Surgical findings and auditory performance after cochlear implant revision surgery

Long-term experience with biohybrid cochlear implants in human neurosensory restoration

OBJECTIVE

The implantation of biohybrid electrodes was introduced a few years ago in our clinic. These electrodes coated with autologous mononuclear cells releasing anti-inflammatory and neuroprotective factors are thought to reduce insertion trauma and maintain the vitality of surviving spiral ganglion neurons. The clinical feasibility of this approach has already been demonstrated. In the present retrospective study, the four-year results of the two sides (classical electrode and biohybrid electrode) in the bilaterally implanted patients were compared in order to investigate possible adverse long-term effects.

METHODS

All patients received a complete audiological diagnosis which also included a speech audiogram and impedance measurement. The measurements were carried out 1 month, 3 months, 6 months, 1 year, 2 years, 3 years and 4 years after implantation. The hearing results were assessed by pure tone audiometry.

RESULTS

All patients showed satisfactory speech understanding and similar impedances on both sides although they had a long-term deafness before implantation of the side provided with a biohybrid electrode array. The results of speech understanding and impedance measurements were stable for years. Cone beam computed tomography was performed in 4 patients three years after implantation and could rule out cochlear ossification. Other complications were also not registered in any of the patients.

CONCLUSION

Due to satisfactory outcomes and lack of complications, the biohybrid electrode is considered to be a safe option in cochlear implantation. The simplicity of application of autologous cells as a source of anti-inflammatory and neuroprotective factors via a biohybrid electrode array is a key step for cell-based, regenerative therapies for deafness.

Implantation and reimplantation: epidemiology, etiology and pathogenesis over the last 30 years

INTRODUCTION

Due to the increasing number of cochlear implant (CI) recipients, growing indications, and the aging population, the reimplantation of CI recipients has become a focus of attention. The aim of this study is to examine the causes, timing, and postoperative speech understanding in a large cohort over the past 30 years.

METHODS

A retrospective data analysis was conducted on over 4000 CI recipients and 214 reimplanted children and adults from 1993 to 2020. This involved collecting and comparing data on causes, manufacturer information, and demographic data. In addition, a comparison of speech understanding in Freiburg monosyllables and numbers before and after reimplantation was carried out.

RESULTS

Children did not exhibit elevated rates of reimplantation. The overall reimplantation rate in the entire cohort was 5%. The CI overall survival rate after 10 years in the entire cohort was 95.2%. Device failure was the most common reason for reimplantation, with 48% occurring within the first 5 years after implantation. The second most common reason was medical complications, with the risk of reimplantation decreasing as more time passed since the initial implantation. There were no significant differences in Freiburg numbers and monosyllable comprehension before and after reimplantation, both in the overall cohort and in the subcohorts based on indications. Even a technical upgrade did not result in a significant improvement in speech understanding.

DISCUSSION

There was no significant difference in the frequency of reimplantation based on patient age, especially when comparing children and adults. Device failure is by far the most common indication for reimplantation, with no significant difference in implant survival between manufacturers. Patients most often choose the same manufacturer for reimplantation. The likelihood of reimplantation decreases with increasing time since the initial implantation. The indication for reimplantation should be carefully considered, as on average, no improved speech understanding is achieved, regardless of the cause, even with a technical upgrade.

Cochlear Implant Device Failures Falling Under the 2020 FDA Voluntary Field Corrective Action: A Systematic Review and Meta-analysis

OBJECTIVE

To compare the rate of device failure for those cochlear implants (CIs) involved in the 2020 Food and Drug Administration (FDA) voluntary field corrective action (VFCA).

DATABASES REVIEWED

Medline, Embase, and Scopus.

METHODS

A systematic review was performed according to the PRISMA guidelines. Publications reporting institutional experiences with implants affected by the VFCA were included. Outcomes assessed included etiology of, rate of, and time to failure and pre-/post-device failure speech perception testing. All outcomes reported in at least two independent studies were included in a meta-analysis.

