Trans-mastoid plugging of superior semicircular canal dehiscence: long-term follow-up.

OBJECTIVE: To evaluate the long-term outcomes of trans-mastoid plugging of superior semicircular canal dehiscence (SSCD), focusing on complicated cases. METHODS: In this cohort study, we included all patients who underwent trans-mastoid plugging of SSCD between 2009 and 2019. We evaluated the symptoms (autophony, sound-/pressure-induced vertigo, disequilibrium, aural fullness and pulsatile tinnitus) before and 1 year after surgery in the medical records. We systematically assessed the current symptoms 6.2 ± 3 years postoperative (range 2.2-12.3 years) using questionnaires sent by post and validated by telephone interviews. We also documented any complications and the need for further procedures. We compared pure tone and speech audiometry before and 1 year after surgery. Finally, the degree of mastoid pneumatisation and mastoid tegmen anatomy were reviewed on preoperative CT scans. RESULTS: We included 24 ears in 23 patients. No complications were recorded, and none required a second procedure for SSCD. Following surgery, oscillopsia and Tullio phenomena resolved in all patients. Hyperacusis, autophony, and aural fullness were also settled in all patients except one. Balance impairment persisted to some degree in 35% of patients. No deterioration over the years was reported regarding the above symptoms. On average, bone conduction pure tone average pre- and 1 year postoperative were 13.7 ± 17 and 20.5 ± 18 dB, respectively (P = 0.002). Air bone gaps were reduced from 12.7 ± 8 to 5.9 ± 6 (P = 0.001). Two patients had a significant sclerotic mastoid, three had a prominent low-lying mastoid tegmen, and two had both. Anatomy had no effect on outcome. CONCLUSION: Trans-mastoid plugging of SSCD is a reliable and effective technique which achieves long-lasting symptom control, even in cases with sclerotic mastoid or low-lying mastoid tegmen.

Contemporary surgical issues in paediatric cochlear implantation.

OBJECTIVE: To review the contemporary surgical issues in paediatric cochlear implantation (CI) based on published evidence. DESIGN: Narrative literature review. RESULTS: Surgical challenges in paediatric CI are discussed, with respect to post meningitic labyrinthitis ossificans; cochlear malformation; cochlear implantation in infants; auditory neuropathy and cochlear nerve deficiency; bilateral cochlear implantation; hearing preservation; otitis media; and device failure. CONCLUSION: Early CI is recommended if bacterial meningitis causes profound sensorineural hearing loss (SNHL). CI in cochleovestibular malformation requires pre-operative imaging to plan surgical technique, choice of electrode, and to anticipate complication. Children with congenital severe to profound SNHL should undergo early bilateral simultaneous implantation, preferably before 12 months of age, except those with auditory neuropathy spectrum disorder who should be implanted after one year. Soft surgical technique should be deployed in an attempt to preserve any residual hearing. Otitis media with effusion is not a contraindication to cochlear implantation, but active or recurrent acute otitis media requires resolution of infection with grommet insertion pre-operatively. Device failure in CI recipients requires a stepwise audiological, medical, radiological, and device integrity assessment to determine the need for reimplantation.

Anatomic comparison of nasal versus lateral surgical access to the petrous apex.

To compare anatomic access to the petrous apex via the nasal and lateral approaches. Hundred consecutive fine-cut CT temporal bones at the Royal Melbourne Hospital from July 27, 2007 to October 30, 2010 were reviewed. Easy lateral access allowed use of a 4 mm burr past vital structures. Easy nasal access was defined as sphenoid pneumatization to/beyond the posterior sella and laterally beyond the maxillary/vidian nerves. Three patients with petrous apex pathology were also reviewed. Easy lateral and nasal access occurred in 74 (37%) and 79 (39.5%) sides, respectively. Easy nasal and lateral access were not strongly correlated (r = 0.10, P = 0.15). A well-pneumatized mastoid (62.5%) was strongly correlated with a large sphenoid (63%, P < 0.001). Pneumatization of the mastoid corresponds to sphenoid sinus size. However, surgical access to the petrous apex is more determined by proximity of vital structures. Easy surgical access via the nasal or lateral approaches was not strongly correlated. Petrous apex lesions requiring surgery should be considered for both approaches.

