Implanting Obstructed and Malformed Cochleae

Brazilian Society of Otology task force - cochlear implant ‒ recommendations based on strength of evidence

OBJECTIVE

To make evidence-based recommendations for the indications and complications of Cochlear Implant (CI) surgery in adults and children.

METHODS

Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on cochlear implantation were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions.

RESULTS

The topics were divided into 2 parts: (1) Evaluation of candidate patients and indications for CI surgery; (2) CI surgery - techniques and complications.

CONCLUSIONS

CI is a safe device for auditory rehabilitation of patients with severe-to-profound hearing loss. In recent years, indications for unilateral hearing loss and vestibular schwannoma have been expanded, with encouraging results. However, for a successful surgery, commitment of family members and patients in the hearing rehabilitation process is essential.

New Instruments for the Management of Cochlear Implantation in an Individual with a Fracture of the Temporal Bone and Cochlear Ossification

Cochlear implant surgery can be highly complex in cases where ossification of the internal ear has taken place. In this case report, we report the use of new technological instruments to optimise the surgical process of implantation. These were the combined use of a surgical approach extended by a subtotal petrosectomy, a pre-operative radiological study with the OTOPLAN software for choosing the most suitable electrode array, and a residual functionality test of the auditory nerve using the ANTS test electrode array prior to inserting the cochlear implant electrode array. These were used to successfully treat a case of total deafness caused by a fracture in the temporal bone complicated with ossification of the basal turn of the cochlea. These instruments ensured that the operation was performed with excellent results, reducing the risk of failure to a minimum in this complex case.

Auditory nerve fiber excitability for alternative electrode placement in the obstructed human cochlea: electrode insertion in scala vestibuli versus scala tympani

Objective. The cochlear implant (CI) belongs to the most successful neuro-prostheses. Traditionally, the stimulating electrode arrays are inserted into the scala tympani (ST), the lower cochlear cavity, which enables simple surgical access. However, often deep insertion is blocked, e.g. by ossification, and the auditory nerve fibers (ANFs) of lower frequency regions cannot be stimulated causing severe restrictions in speech understanding. As an alternative, the CI can be inserted into the scala vestibuli (SV), the other upper cochlear cavity.Approach. In this computational study, the excitability of 25 ANFs are compared for stimulation with ST and SV implants. We employed a 3-dimensional realistic human cochlear model with lateral wall electrodes based on aμ-CT dataset and manually traced fibers. A finite element approach in combination with a compartment model of a spiral ganglion cell was used to simulate monophasic stimulation with anodic (ANO) and cathodic (CAT) pulses of 50μs.Main results. ANO thresholds are lower in ST (mean/std =μ/σ= 189/55μA) stimulation compared to SV (μ/σ= 323/119μA) stimulation. Contrary, CAT thresholds are higher for the ST array (μ/σ= 165/42μA) compared to the SV array (μ/σ= 122/46μA). The threshold amplitude depends on the specific fiber-electrode spatial relationship, such as lateral distance from the cochlear axis, the angle between electrode and target ANF, and the curvature of the peripheral process. For CAT stimulation the SV electrodes show a higher selectivity leading to less cross-stimulation of additional fibers from different cochlear areas.Significance. We present a first simulation study with a human cochlear model that investigates an additional CI placement into the SV and its impact on the excitation behavior. Results predict comparable outcomes to ST electrodes which confirms that SV implantation might be an alternative for patients with a highly obstructed ST.