RESULTS

Six studies met criteria for analysis. The overall pooled failure rate was 23.7% (95% CI, 11.6-38.4%). The pooled device, inconclusive, and medical failure rates were 21.5%, 0.2%, and 0.7%, respectively. Pediatric failure rates were higher than those of adults (46.9% [95% CI, 11.2-84.5%] versus 32.6% [95% CI, 8.2-63.7%]). WRS declined with primary implant failure (55.1% [95% CI, 48.0-62.1%] to 34.1% [95% CI, 30.2-38.0%]) but improved after reimplantation (34.1% [95% CI, 30.2-38.0%] to 50.1% [95% CI, 45.2-55.1%]).

CONCLUSIONS

The rate of pooled reported failure for CIs falling under the 2020 VFCA in the literature thus far is 23.7%. The overwhelming majority of these failures were device related, the rates of which were higher in children. Speech perception improved significantly after reimplantation.

Analysis of aided thresholds in children who have undergone cochlear reimplantation: a ten-year follow-up

PURPOSE

To characterize hearing thresholds at frequencies of 500, 1000, 2000 and 4000 Hz in children undergoing reimplantation with a follow-up of at least 10 years.

METHODS

Retrospective review of medical records of children who underwent reimplantation surgery for at least 10 years. The auditory thresholds obtained in free-field pure tone audiometry with the cochlear implant were evaluated at frequencies of 500, 1000, 2000 and 4000 Hz at four different times: 1 (before failure), 2 (activation), 3 (five years after reimplantation) and 4 (ten years after reimplantation, regardless of the time of use of the 2nd CI) in patients with a follow-up of at least 10 years.

RESULTS

Evaluating patients who underwent reimplantation, it was observed that the thresholds of 500, 1000, 2000, 4000 Hz were similar in the long term to those obtained in patients who were implanted only once, thus not presenting damage in the detection of sounds.

CONCLUSION

Reimplantation had no long-term effect on the hearing thresholds obtained in children who underwent this surgery due to internal component failure.

Revision cochlear implant surgery for clinical reasons

Objective

To report the authors' experience in a series of patients treated with cochlear implant (CI) revision surgery due to medical problems.

Methods

Revision CI surgeries performed in a tertiary referral centre for medical reasons not related to skin conditions were reviewed; patients were included if device removal was required.

Results

17 cochlear implant patients were reviewed. The main reasons requiring revision surgery with device removal were: retraction pocket/iatrogenic cholesteatoma (6/17), chronic otitis (3/17), extrusion in previous canal wall down procedures (2/17) or in previous subtotal petrosectomy (2/17), misplacement/partial array insertion (2/17) and residual petrous bone cholesteatoma (2/17). In all cases surgery was performed through a subtotal petrosectomy. Cochlear fibrosis/ossification of the basal turn was found in 5 cases and uncovered mastoid portion of the facial nerve in 3 patients. The only complication was an abdominal seroma. A positive difference was observed between the number of active electrodes and comfort levels before and after revision surgery.

Conclusions

In CI revision surgeries performed for medical reasons, subtotal petrosectomy offers invaluable advantages and should be considered as first choice during surgical planning.

Cochlear Reimplantation Rate and Cause: a 22-Year, Single-Center Experience, and a Meta-Analysis and Systematic Review

OBJECTIVES

In terms of cochlear reimplantation, there is no consensus on the definition, range, or calculation formulation for the reimplantation rate. This study aims to put forward a relatively standardized and more explicit definition based on a literature review, calculate the rate of cochlear reimplantation, and examine the classification and distribution of the reimplantation causes.

DESIGN

A systematic review and retrospective study. A relatively clearer definition was used in this study: cochlear reimplantation is the implantation of new electrodes to reconstruct the auditory path, necessitated by the failure or abandonment of the initial implant. Seven English and Chinese databases were systematically searched for studies published before July 23, 2021 regarding patients who accepted cochlear reimplantation. Two researchers independently applied the inclusion and exclusion criteria to select studies and complete data extraction. As the effect size, the reimplantation rate was extracted and synthesized using a random-effects model, and subgroup and sensitivity analyses were performed to reduce heterogeneity. In addition, a retrospective study analyzed data on cochlear reimplantation in a tertiary hospital from April 1999 to August 2021. Kaplan-Meier survival analysis and the log-rank test were adopted to analyze the survival times of cochlear implants and compare them among different subgroups.

