Two training tasks were included, one based around discriminating isolated words, and the other around discriminating words in sentences. Compliance with the protocol was good, with eight out of eleven participants completing approximately 15 hours of training, as instructed. A significant improvement of eight percentage points was found on a test of consonant discrimination, but there were no significant improvements on sentence tests or on a test of vowel discrimination. Self-reported benefits were variable and generally small. Further research is needed to establish whether auditory training is particularly effective for identifiable sub-groups of cochlear-implant users.

Spatial hearing disability after acoustic neuroma removal.

OBJECTIVES/HYPOTHESIS: Previous studies on hearing loss (HL) after acoustic neuroma removal concentrate mainly on pure-tone hearing results rather than hearing disability. Our objectives were to use the Speech, Spatial and Qualities of Hearing scale (SSQ), a comprehensively validated questionnaire, to characterize and quantify the auditory disabilities that patients experience with a profound unilateral HL after acoustic neuroma removal. STUDY DESIGN: Forty-four patients with profound unilateral HL after acoustic neuroma surgery completed the SSQ. Their findings were compared with those of a control population sample matched for age, sex, and hearing level in the better hearing ear. RESULTS: In comparison with controls, with use of analysis of variance, acoustic neuroma patients scored poorly on all items except for the identification of sounds and objects (P = .123). The greatest difficulties involved speech in the presence of noise, situations of multiple speech-streams and switching (such as listening to someone speaking and the television at the same time), the location of unseen objects, and increased listening effort (P < .05). CONCLUSION: This study demonstrates that, compared with a control population, these patients experience a significant range of auditory disabilities. It is important that clinicians be aware of the impact of such a profound unilateral HL and its potential to affect daily life. Patient counseling prior to surgery is essential, especially in patients whose loss of binaural hearing could constitute a major disability.

An Assessment of the Clinical Acceptability of Direct Acoustic Cochlear Implantation for Adults With Advanced Otosclerosis in the United Kingdom.

HYPOTHESIS: Assess the clinical acceptability of direct acoustic cochlear implantation for patients with advanced otosclerosis and the support for conducting a controlled trial of its effectiveness in the United Kingdom. BACKGROUND: Emerging evidence supports the efficacy of direct acoustic cochlear implantation in patients with advanced otosclerosis whose needs cannot be managed using the combination of stapes surgery and hearing aids. A controlled trial would provide evidence for its effectiveness and cost-effectiveness to healthcare commissioners. METHODS: An online survey of clinical professionals was constructed to characterize current standard of care for patients with advanced otosclerosis and to assess whether clinicians would be willing to refer patients into a trial to evaluate direct acoustic cochlear implantation. A consensus process was conducted to define inclusion criteria for the future trial. RESULTS: No survey respondent considered direct acoustic cochlear implantation to be inappropriate with a majority indicating that they would refer patients into a future trial. The consensus was that there is a lack of available treatment options for those patients with bone conduction thresholds worse than 55 dB HL and who did not meet current criteria for cochlear implantation. CONCLUSION: The present study confirms that a controlled trial to evaluate the effectiveness of direct acoustic cochlear implantation would have the support of clinicians in the United Kingdom. A feasibility study would be required to determine whether patients who meet the inclusion criteria could be recruited in a timely manner and in sufficient numbers to conduct a formal evaluation of effectiveness.

Neurocognitive factors in sensory restoration of early deafness: a connectome model.

Progress in biomedical technology (cochlear, vestibular, and retinal implants) has led to remarkable success in neurosensory restoration, particularly in the auditory system. However, outcomes vary considerably, even after accounting for comorbidity-for example, after cochlear implantation, some deaf children develop spoken language skills approaching those of their hearing peers, whereas other children fail to do so. Here, we review evidence that auditory deprivation has widespread effects on brain development, affecting the capacity to process information beyond the auditory system. After sensory loss and deafness, the brain's effective connectivity is altered within the auditory system, between sensory systems, and between the auditory system and centres serving higher order neurocognitive functions. As a result, congenital sensory loss could be thought of as a connectome disease, with interindividual variability in the brain's adaptation to sensory loss underpinning much of the observed variation in outcome of cochlear implantation. Different executive functions, sequential processing, and concept formation are at particular risk in deaf children. A battery of clinical tests can allow early identification of neurocognitive risk factors. Intervention strategies that address these impairments with a personalised approach, taking interindividual variations into account, will further improve outcomes.

Acoustic schwannomas: awareness of radiologic error will reduce unnecessary treatment.