Multicenter Clinical Investigation of a New Active Osseointegrated Steady-State Implant System.

OBJECTIVE: A new active transcutaneous bone conduction hearing implant system that uses piezoelectric technology has been developed: an active osseointegrated steady-state implant system (OSI). This was the first clinical investigation undertaken to demonstrate clinical performance, safety, and benefit of the new implant system. STUDY DESIGN AND SETTING: A multicenter prospective within-subject clinical investigation was conducted. PATIENTS: Fifty-one adult subjects with mixed and conductive hearing loss (MHL/CHL, n = 37) and single-sided sensorineural deafness (SSD, n = 14) were included. MAIN OUTCOME MEASURE: Audiological evaluations included audiometric thresholds, speech recognition in noise, and quiet. Hearing and health-related patient-reported outcomes (PROs; health utilities index [HUI], abbreviated profile of hearing aid benefit [APHAB], and speech, spatial of qualities of hearing scale [SSQ]), daily use, surgical and safety parameters were collected. RESULTS: Intra- and postoperative complications were few. One implant was removed before activation due to post-surgical infection. Compared with the preoperative softband tests, a significant improvement in speech recognition-in-noise was observed in the MHL/CHL group (-7.3 dB, p ≤ 0.0001) and the SSD group (-8.1 dB, p = 0.0008). In quiet, word recognition improved in the MHL/CHL group, most markedly at lower intensity input of 50 dB SPL (26.7%, p ≤ 0.0001). The results of all PROs showed a significant improvement with the new device compared with preoperative softband in the MHL/CHL group. In the SSD group significant improvements were observed in the APHAB and SSQ questionnaires. DISCUSSION: The results confirmed the clinical safety, performance, and benefit of this new treatment modality for subjects with CHL, MHL, and SSD.

Comparison of two frequency-to-electrode maps for acoustic-electric stimulation.

The fitting of a cochlear implant together with aided residual hearing was evaluated by means of matching frequency and/or perceived pitch between acoustic and electric modalities. Five cochlear implant users with the Nucleus Freedom electrode array with residual acoustic hearing participated. Psychophysical procedures were used to create a map in which the implant was programmed to provide the listener with high-frequency information only above the frequency at which acoustic hearing was no longer considered useful. This was compared to a second map which provided the full frequency range. Listeners wore each map for a number of weeks before speech recognition was measured in quiet and noise. Post-operatively across subjects, average hearing thresholds worsened by 27 dB. However, cochlear implantation provided superior recognition of speech compared to pre-operative scores, with the best results found when subjects were wearing their hearing aids together with the implant. No significant differences were found between the two maps on speech tests when subjects were wearing their implant together with hearing aid/s. In conclusion, the combination of a cochlear implant together with hearing aid/s was effective at providing speech perception benefits for the listeners of the current study, regardless of the frequency-to-electrode allocation selected.

Speech Perception Outcomes for Adult Cochlear Implant Recipients Using a Lateral Wall or Perimodiolar Array.

AIM: To assess the speech perception outcomes of adult CI recipients with significant preimplant low frequency hearing, examining differences between perimodiolar and lateral wall electrode placement in order to provide clinical guidance for clinicians and surgeons. METHODS: A prospective cohort study was undertaken identifying all adults who received a thin straight electrode array (TSEA) at the Royal Victorian Eye & Ear Hospital (RVEEH) from 2010 to 2015 and who had a preimplant low frequency pure tone median ≤70 dB HL (n = 63). A retrospective review was completed of the RVEEH database to identify a comparison group who had been implanted with a perimodiolar electrode array, comprising adults implanted between 2004 and 2011 (PM Group) with preimplant hearing equivalent to the TSEA group (n = 70). The TSEA Group were further divided into subgroups in which n = 19 used EAS (TSEA-EAS) and n = 44 who used electric-only hearing (TSEA-Standard). RESULTS: There was no significant difference in median speech perception outcomes between the TSEA and PM Groups (TSEA 61.7%, PM 67.3%, p = 0.954). A significant difference was found between the TSEA-EAS and TSEA-Standard subgroups for median speech perception outcome (TSEA-EAS median 73.5%, TSEA-Standard median 58.3%, p = 0.043). CONCLUSIONS: Significant speech perception benefit following cochlear implantation was achieved with both the perimodiolar and lateral wall electrode arrays and no significant difference was found between outcomes with those array types in this population of adults with functional low frequency hearing pre-implant. Those that received a TSEA, had preserved hearing, and utilised an EAS sound processor performed better than their peers with a TSEA and electric-only hearing.

