Cochlear implant complications in 403 patients: Comparative study of adults and children and review of the literature

Neurosensory Prosthetics: An Integral Neuromodulation Part of Bioelectronic Device

Bioelectronic medicines (BEMs) constitute a branch of bioelectronic devices (BEDs), which are a class of therapeutics that combine neuroscience with molecular biology, immunology, and engineering technologies. Thus, BEMs are the culmination of thought processes of scientists of varied fields and herald a new era in the treatment of chronic diseases. BEMs work on the principle of neuromodulation of nerve stimulation. Examples of BEMs based on neuromodulation are those that modify neural circuits through deep brain stimulation, vagal nerve stimulation, spinal nerve stimulation, and retinal and auditory implants. BEDs may also serve as diagnostic tools by mimicking human sensory systems. Two examples of in vitro BEDs used as diagnostic agents in biomedical applications based on in vivo neurosensory circuits are the bioelectronic nose and bioelectronic tongue. The review discusses the ever-growing application of BEDs to a wide variety of health conditions and practices to improve the quality of life.

Cost-Effectiveness of Screening Preschool Children for Hearing Loss in Australia

OBJECTIVES

While all newborns in Australia are tested for congenital hearing loss through universal newborn hearing screening programs, some children will acquire hearing loss in their first five years of life. Delayed diagnosed or undiagnosed hearing loss in children can have substantial immediate- and long-term consequences. It can significantly reduce school readiness, language and communication development, social and emotional development, and mental health. It can also compromise lifetime educational achievements and employment opportunities and future economic contribution to society through lost productivity. The need for a universal hearing screening program for children entering their first year of primary school has been noted in two separate Australian Government hearing inquiries in the last decade. Sound Scouts is a hearing screening application (app) that tests for hearing loss in children using a tablet or mobile device, supervised by parents at home. It tests for sensorineural or permanent conductive hearing loss and central auditory processing disorder in children. In 2018 the Australian Government funded the roll-out of Sound Scouts to allow up to 600,000 children to test their hearing using Sound Scouts. This study estimated the cost-effectiveness of screening 5-year-old children for hearing loss using Sound Scouts at home, compared with no screening.

DESIGN

A decision-analytic model was developed to estimate the incremental costs and quality-adjusted life years (QALYs) of administering Sound Scouts over a 20-year time horizon. Testing accuracy was based on comparing Sound Scouts test results to clinical test results while other parameters were based on published data. Costs were estimated from the perspective of the Australian health care system. Univariate and probabilistic sensitivity analyses were undertaken.

RESULTS

Sound Scouts is estimated to result in an average incremental cost of A$61.02 and an average incremental increase in QALYs of 0.01. This resulted in an incremental cost-effectiveness ratio of A$5392 per QALY gained, which is likely to be considered cost-effective by Australian decision makers. Screening with Sound Scouts was found to have a 96.2 per cent probability of being cost-effective using a threshold of A$60,000 per QALY gained.

CONCLUSIONS

Using Sound Scouts to screen five-year-old children for hearing loss (at home) is likely to be cost-effective. Screening children using Sound Scouts will result in early identification and intervention in childhood hearing loss, thereby reducing early childhood disadvantage through cumulative gains in quality of life, education, and economic outcomes over their lifetime.

Does Frailty or Age Increase the Risk of Postoperative Complications Following Cochlear Implantation?

Objective

To evaluate whether frailty or age increases the risk of postoperative complications following cochlear implant (CI) surgery.

Study Design

Retrospective cohort study.

Setting

Tertiary academic center.

Methods

An evaluation of all adult patients undergoing cochlear implantation between 2006 and 2020 was performed. The 5-item Modified Frailty Index (mFI-5, comprising preoperative history of pulmonary disease, heart failure, hypertension, diabetes, and partially/totally dependent functional status) was calculated for all patients included in analysis in addition to demographic characteristics. The primary outcome was postoperative complications following CI within a 3-month period. Major complications included myocardial infarction, bleeding, and cerebrospinal fluid leak, among others. Predictors of postoperative complications were examined using multivariable logistic regression reporting odds ratios (ORs) and 95% CIs.

Results

There were 520 patients included for review with a median age of 68 (range, 18-94) years and a slight male predominance (n = 283, 54.4%). There were 340 patients (65.4%) who were robust (nonfrail) with an mFI of 0, while 180 (34.6%) had an mFI of ≥1. There were 20 patients who experienced a postoperative complication (3.85%). There was no statistically significant association between postoperative complications as a result of preoperative frailty (OR, 1.56; 95% CI, 0.98-2.48, P = .06) or age as a continuous variable (OR, 0.99; 95% CI, 0.97-1.02, P = .51).

Conclusions

CI is safe for elderly and frail patients and carries no additional risk of complications when compared to younger, healthier patients. While medical comorbidities should always be considered perioperatively, this study supports the notion that implantation is low risk in older, frail patients.

Cochlear implantation in patients with Meniere's disease: A systematic review

BACKGROUND

Meniere's disease (MD) is an idiopathic disorder of the inner ear, which manifests as cochleo-vestibular dysfunction. Hearing loss will progress to a profound levelin a subset of patients with MD, and vestibular interventions can independently cause loss of hearing. The aim of this study was to systematically review the published literature describing the safety and efficacy of CI in patients with MD.

MATERIALS AND METHODS

A systematic literature review was conducted in accordance PRISMA guidelines to identify articles that assessed at least one functional outcome in patients with MD who underwent CI. Demographic information, disease history, MD symptoms, outcomes measures, and complications related to CI were extracted from included studies.

RESULTS

In total, 17 studies were included, and 182 patients with MD underwent CI. The weighted-mean age was 61.9 years (range 27-85). Study objective and methodology varied, and there was significant heterogeneity in CI outcome measures reported. In total, 179 (98.3%) of 182 patients reported objective improvements in at least one hearing metric after CI. A total of 69 patients (37.9%) reported vertigo or severe dizziness prior to CI, compared to 22 patients (15.4%) postoperatively. Two studies reported significant reductions in postoperative Tinnitus Handicap Inventory score (THI). Quality of life assessments varied between studies. Complications rates were low with only nine patients (4.9%) reporting a serious CI-related complication.

CONCLUSIONS

This systematic review evaluated 17 studies describing the safety and efficacy of CI in patients with MD and encountered many challenges due to small sample sizes, and heterogeneity in study design and outcomes measured. Despite these limitations, this study of 182 patients is to the best of our knowledge the largest systematic review evaluating the safety and efficacy of CI in MD. The results of this study support the need for a standardized approach to evaluating outcomes of CI in patients with MD in future studies.

Cochlear Implant Failure in the Pediatric Population

BACKGROUND AND OBJECTIVES

In cochlear implant (CI) surgery, the results and causes of revision and reimplantation may guide surgeons in establishing surgical protocols for revision surgery with safe audiological outcomes. The aim of this study was to review our experience in terms of etiology, surgical strategy, and hearing outcomes in pediatric patients who underwent CI removal and reimplantation.

SUBJECTS AND PURPOSE

All patients received implants of the same brand. Pre and postoperative Categories of Auditory Performance score and aided free-field pure tone audiometry thresholds were noted. In vivo integrity tests were performed for each patient and the results of ex vivo tests of each implant were obtained from manufacturer.

RESULTS

A total of 149 CIs were placed in 121 patients aged <18 years. The revision rate in children was 6.7% (10/121 children). Six patients had a history of head injury leading to a hard failure. The causes of reimplantation in others were soft failure (n=1), electrode migration (n=1), infection (n=1), and other (n=1). All patients showed better or similar postreimplantation audiological performance compared with pre-reimplantation results.

CONCLUSIONS

It is very important to provide a safe school and home environment and educate the family for reducing reimplantation due to trauma. Especially for active children, psychiatric consultation should be continued postoperatively.

Reimplantation of an Extruding Cochlear Implant

Cochlear implants have successfully improved hearing in severe and profoundly deaf patients in addition to improving their quality of life. Implant extrusion and wound infection of a cochlear implant are one of the most common postoperative complications, although it does not occur frequently (1.5%-5% of cases).^1,2 We present a case of an extruding cochlear implant with dehiscence that was successfully reimplanted, a procedure of which there have been few previous reports in the literature.

