An overview of risk factors, management and prevention of cochlear implant infections.

PURPOSE OF REVIEW: With cochlear implantation becoming increasingly performed worldwide, an understanding of the risk factors, preventive measures, and management of cochlear implant (CI) infection remains important given the significant morbidity and cost it conveys. RECENT FINDINGS: At the turn of the 21st century there was a decrease in rates of CI infection, particularly meningitis, following the discontinuation of positioner use for CI. However, in more recent years rates of CI infection have remained largely static. Recently, studies evaluating preventive measures such as pneumococcal vaccination, S. aureus decolonization and surgical antibiotic prophylaxis have emerged in the literature. SUMMARY: Prompt recognition of CI infection and appropriate investigation and management are key, however at present treatment is largely informed by cohort and case-control studies and expert opinion. Preventive measures including pneumococcal vaccination, S. aureus decolonization and preoperative antibiotic prophylaxis play a role in reducing rates of CI infection. However, there remains a need for well designed clinical trials to provide higher level evidence to better guide preventive measures for, and management decisions of, CI infections in the future.

Bilateral intracochlear schwannomas: histopathological confirmation and outcomes following tumour removal and cochlear implantation with lateral wall electrodes.

Intracochlear schwannomas (ICS) are very rare benign tumours of the inner ear. We present histopathological proof of the extremely rare bilateral occurrence of intracochlear schwannomas with negative blood genetic testing for neurofibromatosis type 2 (NF2). Bilateral schwannomas are typically associated with the condition NF2 and this case is presumed to have either mosaicism for NF2 or sporadic development of bilateral tumours. For progressive bilateral tumour growth and associated profound hearing loss, surgical intervention via partial cochleoectomy, tumour removal, preservation of the modiolus, and simultaneous cochlear implantation with lateral wall electrode carrier with basal double electrode contacts was performed. The right side was operated on first with a 14-month gap between each side. The hearing in aided speech recognition for consonant-nucleus-consonant (CNC) phonemes in quiet improved from 57% to 83% 12 months after bilateral cochlear implantation (CI). Bilateral intracochlear schwannomas in non-NF2 patients are extremely rare but should be considered in cases of progressive bilateral hearing loss. Successful tumour removal and cochlear implantation utilizing a lateral wall electrode is possible and can achieve good hearing outcomes.

Early detection of hearing loss for infants in Western Australia: Comparison to international benchmarks.

AIM: To assess the degree to which timely audiological assessment of congenital hearing loss is achieved at our institution - Perth Children's Hospital, Western Australia, and to review cases which breached this timeframe in order to address barriers to timely assessment. The benchmark used to determine timely assessment is that set out by The Joint Committee on Infant Hearing (JCIH) in which diagnostic audiological testing occurs by three months of age for those who do not pass newborn hearing screening. METHODS: A retrospective chart review of infants who underwent diagnostic auditory assessment at Perth Children's Hospital between 2016-2019. A total of 151 children were identified as meeting the inclusion criteria and their medical files were reviewed. Time to first dABR was the time point for whether testing was achieved within the 3 month timeframe. RESULTS: Of the 151 children who underwent dABR assessments, 1 was identified as having breached the 90 day time limit (tested on day 91) for which no valid reason for delay could be identified. The timely delivery of dABR assessments in 99.3% of cases within this cohort compares favourably with the literature. CONCLUSIONS: Conclusion Timely diagnostic audiological assessment is achievable for children with congenital hearing loss. The reasons for patients breaching this timeframe are explored in the paper along with factors which may help avoid delays.

Infectious complications and optimising infection prevention for children with cochlear implants.