RESULTS

A total of 144 articles were included, with 85,851 initial cochlear implantations and 4276 cochlear reimplantations. The pooled rate of cochlear reimplantation was 4.7% [95% CI (4.2% to 5.1%)] in 1989 to 2021, 6.8% [95% CI (4.5% to 9.2%)] before 2000, and 3.2% [95% CI (2.7% to 3.7%)] after 2000 ( P =0.003). Device failures accounted for the largest proportion of reimplantation (67.6% [95% CI (64.0% to 71.3%)], followed by medical reasons (28.9% [95% CI (25.7% to 32.0%)]). From April 1999 to August 2021, 1775 cochlear implants were performed in West China Hospital (1718 initial implantations and 57 reimplantations; reimplantation rate 3.3%). In total, 45 reimplantations (78.9%) were caused by device failure, 10 (17.5%) due to medical reasons, and 2 (3.5%) from unknown reasons. There was no difference in the survival time of implants between adults and children ( P = 0.558), while there existed a significant difference between patients receiving implants from different manufacturers ( P < 0.001).

CONCLUSIONS

The cochlear reimplantation rate was relatively high, and more attention should be paid to formulating a standard definition, calculation formula, and effect assessment of cochlear reimplantation. It is necessary to establish a sound mechanism for long-term follow-up and rigorously conduct longitudinal cohort studies.

Voluntary Field Recall of Advanced Bionics HiRes Cochlear Implants: A Single-Institution Experience

OBJECTIVES

In 2020, Advanced Bionics (AB) announced a recall of two cochlear implant (CI) models, the "HiRes Ultra" and "HiRes Ultra 3D", because of reports of hearing degradation. The present study examines clinical parameters and patient features in cases of device failure and evaluates outcomes after reimplantation.

MATERIALS AND METHODS

A series of 52 patients implanted with the recalled devices experienced suspected device failure and subsequently underwent revision CI placement at a tertiary academic medical center between December 2019 and November 2021.

RESULTS

Consonant-nucleus-consonant scores and individual phonemes increased significantly between patients' preoperative evaluation and primary cochlear implantation. Performance declined significantly before revision and recovered after revision CI placement. Similarly, pure-tone average thresholds improved between preoperative and primary CI, fell before revision surgery, and were corrected with revision implantation. As a group, patients reached their peak hearing performance significantly faster after revision CI (mean ± standard deviation, 53.4 ± 51.8 d) compared with their primary CI (mean ± standard deviation, 260.6 ± 245.9 d). Electrical field imaging performed by AB and device impedance measurements were found to be abnormal in the basally positioned electrodes (electrodes 9-16).

CONCLUSION

Hearing performance degradation is significant in AB Ultra device failures and seems to be linked to the basal-most electrodes in the array. Revision outcomes have been robust, necessitating continued monitoring of affected patients and support for reimplantation procedures.

LEVEL OF EVIDENCE

IV.

Cochlear Implant Salvage in Case of Grounding Wire Extrusion

OBJECTIVES

Cochlear implantation (CI) is a safe and effective procedure for hearing rehabilitation, with few major complications. Device exposure or extrusion is a rare but major complication that often necessitates explantation due to wound dehiscence or infection. The objective of this report is to present a previously undescribed case in which the cochlear implant grounding wire extruded in 16-month-old patient 3 months post-operatively in the absence of trauma or infection.

METHODS

We reviewed the case report and the pertinent literature.

RESULTS

A 16-month old male suffered extrusion of his left cochlear implant grounding wire without known etiology 86 days post-operatively after bilateral cochlear implantation. The patient was taken for surgery, and the electrode was reimplanted without complication followed by 48 hours of prophylactic intravenous antibiotics. Nine month follow up revealed the implant functioning appropriately, with no further major complications encountered.

CONCLUSION

We present this unique case to demonstrate that a cochlear implant grounding wire extrusion is not necessarily an indication for explantation in the absence of infection.