Traumatic Cochlear Implant Electrode Extrusion: Considerations, Management, and Outcome

Cochlear implantation is the mainstay for patients with severe to profound hearing loss that do not benefit from hearing aids. Falls and head trauma can cause direct damage to the implant, of which hard failure is the most common complication. Traumatic electrode migration is an uncommon occurrence. Our patient underwent successful electrode advancement of a partially migrated, normal functioning electrode two months after head injury. We discuss the factors influencing the decision-making process, progress, and outcomes.

Wideband Acoustic Immittance in Cochlear Implant Recipients: Reflectance and Stapedial Reflexes

OBJECTIVES

to characterize differences in wideband power reflectance for ears with and without cochlear implants (CIs), to describe electrically evoked stapedial reflex (eSR)-induced changes in reflectance, and to evaluate the benefit of a broadband probe for reflex threshold determination for CI recipients. It was hypothesized that reflectance patterns in ears with CIs would be consistent with increased middle ear stiffness and that reflex thresholds measured with a broadband probe would be lower compared with thresholds obtained with a single-frequency probe.

DESIGN

Eleven CI recipients participated in both wideband reflectance and eSR testing. Ipsilateral reflexes were measured with three probes: a broadband chirp (swept from 200 to 8000 Hz), a 226 Hz tone, and a 678 Hz tone. Wideband reflectance measures acquired from 28 adults without CIs and with normal middle ear function served as a normative data set for comparison.

RESULTS

Considering the group data, average reflectance was significantly greater for ears with CIs across 250 to 891 Hz and 4238 to 4490 Hz compared with the normative data set, although individual reflectance curves were variable. Some CI recipients also had low 226 Hz admittance, which contributed to the group finding, considering the control group had clinically normal 226 Hz admittance by design. Electrically evoked stapedial reflexes were measurable in nine of 14 ears (64.3%) and in 24 of 46 electrodes (52.5%) tested. Reflex-induced changes in reflectance patterns were unique to the participant/ear, but similar across activators (electrodes) within a given ear. In addition, reflectance values at or above 1000 Hz were affected most by activating the stapedial reflex, even in ears with clinically normal 226 Hz admittance. This is a higher-frequency range than has been reported for acoustically evoked reflex-induced reflectance changes and is consistent with increased middle ear stiffness at rest. Electrically evoked reflexes could be measured more often with the 678 Hz or the broadband probe compared with the 226 Hz probe tone. Although reflex thresholds were lower with the broadband probe compared with the 678 Hz probe in 16 of 24 conditions, this was not a statistically significant finding (Wilcoxon signed-rank test; p = 0.072).

CONCLUSIONS

The applications of wideband acoustic immittance measurements (reflectance and reflexes) should also be considered for ears with CIs. Further work is needed to describe changes across time in ears with CIs to more fully understand the reflectance pattern indicating increased middle ear stiffness and to optimize measuring eSRs with a broadband probe.

Prevalence of Surgical, Anesthetic, and Device-related Complications Among Infants Implanted Before 9 and 12 Months of Age Versus Older Children: Evidence for the Continued Expansion of Pediatric Cochlear Implant Candidacy Criteria

OBJECTIVE

To compare the prevalence of surgical, anesthetic, and device-related complications among infants and older children receiving cochlear implantation (CI).

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary academic referral center.

PATIENTS

Pediatric patients who underwent CI from November 1990 to January 2020.

INTERVENTION

CI.

MAIN OUTCOME MEASURES

Surgical, anesthetic, and device-related complication rates were compared by age group (<12 versus 12-23 versus 24+ months with subset analysis of <9 versus 9-11 months).

RESULTS

A total of 406 primary pediatric CI surgeries encompassing 482 ears were analyzed, including 45 ears in 23 patients implanted less than 9 months and 89 ears in 49 patients less than 12 months. No anesthetic complications occurred. Postoperative surgical and device-related complication rates were not significantly different among the less than 12, 12 to 23, and 24+ month groups (16% versus 16% versus 12%; p = 0.23) or between the less than 9 and 9 to 11 month groups (22% versus 9%; p = 0.09). Thirty-day readmission was significantly higher for patients less than 12 months compared with patients 24+ months (6% versus <1%; p = 0.011), but was not significantly higher compared with patients 12 to 23 months (6% versus 3%; p = 0.65). Reoperation rates did not differ significantly among the less than 12, 12 to 23, and 24+ month groups (10% versus 7% versus 6%; p = 0.31).

CONCLUSIONS

The prevalence of surgical, anesthetic, and device related complications was not significantly different among infants implanted less than 9 or less than 12 months of age when compared with older children. These data provide evidence for the continued expansion of pediatric cochlear implant candidacy criteria to include appropriately selected infants less than 9 months of age.

Mastoid pressure dressing - Current practice amongst Canadian pediatric cochlear implant surgeons

OBJECTIVES

Mastoid pressure dressing (MPD) has routinely been used following major ear surgery, such as cochlear implant (CI) surgery, to prevent postoperative wound complications. To date, controlled studies have suggested no difference in the incidence of wound complications following MPD use. However, there is a variation in the practice of MPD usage across pediatric CI surgeons. In this study, we aimed to identify the most common type of postoperative dressing management after pediatric cochlear implantation and the factors in the decision-making process for post-surgical care amongst Canadian pediatric CI surgeons.

METHODS

Canadian Otolaryngologists who perform pediatric CI surgery were identified (n = 18) and contacted via email to complete a short online questionnaire regarding current post-operative head dressing practice following CI surgery. Descriptive statistics were used to analyze the response data.

RESULTS

The participants provided an approximate number of CI's they performed in 2016. 100% of the recipients completed the survey. Approximately 376 CI's were completed in 2016 with an average of 21 CI's per surgeon. 61% of participants routinely used MPDs following surgery justified by reasons such as wound protection, institutional standard of care, and physician's original training practice.

CONCLUSION

There is no clear consensus on the use of MPDs amongst Canadian pediatric CI surgeons. Since the current evidence in the literature suggests no difference in wound complication incidence post-surgery with MPD use, a change in postoperative dressing management to non-use in those that employ this practice may be justified. Eliminating the usage of a MPD may also have potential economic benefits. Further prospective controlled studies may be warranted.

Risk Factors for Facial Nerve and Other Nonauditory Side Effects Following Cochlear Implantation

OBJECTIVE

The purpose of this study was to characterize a cohort of patients with nonauditory side-effects (NASx) following cochlear implant (CI) surgery.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

One hundred twenty three multichannel CI recipients with intraoperative facial nerve stimulation (FNS).

INTERVENTIONS

Intraoperative electrical auditory brainstem responses (eABR) during CI surgery.

MAIN OUTCOME MEASURES

Nonauditory side effects post-CI activation.

RESULTS

Intraoperative FNS was identified in 2.26% of patients (123/5441), of whom, 34% (42/123) experienced VII stimulation on CI activation. Pain was experienced by 22% (27/123) and vestibular dysfunction was experienced by 4% (5/123) of cases. All case who experienced pain and/or vestibular NASx also experienced VII stimulation. The majority of cases were managed by CI remapping or observation and habituation.Significant relationships were found between etiology of hearing loss and presence of FNS upon initial activation (p < 0.05). No significance was found between FNS intraoperatively and at initial activation for all assumed mechanisms of hearing loss (p > 0.05) with the exceptions of acquired hearing loss of undetermined etiology and toxic etiology group (p < 0.05).There was no significant impact of implant array design (p > 0.05).

CONCLUSIONS

This study has characterized patients with NASx in a large cohort of CI patients. One third of cases identified with FNS intraoperatively, developed NASx post-CI activation. Risk factors for NASx postactivation include high-risk etiologies and intraoperative objective measures (i.e., eABR). This may assist surgeons and audiologists to identify at-risk patients who may need modifications in CI program planning.

Failure and Revision Surgery After Cochlear Implantation in the Adult Population: A 10-year Single-institution Retrospective and Systematic Review of the Literature

OBJECTIVE

To characterize failure rate and etiology after cochlear implantation; to identify predictors and describe outcomes after implant failure.

STUDY DESIGN

Retrospective chart review and systematic review of the literature using PubMed and Embase.

SETTING

Academic Cochlear Implant Center.

SUBJECT POPULATION

Four hundred ninety-eight devices in 439 distinct adult patients.

INTERVENTIONS

Unilateral or bilateral cochlear implantation.