AIM: To describe the clinical epidemiology of children receiving cochlear implants, as well as the management and outcomes of cochlear implant infections and adherence to infection prevention measures. METHODS: A retrospective observational study was conducted in children ≤18 years who received cochlear implants in Western Australia's tertiary paediatric hospital. Information was obtained from medical and laboratory records regarding demographics, indication for implant, implant infection and preoperative Staphylococcus aureus screening/decolonisation. Immunisation history was examined using the Australian Immunisation Register. RESULTS: Overall, 118 children received cochlear implants, with 158 devices inserted (599 cochlear implant insertion-years). An implant infection rate of 3.8% (6/158) was identified during the study period (four pneumococcal and two community-acquired methicillin resistant S. aureus infections). All required surgical management, with an overall median duration of antibiotic therapy of 37 days (interquartile range (IQR) 29-48) and median length of stay of 8 days (IQR 8-9.5). All devices were retained and there were no relapses or deaths. Half of the children who developed cochlear implant infections (50%, 3/6) were up-to-date with additional pneumococcal vaccinations and no children (0%, 0/118) received S. aureus screening/decolonisation before implant insertion. CONCLUSIONS: Favourable outcomes were achieved with cochlear implant retention; however, the treatment was burdensome for families. We demonstrate significant scope to improve adherence to existing infection prevention strategies and provide direction for optimising preventative measures in the future. These include ensuring parental education, additional pneumococcal vaccinations and S. aureus decolonisation which are delivered as an infection prevention bundle to the growing population of infants receiving cochlear implants.

Extended scope of practice audiology in the ENT outpatient clinic - a pilot study.

OBJECTIVE: To investigate the feasibility of using an extended scope (ES) audiology service to provide care to non-urgent adult patients waiting for an Ear Nose and Throat (ENT) appointment. DESIGN: Based on suitability criteria developed by the Audiology and ENT departments, an internal review of the ENT wait list identified patients who would be suitable for an ES audiology clinic. STUDY SAMPLE: 220 non-urgent patients on the ENT wait list with hearing loss and/or tinnitus. RESULTS: A total of 220 patients were transferred from the ENT wait list to the ES audiology clinic: 200 (90.9%) were seen by the ES Audiologist and 20 (9.1%) patients self-discharged or did not attend the appointment. Out of the 200 patients seen, 175 (87.5%) were assessed, managed and discharged without the need for input from an Otologist. The remaining 25 (12.5%) patients needed an Otologist's input. CONCLUSION: This study has demonstrated the feasibility of an ES audiology clinic in a tertiary teaching hospital. Of those seen by ES audiologist, 87.5% were discharged from the ENT wait list without medical intervention. This model may represent an effective alternative pathway for lengthy outpatient waiting list management whilst providing patients with timely access to care.

Biguanide Pharmaceutical Formulations and the Applications of Bile Acid-Based Nano Delivery in Chronic Medical Conditions.

Biguanides, particularly the widely prescribed drug metformin, have been marketed for many decades and have well-established absorption profiles. They are commonly administered via the oral route and, despite variation in oral uptake, remain commonly prescribed for diabetes mellitus, typically type 2. Studies over the last decade have focused on the design and development of advanced oral delivery dosage forms using bio nano technologies and novel drug carrier systems. Such studies have demonstrated significantly enhanced delivery and safety of biguanides using nanocapsules. Enhanced delivery and safety have widened the potential applications of biguanides not only in diabetes but also in other disorders. Hence, this review aimed to explore biguanides' pharmacokinetics, pharmacodynamics, and pharmaceutical applications in diabetes, as well as in other disorders.

The Role of Preoperative Steroids for Hearing Preservation Cochlear Implantation: Results of a Randomized Controlled Trial.

OBJECTIVES: To determine whether preoperative steroids can improve hearing outcomes in cochlear implantation (CI). METHODS: This is a randomized controlled trial involving 30 postlingual deaf CI patients. Subjects had preoperative thresholds of better than or equal to 80 dB at 125 and 250 Hz, and better than or equal to 90 dB at 500 and 1,000 Hz. The subjects were randomized to a control group, an oral steroid group (receiving 1 mg/kg/day of prednisolone for 6 days prior to surgery), or a transtympanic steroid group (receiving a single dose of 0.5 mL of 10 mg/mL dexamethasone at 24 h prior to surgery). RESULTS: The subjects receiving transtympanic steroids had a significant decrease in the pure tone average over 3 months compared to the control and oral steroid group, which persisted over 12 months (p < 0.05). CONCLUSION: A single dose of preoperative transtympanic steroids prior to CI appears to have a beneficial effect, at least in the short term, with minimal effects seen in the longer term.