Research Status and Future Development of Cochlear Reimplantation

Cochlear implants are the most successful sensory prostheses worldwide, and they can be useful for patients with severe and profound hearing impairment. However, various complications, including infection, pain, and device failure which is mainly due to falls and trauma, are associated with the use of cochlear implants. Reimplantation is required to replace the initial device in severe complications. Nevertheless, reimplantation can present certain surgical risks and may impose a significant economic and psychological burden on patients and their families; therefore, it requires greater attention and focus. This article presents a review of the literature on cochlear reimplantation and summarizes the current status, knowledge gaps, and future research directions on cochlear reimplantation. Since 1980s, cochlear reimplantation techniques can be considered to be relatively mature; however, some clinical and scientific problems remain unresolved, including the lack of a unified definition of cochlear reimplantation, non-standardized calculation of the reimplantation rat, and insufficient effect assessment. This review highlights the urgent need to establish an international consensus statement on cochlear reimplantation research to standardize the definition, calculation formulas of reimplantation rate, and follow-up systems.

Scalar position, dislocation analysis and outcome in CI reimplantation due to device failure

Objective

Due to increasing indication for cochlear implantation (CI), reimplantation and technical upgrades their consequences are a special focus in CI surgery research. The aim of this study is to examine the indication and influences on both morphological position of the electrode array and audiological outcome following reimplantation.

Design

This is a retrospective analysis of adult CI patients reimplanted between 2004 and 2019. We evaluated the scalar position in pre- and postoperative cone beam computed tomography (CBCT) after CI and reimplantation and examined the indication for and the audiological outcome following reimplantation.

Results

The reimplanted patients showed stable and comparable audiological results for monosyllables and numbers for best fitted situation before and following reimplantation. Technical upgrades did not result in a significant improvement of speech perception. CBCT scans of reimplanted ears did not show significant increased rates of scalar dislocation or partial insertion.

Conclusion

Even with a technical upgrade, reimplantation does not improve speech perception outcome in CI patients. Therefore, the indication to reimplant should be approved critically. Reimplantation does not lead to a significantly increased risk for partial insertion, scalar dislocation or diminished electrode array insertion angle.

Auditory performance after cochlear reimplantation

AIM

The aim of this study was to evaluate the impact of cochlear reimplantation (CR) on hearing performance in children and adults with severe to profound hearing loss.

MATERIAL AND METHODS

Retrospective observational study.

OBJECTIVES

The main objective of this study was to determine whether there was a difference in hearing performance before and after CR. Secondary objectives were to analyze reasons for CR; to assess correlations between auditory performance and complete electrode reinsertion during CR, age, gender, explantation-to-CR interval, and interval between first implantation and CR; and to assess difference in APCEI score and the French evaluation protocol for implanted patients before and after CR.

RESULTS

Comparison of speech perception scores before and after explantation-reimplantation showed no significant difference (P>0.005) at 1 year or at 2 years after CR. In 80% of cases, reimplantation was due to hard implant failure. In other cases, it was undertaken for soft failure (diminished performance but no abnormalities on integrity testing) (8%), medical reasons (6%), or undetermined reasons (6%). There was no significant correlation between auditory performance at 1 or 2 years and complete or incomplete reinsertion of electrodes, age, gender, explantation-to-CR interval, or interval between first implantation and CR (P>0.005). For the adult subgroup, the French evaluation protocol scores did not differ after reimplantation (P=0.62). Likewise, for the child sub-group, APCEI and CAP results did not deteriorate after reimplantation.

CONCLUSION

Reimplantation had no negative impact on hearing and speech perception, but provided performance equivalent to or better than after initial implantation.

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.

Rates, Indications, and Speech Perception Outcomes of Revision Cochlear Implantations

Revision cochlear implant (RCI) is a growing burden on cochlear implant programs. While reports on RCI rate are frequent, outcome measures are limited. The objectives of the current study were to: (1) evaluate RCI rate, (2) classify indications, (3) delineate the pre-RCI clinical course, and (4) measure surgical and speech perception outcomes, in a large cohort of patients implanted in a tertiary referral center between 1989–2018. Retrospective data review was performed and included patient demographics, medical records, and audiologic outcomes. Results indicated that RCI rate was 11.7% (172/1465), with a trend of increased RCI load over the years. The main indications for RCI were device-related failures (soft-45.4%, hard-23.8%), medical failure (14%), trauma (8.1%), and surgical failure (6.4%). Success rate was 98.8%. Children comprised 78% (134) of the cohort and were more likely than adults to undergo RCI. Most (70%) of the RCIs were performed within 10 years from primary implantation. Speech perception outcome analysis revealed unchanged or improved performance in 85% of the cases and declined performance in 15%. Current findings confirm that RCI is a safe with high clinical efficacy; however, the non-negligible percentage of patients that exhibited declined performance post-RCI should be considered in decision-making processes regarding RCI. Routine follow-up during their first years post-implantation is warranted.