Cochlear Implantation by Veria Technique in Abnormal Cochlea: Our Experience

This study describes the clinical profile, operative findings, surgical technique, type of implant and complications encountered in implantation of abnormal cochlea by the transcanal (veria) technique in a tertiary care centre. This is a retrospective study done amongst 337 patients who underwent cochlear implantation by veria technique between January 2013 to August 2023. Based on pre-operative imaging with high-resolution computed tomography and magnetic resonance imaging the cochleovestibular malformations in this study were classified according to Sennaroglu classification and the cochlear ossification was graded from I to IV. Amongst the 337 patients who underwent cochlear implantation during the study period there were 79 cases (23.4%) with abnormalities of cochlea. This included 45 patients (13.4%) with congenital malformations, 20 patients (5.9%) with cochlear fibrosis and 14 patients (4.2%) with cochlear ossification. The commonest cochlear malformation was Incomplete Partition 2 which was present in 21 patients (46.7%). The other common malformations were cochlear hypoplasia (31.1%), Incomplete Partition 1(13.3%) and common cavity (8.9%). Out of the 20 patients with cochlear fibrosis, 17 patients had fibrosis only in the basal turn. Out of the 14 patients with cochlear ossification 8 patients (57.1%) had a grade 1 ossification, 2 patients (14.3%) had a grade 2 ossification and 4 patients (28.6%) had a grade 3 ossification. One of the patients required re-exploration for correcting the placement of electrode. The type of implant were chosen depending on individual malformation or length of ossification and fibrosis. In the past, inner ear anomalies were considered as a contraindication for cochlear implantation however it is now possible to implant most of these abnormal cochlea by careful planning, a modification of the surgical technique and the type of electrode used.

Programming Levels and Speech Perception in Pediatric Cochlear Implant Recipients With Enlarged Vestibular Aqueduct or GJB2 Mutation

OBJECTIVE

To determine the relationship between hearing loss etiology, cochlear implant (CI) programming levels, and speech perception performance in a large clinical cohort of pediatric CI recipients.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary care hospitals.

PATIENTS

A total of 136 pediatric CI recipients (218 ears) were included in this study. All patients had diagnoses of either enlarged vestibular aqueduct (EVA) or GJB2 (Connexin-26) mutation confirmed via radiographic data and/or genetic reports. All patients received audiologic care at either Boston Children's Hospital or Massachusetts Eye and Ear in Boston, MA, between the years 1999 and 2020.

MAIN OUTCOME MEASURES

Electrode impedances and programming levels for each active electrode and speech perception scores were evaluated as a function of etiology (EVA or GJB2 mutation).

RESULTS

Children with EVA had significantly higher impedances and programming levels (thresholds and upper stimulation levels) than the children with GJB2 mutation. Speech perception scores did not differ as a function of etiology in this sample; rather, they were positively correlated with duration of CI experience (time since implantation).

CONCLUSIONS

Differences in electrode impedances and CI programming levels suggest that the electrode-neuron interface varies systematically as a function of hearing loss etiology in pediatric CI recipients with EVA and those with GJB2 mutation. Time with the CI was a better predictor of speech perception scores than etiology, suggesting that children can adapt to CI stimulation with experience.

Cochlear implantation for post-meningitis deafness with cochlear ossification: diagnosis and surgical strategy

BACKGROUND

Cochlear ossification (CO) after meningitis can cause profound sensorineural hearing loss (SNHL). Cochlear implantation (CI) is the ideal treatment strategy for CO.

AIMS

To explore the strategy for CI in patients with CO after meningitis.

MATERIALS AND METHODS

In this retrospective study, the medical records of patients diagnosed with profound SNHL due to CO after meningitis and who underwent CI in our department between September 2010 and September 2021 were collected and reviewed. Their imaging and surgical findings were analyzed.

RESULTS

The data of 26 patients with unilateral CI were reviewed. All patients underwent preoperative temporal high-resolution computed tomography (HRCT) and 22 patients magnetic resonance imaging (MRI). The sensitivity of HRCT was 61.5% (10/26), whereas that of MRI was 81.8% (18/22). Combined HRCT and MRI achieved a detection rate of 92.3% (24/26). Twenty-two and four patients underwent complete and partial electrode implantations, respectively.

CONCLUSIONS AND SIGNIFICANCE

Preoperative temporal bone HRCT and MRI are essential for determining whether a patient is suitable for CI and surgical planning. A false-negative diagnosis is possible when diagnosing CO, but combined HRCT and MRI can improve the positive rate of preoperative diagnosis of CO post meningitis. Early CI is recommended.

Cochlear Implantation in Advanced Otosclerosis: Pitfalls and Successes

Purpose of Review

This review will highlight recent outcome-based evidence guiding decision making for cochlear implantation in advanced otosclerosis, related complications, and technical surgical considerations in otosclerosis and the obstructed cochlea.