Glucocorticoid for Hearing Preservation After Cochlear Implantation: A Systemic Review and Meta-analysis of Animal Studies.

OBJECTIVES: To conduct systematic review and meta-analyses of preclinical studies describing the efficacy of glucocorticoids administered via different routes for hearing preservation after cochlear implantation. DATA SOURCES: A literature search was performed in PubMed to identify peer-reviewed articles published before December 31, 2017, with no language restrictions. Search components were "Cochlear implant," "Glucocorticoids," and "Hearing preservation." The results were specified for animal studies. STUDY SELECTION: Original studies in which glucocorticoids were administered before or during cochlear implantation in animal models and hearing threshold shifts were measured using auditory brainstem response. DATA EXTRACTION: Quality of included studies was assessed using the SYstematic Review Centre for Laboratory animal Experimentation protocol. Threshold Shift reduction between the "study" and "control" groups at 1-month postimplantation was the parameter used to evaluate hearing preservation. DATA SYNTHESIS: The random-effects models were used to combine the results of selected studies. Separate meta-analyses were performed for drug-eluting electrodes, systemic, and local administration. CONCLUSIONS: Administering either systemic or topical glucocorticosteroids had a significant effect on preserving low and high-frequency hearing. Topical administration was equally effective across a range of concentration levels and provided maximal hearing preservation when applied 120 minutes before implantation. The effect of systemic treatment was achieved with high doses, equivalent to 26 mg of dexamethasone per day in humans. No significant effect was found with the use of drug-eluting electrodes and more studies are needed to characterise the utility and efficacy of this administration method.

Laser-assisted stapedotomy with a Nitinol heat-crimping prosthesis: Outcomes compared with a platinum fluoroplastic prosthesis.

OBJECTIVE: To assess the hearing outcomes achieved with a Nitinol heat-crimping prosthesis when used with a laser-assisted stapedotomy for otosclerosis. STUDY DESIGN: Prospective assessment of 50 stapedotomies performed in 48 patients. Data collected included audiological results and duration of hospital admission. Outcomes were compared with a previously reported series of 66 stapedotomies performed in 59 patients. SETTING: Tertiary referral center and private practice. RESULTS: In the Nitinol group, hearing was improved in all cases (100%). The air-bone gap (ABG) was closed to within 10 dB in 48 (96%). This group's results are significantly better (P < or = 0.01) than those of the platinum fluoroplastic group, in whom ABG was within 10 dB in 74 percent. CONCLUSION: Laser-assisted stapedotomy, under local anesthesia with sedation, using a Nitinol heat-crimping prosthesis is a safe, well-tolerated technique with which excellent audiological results can be achieved.

Initial clinical experience with a totally implantable cochlear implant research device.