Piloting the recording of electrode voltages (REVS) using surface electrodes as a test to identify cochlear implant electrode migration, extra-cochlear electrodes and basal electrodes causing discomfort

OBJECTIVES

To determine if Electrode Voltage (EV) measurements are potentially suitable as a test for detecting extra-cochlear electrodes in cochlear implants (CIs).

METHODS

EV measurements were made using surface electrodes in live mode in 17 adult cochlear implant (CI) users. Repeatability, the effects of stimulation level, CI active electrode position, (active) recording electrode position and stimulation mode (for Nucleus devices) were investigated.

RESULTS/DISCUSSION

Recordings made in monopolar mode showed good repeatability when the active recording electrode was placed on the ipsilateral earlobe; voltages increased linearly with stimulation level as expected. EVs for basal electrodes differed greatly between partially inserted/migrated devices, fully inserted devices with all electrodes activated, and those with deactivated basal electrodes [χ²(2) = 10.2, p < 0.05 for the most basal electrode]. EVs for Nucleus devices were small for electrodes on the array when compared to those for monopolar return electrodes, except for the participant with extra-cochlear electrodes. We argue that fibrosis around the electrode array facilitated current flow across the round window in this case.

CONCLUSION

The test appears to be a viable approach to detect electrode migration and extra-cochlear electrodes in adult CI users and may also be sensitive to discomfort caused by current leakage from the basal end of the cochlea.

Cochlear Implant Surgery: Endomeatal Approach versus Posterior Tympanotomy

The aim of the present study was to compare the posterior tympanotomy (PT) technique to the endomeatal approach. The endomeatal approach (EMA) for Cochlear Implant (CI) surgery was performed on 98 patients with procident lateral sinus or a small mastoid cavity, on 103 ears (Group A). Conventional mastoidectomy and PT was performed on the other 104 patients, on 107 ears (Group B). Data on all patients were then collected for the following: intra- and post-operative complications, Tinnitus Handicap Inventory (THI), Vertigo Symptom Scale (VSS), duration of surgery, and postoperative discomfort. The difference in the total number of major and minor complications between the case group and the control group was not statistically significant. There was a statistically significant difference in discomfort between the two groups using the Visual Analogue Scale (VAS), both immediately postsurgery (p = 0.02) and after one month (p = 0.04). The mean duration of surgery was 102 ± 29 min for EMA and 118 ± 15 min for the PT technique (p = 0.008). EMA is a faster technique resulting in reduced postoperative patient discomfort in comparison to the PT method. The experience of the surgeon as well as the correct choice of surgical technique are fundamental to successful outcomes for cochlear implant surgery.

Evaluation of Subtotal Petrosectomy Technique in Difficult Cases of Cochlear Implantation

OBJECTIVES

To assess the validity of the subtotal petrosectomy (STP) technique in problematic cases of cochlear implant (CI) surgery, and review indications, outcomes, and related controversies.

STUDY DESIGN

This is a retrospective review of data from a private quaternary referral center of otology and skull base surgery.

PATIENTS AND METHODS

A review of patients who underwent CI with STP (STP-CI) as the leading approach was performed. Demographics, indications, surgical details, and main outcomes were evaluated. The surgeries performed were usually single-stage procedures encompassing a comprehensive mastoidectomy, blind sac closure of the external auditory canal (EAC), and mastoid obliteration with autologous fat.

RESULTS

A total of 107 cases were included. Mean follow-up was 7.1 years (range 1-13 years). The most frequent indication for STP-CI was chronic otitis media with/without cholesteatoma (32.7%), followed by open mastoid cavity (26.1%), and cochlear ossification (17.7%). Other difficult conditions where STP facilitates successful implantation include inner-ear malformations, temporal-bone trauma, unfavorable anatomic conditions, and revision surgery. A planned staged procedure was performed in 3 cases. The rate of major complications was 5.6% (n = 6). Three patients developed postauricular wound dehiscence which eventually resulted in device extrusion. No cases of recurrent/entrapped cholesteatoma, EAC breakdown, or meningitis were encountered. This is the largest single-center series of STP-CI reported in the literature.