Recent Findings

Cochlear implantation in advanced otosclerosis results in consistent, excellent auditory outcomes with improvement in both objective speech recognition scores and subjective quality of life measures. Facial nerve stimulation may occur at higher rates in otosclerosis cochlear implant recipients. Cochlear implantation in the setting of luminal obstruction in osteosclerotic patients may be managed with altered surgical technique to achieve successful auditory improvements. Pre-operative imaging with high resolution CT or MRI may help anticipate intraoperative challenges and post-operative complications in cochlear implantation.

Summary

Cochlear implantation is an established, successful treatment for profound hearing loss in advanced otosclerosis. Surgeon knowledge of outcomes, complications, and potential surgical challenges is important to appropriately counsel patients regarding auditory rehabilitation options in advanced otosclerosis.

Revision cochlear implantation using a double array device in the post-meningitis ossified cochlea

PURPOSE

To describe the surgical technique and outcome in a series of patients who underwent revision cochlear implantation using a double array or split electrode device. All patients developed ossified cochleae due to meningitis and were functioning poorly with the previous implant.

METHODS

Four patients between the ages of 4-15 years underwent revision with five double-array cochlear implant devices. One patient underwent bilateral revision surgery. All patients had previous meningitis with CT and MRI imaging studies that demonstrated completely ossified cochleae. The time interval range between the disease and the initial cochlear implantation and was 4 months to 3 years. The patient's data were retrospectively analyzed with emphasis on the surgical technique, the number of electrodes inserted, and the number of active electrodes at follow-up. In addition, pre and post-revision surgery function was compared.

RESULTS

The revision surgery was carried out 2-11 years after the initial surgery. Two tunnels, basal and apical, were drilled in the ossified cochlea. In each of the tunnels, 5 to 11 electrodes were inserted. While the number of active electrodes before revision was 0-5, after revision with the double array, it was increased to 8-12, resulting in improved auditory and speech function.

CONCLUSION

Revision cochlear implantation with a double array implant using the two tunnel technique can increase the number of active electrodes. This leads to a better outcome in post-meningitis children with completely ossified cochleae and a poor functioning previous device.

MRI of the Internal Auditory Canal, Labyrinth, and Middle Ear: How We Do It

MRI is firmly established as an essential modality in the imaging of the temporal bone and lateral skull base. It is used to evaluate normal anatomic structures, evaluate for vestibular schwannomas, assess for inflammatory and/or infectious processes, and detect residual and/or recurrent cholesteatoma. It is also extensively used in pre- and postoperative evaluations, particularly in patients with vestibular schwannomas and candidates for cochlear implantation. Nevertheless, despite the widespread use of MRI for these purposes, many radiologists remain unfamiliar with the complex anatomy and expected imaging findings with such examinations. The purpose of this review is to provide an overview of the most useful MRI sequences for internal auditory canal and labyrinthine imaging, review the relevant anatomy, and discuss the expected appearances of the most commonly encountered pathologic entities. In addition, the features at pre- and postprocedural MRI will be discussed to help ensure that diagnostic radiologists may be of greatest use to the ordering physicians. © RSNA, 2020.

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.

Anatomical landmarks for cochlear implantatıon in ossifıed cochleas

PURPOSE

In this study, we aimed to introduce the facial nerve as a new anatomical landmark which can be used in ossified cochleas during cochlear implantation. We also set out to define a safe line to preserve the internal auditory canal (IAC) while drilling the basal turn of the cochlea.

METHODS

Thirty patients who had temporal computed tomography (CT) were studied. The distances from the facial nerve and the round window to the IAC, carotid artery, and jugular bulb were measured in the reformatted CT images. We have created a line in the direction of the stapedial tendon from the round window to the IAC and called it ROWIAC (Round window-IAC) line. We have investigated whether this line intersects the IAC and measured the distances from this line to the IAC.

RESULTS

Fifty-four temporal CT scans were included to the study. The mean distances from the facial nerve to the IAC, carotid artery, and jugular bulb were 8.8 ± 0.9, 15.0 ± 2.0, and 12.2 ± 2.9 mm, respectively. The mean distances from the round window to these structures were 3.8 ± 0.7, 9.4 ± 2.2, and 8.3 ± 2.9 mm, respectively. ROWIAC line did not intersect the IAC in any of the patients. The mean distance between this line and the IAC was 0.8 ± 0.4 mm.