OBJECTIVE: To measure the intra- and interobserver error in size estimation of acoustic schwannomas from magnetic resonance imaging (MRI) scans by experienced radiologists to determine whether small amounts of tumor growth that may affect management (2 mm) could be reliably measured in clinical practice. DESIGN: Duplicated, blinded size estimation of acoustic neuromas (according to American Academy of Otolaryngology-Head and Neck Surgery guidelines, 1995) from MRI scans of patients with acoustic neuromas. SETTING: Tertiary referral teaching hospital and DGH. PARTICIPANTS: Four radiologists (including 2 dedicated neuroradiologists) measuring positive MRI scans of 26 patients with an acoustic neuroma. MAIN OUTCOME MEASURE: Intraradiologist and inter-radiologist repeatability coefficients in millimeters for the maximal tumor diameter in the anteroposterior (AP) axis, medial-longitudinal (ML) axis, and the square-root of the product of these two measurements. Repeatability coefficients give the 95% range within which the differences in repeated measurements lie. RESULTS: The intraradiologist repeatability for AP and ML measurements ranged from 1.51 to 6.03 mm and 2.01 to 3.83 mm, respectively. The repeatability of the square-root of the product ranged from 1.43 to 4.94 mm. The inter-radiologist repeatability was 6.48 mm and 7.46 mm for the AP and ML measurements, respectively, giving a repeatability of 3.65 mm for the square-root of the product. CONCLUSION: The study indicates that, in routine clinical practice, differences in tumor size of the order of 2 mm cannot be reliably measured, even by the same radiologist. Thus, reported growth of acoustic tumors should be interpreted with caution, especially if this is the criterion for recommending treatment.

Long-term functional outcomes and academic-occupational status in implanted children after 10 to 14 years of cochlear implant use.

OBJECTIVES: To assess a group of consecutively implanted children over 10 years after implantation with regard to implant device use and function, speech perception, and speech intelligibility outcomes; and to document current academic or occupational status. STUDY DESIGN: A prospective longitudinal study assessing device function, device use, speech perception, speech intelligibility, and academic/occupational status of implanted deaf children. SETTING: Pediatric tertiary referral center for cochlear implantation. METHODS: The auditory performance and speech intelligibility development of 30 profoundly deaf children were rated before cochlear implantation and at 5 and 10 years after implantation using the Categories of Auditory Performance and the Speech Intelligibility Rating. The academic and/or occupational status of the participants after 10 years of implant experience was documented. All children received a Nucleus multichannel cochlear implant between the ages of 2.5 and 11 years (mean age at implantation, 5.2 yr). Implant experience ranged from 10 to 14 years of use. RESULTS: After 10 years of implant experience, 26 subjects (87%) reported that they always wore their device; 2 subjects (7%), frequently; and 1 subject (3%), occasionally. Only one child had discontinued use of his device. After 10 years of implant use, 26 (87%) of the children understood a conversation without lip reading and 18 (60%) used the telephone with a familiar speaker. Ten years after implantation, 23 (77%) of the subjects used speech intelligible to an average listener or a listener with little experience of a deaf person's speech. One-third to one-half of the implanted children continued to demonstrate improvements at 5 to 10 years of implant use. Of the 30 implanted children, 8 (26.7%) experienced nine device failures. The length of time from identification of the first faulty electrode to reimplant surgery ranged from 2 weeks to 5.5 years, as several failures were gradual or intermittent. However, all children were successfully reimplanted. At the end of the study (10-14 yr after implantation), 19 subjects were in secondary school for children aged 11 to 16 years: 6 were in mainstream schools, 7 were in specialist hearing-impaired units attached to a mainstream secondary school, and 6 were in schools for the deaf. Of the remaining 11 subjects, 4 were in college studying vocational subjects, 2 were in a university studying for a bachelor's degree, 3 were working full-time, 1 was working and going to a university part-time, and 1 was a full-time mother of two young children. CONCLUSION: All but 1 of the 30 implanted children continue using their devices 10 to 14 years after implantation, showing significant progress in speech perception and production. Device failure was frequent, but successful reimplantation occurred in all cases. One-third to one-half of the implanted children in this study continued to demonstrate improvements at 5 to 10 years of implant use. All children are studying or working and are actively involved in their local communities. The results suggest that cochlear implantation provides long-term communication benefit to profoundly deaf children that does not plateau for some subjects even after reimplantation. This study further indicates that cochlear implant centers need the structure and funding to provide long-term support, counseling, audiologic follow-up, rehabilitation, and device monitoring to implanted children.

Hearing preservation in acoustic neuroma surgery: the impact of different patient selection criteria.