CONCLUSIONS

When CI is intended in technically challenging cases or associated with a high risk of complications, STP is effective and reliable. Safe implantation and excellent long-term outcomes can be achieved provided surgical steps are properly followed. Single-stage procedures can be performed in most cases, even when there is active middle-ear disease.

Electrode Afterload: A Valuable Technique in a Case of Short Electrode Insertion

Introduction. The location of the electrode inside the cochlea is important for speech performance. However, many variables, including array length, insertion depth, and individual anatomy, may affect the intracochlear position of the electrode. Insertion deeper than 20 mm and revision surgery are critical situations in which residual hearing and electrode integrity may be at risk. This case report challenges this hypothesis and raises the following question: is it possible to achieve a better speech understanding with an electrode afterload without compromising residual hearing? Case Report. A 73-year-old female patient showed up for evaluation of hearing loss. The patient was operated four times in an external hospital due to cholesteatoma formation in the right ear. Related to a poor aided speech understanding, a CI-surgery was performed. 5 months after the surgery, the subject returned with poor speech understanding. A revision surgery was performed, where the first white marker of the electrode was seen in the round window (20 mm). The electrode was inserted 4 mm deeper into the cochlea. After six and twelve months, the results of the Freiburger monosyllabic speech test improved till 25% and 45%, respectively. Discussion. Hearing preservation is possible with a revisional deeper insertion from 20 mm to 24 mm. In this case, a partial obliteration of an open cavity made the electrode surgically easily accessible. This allowed the deeper insertion during the revision surgery. In a regular surgical field with a posterior tympanotomy, the revision surgery is more challenging and brings the electrode into the risk of an iatrogenic destruction. Conclusion. This case of an electrode afterload after having inserted the electrode initially to mm, demonstrates that hearing can be preserved and speech perception can improve after performing this maneuver.

Cochlear implant failures and reimplantation: A 30-year analysis and literature review

OBJECTIVES/HYPOTHESIS

The objectives of the study were to present an institutional experience with device failures and cochlear reimplantation rates over a 30-year period and to perform a detailed literature review.

STUDY DESIGN

Retrospective institutional experience and literature review.

METHODS

A review of cochlear implant failures over a period of 30 years, between January 1988 and March 2017, at a single institution was conducted. Cochlear implant failures were calculated based on manufacturer, type of failure, and overall failure rate. Survival analysis was performed using Kaplan-Meier curves. An electronic search of the PubMed, Web of Science, and EMBASE databases revealed 24 articles on the topic of cochlear device failure. Data on reimplantation and device failure rates were extracted from this literature review and analyzed.

RESULTS

A total of 804 cochlear implantations were reviewed from three manufacturers. The institutional reimplantation rate was 2.9% compared to the pooled rate of 6.0% calculated from the literature review. Medical failures accounted for 0.5% of the overall failures, device failures accounted for 1.6%, and inconclusive failures account for 0.7%. Survival analysis revealed a significant difference among manufacturers. An improved device failure rate was noted in the adult population (0.8%) as compared to the pediatric population (2.8%).

CONCLUSIONS

This 30-year review represents one of the longest series in the literature examining reimplantation, device failure, and medical failure rates. Cochlear implant survival varied by manufacturer and was significantly better in adult compared to pediatric patients.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:782-789, 2020.

Speech Recognition Outcomes After Cochlear Reimplantation Surgery

This study compares speech recognition outcomes before and after cochlear reimplantation surgery, in relation to clinical factors known before and at time of surgery. Between 2006 and 2015, 2,055 adult cochlear implant surgeries were conducted at this center, of which 87 were reimplantation surgeries (4.2%). Speech recognition scores (SRS) assessed before and after reimplantation were available for 54 adults. Overall, SRS measured after reimplantation were similar to the best SRS obtained by the patient and greater than the last SRS measured before surgery. Additional complications were noted in the clinical files of all patients for which reimplantation was considered unsuccessful (16%).