OBJECTIVE: To evaluate the effectiveness and issues associated with a research totally implantable cochlear implant (TIKI). STUDY DESIGN: Limited patient trial. SETTING: Tertiary referral center. PATIENTS: Three adult human subjects with severe-to-profound sensorineural hearing loss. INTERVENTIONS: Subjects were implanted with a research TIKI developed by Cochlear Limited and the Co-operative Research Centre for Cochlear Implant and Hearing Aid Innovation. The TIKI has a lithium ion rechargeable battery, a package-mounted internal microphone, and sound-processing electronics that enable the use of "invisible hearing" without the use of an external device. The TIKI also functions with an external ESPrit 3G sound processor as a conventional cochlear implant. The standard surgical technique was modified to accommodate the larger device package. Postoperatively, subjects used TIKI in both invisible hearing and the conventional ESPrit 3G modes. MAIN OUTCOME MEASURES: Device use was recorded in both invisible hearing and ESPrit 3G listening modes. Performance of the internal battery and microphone was assessed over time. Psychophysical MAP data were collected, and speech perception was measured at 1, 3, 6, and 12 months postoperatively in both listening modes. RESULTS: There were no surgical or postoperative complications. All subjects use both invisible hearing and conventional ESPrit 3G modes. Speech perception outcomes for all patients showed improvement from preoperative scores. As a consequence of the reduced sensitivity of the implanted microphone, speech perception results using the invisible hearing mode were significantly lower than the ESPrit 3G mode. Subjects reported some body noise interference that limited use of the invisible hearing mode; however, all continue to use the invisible hearing mode on a limited daily basis. The rechargeable battery functioned well, with a cycle time indicating the low-power implant design is effective and will deliver long battery life. CONCLUSION: This study demonstrates that the challenges in developing a safe and effective TIKI can be overcome. Three subjects implanted with the research TIKI all reported benefit from routine use. For each subject, hearing outcomes using invisible hearing mode were not as good as when using the external ESPrit 3G sound processor in the conventional mode.

Effect of cochlear implantation on middle ear function: A three-month prospective study.

OBJECTIVES/HYPOTHESIS: To determine if cochlear implantation has a delayed effect on the middle ear conductive hearing mechanism by measuring laser Doppler vibrometry (LDV) of the tympanic membrane (TM) in both implanted and contralateral control ears preoperatively and 3 months postoperatively, and then comparing the relative change in LDV outcome measures between implanted and control ears. STUDY DESIGN: Prospective cohort study. METHODS: Eleven preoperative adult unilateral cochlear implant recipients in previously unoperated ears with normal anatomy and aerated temporal bones were included in this study. The magnitude and phase angle of umbo velocity transfer function in response to air- conduction (AC) stimulus, and the magnitude of umbo velocity in response to bone- conduction (BC) stimulus were measured in the implant ear and the contralateral control ear preoperatively and 3 months postoperatively and compared. RESULTS: No significant changes in the magnitude or phase angle of TM velocity in response to either AC or BC stimulus were observed in the implanted ear relative to the contralateral control ear 3 months following cochlear implantation. CONCLUSIONS: From the results of LDV measurements, it can be said that cochlear implantation has no significant delayed effect on the middle ear conductive mechanism. LEVEL OF EVIDENCE: 4. Laryngoscope, 128:1207-1212, 2018.

Indications for and outcomes of mastoid obliteration in cochlear implantation.

OBJECTIVE: To review the indications, efficacy, and long-term outcomes of mastoid obliteration in cochlear implant surgery. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Seventeen patients who underwent a mastoid obliteration procedure to facilitate the insertion of a cochlear implant between 1978 and 2005. INTERVENTION: Mastoid obliteration procedure before cochlear implantation. MAIN OUTCOME MEASURES: Revision rate of the mastoid obliteration and cochlear implantation, postoperative audiometric scores (consonant-nucleus-consonant words/phonemes, Central Institute for the Deaf sentences, City University New York sentences in quiet and in noise), and incidence of complications. RESULTS: There were 17 patients with a median age of 60 years (range, 3-79 yr). Eight patients required mastoid obliteration for active chronic suppurative otitis media before cochlear implantation. Another 8 patients had existing mastoid cavities requiring obliteration (modified radical [n = 5] and fenestration cavities [n = 3]). A single patient with a sclerotic mastoid and an anterior sigmoid sinus underwent obliteration because of inadequate surgical access. The technique of obliteration was radical mastoidectomy with eustachian tube occlusion, blind sac closure of the external auditory canal, and cavity obliteration with either temporalis muscle flap (n = 15) or abdominal fat (n = 2). Cochlear implantation and mastoid obliteration were performed as a two-stage procedure in 10 patients and as a single-stage procedure in 7. Two patients required revision of the mastoid obliteration. At follow-up, all patients had stable obliterated cavities. Fifteen patients obtained significant improvement in speech discrimination scores, whereas 2 patients obtained some benefit from the cochlear implant through the perception of environmental sounds. CONCLUSION: For patients with chronic suppurative otitis media or existing mastoid cavities, the obliteration with temporalis muscle or abdominal fat is an effective technique to facilitate safe cochlear implantation.