Remote paediatric ear examination comparing video-otoscopy and still otoscopy clinician rated outcomes.

OBJECTIVE: Telemedicine, particularly real time video-otoscopy in rural and remote Australia holds great potential in assessing and managing otology conditions. There is good evidence of store and forward images for assessment, however limited evidence exists for the use of real-time video-otoscopy. The objective of this study was to assess the validity of using real time video-otoscopy, compared to standard store and forward still image otoscopy, in a paediatric population. METHOD: Fifty-two paediatric tympanic membranes in 27 patients were examined and photographed by a telehealth facilitator with prior otoscope training. This occurred at two rural Western Australian health centre sites. These images were stored and forwarded to a tertiary paediatric hospital for otolaryngology department assessment on the day of real-time video-otoscopy consultation. During this consultation the same twenty-seven patients underwent real-time video-otoscopy assessment, which was recorded. Across six domains including, image quality, focus, light, cerumen amount, field of view and tympanic membrane landmarks, real-time video-otoscopy was compared against still image capture. The recording of each real-time video-otoscopy and still image tympanic membrane was assessed by two otology specialists for the ability to diagnose each as either normal or abnormal. An inter-rater reliability agreement was then calculated. RESULTS: There was greater image adequacy across five of the six domains for real time video-otoscopy compared to standard store and forward otoscopy images. Substantial agreement in diagnosing each tympanic membrane as either normal or abnormal between each rater was evident. CONCLUSION: This study supports the use of real time video-otoscopy during telemedicine consultation. With greater image quality, focus, light, field of view and identification of tympanic membrane landmarks video-otoscopy compared to still images has broad clinical applications. This includes primary assessment of the tympanic membrane and post operative follow-up clinical settings. Video-otoscopy offers a promising new way to over-come barriers in delivering ear health care in rural populations.

Primary contact physiotherapy for patients with suggested vestibulopathy for an Australian ENT clinic: a retrospective cohort study.

OBJECTIVE: To examine the newly established role of a primary contact physiotherapist in an ENT clinic, in an Australian cohort and context, over two phases of development. METHODS: A retrospective cohort study was conducted with data collected from a medical record audit. Over the study duration, the primary contact physiotherapist completed initial appointments with patients; follow-up appointments were subsequently conducted by medical staff. RESULTS: There was a 46 per cent reduction in patients with suggested vestibulopathy requiring an ENT medical review. This reduction could hypothetically increase to 71 per cent with follow-up primary contact physiotherapist appointments. Improvements in the service delivery model and a primary contact physiotherapist arranging diagnostic assessments could improve waitlist times and facilitate better utilisation of medical staff time. CONCLUSION: The primary contact physiotherapist can help in the management of patients with suspected vestibulopathy on an ENT waitlist. This is achieved through: a reduction of patients requiring ENT review, improvements to waitlist time and improved utilisation of medical specialists' time.

Novel ENT live telehealth and live video-otoscopy clinics in remote Australia: outcomes and comparisons to traditional clinic models.

BACKGROUND: Coronavirus disease 2019 challenged the delivery of healthcare in Australia, disproportionately impacting vulnerable patients, including Aboriginal and/or Torres Strait Islander peoples and those living in remote regions. The otolaryngology service provided to remote Western Australia adapted to these barriers by altering clinical consultations to a digital model. METHODS: A review was undertaken of patients in regional Western Australia. Demographics and clinical outcomes from 20 live telehealth clinics were retrospectively reviewed and compared to 16 face-to-face clinics. RESULTS: The demographics of patients reviewed in both live telehealth and face-to-face clinics were similar, except for a larger proportion of Aboriginal and/or Torres Strait Islander patients utilising telehealth. The outcomes of patients reviewed through each model of care were comparable. Live video-otoscopy provided diagnostic quality images in 92 per cent of cases. CONCLUSION: The findings of our review suggest that, despite its limitations, a large proportion of ENT patients may be safely assessed through a live telehealth model.