CONCLUSION

We propose that facial nerve and ROWIAC line can be used as potential landmarks during cochlear implantation in ossified cochleas to protect the adjacent neurovascular structures.

Auditory Detection Thresholds and Cochlear Resistivity Differ Between Pediatric Cochlear Implant Listeners With Enlarged Vestibular Aqueduct and Those With Connexin-26 Mutations

Purpose The goal of this study was to evaluate differences in the electrode-neuron interface as a function of hearing loss etiology in pediatric cochlear implant (CI) listeners with enlarged vestibular aqueduct (EVA) syndrome and in those with autosomal recessive connexin-26 mutations (DFNB1). Method Fifteen implanted ears (9 participants, 5 ears with EVA, 10 ears with DFNB1) were assessed. Single-channel auditory detection thresholds were measured using broad and spatially focused electrode configurations (steered quadrupolar; focusing coefficients = 0 and 0.9). Cochlear resistivity estimates were obtained via electrode impedances and electrical field imaging. Between-group differences were evaluated using linear mixed-effects models. Results Children with EVA had significantly higher auditory detection thresholds than children with DFNB1, irrespective of electrode configuration. Between-group differences in thresholds were more pronounced on apical electrodes than on basal electrodes. In the apex, electrode impedances and electrical field imaging values were higher for children with EVA than for those with DFNB1. Conclusions The electrode-neuron interface differs between pediatric CI listeners with DFNB1 and those with EVA. It is possible that optimal clinical interventions may depend, in part, on hearing loss etiology. Future investigations with large samples should investigate individualized CI programming strategies for listeners with EVA and DFNB1.

Assessing the Benefit-Risk Profile for Pediatric Implantable Auditory Prostheses

BACKGROUND/AIMS

Children with congenital cochleovestibular abnormalities associated with profound hearing loss have few treatment options if cochlear implantation does not yield benefit. An alternative is the auditory brainstem implant (ABI). Regulatory authority device approvals currently include a structured benefit-risk assessment. Such an assessment, for regulatory purposes or to guide clinical decision making, has not been published, to our knowledge, for the ABI and may lead to the design of a research program that incorporates regulatory authority, family, and professional input.

METHODS

Much structured benefit-risk research has been conducted in the context of drug trials; here we apply this approach to device studies. A qualitative framework organized benefit (speech recognition, parent self-report measures) and risk (surgery- and device-related) information to guide the selection of candidates thought to have potential benefit from ABI.

RESULTS

Children with cochleovestibular anatomical abnormalities are challenging for appropriate assessment of candidacy for a cochlear implant or an ABI. While the research is still preliminary, children with an ABI appear to slowly obtain benefit over time. A team of professionals, including audiological, occupational, and educational therapy, affords maximum opportunity for benefit.

CONCLUSIONS

Pediatric patients who have abnormal anatomy and are candidates for an implantable auditory prosthetic require an individualized, multisystems review. The qualitative benefit-risk assessment used here to characterize the condition, the medical need, potential benefits, risks, and risk management strategies has revealed the complex factors involved. After implantation, continued team support for the family during extensive postimplant therapy is needed to develop maximum auditory skill benefit.

Auditory brainstem implant in postmeningitis totally ossified cochleae

INTRODUCTION

An auditory brainstem implant (ABI) is an option for auditory rehabilitation in patients with totally ossified cochleae who cannot receive a conventional cochlear implant.

OBJECTIVE

To evaluate the outcomes in audiometry and speech perception tests after the implantation of an ABI via the extended retrolabyrinthine approach in patients with postmeningitis hearing loss.

MATERIALS AND METHODS

Ten patients, including children and adults, with postmeningitis hearing loss and bilateral totally ossified cochleae received an ABI in a tertiary center from 2009 to 2015. The extended retrolabyrinthine approach was performed in all the patients by the same surgeons. A statistical analysis compared pure tonal averages and speech perception tests before and at least 12 months after the ABI activation.