Hearing Preservation Outcomes for 139 Cochlear Implant Recipients Using a Thin Straight Electrode Array.

OBJECTIVE: To assess the hearing preservation outcomes in a large group of adult cochlear implant recipients implanted with a thin straight electrode array using atraumatic surgical techniques. Factors affecting hearing preservation will be investigated. STUDY DESIGN: Prospective cohort study undertaken at the Royal Victorian Eye and Ear Hospital in Melbourne, Australia from December 2010 to May 2015. SETTING: Tertiary academic hospital. PATIENTS: One hundred thirty-nine adults undergoing cochlear implantation (CI). MAIN OUTCOME MEASURE: Primary outcome measure of interest was pre and postoperative pure-tone audiometry. RESULTS: Median low-frequency hearing change for the whole group of 139 recipients was -22.5 dB at the 3 months postop point. Eighty-six participants had functional preoperative low-frequency hearing (≤70 dB average at 250 and 500 Hz). Of these, 90.7% retained measureable hearing at 3 months postimplant. 39.5% of this original 86 participants retained functional hearing at 3 months postimplant. At 12 months postimplant, those who retained functional hearing at 3 months had no significant change in hearing. The group who lost functional hearing continued to have a significant deterioration in low-frequency hearing. Degree of hearing loss preimplant was identified as a predictor for the preservation of hearing postoperatively. CONCLUSION: Preservation of hearing is possible following atraumatic cochlear implant surgery with a thin straight electrode array. The amount of hearing preserved seems to be variable, and factors related to this variability are not yet known. The results of the present study suggest preoperative low-frequency hearing at or better than 45 dB may be related to preservation of functional hearing.

Effects of vestibulo-ocular reflex exercises on vestibular compensation after vestibular schwannoma surgery.

OBJECTIVE: To assess vestibular function in a large group of vestibular schwannoma patients so that we could determine whether simple vestibular exercises speed vestibular dysfunction recovery after tumor removal surgery. STUDY DESIGN: A prospective investigation of the vestibular dysfunction experienced by patients in the first 12 weeks after surgery. SETTING: Vestibular investigation unit at a tertiary referral institution. PATIENTS: Sixty-five patients with identified vestibular schwannoma referred for preoperative vestibular investigations. Thirty-two men and 33 women, with a mean age 51 years (range, 24-77 yr). INTERVENTIONS: There were 27 control patients, 30 exercise patients, and 8 patients that had balance physiotherapy. Exercise patients began simple vestibulo-ocular reflex gaze stabilization exercises 3 days after surgery. MAIN OUTCOME MEASURES: Postoperative vestibular function testing was performed at 2 to 3, 6 to 7, and 10 to 12 weeks after surgery. Objective measurements of vestibular compensation status were as follows: spontaneous nystagmus and sinusoidal harmonic acceleration asymmetry and gain values. Dizziness Handicap Inventory questionnaires were used to assess subjective perceptions. RESULTS: The main findings were reduced dispersion in vestibulo-ocular reflex asymmetry at 2 to 3 weeks, reduced mean in asymmetry at 6 to 7 weeks, less dizziness/imbalance according to the Dizziness Handicap Inventory questionnaire, and that preoperative caloric tests did not predict postoperative severity of vestibular systems. CONCLUSION: This large study provided unique evidence that a program of simple vestibular exercises and education can speed the rate of compensation after vestibular schwannoma surgery.

Cochleostomy site: implications for electrode placement and hearing preservation.