OBJECTIVES/HYPOTHESIS: The aim of the present study was to assess whether applying the various selection criteria for hearing preservation surgery on the same group of patients with acoustic neuroma leads to significantly different numbers of patients being considered suitable for this kind of surgery. STUDY DESIGN: We used different selection criteria for hearing conservation surgery based on a range of studies in the published literature. We applied these criteria to a consecutive group of patients presenting to our unit with acoustic neuroma. We then calculated the numbers of patients deemed suitable for hearing preservation surgery as a function of these different selection criteria. METHODS: Studies with published selection criteria, total numbers of patients, and numbers of patients suitable for hearing preservation surgery were found in the literature. These selection criteria were applied to our patient data. A chi2 statistical analysis was used to assess whether applying different selection criteria to the same group of patients (the subjects of the present study) resulted in different numbers of patients suitable for hearing preservation surgery. RESULTS: The numbers of patients suitable for hearing preservation showed wide variation, ranging from 8 (10%) to 45 (56%) patients (of the total number of 80 patients in the present study). The chi2 statistical analysis revealed that the various selection criteria did have an effect on the numbers of patients suitable for hearing preservation surgery, and the statistical significance reached the level of P<.001. CONCLUSIONS: Different selection criteria lead to significantly different numbers of patients being considered suitable for hearing preservation surgery. Consensus and agreed selection criteria would help set patient expectations, refine candidate selection, and facilitate the comparison of outcomes across centers.

Development of spoken language grammar following cochlear implantation in prelingually deaf children.

OBJECTIVES: To assess the development of grammar comprehension in spoken language in prelingually deaf children following cochlear implantation and compare their grammatical abilities with those of their hearing peers. DESIGN: A prospective study of 82 consecutive prelingually deaf children up to 5 years following implantation. The children were less than 7 years old at the time of implantation (mean age +/- SD, 4.2 +/- 1.3 years). All received the same multichannel cochlear implant system. No child was lost to follow-up and there were no exclusions from the study. SETTING: Tertiary referral cochlear implant center. METHODS: The children were assessed using the Test for Reception of Grammar. This individually administered, multiple-choice test designed to assess the understanding of grammatical contrasts in the English language also allows direct comparison of grammar comprehension between test subjects and their normal-hearing peers. RESULTS: Before implantation, only a small proportion (2%) of prelingually deaf children were above the first percentile of their normal-hearing peers. This percentage increased to 40% and 67%, respectively, 3 and 5 years after implantation; and 5 years after implantation, 20% of the children performed between the 25th and the 75th percentile or better. In the subgroup of children who received their cochlear device before the age of 4 years, this percentage reached 36%. CONCLUSIONS: Spoken language grammar acquisition in prelingually deaf children with a cochlear implant was found to be considerably delayed. However, there was a clear trend toward the development of grammar skills following cochlear implantation, and the greatest advance was made by children who received their implant at a younger age. These findings support the present trend toward early implantation.

Surgery and functional outcomes in deaf children receiving cochlear implants before age 2 years.

OBJECTIVE: To examine the feasibility of cochlear implantation in children younger than 2 years regarding surgery and functional outcomes. DESIGN: Prospective study. SETTING: Tertiary pediatric cochlear implant center. PATIENTS: A consecutive sample of 12 children younger than 2 years at the time of cochlear implantation (8 boys and 4 girls). The cause of hearing loss was meningitis in 6 children and congenital in 6. INTERVENTIONS: Multichannel cochlear implantation using the Nucleus C124M (Cochlear Co, Sydney, Australia) device. Functional outcome was assessed using the Listening Progress Profile and the Categories of Auditory Performance. MAIN OUTCOME MEASURES: Perioperative and postoperative surgical complications and functional outcome. RESULTS: Eight children had a completely patent cochlea. Four children required a 3- to 5-mm drilling to reach the scala tympani because of ossification after meningitis. Full insertion was achieved in 11 patients; the other child received 18 electrodes. One patient had temporary facial nerve weakness; 2 others had wound edema and serous discharge that resolved with conservative management. In the longer term, 1 child experienced a single episode of acute otitis media; another had recurrent episodes of otitis media. Mean Listening Progress Profile scores increased from 1 to 42 and median Categories of Auditory Performance scores increased from 0 to 5 at 2 years postsurgery. Comparison with the scores in the 2- to 5-year group showed no significant differences. No significant tuning difficulties were experienced with all children. CONCLUSIONS: Cochlear implantation is feasible in children younger than 2 years without significant surgical complications or particular tuning difficulties. Functional results 2 years after implantation were as good as or better than those of children who underwent implantation between ages 2 and 5 years.

Minimal access surgery for pediatric cochlear implantation.