Long-Term Cochlear Implant Sound Processor Usage in Children with Single-Sided Deafness.

OBJECTIVE: To assess cochlear implant (CI) sound processor usage over time in children with single-sided deafness (SSD) and identify factors influencing device use. STUDY DESIGN: Retrospective, chart review study. SETTING: Pediatric tertiary referral center. PATIENTS: Children with SSD who received CI between 2014 and 2020. OUTCOME MEASURE: Primary outcome was average daily CI sound processor usage over follow-up. RESULTS: Fifteen children with SSD who underwent CI surgery were categorized based on age of diagnosis and surgery timing. Over an average of 4.3-year follow-up, patients averaged 4.6 hours/day of CI usage. Declining usage trends were noted over time, with the first 2 years postactivation showing higher rates. No significant usage differences emerged based on age, surgery timing, or hearing loss etiology. CONCLUSIONS: Long-term usage decline necessitates further research into barriers and enablers for continued CI use in pediatric SSD cases.

Early Experience with a Novel Treatment for Menière's Disease: A Long Acting Dexamethasone Formulation for Precise Delivery to the Round Window Membrane.

OBJECTIVE: To investigate the safety and feasibility of precise delivery of a long-acting gel formulation containing 6% dexamethasone (SPT-2101) to the round window membrane for the treatment of Menière's disease. STUDY DESIGN: Prospective, unblinded, cohort study. SETTING: Tertiary care neurotology clinic. PATIENTS: Adults 18 to 85 years with a diagnosis of unilateral definite Menière's disease per Barany society criteria. INTERVENTIONS: A single injection of a long-acting gel formulation under direct visualization into the round window niche. MAIN OUTCOME MEASURES: Procedure success rate, adverse events, and vertigo control. Vertigo control was measured with definitive vertigo days (DVDs), defined as any day with a vertigo attack lasting 20 minutes or longer. RESULTS: Ten subjects with unilateral Menière's disease were enrolled. Precise placement of SPT-2101 at the round window was achieved in all subjects with in-office microendoscopy. Adverse events included one tympanic membrane perforation, which healed spontaneously after the study, and two instances of otitis media, which resolved with antibiotics. The average number of DVDs was 7.6 during the baseline month, decreasing to 3.3 by month 1, 3.7 by month 2, and 1.9 by month 3. Seventy percent of subjects had zero DVDs during the third month after treatment. CONCLUSIONS: SPT-2101 delivery to the round window is safe and feasible, and controlled trials are warranted to formally assess efficacy.

A hospital-based asynchronous ENT telehealth service for children with otitis media: Cost-minimisation and improved access.

AIM: The purpose of this study is to explore the effectiveness of a hospital-based asynchronous ear, nose, and throat (ENT) telehealth service (the Ear Portal) in reducing cost and improving access for children with otitis media. METHODS: Participants were recruited to the Ear Portal from a tertiary hospital ENT waiting list. Ear and hearing assessments were conducted during appointments by the Ear Portal research assistant, and data was stored for an asynchronous review by the Ear Portal multidisciplinary team. A cost-minimisation analysis was conducted for the Ear Portal and the standard care pathways. Waiting times to provide care for both pathways were calculated for children with semi-urgent (i.e. Category 2) and non-urgent (i.e. Category 3) referrals. RESULTS: The running cost for the Ear Portal was $67.70 for initial appointments and $37.34 for follow-up appointments. Conversely, the running cost for the standard care pathway was $154.65 for initial appointments and $86.10 for follow-up appointments. A total of 223 appointments were required to offset the initial Ear Portal investment of $19,384.00. The median waiting time for the Ear Portal from initial contact to care plan delivery was <30 days, whereas the median waiting times for children in the standard care pathway were 291 days (interquartile range (IQR) = 117) for Category 2 and 371 days (IQR = 311) for Category 3 referrals. CONCLUSION: Under the current circumstances, the Ear Portal service can reduce costs for the health care system by reducing marginal costs per patient in addition to providing ENT specialist care within the clinically recommended timeframes.