Cochlear implant revision surgeries in children

Introduction

The surgery during which the cochlear implant internal device is implanted is not entirely free of risks and may produce problems that will require revision surgeries.

Objective

To verify the indications for cochlear implantation revision surgery for the cochlear implant internal device, its effectiveness and its correlation with certain variables related to language and hearing.

Methods

A retrospective study of patients under 18 years submitted to cochlear implant surgery from 2004 to 2015 in a public hospital in Brazil. Data collected were: age at the time of implantation, gender, etiology of the hearing loss, audiological and oral language characteristics of each patient before and after cochlear implant surgery and any need for surgical revision and the reason for it.

Results

Two hundred and sixty-five surgeries were performed in 236 patients. Eight patients received a bilateral cochlear implant and 10 patients required revision surgery. Thirty-two surgeries were necessary for these 10 children (1 bilateral cochlear implant), of which 21 were revision surgeries. In 2 children, cochlear implant removal was necessary, without reimplantation, one with cochlear malformation due to incomplete partition type I and another due to trauma. With respect to the cause for revision surgery, of the 8 children who were successfully reimplanted, four had cochlear calcification following meningitis, one followed trauma, one exhibited a facial nerve malformation, one experienced a failure of the cochlear implant internal device and one revision surgery was necessary because the electrode was twisted.

Conclusion

The incidence of the cochlear implant revision surgery was 4.23%. The period following the revision surgeries revealed an improvement in the subject's hearing and language performance, indicating that these surgeries are valid in most cases.

Pediatric Cochlear implant soft failure

PURPOSE

Hard cochlear implant failures are diagnosed by objective tests whereas soft failures are suspected on the basis of clinical signs and symptoms. This study reviews our experience with children in tertiary pediatric medical center who underwent revision cochlear implantation, with emphasis on soft failures.

MATERIALS AND METHODS

Children (age<18years) who underwent revision cochlear implantation from 2000 to 2012 were identified by database search. Pre- and post-explantation data were collected.

RESULTS

Twenty-six revision surgeries were performed, accounting for 7.4% of all cochlear implant surgeries at our center during the study period. The pre-explantation diagnosis was hard failure in 7 cases (27%), soft failure in 12 (46%), and medical failure in 7 (27%). On post-explantation analysis, 7/12 devices from the soft-failure group with a normal integrity test had abnormal findings, yielding a 63% false-negative rate (12/19) for the integrity test. All children regained their initial performance. Compared to hard failures, soft failures were associated with a shorter median time from first implantation to symptom onset (8 vs 25months) but a significantly longer time from symptom onset to revision surgery (17.5 vs 3months; P=0.004).

CONCLUSIONS

Soft cochlear implant failure in young patients poses a diagnostic challenge. A high index of suspicion is important because a delayed diagnosis may have severe consequences for language development. A normal integrity test does not unequivocally exclude device failure and is unrelated to functional outcome after revision surgery. Better education of parents and rehabilitation teams is needed in addition to more accurate diagnostic tests.

Comparisons of Auditory Performance and Speech Intelligibility after Cochlear Implant Reimplantation in Mandarin-Speaking Users

Objectives. We evaluated the causes, hearing, and speech performance before and after cochlear implant reimplantation in Mandarin-speaking users. Methods. In total, 589 patients who underwent cochlear implantation in our medical center between 1999 and 2014 were reviewed retrospectively. Data related to demographics, etiologies, implant-related information, complications, and hearing and speech performance were collected. Results. In total, 22 (3.74%) cases were found to have major complications. Infection (n = 12) and hard failure of the device (n = 8) were the most common major complications. Among them, 13 were reimplanted in our hospital. The mean scores of the Categorical Auditory Performance (CAP) and the Speech Intelligibility Rating (SIR) obtained before and after reimplantation were 5.5 versus 5.8 and 3.7 versus 4.3, respectively. The SIR score after reimplantation was significantly better than preoperation. Conclusions. Cochlear implantation is a safe procedure with low rates of postsurgical revisions and device failures. The Mandarin-speaking patients in this study who received reimplantation had restored auditory performance and speech intelligibility after surgery. Device soft failure was rare in our series, calling attention to Mandarin-speaking CI users requiring revision of their implants due to undesirable symptoms or decreasing performance of uncertain cause.