Intraoperative Correction of Cochlear Implant Electrode Translocation

2021 ◽  
pp. 1-5
Author(s):  
William G. Morrel ◽  
Nauman F. Manzoor ◽  
Benoit M. Dawant ◽  
Jack H. Noble ◽  
Robert F. Labadie
Keyword(s):  
Cochlear Implant ◽  
Average Distance ◽  
Electrode Array ◽  
High Rate ◽  
Insertion Depth ◽  
Electrode Contact ◽  
Temporal Bones ◽  
Hearing Outcomes ◽  
Rate Of Success

<b><i>Introduction:</i></b> Translocation of precurved cochlear implant (CI) electrodes reduces hearing outcomes, but it is not known whether it is possible to correct scalar translocation such that all electrodes reside fully in the scala tympani (ST). <b><i>Methods:</i></b> Six cadaveric temporal bones were scanned with CT and segmented to delineate intracochlear anatomy. Mastoidectomy with facial recess was performed. Precurved CI electrodes (CI532; Cochlear Limited) were implanted until scalar translocation was confirmed with postoperative CT. Then, electrodes were removed and replaced. CT scan was repeated to assess for translocation correction. Scalar position of electrode contacts, angular insertion depth (AID) of the electrode array, and <i>M</i>– (average distance between each electrode contact and the modiolus) were measured. An in vivo case is reported in which intraoperative translocation detection led to removal and replacement of the electrode. <b><i>Results:</i></b> Five of 6 cadaveric translocations (83%) were corrected with 1 attempt, resulting in full ST insertions. AID averaged 285 ± 77° for translocated electrodes compared to 344 ± 28° for nontranslocated electrodes (<i>p</i> = 0.109). <i>M</i>– averaged 0.75 ± 0.18 mm for translocated electrodes and 0.45 ± 0.11 mm for nontranslocated electrodes (<i>p</i> = 0.016). Reduction in <i>M</i>– with translocation correction averaged 38%. In the in vivo case, translocation was successfully corrected in a single attempt. <b><i>Conclusion:</i></b> Scalar translocation of precurved CI electrodes can be corrected by removal and reinsertion. This significantly improves the perimodiolar positioning of these electrodes. There was a high rate of success (83%) in this cadaveric model as well as a successful in vivo attempt.

Development and Characterization of an Electrocochleography-Guided Robotics-Assisted Cochlear Implant Array Insertion System

2021 ◽  
pp. 019459982110492
Author(s):  
Allan M. Henslee ◽  
Christopher R. Kaufmann ◽  
Matt D. Andrick ◽  
Parker T. Reineke ◽  
Viral D. Tejani ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Real Time ◽  
Signal To Noise Ratio ◽  
Electrode Array ◽  
High Signal ◽  
Animal Testing ◽  
Signal To Noise ◽  
Noise Ratio ◽  
Hearing Outcomes

Objective Electrocochleography (ECochG) is increasingly being used during cochlear implant (CI) surgery to detect and mitigate insertion-related intracochlear trauma, where a drop in ECochG signal has been shown to correlate with a decline in hearing outcomes. In this study, an ECochG-guided robotics-assisted CI insertion system was developed and characterized that provides controlled and consistent electrode array insertions while monitoring and adapting to real-time ECochG signals. Study Design Experimental research. Setting A research laboratory and animal testing facility. Methods A proof-of-concept benchtop study evaluated the ability of the system to detect simulated ECochG signal changes and robotically adapt the insertion. Additionally, the ECochG-guided insertion system was evaluated in a pilot in vivo sheep study to characterize the signal-to-noise ratio and amplitude of ECochG recordings during robotics-assisted insertions. The system comprises an electrode array insertion drive unit, an extracochlear recording electrode module, and a control console that interfaces with both components and the surgeon. Results The system exhibited a microvolt signal resolution and a response time <100 milliseconds after signal change detection, indicating that the system can detect changes and respond faster than a human. Additionally, animal results demonstrated that the system was capable of recording ECochG signals with a high signal-to-noise ratio and sufficient amplitude. Conclusion An ECochG-guided robotics-assisted CI insertion system can detect real-time drops in ECochG signals during electrode array insertions and immediately alter the insertion motion. The system may provide a surgeon the means to monitor and reduce CI insertion–related trauma beyond manual insertion techniques for improved CI hearing outcomes.