MAIN OUTCOME MEASURES

Implant failure rate and etiology.

RESULTS

A total of 32 devices (5.9%) failed in 31 patients encompassing the following failure types in accordance with the European Consensus Statement of Cochlear Implants: 17 device failures (53.1%), 11 failures due to performance decrement/adverse reactions (34.4%), and 4 medical reasons (12.9%). There was no significant difference in age, sex, or manufacturer between patients with and without failures. Twenty-five percent of patients with failure leading to explantation had childhood onset of deafness compared to 12.1% of patients with adult-onset hearing loss (OR = 2.42; p = 0.04). Performance decrement/adverse reaction patients had an older average age at implantation compared to device failure patients (mean 68.5 yr 95% CI: 59.9-77.1 vs mean 47.6 yr, CI: 39.9-55.3, p < 0.01). There was no significant difference in time to failure, sex, or device manufacturer between the different types of failures. Twenty-nine patients who experienced CI failure underwent a revision surgery, while the remaining two opted for explantation without reimplantation. One patient who underwent revision surgery subsequently presented with a second failure and underwent a second revision, which was successful.In our systematic review, 815 citations were reviewed, and 9 studies were selected for inclusion. Overall failure rate across all studies was 5.5%. Device failure was the leading cause of failure in the majority (6/9) of studies, accounting for 40.8% of all failures. Medical reasons were the second leading cause at 33.6%, followed by performance decrement/adverse reaction (20.9%) and other (4.8%).

CONCLUSIONS

Cochlear implant failure is a rare phenomenon. Childhood-onset of hearing loss appears to be associated with an increased risk of overall failure. Older patients are at increased risk for performance decrement/adverse reaction. Revision surgery success rates remain very high and patients with failure of any cause should be offered explantation with concurrent reimplantation.

Pain After Cochlear Implantation Without Signs of Inflammation: A Systematic Review

OBJECTIVES

This review summarizes current evidence on causes and management strategies for delayed pain post-cochlear implantation (CI) surgery, without clinical evidence of inflammation or infection.

METHODS

The systematic review was undertaken in line with Preferred Reporting Items for Systematic review and Meta-Analysis Protocols 2015 guidelines. A literature search was undertaken, with inclusion of patients who underwent CI and presented with delayed pain (>3 months post-operatively) around their device site without an identifiable cause. Analysis was undertaken using MATLAB (MathWorks, Natick, MA) and the R-software package (www.r-project.org).

RESULTS

4 articles (48 patients), all retrospective case series, met inclusion criteria. The mean onset of pain post-CI was 60 months and mean follow-up was 15.8 months, there was no difference in the prevalence of pain between device brands (p=0.13). The majority (90%) did not have any hearing deterioration, and investigations did not reveal a cause for the pain in any of the patients. In terms of management, medical therapies, including oral therapy (analgesia, non-steroidal anti-inflammatories, antibiotics) and local treatments (topical, injections) resolved pain in 41% and 63%, respectively. Surgical intervention (explantation, magnet replacement, tympanic neurectomy), where undertaken, resolved pain in 100%. A minority had an identifiable infective microorganism cultured from intra-operative soft tissue or biofilm samples.

CONCLUSIONS

Evidence for the causes and management of delayed pain post-CI without clinical evidence of inflammation is scarce. A stepwise approach is deemed best, with decisions being made on an individual basis, evaluating each patient's specific circumstances and priorities. Further evaluation of explanted devices would allow for better understanding of the causes and treatment of this group of patients.

Minimally Invasive Cochlear Implantation Assisted by Intraoperative CT Scan Combined to Neuronavigation

OBJECTIVE

The objective of this work was to study the feasibility of minimally invasive cochlear implantation under intraoperative computerized tomography-scan coupled to navigation.

MATERIALS AND METHODS

Five human resin temporal bones (two adults and three children) were used. Initially, a temporal bone imaging was obtained by the intraoperative CT-scan coupled to the navigation (O-ARM). The navigation-assisted drilling began at the mastoid surface creating a conical tunnel (4-2 mm in diameter) through the facial recess and down to the round window. A cochleostomy was performed based on the navigation. A sham electrode array was inserted in the drilled tunnel and into the cochlea.Postoperative CT-scan and dissection were performed to evaluate the trajectory, and possible injury to the external auditory canal, ossicles, or facial nerve.

RESULTS

The mean duration of the procedure was 24.4 ± 3.79 minutes (range, 15-35). Cochleostomy was possible in all cases without injury to other structures. The sham array was inside the cochlea in all cases. The mean distance between the drilled canal and the mastoid portion of the facial nerve was 1.2 ± 0.07 mm (range, 1.08-1.38). The mean tracking error was 0.6 ± 0.26 mm (range, 0.20-0.72) at the entry point, 0.6 ± 0.33 mm (range, 0.2-1.02) at the facial nerve and 0.4 ± 0.07 mm (range, 0.36-0.51) at the cochleostomy.

CONCLUSION

Cochlear implantation through a minimally invasive approach assisted by intraoperative imaging combined with navigation was feasible in operating room environment and experimental conditions.

Management of Severe Cochlear Implant Infections-35 Years Clinical Experience

OBJECTIVE

Infectious complications occurring in cochlear implant (CI) recipients is of potentially major impact. A better understanding of severe infections in this cohort is necessary.

DESIGN

Single-center, retrospective cohort study. Level of Evidence 2B.

SETTING

Single-center, retrospective cohort study at a tertiary referral hospital.

PARTICIPANTS AND INTERVENTIONS

We included all patients who received a CI at our institution between 1983 and end of 2018 (4,622 implantations).

MAIN OUTCOMES

Prevalence, incidence, risk factors, and functional outcomes in severe implant infections.

RESULTS

There was an overall prevalence of 0.65% of severe CI infections. The cumulative incidence decreased after the year 2000, with lower infection rates with newer implant models. Patients with local risk factors were more susceptible to implant infection. In most patients, delayed re-implantation was successful. Speech-perception after re-implantation was comparable to pre-revision performance.

CONCLUSIONS

Modified implant design and improved surgical technique has led to a decrease in the prevalence and incidence of infected implants. In severe implant infections, active surgical and antimicrobial management is required, to achieve good long-term results.

The cost-effectiveness of Cochlear implants in Swedish adults

BACKGROUND

Research has shown unilateral cochlear implants (CIs) significantly improve clinical outcomes and quality of life in adults. However, only 13% of eligible Swedish adults currently use a unilateral CI. The objective was to estimate the cost-effectiveness of unilateral CIs compared to a hearing aid for Swedish adults with severe to profound hearing loss.

METHODS

A Markov model with a lifetime horizon and six-month cycle length was developed to estimate the benefits and costs of unilateral CIs from the Swedish health system perspective. A treatment pathway was developed through consultation with clinical experts to estimate resource use and costs. Unit costs were derived from the Swedish National Board of Health and Welfare and the Swedish Association of Local Authorities and Regions. Health outcomes were reported in terms of Quality Adjusted Life Years (QALYs).

RESULTS

Unilateral CIs for Swedish adults with severe to profound hearing loss are likely to be deemed cost-effective when compared to a hearing aid (SEK 140,474 per QALY gained). The results were most sensitive to the age when patients are implanted with a CI and the proportion of patients eligible for CIs after triage.

CONCLUSIONS

An increase in the prevalence of Swedish adults with severe to profound hearing loss is expected as the population ages. Earlier implantation of unilateral CIs improves the cost-effectiveness among people eligible for CIs. Unilateral CIs are an efficacious and cost-effective option to improve hearing and quality of life in Swedish adults with severe to profound hearing loss.