The effects of insertion speed on inner ear function during cochlear implantation: a comparison study.

OBJECTIVE: To investigate the insertion speed and its impact on electrode insertion characteristics, hearing preservation and clinical vestibular function in a prospective cohort study with a retrospective control group at a tertiary otology/neurotology centre. INTERVENTIONS: Hearing-preserving cochlear implantation using systemic and topical steroids in conjunction with a round-window approach, a complete cochlear coverage electrode and two different electrode insertion speeds [60 mm/min (n = 18) vs. 15 mm/min (n = 22)] was performed. RESULTS: The insertion speed had a significant impact on various insertion characteristics as well as hearing preservation and vestibular function. In conclusion, a slow electrode insertion speed appears to facilitate full electrode insertion, reduce the occurrence of insertion resistance as well as promote preservation of residual hearing and vestibular function after cochlear implantation.

Middle Ear Osteoma With Assimilation of Ossicles: An Unusual Case of Conductive Hearing Loss.

We present a case report of a middle ear osteoma presenting as gradual unilateral conductive hearing loss in a healthy 32-year-old lady. The decision for treatment was influenced by the relatively small burden of the disease, and the size and location of the osteoma, which made the decision for surgical excision prohibitively difficult. Taking patient wishes and circumstances into account, the decision was made for a bone conduction hearing implant in conjunction with close follow-up.

Results of a Novel, Nonsurgical Bone-Conduction Hearing Aid for the Treatment of Conductive Hearing Loss in Australian Children.

OBJECTIVE: To determine and compare the benefits a novel adhesive bone-conduction system and a conventional bone-conduction hearing aid (BCHA) on a softband for children with conductive hearing loss. STUDY DESIGN: Prospective, single-subject randomized, crossover trial. SETTING: Tertiary referral center in Australia. PARTICIPANTS: Eight children aged from 4 to 17 years with conductive hearing loss. INTERVENTION: Rehabilitative with participants using the novel adhesive bone-conduction aid and a BCHA. MAIN OUTCOME MEASURES: Aided thresholds, as well as speech perception in quiet, unaided and aided with the novel adhesive bone-conduction aid and BCHA on a softband. For the six older children, speech in noise testing was also conducted. RESULTS: The mean unaided four frequency average hearing levels was 48 dB HL for air conduction, 10.5 dB HL for bone conduction, with a mean air-bone gap in the aided ear of 37.5 dB HL.Four-frequency average hearing level aided thresholds were 20.2 dB for the novel device and 19.8 dB for the BCHA, with no significant difference between the devices. Aided monosyllabic word scores improved from an average of 45% in the unaided condition to 81.6 and 85% for the novel adhesive and BCHA devices, respectively. Aided speech in noise performance improved, on average, by 1.6 dB SNR when wearing the BCHA and the novel adhesive device, with no significant difference in performance between the two devices. CONCLUSIONS: The novel device provided equivalent performance to the BCHA on all measures and can be considered as an alternative device for pediatric patients with conductive hearing loss.

Decision making in bone conduction and active middle ear implants - hearing outcomes and experiences over a 10-year period.