CONCLUSIONS: With recent increased interest in minimizing intracochlear trauma and preserving residual hearing during cochlear implantation, increased attention must be paid to the cochleostomy site. The results of this paper demonstrate that the cochleostomy must be made inferior, rather than anterior, to the round window to ensure scala tympani insertion and to decrease the likelihood of insertion-induced intracochlear damage during electrode insertion. OBJECTIVE: To describe the complex anatomy of the hook region of the cochlea, specifically in relation to the optimal placement of the cochleostomy for cochlear implant electrode insertion to potentially achieve hearing preservation. The authors believe that previous industry recommendations and described surgical techniques have resulted in cochleostomies being placed in anatomical positions that possibly result in electrode insertions that damage the basilar membrane and/or other cochlear structures. MATERIAL AND METHODS: The results of a number of temporal bone studies were reviewed with attention being paid to the anatomical relationship of the basilar membrane and spiral ligament to the round window membrane. For different cochleostomy sites the potential for damage to intracochlear structures, particularly the basilar membrane and organ of Corti, was assessed. RESULTS: The review of electrode insertion studies into human temporal bones, as well as a post-mortem anatomical study of implanted temporal bones, showed an increased risk of scala vestibuli insertions and insertion-induced damage to intracochlear structures when the cochleostomy was performed more anterior to the round window. These results were endorsed by studies detailing the anatomy of the hook region of the cochlea.

The Cochlear Baha 4 Attract System - design concepts, surgical technique and early clinical results.

Bone conduction implant systems utilize osseointegrated fixtures to transmit sound through the bones of the skull. They allow patients with hearing loss to receive acoustic signals directly to the inner ear, bypassing the outer and middle ear. The new Cochlear™ Baha(®) Attract System (Cochlear Bone Anchored Solutions AB, Mölnlycke, Sweden) has been designed as a non-skin penetration hearing implant. The system uses magnetic coupling to hold the external sound processor in place and transmit acoustic energy. An implantable magnet is anchored to the skull via a single osseointegrated fixture, maximizing the efficiency of energy sound transfer. The interposed soft tissue is protected by a SoftWear pad that evenly distributes pressure in order to minimize the risk of pressure necrosis. This article summarizes the design features and early clinical results of the Baha 4 Attract System and provides context as to its place in the broader hearing aid market.

Assessment of hearing in infants with moderate to profound impairment: the Melbourne experience with auditory steady-state evoked potential testing.

Auditory steady-state evoked potential (ASSEP) testing has been used in the assessment of hearing in infants at the University of Melbourne School of Audiology Clinic during the past 10 years. This study examines the evoked potential and behavioral hearing test findings for 200 children in whom permanent, moderate to profound hearing loss was diagnosed with the ASSEP procedure. The ASSEP audiograms were obtained with amplitude and frequency modulated tones at octave frequencies (500 to 4,000 Hz). In 184 infants, the hearing loss appeared to be of sensorineural origin. For these children, there was a strong correlation between ASSEP findings and behavioral thresholds, with Pearson r coefficients ranging from 0.81 to 0.93 with test frequency. As such, the ASSEP findings obtained in the first months of life were accurate enough to form a basis for fitting amplification and early intervention. For the 16 children whose hearing loss appeared to be the result of auditory neuropathy, however, ASSEP thresholds showed little or no relationship to the behavioral audiogram.

Planned simultaneous bilateral cochlear implant operations: how often do children receive only one implant?

OBJECTIVE: The aim of this study was to determine the proportion of planned simultaneous cochlear implant operations that do not result in simultaneous cochlear implants on the day of surgery. The frequency with which this occurs has not been reported in the literature, and such information is important for parents' pre-operative decision making. METHODS: A retrospective review was conducted of pediatric cochlear implant operations performed in the period January 2007-July 2010 at the Melbourne Cochlear Implant Clinic. The number of planned simultaneous cochlear implant procedures and the results of these surgeries were catalogued. Reasons for not proceeding with simultaneous cochlear implants as planned were also identified. RESULTS: In the time period examined, there were a total of 50 planned simultaneous cochlear implant operations. Of these planned simultaneous operations, 22% did not result in bilateral cochlear implants on the day of surgery, with all children involved receiving a first-side cochlear implant only. In the majority of cases, the reason for a first-side cochlear implant only was otitis media. CONCLUSION: In the time period examined, a considerable proportion of planned simultaneous cochlear implant operations did not result in simultaneous bilateral implantation on the day of surgery. It is important that the likelihood of this outcome is discussed with families during pre-operative counseling as it may influence their decision making.