Vestibular Organ and Cochlear Implantation-A Synchrotron and Micro-CT Study

Background: Reports vary on the incidence of vestibular dysfunction and dizziness in patients following cochlear implantation (CI). Disequilibrium may be caused by surgery at the cochlear base, leading to functional disturbances of the vestibular receptors and endolymphatic duct system (EDS) which are located nearby. Here, we analyzed the three-dimensional (3D) anatomy of this region, aiming to optimize surgical approaches to limit damage to the vestibular organ. Material and Methods: A total of 22 fresh-frozen human temporal bones underwent synchrotron radiation phase-contrast imaging (SR-PCI). One temporal bone underwent micro-computed tomography (micro-CT) after fixation and staining with Lugol's iodine solution (I2KI) to increase tissue contrast. We used volume-rendering software to create 3D reconstructions and tissue segmentation that allowed precise assessment of anatomical relationships and topography. Macerated human ears belonging to the Uppsala collection were also used. Drilling and insertion of CI electrodes was performed with metric analyses of different trajectories. Results and Conclusions: SR-PCI and micro-CT imaging demonstrated the complex 3D anatomy of the basal region of the human cochlea, vestibular apparatus, and EDS. Drilling of a cochleostomy may disturb vestibular organ function by injuring the endolymphatic space and disrupting fluid barriers. The saccule is at particular risk due to its proximity to the surgical area and may explain immediate and long-term post-operative vertigo. Round window insertion may be less traumatic to the inner ear, however it may affect the vestibular receptors.

One-stage cochlear implantation in patients with chronic otitis media using canal wall up mastoidectomy

BACKGROUND

Cochlear implantation (CI) with subtotal petrosectomy was recommended to avoid the complications for patients with chronic otitis media (COM).

OBJECTIVES

To evaluate the surgical outcomes of CI in patients with COM using a one-stage operation with canal wall up mastoidectomy (CWUM).

METHODS

Thirty-five patients with COM who underwent CI with CWUM as a one-stage between 2009 and 2017 were participated. They divided into those with inactive COM and active COM. The anatomical success rate, postoperative complication, and hearing outcomes were analyzed.

RESULTS

Twenty-four patients had inactive COM and seven with active COM. Three of the 31 patients (9.7%) had otorrhea from the ear undergone surgery. Two of these three patients had myringitis after CI and their symptoms improved after conservative management. Although infection of the tympanic membrane in the third patient was controlled after conservative management, a perforation was left. Postoperative otorrhea occurred in two patients (8.3%) in the inactive COM group and one patient (14.3%) in the active COM group.

CONCLUSION

This study indicates that infection control and successful implantation can be achieved through a one-stage CI operation with CWUM in selected patients with COM.HIGHLIGHTSAlthough COM was once considered a contraindication to CI, CI in patients with COM has been made feasible by STP before CI or simultaneously with CI.Simultaneous CI with CWUM was performed for 31 patients with COM.Three patients (9.7%) had minor complications after the surgery and only one patient experienced device explantation which was due to device failure.

Cochlear Implantation in Chronic Otitis Media with and without Cholesteatoma: Surgical Considerations and Auditory Outcomes

INTRODUCTION

Cochlear implant (CI) surgery is a safe and standardized procedure in the presence of normal temporal bone anatomy. However, in the surgery of patients with chronic otitis media (COM), the surgeon may encounter several problems. The aim of this study was to evaluate the impact of COM with and without cholesteatoma on surgical and auditory outcomes of CIs.

METHODS

The study group consisted of 39 patients with COM who received CIs. Age- and gender-matched 38 standard CI patients served as controls. The surgical techniques and complications, pure tone audiometry (PTA) scores, speech discrimination scores (SDS), and the International Outcome Inventory for Hearing Aids (IOI-HA) questionnaire results of the groups were compared.

RESULTS

The presence of COM was associated with a higher rate of complication than controls. Staging the surgeries, presence or absence of cholesteatoma, and type of surgical technique were not associated with surgical outcomes and complications (p > 0.05). There was no significant difference between the groups in terms of postoperative PTA scores, SDS, and IOI-HA scores (p > 0.05).

CONCLUSION

Postoperative complications like device failure and skin breakdown are increased in cases of COM compared to standard CI surgeries. However, that increase is not associated with staging the surgeries, presence or absence of cholesteatoma, and type of ear surgery performed. It is advocated to close the external ear canal and eustachian tube without mastoid obliteration in the presence of a radical mastoidectomy cavity, which will decrease the postoperative complication rates and allow for radiological follow-up with computed tomography for the possibility of cholesteatoma recurrence. The auditory benefits of CI in patients with and without COM are comparable.

Delayed facial palsy after cochlear implantation caused by reactivation of Herpesvirus: A case report and review of the literature

Cochlear implantation has many complications; however, delayed facial palsy is relatively rare. In this report, we present the case of a 60-year-old woman with delayed facial palsy after cochlear implantation. Eleven days after the operation, the patient complained of right facial palsy (Yanagihara score 6, House-Brackmann [HB] grade VI). Herpes virus reactivation and local bacterial infection were considered as possible causes of the facial paralysis. A blood test revealed an increase in viral antibody titer, and the patient was diagnosed as having herpes virus reactivation. She was treated with antiviral therapy for the facial palsy until resolution. Slight mouth weakness continued even at 1.5 months (Yanagihara score 34, HB II) but eventually resolved at 3 months (Yanagihara score 40, HB I). Delayed facial palsy is a rare but serious complication that can occur with viral reactivation regardless of the competence of the surgical procedure. Therefore, it is important to inform patients preoperatively regarding the risk of not only immediate but also delayed postoperative facial paralysis.

Evaluating Reasons for Revision Surgery and Device Failure Rates in Patients Who Underwent Cochlear Implantation Surgery

Importance

Understanding the reasons for cochlear implant (CI) revision surgery and device failure rates is important for clinicians when counseling patients who are considering CI.

Objectives

To analyze the revision surgery rate, reasons for revision surgery, and device failure and survival rates of different device models in recipients of CIs.

Design, Setting, and Participants

In this cohort study, cochlear implants at Samsung Medical Center, a tertiary referral center, were retrospectively reviewed. Patients who underwent CI surgery from October 2001 to March 2019 were included. In the device survival analysis, the first revision surgery was considered the primary event, and the end point of observation was June 1, 2019.

Interventions

Therapeutic and rehabilitative CI surgery.

Main Outcomes and Measures

The revision surgery rate, reasons for revision surgery, and the failure and survival rates of different device models were analyzed. The Kaplan-Meier method and the log-rank test were used to present both the device survival and cumulative survival curves with rates.

Results

In this study, 43 of 925 patients with CIs (4.6%) underwent a revision surgery. Device failure was the most common reason (28 of 43 patients [65%]). Flap-associated problems and migration of the inner device were the next most important reasons (4 of 43 [9.3%] each). Overall, the 10-year cumulative survival rate of CI surgery was 94.4%, and the device survival rate was 96.0%. Thirteen different CI devices from 4 different manufacturers were implanted, and no meaningful differences in device failure were found among CI manufacturers or devices (hazard ratios for cumulative survival: Cochlear, 1.67 [95% CI, 0.72-3.88]; Advanced Bionics, 1.67 [95% CI, 0.61-4.53]; Med-El, reference; hazard ratios for device survival: Cochlear, 1.65 [95% CI, 0.55-4.99]; Advanced Bionics, 1.93 [95% CI, 0.56-6.74]; Med-El, reference). Several recalls were issued by manufacturers during the study period, and after excluding the recalled devices, the device survival rates for 5, 10, and 15 years were 98.2%, 97.7%, and 94.9%, respectively.

Conclusions and Relevance

Generally, implanted devices remain safe and stable for a long time, and no significant differences in survival rates were found between device types or manufacturers. Device failure was the main reason for CI revision, followed by flap-associated problems and migration of the inner device.

Retrospective study of cochlear implantations at a single facility focusing on postoperative complications

OBJECTIVE

Although cochlear implantation (CI) is a relatively safe operation, postoperative complications sometimes occur. We reviewed the frequency and severity of complications of CI at our hospital. We compared our results with previously reported complications and considered measures to improve patient outcomes.

METHODS

This retrospective study examined the medical records of 70 patients who received CI between March 2005 and December 2018. We collected the following data: age at the time of the first surgery, etiology of hearing impairment, date of implantation, type of implanted devices, and complications. Surgical complications were divided by time into perioperative, early, and late, and by severity into major or minor.

RESULTS

Records of 38 adults and 32 children were analyzed. Bilateral CI was performed in 16 patients, 8 of whom were sequential, and unilateral CI was performed in 54 patients. The total number of operations was 78 for 86 CI. Complications were observed in 15 of 78 operations (19%), and the rates of minor and major complications were 15% and 4%, respectively. Complication rates were 21% (8/39) for children and 10% (4/39) for adults. All of the perioperative and early complications were minor. There were three major complications, all of which were infections presenting with mastoiditis and subcutaneous or subperiosteal abscesses. One case required reimplantation twice because of recurrent mastoiditis and temporal abscess.