OBJECTIVES: To review the decision-making paradigm in the recommendations of BCI and aMEI overlapping candidacy for patients with conductive or mixed HL, and to determine if there are differences in hearing and quality of life outcomes between these implantable hearing devices. METHODS: Retrospective data from patients receiving BCI or aMEI in the past decade were analysed. Patients were grouped into: 1. BCI candidates, 2. BCI or aMEI candidates, and 3. aMEI candidates. We compared outcomes and examined the impact of BC threshold, age at implantation, and duration of hearing loss on candidacy. RESULTS: 89 participants were included: 30 BCI, 37 aMEI, and 22 BCI or aMEI candidates. All groups performed similarly in aided sound field threshold testing. BCI group had lower speech scores in quiet compared to 'BCI or aMEI.' No significant differences were found in APHAB global scores. BC threshold, duration of hearing loss, and age at implantation had no significant effects. DISCUSSION: Outcomes were generally similar across groups, except for higher effective gain in the aMEI group. CONCLUSION: Our proposed patient pathway and decision-making approach facilitate candidate selection for aMEI and BCI, aiming to optimise outcomes.

Evaluation of the Performance of OTOPLAN-Based Cochlear Implant Electrode Array Selection: A Retrospective Study.

Otoplan is a surgical planning software designed to assist with cochlear implant surgery. One of its outputs is a recommendation of electrode array type based on imaging parameters. In this retrospective study, we evaluated the differences in auditory outcomes between patients who were implanted with arrays corresponding to those recommended by the Otoplan software versus those in which the array selection differed from the Otoplan recommendation. Pre-operative CT images from 114 patients were imported into the software, and array recommendations were generated. These were compared to the arrays which had actually been implanted during surgery, both in terms of array type and length. As recommended, 47% of patients received the same array, 34% received a shorter array, and 18% received a longer array. For reasons relating to structure and hearing preservation, 83% received the more flexible arrays. Those who received stiffer arrays had cochlear malformations or ossification. A negative, although non-statistically significant correlation was observed between the CNC scores at 12 months and the absolute value of the difference between recommended array and implanted array. In conclusion, clinicians may be slightly biased toward shorter electrode arrays due to their perceived greater ability to achieve full insertion. Using 3D imaging during the pre-operative planning may improve clinicians' confidence to implant longer electrode arrays, where appropriate, to achieve optimum hearing outcomes.

Using x-ray micro computed tomography to quantify intracochlear fibrosis after cochlear implantation in a Guinea pig model.

Cochlear implants (CIs) allow individuals with profound hearing loss to understand speech and perceive sounds. However, not all patients obtain the full benefits that CIs can provide and the cause of this disparity is not fully understood. One possible factor for the variability in outcomes after cochlear implantation, is the development of fibrotic scar tissue around the implanted electrode. It has been hypothesised that limiting the extent of fibrosis after implantation may improve overall CI function, and longevity of the device. Currently, histology is often used to quantify the extent of intracochlear tissue growth after implantation however this method is labour intensive, time-consuming, often involves significant user bias, and causes physical distortion of the fibrosis. Therefore, this study aimed to evaluate x-ray micro computed tomography (µCT) as a method to measure the amount and distribution of fibrosis in a guinea pig model of cochlear implantation. Adult guinea pigs were implanted with an inactive electrode, and cochleae harvested eight weeks later (n = 7) and analysed using µCT, to quantify the extent of tissue reaction, followed by histological analysis to confirm that the tissue was indeed fibrotic. Cochleae harvested from an additional six animals following implantation were analysed by µCT, before and after contrast staining with osmium tetroxide (OsO4), to enhance the visualisation of soft tissues within the cochlea, including the tissue reaction. Independent analysis by two observers showed that the quantification method was robust and provided additional information on the distribution of the response within the cochlea. Histological analysis revealed that µCT visualised dense collagenous material and new bone formation but did not capture loose, areolar fibrotic tissue. Treatment with OsO4 significantly enhanced the visible tissue reaction detected using µCT. Overall, µCT is an alternative and reliable method that can be used to quantify the extent of the CI-induced intracochlear tissue response and will be a useful tool for the in vivo assessment of novel anti-fibrotic treatments.