OBJECTIVE: To develop a minimal access approach for pediatric cochlear implantation to improve the acceptability of the procedure for parents, children, and the wider community, and to reduce flap-related complications of the procedure. STUDY DESIGN: Prospective evaluation of a new surgical technique. METHOD: A new approach was developed through a short, oblique, straight postauricular incision without shaving any hair. It involved drilling the bony well for the implant inside a small subperiosteal pocket. PATIENTS: Twenty-three consecutively implanted children with the Nucleus implanted system, whose median age was 3.2 years (mean 4.1 years, range 1.6-11.2 years. RESULTS: The technique proved feasible in all the 23 children, and no major complications were encountered. Three instances of wound edema were observed early in the series; by minimizing tissue elevation and overzealous retraction, these complications were not encountered subsequently. The approach was warmly endorsed by parents, children, and caregivers, who greatly appreciated the minimal impact of the approach. CONCLUSION: The proposed new approach is very well accepted by implanted children and their families, reduces the psychologic trauma of the intervention, and has less risks of flap complications.

Acoustic neuroma management: an evidence-based medicine approach.

BACKGROUND: Partisan claims supporting the use of microsurgical resection, radiologic surveillance, and radiosurgery in acoustic neuroma management appear widely in the published literature. However, the strength of the evidence supporting these claims has not been assessed, and the management of acoustic tumors continues to be controversial. METHODS: The English-language medical literature for the past 23 years was searched for articles dealing with outcomes after acoustic neuroma management. The quality of evidence in each article was classified according to the categories of evidence as defined by a standard appraisal instrument for clinical guidelines. RESULTS: The search produced 111 articles reporting outcomes after acoustic neuroma management. From the 111 studies, 78 (70.3%) concerned surgery, 20 (18%) concerned radiosurgery, 9 (8.1%) concerned radiologic surveillance, and 4 (3.6%) compared different methods of management. From these studies, 95 (85.6%) represented Type III evidence, 6 (5.4%) represented Type IV evidence, and in 10 (9%) a clear-cut definition between Type III and Type IV could not be made. No study was supported by Type I or Type II evidence. CONCLUSIONS: The evidence supporting the various methods of acoustic neuroma management is of low quality (Type III or Type IV evidence). Well-designed comparisons between treatment methods do not exist, and therefore claims by clinicians favoring a particular treatment are unfounded. Better quality of evidence from large, well-designed, randomized clinical trials should now be undertaken at the points of clinical equipoise to address the true merits of each modality of acoustic neuroma management.

Surgical complications and their management in a series of 300 consecutive pediatric cochlear implantations.

OBJECTIVE: To report the short- and long-term complications encountered in a large number of consecutive children undergoing implantation in a single center. The current study also describes the management and sequelae of each complication. STUDY DESIGN: Prospective study assessing the surgical findings and complications of deaf children undergoing implantation. SETTING: Pediatric tertiary referral center for cochlear implantation. PATIENTS: The present study includes 300 consecutive children undergoing implantation, with a mean age at implantation of 5.1 years, ranging from 1.3 to 16.9 years. Of these children, 196 (65%) had congenital deafness of unknown cause. The commonest known cause was meningitis (73 of 300 [24%]) followed by congenital cytomegalovirus infection (17 of 300 [6%]). Children have been followed up regularly after implantation, typically at yearly intervals after the first year. The mean duration of follow-up at the time of the study was 4 years (range, 0.1-14 yr). RESULTS: There were no major perioperative (within 1 d after surgery) or major early postoperative (within 1 wk after surgery) complications. In the same periods, there were 19 and 15 minor complications, respectively. These complications (e.g., eardrum perforation, hematoma, flap swelling, wound infection, temporary facial weakness) settled with conservative treatment or minor intervention. With regard to the late surgical complications (>1 wk after surgery), there were 7 major (e.g., severe flap infection requiring explantation, cholesteatoma, persistent eardrum perforation) and 14 minor complications (e.g., mild flap infection, flap swelling, hematoma). A number of complications were encountered even 14 years after the original operation, and some of them needed repeated interventions, highlighting the importance of long-term follow-up. However, most of the complications occurred very close to the surgical procedure (<1 yr). CONCLUSION: An overall rate of 2.3% for major surgical complications and an overall rate of 16% for minor surgical complications suggest that cochlear implantation is a relatively safe surgical operation in experienced centers. Most surgical complications are minor and can be managed with conservative treatment or minor surgical intervention. However, meticulous attention to surgical detail, especially handling soft tissues and leaving the posterior canal wall intact, and long-term follow-up are of paramount importance in minimizing the incidence of surgical complications.