CONCLUSIONS

There was no significant difference in the incidence of complications between children and adults, but all major complications were infection in pediatric cases. Careful attention is needed to prevent postoperative infection.

Using haptic stimulation to enhance auditory perception in hearing-impaired listeners

INTRODUCTION

Hearing-assistive devices, such as hearing aids and cochlear implants, transform the lives of hearing-impaired people. However, users often struggle to locate and segregate sounds. This leads to impaired threat detection and an inability to understand speech in noisy environments. Recent evidence suggests that segregation and localization can be improved by providing missing sound-information through haptic stimulation.

AREAS COVERED

This article reviews the evidence that haptic stimulation can effectively provide sound information. It then discusses the research and development required for this approach to be implemented in a clinically viable device. This includes discussion of what sound information should be provided and how that information can be extracted and delivered.

EXPERT OPINION

Although this research area has only recently emerged, it builds on a significant body of work showing that sound information can be effectively transferred through haptic stimulation. Current evidence suggests that haptic stimulation is highly effective at providing missing sound-information to cochlear implant users. However, a great deal of work remains to implement this approach in an effective wearable device. If successful, such a device could offer an inexpensive, noninvasive means of improving educational, work, and social experiences for hearing-impaired individuals, including those without access to hearing-assistive devices.

Hearing Loss in Children: A Review

IMPORTANCE

Hearing loss in children is common and by age 18 years, affects nearly 1 of every 5 children. Without hearing rehabilitation, hearing loss can cause detrimental effects on speech, language, developmental, educational, and cognitive outcomes in children.

OBSERVATIONS

Consequences of hearing loss in children include worse outcomes in speech, language, education, social functioning, cognitive abilities, and quality of life. Hearing loss can be congenital, delayed onset, or acquired with possible etiologies including congenital infections, genetic causes including syndromic and nonsyndromic etiologies, and trauma, among others. Evaluation of hearing loss must be based on suspected diagnosis, type, laterality and degree of hearing loss, age of onset, and additional variables such as exposure to cranial irradiation. Hearing rehabilitation for children with hearing loss may include use of hearing aids, cochlear implants, bone anchored devices, or use of assistive devices such as frequency modulating systems.

CONCLUSIONS AND RELEVANCE

Hearing loss in children is common, and there has been substantial progress in diagnosis and management of these cases. Early identification of hearing loss and understanding its etiology can assist with prognosis and counseling of families. In addition, awareness of treatment strategies including the many hearing device options, cochlear implant, and assistive devices can help direct management of the patient to optimize outcomes.

Antifibrotic strategies for medical devices

A broad range of medical devices initiate an immune reaction known as the foreign body response (FBR) upon implantation. Here, collagen deposition at the surface of the implant occurs as a result of the FBR, ultimately leading to fibrous encapsulation and, in many cases, reduced function or failure of the device. Despite significant efforts, the prevention of fibrotic encapsulation has not been realized at this point in time. However, many next-generation medical technologies including cellular therapies, sensors and devices depend on the ability to modulate and control the FBR. For these technologies to become viable, significant advances must be made in understanding the underlying mechanism of this response as well as in the methods modulating this response. In this review, we highlight recent advances in the development of materials and coatings providing a reduced FBR and emphasize key characteristics of high-performing approaches. We also provide a detailed overview of the state-of-the-art in strategies relying on controlled drug release, the surface display of bioactive signals, materials-based approaches, and combinations of these approaches. Finally, we offer perspectives on future directions in this field.

Predictive factors of vertigo following cochlear implantation in adults

OBJECTIVES

The occurrence of vertigo after cochlear implantation surgery is one of the most common complications, and often transient. The purpose of this study was to evaluate the occurrence of vertigo after unilateral or bilateral cochlear implantation as well as to identify potential predictive factors.

MATERIALS AND METHODS

Patients who have undergone cochlear implantation and vestibular assessment pre- and postoperatively were included retrospectively. The presence of vertigo before and after surgery was noted. Postoperative vertigo duration was divided into 3 categories: immediate postoperative (less than 2 months), transient postoperative (between 2 months and 1 year), and persistent postoperative (greater than 1 year). Pre- and postoperative vestibular assessment results (caloric irrigation and VEMP tests) as well as patients' age, operated side, surgical technique for round window access, and characteristics of the electrode array were all analyzed as potential predictive factors of postoperative vertigo.

RESULTS

A total of 166 cochlear implants (137 patients) were included in the study, with a mean age of 57.5 ± 16.4 years. Of these, 36% developed postoperative vertigo, of which 19.3% was immediately postoperative. At 1 year postoperatively, 6 cases (3.6%) had persistent disabling vertigo, with 2 cases (1.2%) having no history of vertigo prior to cochlear implantation. Regarding caloric irrigation, 21% of the patients had a vestibular deficiency before surgery, and the same percentage had decreased vestibular responses. At 2 months after cochlear implantation, 31% of the patients exhibited an alteration in their vestibular test results, and 23.5% had experienced immediate postoperative vertigo. None of the factors studied (age, operated side, surgical technique, electrode array characteristics, and vestibular test alteration) correlated with the occurrence of short-term or long-term postoperative vertigo.

CONCLUSION

The occurrence of vertigo after cochlear implantation is difficult to predict by the healthcare team and may develop into an invalidating condition. Each vestibular examination performed routinely only evaluates a specific vestibular organ dysfunction. Therefore, combining several vestibular assessments tests before and after cochlear implantation can increase their sensitivity of predicting the occurrence and eventual persistence of this symptom.

Seizure as Early Presentation of a Pneumocephalus after Cochlear Implant: A Case Report

Pneumocephalus after cochlear implantation is very rare with five reported cases in the literature. The presence of clinical features in the immediate postoperative period has never been reported, because they occur weeks after surgery. These neurological manifestations can compromise the patient's life; thus, it is important to have proper knowledge and management of these manifestations. We present a case report with a review of the literature. A 35-year-old man began having seizures a few hours after a cochlear implantation. Computed tomography (CT) scan revealed a pneumocephalus and bone defect at the level of the electrode's drilling path, not objected during the surgery. The patient was handled conservatively, and in subsequent reviews, CT objected reabsorption of the pneumocephalus. The presence of a pneumocephalus should be taken into account in the neurological features of a patient with cochlear implant, especially if mastoid bone defects are suspected during surgery. The management of the pneumocephalus will, in most cases, be conservative, consisting of clinical observation and imaging tests. Surgical treatment is reserved for situations in which the clinical manifestations are very symptomatic and when they are tension pneumocephalus.

Cochlear implantation in children without preoperative computed tomography diagnostics. Analysis of procedure and rate of complications

INTRODUCTION

To evaluate the safety in cochlear implantation without preoperative computed tomography diagnostics, which was implemented into the protocol of cochlear implantation in 2013, since in the year before, new evidence concerning the risks of ionizing radiation especially in children arose.

METHODS

In this retrospective data analysis 89 children under 36 months, which were cochlear implanted from 2008 until 2018 at a tertiary referral centre with a large cochlear implant program were analysed. Fortyfour of the children were implanted before the date of change in 2013 and 45 in the following years up to now. The data about the operative procedures, the postoperative care and the complication rate before and after implementation of the new protocol were compared.

RESULTS

Before the date of change in 2013, 100% of patients received preoperative CT diagnostics, in the following years 13.3%. No difference in the duration of surgery, the procedure related and the late complications between the two groups was identified.

CONCLUSION

Cochlear implantation in very young children under the age of 36 months without preoperative radiological diagnostics by CT scan of the temporal bone is a safe procedure without additional risks for the patients.

The effect of tinnitus on hearing-related quality of life outcomes in adult cochlear implant recipients

OBJECTIVE

To describe the effect of tinnitus distress on the hearing-related quality of life (QoL) outcomes over time in adult cochlear implant (CI) recipients.

DESIGN

A retrospective, longitudinal study of adult CI recipients was conducted. Hearing-related QoL and tinnitus distress were assessed using the Abbreviated Profile of Hearing Aid Benefit (APHAB) and the Tinnitus Reaction Questionnaire (TRQ) preoperatively and at 6-months, 12-months and >24-month postoperatively. The association between tinnitus distress and hearing-related QoL outcomes over time was investigated. Furthermore, 13 potential predictive factors were identified from the retrospective dataset. Multiple regression analyses were performed to identify variables that influence hearing-related QoL outcomes over time.