The new Nucleus 5 model cochlear implant: a new surgical technique and early clinical results.

OBJECTIVE: The Nucleus 5 or CI500 series cochlear implants are the new generation of Nucleus(®) cochlear implants. The receiver-stimulator package has a low profile without a pedestal projecting from the medial surface. This study aimed to demonstrate that the new design can facilitate a minimally invasive surgical approach, without the need for tie-down sutures and without a seat drilled for the receiver-stimulator package. METHODS: The surgical technique involved placing the device directly on the surface of the bone in a secure sub-periosteal pocket with a channel drilled for the lead. A well or ramped seat was not drilled and tie-down sutures were not used. Measurements were taken from the transmitting coil to the tragus and the coil to the lobule immediately after implantation, and serially thereafter to document implant position. RESULTS: To date, over 200 implants have been performed with the Nucleus 5 device. In all cases, healing was uneventful without major complications. Of 137 patients with at least 6-week follow-up data, 8% showed a measurement change of greater than 1 cm whereas only 4.4% demonstrated any clinically evident movement. None had any complications relating to migration and none required repositioning of the device. DISCUSSION: The new design can safely be inserted without drilling a well for the receiver-stimulator package. Some early post-operative movement of the package was observed which caused no clinical impact. This modified surgical technique reduces the risk of intracranial complications and reduces operating time.

Future technology in cochlear implants: assessing the benefit.

It has been over 50 years since Djourno and Eyries first attempted electric stimulation in a patient with deafness. Over this time, the Cochlear Implant (CI) has become not only remarkably successful, but increasingly complex. Although the basic components of the system still comprise an implanted receiver stimulator and electrode, externally worn speech processor, microphone, control system, and power source, there are now several alternative designs of these components with different attributes that can be variably combined to meet the needs of specific patient groups. Development by the manufacturers has been driven both by these various patient needs, and also by the desire to achieve technological superiority, or at least differentiation, ultimately in pursuit of market share. Assessment of benefit is the responsibility of clinicians. It is incumbent on both industry and clinicians to ensure appropriate, safe, and affordable introduction of new technology. For example, experience with the totally implanted cochlear implant (TIKI) has demonstrated that quality of hearing is the over-riding consideration for CI users. To date, improved hearing outcomes have been achieved by improvements in: speech processing strategies; microphone technology; pre-processing strategies; electrode placement; bilateral implantation; use of a hearing aid in the opposite ear (bimodal stimulation); and the combination of electric and acoustic stimulation in the same ear. The resulting expansion of CI candidacy, with more residual hearing, further improves the outcomes achieved. Largely facilitated by advances in electronic capability and computerization, it can be expected that these improvements will continue. However, marked variability of results still occurs and we cannot assure any individual patient of their outcome. Realistic goals for implementation of new technology include: improved hearing in noise and music perception; effective invisible hearing (no external apparatus); automated fitting; and reduction in outcome variability. This paper provides examples of relevant potential future technologies that can be applied to reach these goals. In the quest for better outcomes, future technology must deliver improved reliability and usability for both clinicians and recipients that does not compromise safety and is affordable. One of the challenges related to the introduction of new technologies is the 'classification' of CI systems and the framework under which sufficient change and increased benefit can be demonstrated to establish a claim of 'new generation CI' and hence increased reimbursement from third-party payers. Significant improvements in hearing outcomes and quality of life associated with CI design changes are difficult to measure, particularly when there is such dramatic benefit from the intervention of cochlear implantation from the individual's perspective. Manufacturers and clinicians need to be objective and undertake appropriate safety studies and long-term and multi-centre clinical trials to ensure that the introduction of new technology is both safe and effective and supported by health systems worldwide.