RESULTS

Eight patients (80%) showed improvements in tonal audiometry and the word and vowel perception tests after an average follow-up of 3.3 years. Two patients recognized up to 40% of the closed-set sentences without lip-reading. Two patients had no auditory response.

CONCLUSIONS

The ABI improved hearing performance in audiometry and speech perception tests in cases of postmeningitis hearing loss. The extended retrolabyrinthine approach is a safe surgical option for patients with postmeningitis hearing loss and bilateral totally ossified cochleae.

Comparative Impacts of Scala Vestibuli Versus Scala Tympani Cochlear Implantation on Auditory Performances and Programming Parameters in Partially Ossified Cochleae

OBJECTIVE

To compare scala vestibuli versus scala tympani cochlear implantation in terms of postoperative auditory performances and programming parameters in patients with severe scala tympani ossification.

STUDY DESIGN

Retrospective case-control study.

SETTING

Tertiary referral center.

PATIENTS

One hundred three pediatric and adult patients who underwent cochlear implant surgery between 2000 and 2016. Three groups were formed: a scala vestibuli group, a scala tympani with ossification group, and a scala tympani without ossification group. Patients were matched based on their age, sex, duration of deafness, and side of implantation (ratio of 1:2:2).

INTERVENTIONS

Postoperative evaluation of auditory performances and programming parameters following intensive functional rehabilitation program completion.

MAIN OUTCOME MEASURES

Multimedia adaptive test (MAT), hearing in noise test (HINT SNR +10 dB, HINT SNR +5 dB, and HINT SNR +0 dB), impedances, neural response telemetry thresholds (NRT), neural response imaging thresholds (NRI), comfortable levels (C-levels), and threshold levels (T-levels) were compared between groups.

RESULTS

Twenty-one patients underwent scala vestibuli cochlear implantation: 19 adults and two children. Auditory performances were similar between groups, although sentence recognition in a noisy environment was slightly higher in the scala vestibuli group. Impedance values were also higher in the scala vestibuli group, but all other programming parameters were similar between groups.

CONCLUSIONS

We present the largest series of patients with scala vestibuli cochlear implantation. This approach provides at least comparable auditory performances without having any deleterious effects on programming parameters. This viable and useful insertion route might be the primary surgical alternative when facing partial cochlear ossification.

Programming characteristics of cochlear implants in children: effects of aetiology and age at implantation

OBJECTIVE

We investigated effects of aetiology and age at implantation on changes in threshold (T) levels, comfortable (C) levels and dynamic range (DR) for cochlear implants (CIs) in children over the first five years of life.

DESIGN

Information was collected at 6 months post-activation of CIs, and at 3 and 5 years of age.

STUDY SAMPLE

One hundred and sixty-one children participating in the Longitudinal Outcomes of Children with Hearing Impairment (LOCHI) study.

RESULTS

Children with neural and structural cochlear lesions had higher T-levels and C-levels as compared to those without these conditions. Parameter settings varied from manufacturer's defaults more often in the former than in the latter group. Investigation of the effect of age at implantation for children without neural and structural cochlear lesions showed that those implanted at ≤12 months of age had higher T-levels and narrower DR at 6 months post-activation, as compared to the later-implanted group. For both early- and later-implanted groups, the C-levels at 6 months post-activation were lower than those at age 3 and 5 years. There were no significant differences in T-levels, C-levels, or DR between age 3 and 5 years.

CONCLUSIONS

Aetiology and age at implantation had significant effects on T-levels and C-levels.

Life-threatening unilateral hearing impairments. Review of the literature on the association between inner ear malformations and meningitis

BACKGROUND

Bacterial meningitis is a life threatening disease that can be triggered by a CSF leak through an inner ear malformation. Early identification of the specific type of cochleovestibular dysplasia and the associated risk of meningitis is of vital importance.

OBJECTIVES

The objective of this review is to collect and discuss available data on the association between inner ear malformations and meningitis in children.

METHODS

Electronic databases were crosschecked for obtaining relevant papers published in the last 20 years, and further cases were identified by hand searching through the references. Demographic data were extracted from full texts, together with information on the severity of hearing impairment, the type of inner ear anomaly, the site of cerebrospinal fluid leak, the number of recurrent meningitis episodes.