STUDY SAMPLE

The study sample included 210 adult (≥18 years) CI recipients implanted between 2001 and 2017.

RESULTS

Lower tinnitus distress and younger age at implantation were significant predictors of better hearing-related QoL in adult CI recipients. A significant reduction in tinnitus distress up to two years post-implantation was found, as well as greater tinnitus distress correlating with poorer hearing-related QoL outcomes.

CONCLUSION

Tinnitus distress negatively affects the hearing-related QoL outcomes of adult CI recipients. Tinnitus distress and age at implantation were found to be significant predictors of hearing-related QoL when controlling for other predictive factors.

Clinical efficiency and safety of the oticon medical neuro cochlear implant system: a multicenter prospective longitudinal study

OBJECTIVE

This prospective longitudinal cohort study at six tertiary referral centers in Canada and Denmark describes the clinical efficiency and surgical safety of cochlear implantation with the Oticon Medical Neuro cochlear implant system, including the Neuro Zti implant, the EVO electrode array, and the Neuro One sound processor.

METHODS

Patients were adult cochlear implant candidates with bilateral sensorineural hearing loss.

RESULTS

The mean HINT scores in quiet pre-operatively and at 3, 6, and 12 months post-activation were 13%, 58%, 67%, and 72%, respectively, and in noise (+10 dB SNR) 13%, 46%, 53%, and 59%, respectively. The mean improvement from baseline to 6 months post-activation was 54% in quiet and 40% in noise. The surgical major complication incidence rate was 0% and the post-surgical major complication incidence rate (until 12 months post-activation) was 4%. There was no adverse event that was fatal, that required explantation, or that resulted in sound processor nonuse, and no implant failure.

CONCLUSION

Cochlear implantation with the Oticon Medical Neuro system enables speech identification both in quiet and in noise and audiologic outcomes continue to improve in the year following activation. No substantial adverse events occurred during the surgical implantation procedure and during the 12 months post-activation.

Facial nerve stimulation in a post-meningitic cochlear implant user: using computational modelling as a tool to probe mechanisms and progression of complications on a case-by-case basis

Facial nerve stimulation (FNS) is a side-effect of cochlear implantation that can result in severe discomfort for the user and essentially limits the optimal use of the implant. Three-dimensional cochlear implant modelling research has led to the progression from generic models to user-specific models with one of the intentions to develop model-based diagnostic tools. The objective of this study is to investigate the mechanisms that underlie the manifestation of FNS in the post-meningitic cochleae of a specific CI user through computational modelling. Bilateral models were created using a method previously developed for the construction of a three-dimensional user-specific volume conduction model of the cochlea and was expanded to include the facial nerve geometry. Reduced temporal bone density based on bone densitometry, cochlear duct ossification and degenerate auditory neural fibres were incorporated into a comprehensive FNS model. Auditory and facial nerve thresholds were predicted with the models showing good correspondence to perceptual thresholds and the user's FNS experience. Ossified cochlear ducts appear to aggravate the increase in thresholds caused by the otic capsule's decreased resistivity. This translational case study demonstrates the application of computational modelling as a clinical instrument in the assessment and management of complications with cochlear implantation.

Management of delayed-onset skin flap complications after pediatric cochlear implantation

Purpose

To review delayed-onset skin flap complications associated with pediatric cochlear implantation (CI) in our institute, analyze the etiology, and explore effective treatment strategies.

Methods

Retrospective analyses of 811 children who had undergone cochlear implantation between January 2003 and March 2019 were performed. Twelve (1.48%) patients developed skin flap complications after CI. We present a classification of flap issues and wound histopathology following cochlear implantation. The interventions for flap problems included drug treatment, aspiration, local wound care, revision surgery, and explantation depending on the clinical situation. The temporalis myofascial reconstructive option is discussed.

Results

Seven subjects were cured with conservative treatment. Five cases with flap infection or necrosis underwent revision surgery, with wound closure in three cases (60%) and revision surgery with explantation in the remaining two cases (40%). Explantation ultimately led to wound healing in all cases. They all achieved excellent performance through re-implantation.

Conclusion

Flap complications after CI are rare but treatable. Comprehensive treatments should be developed to achieve a stable and healed wound for CI.

Global Regulatory Review Needed for Cochlear Implants: A Call for FDA Leadership

INTRODUCTION

Using the United States Food and Drug Administration (FDA) as example, we argue that regulatory agencies worldwide should review their guidance on cochlear implants (CIs).

METHODS

This is a position paper, thus the methods are strictly argumentation. Here we give the motivation for our recommendation. The FDA's original approval of implantation in prelingually deaf children was granted without full benefit of information on language acquisition, on childcaregiver communication, and on the lived experience of being deaf. The CI clinical trials, accordingly, did not address risks of linguistic deprivation, especially when the caregiver's communication is not fully accessible to the prelingually deaf child. Wide variability in the effectiveness of CIs since initial and updated approval has been indicated but has not led to new guidance. Children need to be exposed frequently and regularly to accessible natural language while their brains are still plastic enough to become fluent in any language. For the youngest infants, who are not yet producing anything that could be called language although they might be producing salient social signals (Goldstein et al. Child Dev 80:636-644, 2009), good comprehension of communication from caregiver to infant is critical to the development of language. Sign languages are accessible natural languages that, because they are visual, allow full immersion for deaf infants, and they supply the necessary support for this comprehension. The main language contributor to health outcomes is this combination of natural visual language and comprehension in communication. Accordingly, in order to prevent possible language deprivation, all prelingually deaf children should be exposed to both sign and spoken languages when their auditory status is detected, with sign language being critical during infancy and early childhood. Additionally, all caregivers should be given support to learn a sign language if it is new to them so that they can comprehend their deaf children's language expressions fully. However, both languages should be made accessible in their own right, not combined in a simultaneous or total communication approach since speaking one language and signing the other at the same time is problematic.

RESULTS

Again, because this is a position paper, our results are our recommendations. We call for the FDA (and similar agencies in other countries) to review its approval of cochlear implantation in prelingually deaf children who are within the sensitive period for language acquisition. In the meantime, the FDA should require manufacturers to add a highlighted warning to the effect that results with CI vary widely and CIs should not be relied upon to provide adequate auditory input for complete language development in all deaf children. Recent best information on users' experience with CIs (including abandonment) should be clearly provided so that informed decisions can be made. The FDA should require manufacturers' guidance and information materials to include encouragement to parents of deaf children to offer auditory input of a spoken language and visual input of a sign language and to have their child followed closely from birth by developmental specialists in language and cognition. In this way parents can align with providers to prioritize cognitive development and language access in both audio-vocal and visuo-gestural modalities.

DISCUSSION

The arguments and recommendations in this paper are discussed at length as they come up.

The French Cochlear Implant Registry (EPIIC): Cochlear implantation complications

OBJECTIVES

The aim of this study was to evaluate peri- and post-operative complications related to cochlear implantations. We searched for risk factors predicting these complications and analyzed the complications in the youngest and most elderly.

STUDY DESIGN

Retrospective analysis of cochlear implant patients.

MATERIALS AND METHODS

All patients who underwent cochlear implantation in France between January 2012 and December 2016 were anonymized and registered in the EPIIC database. This population included 3483 adults and 2245 children. Their demographic and surgical data and their incidence of peri- or post-operative complications, including their severity, whether major or minor, were all indicated.

RESULTS

The global complication rate was 6.84%. The risk of complication was higher in initial implantation versus reimplantation (P<0.0001). The risk was also higher for bilateral implantation versus unilateral (P<0.0001). Complications were more frequent for patients with cochlear malformation (P=0.002). There was no difference in complication rates across age groups; babies under 1 year old, and the elderly over 80 and even over 90, did not have more complications than the rest of the population. Patients treated in the daily care unit had no more complications than those who were hospitalized for one night or more (P=0.64).

CONCLUSION

Cochlear implantation is a safe technique with a low incidence of complications. The absence of increased risk in patients at the extremes of the age spectrum justifies offering this solution to all, without age limitation.

Pre- and post-operative imaging of cochlear implants: a pictorial review

Cochlear implants are increasingly used to treat sensorineural hearing disorders in both children and adults. Pre-operative computed tomography and magnetic resonance imaging play a pivotal role in patient selection, to rule out findings that preclude surgery or identify conditions which may have an impact on the surgical procedure. The post-operative position of the electrode array within the cochlea can be reliably identified using cone-beam computed tomography. Recognition of scalar dislocation, cochlear dislocation, electrode fold, and malposition of the electrode array may have important consequences for the patient such as revision surgery or adapted fitting.

Cerebrospinal fluid gusher in cochlear implant and its associated factors

Introduction: Cochlear implants (CI) is considered a safe procedure with overall complication rate of 12.5% amongst adult and pediatric population. Cerebrospinal fluid (CSF) gusher is regarded as a common CI intraoperative complication.Objective: In this study, we determined the association between probable associated factors and occurrence of intraoperative CSF gusher.Method: In a retrospective survey, 394 patients with severe to profound sensorineural hearing loss who underwent primary cochlear implantation surgery were evaluated. Patients with incomplete electronic or manual file and those with revision, explantation or reimplantation surgery were excluded.Result: three hundred and ninety-four CI patients with a mean age of 8.74 ± 12.21 years were reviewed 49.62% of them were female. CSF gusher developed in 22 patients (5.58%). Patients with CSF gusher had more structural abnormalities in their CT scans' report. Common cavity malformation and Mondini dysplasia were the most common abnormal reports amongst those with intra-operative CSF gusher.Conclusion: In conclusion, cochlea structural abnormalities affect the incidence of CSF gusher in CI recipients. Common cavity malformation and Mondini dysplasia were associated with an increased incidence of CSF gusher. We insist on more precise pre-operative imaging of those with abnormal cochlea structures to provide the needed management.

A narrative review of the logistic and economic feasibility of cochlear implants in lower-income countries

Objectives: Globally, less than 1% of people who could benefit from a cochlear implant have one and the problem is particularly acute in lower-income countries. Here we give a narrative review of the economic and logistic feasibility of cochlear implant programmes in lower-income countries and discuss future developments that would enable better healthcare. We review the incidence and aetiology of hearing loss in low- and middle-income countries, screening for hearing loss, implantation criteria, issues concerning imaging and surgery, and the professional expertise required. We also review the cost of cochlear implantation and ongoing costs. Findings: The cost effectiveness of cochlear implants in lower-income countries is more limited by the cost of the device than the cost of surgery, but there are also large ongoing costs that will deter many potential users. Conclusions: We conclude that the main barriers to the future uptake of cochlear implants are likely to be logistical rather than technical and cochlear implant provision should be considered as part of a wider programme to improve the health of those with hearing loss.

Genotype-Phenotype Correlation for Predicting Cochlear Implant Outcome: Current Challenges and Opportunities

The use and utility of cochlear implantation has rapidly increased in recent years as technological advances in the field have expanded both the efficacy and eligible patient population for implantation. This review aims to serve as a general overview of the most common hearing disorders that have favorable auditory outcomes with cochlear implants (CI). Hearing loss in children caused by congenital cytomegalovirus infection, syndromic conditions including Pendred Syndrome, and non-syndromic genetic conditions such as hearing impairment associated with GJB2 mutations have shown to be successfully managed by CI. Furthermore, cochlear implantation provides the auditory rehabilitation for the most common etiology of hearing loss in adults and age-related hearing loss (ARHL) or presbycusis. However, in some cases, cochlear implantation have been associated with some challenges. Regarding implantation in children, studies have shown that sometimes parents seem to have unrealistic expectations regarding the ability of CI to provide auditory rehabilitation and speech improvement. Given the evidence revealing the beneficial effects of early intervention via CI in individuals with hearing disorders especially hearing loss due to genetic etiology, early auditory and genetic screening efforts may yield better clinical outcomes. There is a need to better understand genotype-phenotype correlations and CI outcome, so that effective genetic counseling and successful treatment strategies can be developed at the appropriate time for hearing impaired individuals.

[Hearing rehabilitation using a cochlear implant - a way of reducing tinnitus in the elderly]

BACKGROUND

Tinnitus is a common symptom of severe hearing loss or deafness especially in older people. Hearing rehabilitation for these patients is usually only possible with a cochlear implant (CI). In recent years, an increasing number of old and very old patients have been treated with a CI. The aim of this study was to examine the influence of hearing rehabilitation with a CI on the tinnitus of older people.

MATERIALS AND METHODS

In this prospective study 34 patients between the age of 65 and 86 were included, who were unilaterally treated with a CI for the first time. 16 patients (47.1 %) had tinnitus preoperatively. At three time points (preoperative, on initial fitting and six months postoperatively), tinnitus severity was assessed in addition to speech discrimination in patients with tinnitus using the mini-tinnitus questionnaire (Mini-TF12).

RESULTS

Six month postoperatively we found a highly significant improvement of speech discrimination (preoperatively 11.5 ± 17.4, six-month visit 54.4 ± 28.1 %, p = 0.001) that was accompanied by a highly significant reduction in tinnitus severity according to Mini-TF12 scores (preoperatively 6.9 ± 6.5, six-month visit 4.3 ± 3.3, p = 0.001).

CONCLUSIONS

Hearing rehabilitation by means of CI leads to a highly significant reduction of tinnitus severity of pre-operatively existing tinnitus in the elderly.

First MRI With New Cochlear Implant With Rotatable Internal Magnet System and Proposal for Standardization of Reporting Magnet-Related Artifact Size

OBJECTIVE

To report on the first known magnetic resonance imaging (MRI) with a new cochlear implant (CI) with rotatable internal magnet system, to review the literature on MRI in cochlear implantees, and to advocate for standardization of reporting magnet-related artifact size.

STUDY DESIGN

Case report and review of literature.

SETTING

Tertiary care hospital.

RESULTS

A patient with congenital rubella and bilateral profound hearing loss was incidentally found to have a petroclival meningioma. After resection and radiosurgery, she underwent cochlear implantation with the Advanced Bionics HiRes Ultra 3D device (Advanced Bionics LLC, Valencia, CA) with rotatable internal magnet system, due to need for imaging surveillance of residual meningioma. During 1.5 T MRI brain scan without a head wrap, she experienced no adverse events. The images obtained were adequate for visualization of residual tumor. Implant recipients with non-rotatable magnets who undergo MRI, with or without recommended head wrap, may suffer various complications. All images in patients with retained internal magnets are subject to magnet-related artifact, but reports regarding its size are variable and lack detail on how measurements are made.

CONCLUSIONS

MRI in patients with a new CI device with rotatable magnet system may be performed without discomfort or device dislodgement at 1.5 T, even without a head wrap, though external magnet replacement may require multiple attempts due to internal magnet realignment. Despite significant artifact, the structure of interest may still be visualized for accurate diagnosis. Measuring magnet-related artifact size should be standardized by reporting artifact in radii at the image level of maximal signal loss.

Management of Complications in 1452 Pediatric and Adult Cochlear Implantations

Objective

The aim of this study was to determine the short- and long-term complications after cochlear implantation (CI) procedures and to discuss the management and prevention of these complications.

Methods

The study included a total of 1452 pediatric and adult cochlear implantation procedures performed in our clinic from March 2000 through September 2019. Of the 1452 implantations, 1201 were performed in children and 156 in adults. The minimum follow-up period was three months and maximum was 19 years. The mean age of the patients was 6.7±3.9 years (range, 10 months-69 years) at the time of their respective procedures. Complications were classified as major complications requiring reimplantation, major complications not requiring reimplantation and minor complications. All postoperative complications and treatment methods were examined.

Results

A total of 148 (10.1%) complications were observed in the 1452 cochlear implants. Of these, 69 (4.75%) were major and 79 (5.44%) were minor complications. While 40 (2.75%) of the major complications required reimplantation, 29 (1.99%) did not. The most common cause of major complications leading to reimplantation was device failure (29 patients, 1.99%). The most common cause of minor complications was hematoma (21 patients). Total complication rates (6.68%) were significantly higher in children than in adults (3.51%) (p=0.00).

Conclusion

Our 19 years of clinical experience has shown that CI is a successful and safe procedure that can be performed with low major complication rates. It is important to know the possible complications and to manage them correctly.