RESULTS

Sixty-seven cases of meningitis related to inner ear malformation have been identified among 45 papers. Mean age at presentation is 3.60±3.00 (range 0.1-14) years. Average diagnostic delay from the first episode of meningitis is 3.44±3.41 (range 0.00-10.00) years. The number of meningitis episodes that occurred before the correct diagnosis and definitive surgical treatment is 3.27±1.81 (range 1.00-10.00). Unilateral hearing impairment affects 70% of patients. Six patients had normal hearing at presentation. Two children are dead from inner-ear-malformation-related meningitis among reviewed reports.

CONCLUSION

A high number of paediatric patients carrying inner ear malformations, especially when associated with unilateral hearing impairment, could be at risk to develop recurrent bacterial meningitis. Universal newborn hearing screening programs should prompt a diagnostic work-up even in the case of unilateral hearing impairment, in order to prevent inner ear malformation-related meningitis.

Role of HRCT and MRI of the Temporal Bone in Predicting and Grading the Degree of Difficulty of Cochlear Implant Surgery

This study proposes a grading system based on a 10-point scoring chart of high resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) imaging findings in patients being assessed preoperatively for cochlear implantation. This system helps in objectively assessing the degree of difficulty of the surgical procedure and alerts the surgeons to any potential intraoperative complications. This is a prospective study carried out at a tertiary referral center where 55 patients with bilateral profound sensorineural hearing loss were evaluated by HRCT and MRI and subsequently underwent cochlear implantation. HRCT examinations were performed on a 64 slice multidetector CT scanner. MRI examinations were performed on a 3.0 Tesla MRI scanner. A 10-point scoring chart was devised based on specific imaging findings and all patients were assigned potential difficulty scores (PDS) based on HRCT and MRI findings. Surgical times were documented in each case and each imaging point on the scoring chart was correlated with the surgical times. Eight out of theó ten points in the scoring chart proved to be statistically significant in predicting the degree of difficulty of the surgical procedure. After grading the pre-operative imaging examinations based on the 10-point scoring chart we concluded that patients who have PDS between 0 and 3 (Grade 1) have uneventful and uncomplicated surgery with the lowest intraoperative times. Patients with PDS between 4 and 7 alert the surgeon to moderate surgical difficulty and longer intraoperative times. PDS of 8 and above indicate prolonged and difficult surgery.

Implantation of the completely ossified cochlea: an image-guided approach

OBJECTIVES

To report a novel modification of the cochlear drill-out procedure that uses customized microstereotactic frames as drill guides.

PATIENT(S)

A 34-year-old man with an 18-year history of profound bilateral hearing loss and completely ossified cochleae that underwent a previous unsuccessful conventional cochlear drill-out procedure in the contralateral ear.

INTERVENTIONS

Image-guided cochlear implantation using customized microstereotactic frames to drill linear basal and apical cochlear tunnels.

MAIN OUTCOME MEASURES

Transfacial recess cochlear drill-out procedure with full electrode insertion.

RESULTS

Two linear paths were drilled using customized microstereotactic frames targeting the proximal and distal basal turn followed by a full split array insertion. Postoperative imaging confirmed 2 cochlear tunnels straddling the modiolus with adequate clearance of the facial nerve and internal carotid artery. The patient received auditory benefit with device use and did not experience any surgical complication.

CONCLUSION

Successful cochlear implantation in the setting of total scalar obliteration poses a significant challenge. Image guidance technology may assist in navigating the ossified cochlea facilitating safe and precise cochlear tunnel drilling.

Cochlear implant challenges encountered in tuberculous otitis media

Tuberculous otitis media (TOM) is rare in ENT department, and is frequently misdiagnosed as otitis media. Thus early systemic treatment is very important for TOM. We reported a case report with TOM to highlight development of the disease and difficulties in clinical treatment in late stage of TOM. Implantation of ossified and eroded cochlea poses many unique challenges to both the surgeon and programming team. With thorough preparation and complete knowledge about characters of specific issues, implantation would be performed successfully, and patients with ossified cochlear could benefit from cochlear implantation.