Surgical complications of cochlear implantation: a 25-year retrospective analysis of cases in a tertiary academic center

PURPOSE

Despite the advances made in cochlear implantation techniques, the associated complication rates are still high. Here, we aimed to analyze cases, with extensive follow-up data, associated with a large sample of patients to identify complications related to cochlear implants and to present our surgical experience and the technique that we used in order to follow surgical rules/medical purpose to avoid any complications.

METHODS

We retrospectively examined cases involving 2597 patients (1342 males; 1255 females; age 1-88 years) who underwent cochlear implantation procedures between November 1995 and July 2019, and we classified complications as minor and major.

RESULTS

The mean age at the time of implantation was 6.48 (Min: 1/Max: 88) years. The cause of deafness was congenital in 76.5% of the patients and acquired in 16.8%. The overall rate of complications in the study was 3.7% (n = 97). The minor and major complication rates were 3.0 and 0.7, respectively. Further, while the most common minor complication we encountered was vertigo, the most common major complication was implant extrusion.

CONCLUSION

Fixing the cochlear implant receiver-stimulator with the bone-recess technique and sealing the posterior tympanotomy site with a piece of muscle in order to follow surgical rules/medical purpose to avoid any complications. Following the insertion of the electrode into the cochlea, the muscle closure of the cochleostomy site or the round window restores the original anatomy and in order to follow surgical rules/medical purpose to avoid any complications. We have developed this highly effective technique with years of experience and have not had a major surgical complication in 5 years.

Is Hard Failure Still a Common Indication for Revision Surgery in Adult Cochlear Implant Recipients?

OUTCOME OBJECTIVES

STUDY DESIGN:: Retrospective chart review.

SETTING

Single tertiary care center, 2001 to 2016.

PATIENTS

Adult CI recipients were assessed. Inclusion required ≥1 revision surgeries, operative note(s), and postrevision follow-up of 6 months.

INTERVENTIONS

Therapeutic/rehabilitative.

MAIN OUTCOMES MEASURES

Indications for revision (HF, SF, WC, and MM) were tabulated. The incidence of each was compared between cohorts implanted before/after 2011. Additional outcomes included implant usage, explantation rates, and postrevision speech scores.

RESULTS

Four hundred thirty-two patients received 512 CIs. Of these, 30 patients required 38 revisions. Median time to revision was 24.5 months. Frequency by indication was HF (n = 14), SF (n = 12), WC (n = 8), and MM (n = 4). The overall revision rate was 7.4%. There was a significant decline in overall revisions for patients implanted before/after 2011 (10.4 versus3.5%; p = 0.009). No patients implanted after 2011 experienced a HF (p = 0.002). Patients with WC/MM had significantly shorter time to revision compared with patients with HF/SF (p = 0.04). The overall median follow-up was 24 months. Twenty-three of 30 patients are still using their revised CI. Patients revised for HF and MM achieved the best outcomes.

CONCLUSION

7.4% of adult CI recipients required revision surgery. Explantation/immediate reimplantation was an effective management strategy. While HF was the most common indication overall, no patients implanted after 2011 have suffered this complication. The overall revision rate has significantly declined since 2011.

Potential insertion complications with cochlear implant electrodes

Objectives: The aim of this discussion paper and literature review was to estimate the incidence of a variety of complications associated with the surgical placement of cochlear implant (CI) electrode arrays and to discuss the implications and management of sub-optimal electrode placement. Results: A review of the peer-reviewed literature suggests that the incidence of incomplete electrode insertion and kinking is more prevalent in straight arrays and not more than about 2% in CI recipients with normal cochlear anatomy/patency. Incidence of tip fold-over is greater with perimodiolar arrays but also occurs with straight arrays and is typically less than 5%. Conversely, electrode migration is more common with straight arrays, and high rates (up to 46%) have been reported in some studies. Scalar translocations have also been reported for both perimodiolar and straight arrays. Higher rates have been reported for stylet-based perimodiolar electrodes inserted via cochleostomy (up to 56%), but with much lower rates (<10%) with both sheath-based perimodiolar arrays and lateral wall arrays. Electrode positioning complications represent a significant proportion of perioperative CI complications and compromise the level of benefit from the device. Careful surgical planning and appropriate pre- and intraoperative imaging can reduce the likelihood and impact of electrode positioning complications. There is also evidence that newer array designs are less prone to certain complications, particularly scalar translocation. Conclusions: It is important that implanting surgeons are aware of the impact of sub-optimal electrode placement and the steps that can be taken to avoid, identify and manage such complications.

Cochlear Implant Receiver Location and Migration: Experimental Validation Pilot Study of a Clinically Applicable Screening Method

Objectives: Postoperative follow-up after cochlear implantation lacks a reliable screening method to detect cochlear implant receiver device migration. This study aims to validate a clinically applicable method to assess the position and migration of the cochlear implant receiver device.

Study design: Validation study.

Setting: Tertiary university medical center.

Participants and method: To assess the cochlear implant receiver device location, round markers representing the external magnet were placed on both sides of the head of volunteers. Four independent clinicians took measurements of the distances between reference points on the head and the center of the marker. The reference points were: the lateral canthus (LC), tragus tip (TT), the mastoid angle (MA), and the mandibular angle (AM).

Main outcome measures: The inter-clinician reliability was determined by calculating the intraclass correlation coefficient (ICC) and confidence interval (CI) with a two-way mixed model and both consistency and absolute agreement types for each distance.

Results: Eight volunteers were included resulting in 16 individual cases. The consistency type ICC's for each reference point were: LC 0.90 (CI = 0.80, 0.96), TT 0.83 (CI = 0.69, 0.93), MA 0.75 (CI = 0.56, 0.89), and AM 0.29 (CI = 0.05, 0.59). The absolute agreement ICC's were: LC 0.87 (CI = 0.73, 0.95), TT 0.83 (CI = 0.68, 0.93), MA 0.68 (CI = 0.42, 0.86), and AM 0.18 (CI = 0.01, 0.46). The inter-clinician reliability was good to excellent for the lateral canthus and tragus tip reference points.

Conclusions: The cochlear receiver device location can be assessed reliably by measuring the distance between the LC, TT, and the external magnet. This method can be used to registrate implant receiver location after implantation and detect implant migration postoperatively.

DARPA investment in peripheral nerve interfaces for prosthetics, prescriptions, and plasticity

BACKGROUND

Peripheral nerve interfaces have emerged as alternative solutions for a variety of therapeutic and performance improvement applications. The Defense Advanced Research Projects Agency (DARPA) has widely invested in these interfaces to provide motor control and sensory feedback to prosthetic limbs, identify non-pharmacological interventions to treat disease, and facilitate neuromodulation to accelerate learning or improve performance on cognitive, sensory, or motor tasks. In this commentary, we highlight some of the design considerations for optimizing peripheral nerve interfaces depending on the application space. We also discuss the ethical considerations that accompany these advances.

Bioactive Glass Granules Inhibit Mature Bacterial Biofilms on the Surfaces of Cochlear Implants

HYPOTHESIS

Biofilm formation on cochlear implant (CI) surfaces differs between bacterial species and can be reduced by the application of S53P4 bioactive glass.

BACKGROUND

The formation of bacterial biofilms on medical devices, such as cochlear implants, can lead to chronic infections resulting in the need for implant removal. In this study, various surfaces of three CI implant kits from different manufacturers were examined for bacterial biofilm formation and reduction of a pre-existing biofilm by the application of bioactive glass.

METHODS

Biofilm formations of 4 bacterial species causing implant-related infections were tested on 17 different surfaces: Pseudomonas aeruginosa (ATCC9027), Staphylococcus aureus (ATCC6538), Staphylococcus epidermidis (ATCC12228), and Streptococcus pyogenes (ATCC19615). For P. aeruginosa and S. aureus biofilm reduction after application of S53P4 bioactive glass was evaluated.

RESULTS

All tested microbial species formed biofilms on the examined CI surfaces in a strain-dependent manner. For S. aureus, a significantly higher biofilm formation on metal components compared with silicone was found whereas the other strains did not show a material specific biofilm formation. Application of S53P4 bioactive glass resulted in a significant reduction of P. aeruginosa and S. aureus mature biofilm.

CONCLUSION

The four bacteria species displayed biofilm formation on the CI surfaces in a species- and material-specific manner. The results show that bioactive glass can reduce biofilm formation on CI materials in vitro. Future studies are necessary to confirm the results in vivo.