Evaluating Intracochlear Trauma after Cochlear Implant Electrode Insertion through Middle Fossa Approach in Temporal Bones

2017 ◽  
Vol 158 (2) ◽  
pp. 350-357 ◽  
Author(s):  
Juan Carlos Cisneros Lesser ◽  
Rubens de Brito ◽  
Graziela de Souza Queiroz Martins ◽  
Eloisa Maria Mello Santiago Gebrim ◽  
Ricardo Ferreira Bento
Keyword(s):  
Cochlear Implant ◽  
Round Window ◽  
Middle Cranial Fossa ◽  
Middle Fossa ◽  
Insertion Depth ◽  
Middle Fossa Approach ◽  
Basal Turn ◽  
Fresh Frozen ◽  
Electrode Insertion ◽  
Temporal Bones

Objective To evaluate cochlear trauma after cochlear implant insertion through a middle fossa approach by means of histologic and imaging studies in temporal bones. Study Design Prospective cadaveric study. Setting University-based temporal bone laboratory. Subjects and Methods Twenty fresh-frozen temporal bones were implanted through a middle cranial fossa basal turn cochleostomy. Ten received a straight electrode and 10 a perimodiolar electrode. Samples were fixed in epoxy resin. Computed tomography (CT) scans determined direction, depth of insertion, and the cochleostomy to round window distance. The samples were polished by a microgrinding technique and microscopically visualized to evaluate intracochlear trauma. Descriptive and analytic statistics were performed to compare both groups. Results The CT scan showed intracochlear insertions in every bone, 10 directed to the middle/apical turn and 10 to the basal turn. In the straight electrode group, the average number of inserted electrodes was 12.3 vs 15.1 for the perimodiolar group ( U = 78, P = .0001). The median insertion depth was larger for the perimodiolar group (14.4 mm vs 12.5 mm, U = 66, P = .021). Only 1 nontraumatic insertion was achieved and 14 samples (70%) had important trauma (Eshraghi grades 3 and 4). No differences were identified comparing position or trauma grades for the 2 electrode models or when comparing trauma depending on the direction of insertion. Conclusion The surgical technique allows a proper intracochlear insertion, but it does not guarantee a correct scala tympani position and carries the risk of important trauma to cochlear microstructures.

scholarly journals Robot-Assisted Electrode Array Insertion Becomes Available in Pediatric Cochlear Implant Recipients: First Report and an Intra-Individual Study

2021 ◽  
Vol 8 ◽  
Author(s):  
Huan Jia ◽  
Jinxi Pan ◽  
Wenxi Gu ◽  
Haoyue Tan ◽  
Ying Chen ◽  
...  
Keyword(s):  
Cochlear Implantation ◽  
Electrode Array ◽  
Pure Tone Audiometry ◽  
Lateral Wall ◽  
Robot Assisted ◽  
Insertion Depth ◽  
Safety And Reliability ◽  
Radiological Measurements ◽  
Auditory Performance ◽  
Temporal Bones

Background: As an advanced surgical technique to reduce trauma to the inner ear, robot-assisted electrode array (EA) insertion has been applied in adult cochlear implantation (CI) and was approved as a safe surgical procedure that could result in better outcomes. As the mastoid and temporal bones are generally smaller in children, which would increase the difficulty for robot-assisted manipulation, the clinical application of these systems for CI in children has not been reported. Given that the pediatric candidate is the main population, we aim to investigate the safety and reliability of robot-assisted techniques in pediatric cochlear implantation.Methods: Retrospective cohort study at a referral center in Shanghai including all patients of simultaneous bilateral CI with robotic assistance on one side (RobOtol® system, Collin ORL, Bagneux, France), and manual insertion on the other (same brand of EA and CI in both side), from December 2019 to June 2020. The surgical outcomes, radiological measurements (EA positioning, EA insertion depth, mastoidectomy size), and audiological outcomes (Behavior pure-tone audiometry) were evaluated.Results: Five infants (17.8 ± 13.5 months, ranging from 10 to 42 months) and an adult (39 years old) were enrolled in this study. Both perimodiolar and lateral wall EAs were included. The robot-assisted EA insertion was successfully performed in all cases, although the surgical zone in infants was about half the size in adults, and no difference was observed in mastoidectomy size between robot-assisted and manual insertion sides (p = 0.219). The insertion depths of EA with two techniques were similar (P = 0.583). The robot-assisted technique showed no scalar deviation, but scalar deviation occurred for one manually inserted pre-curved EA (16%). Early auditory performance was similar to both techniques.Conclusion: Robot-assisted technique for EA insertion is approved to be used safely and reliably in children, which is possible and potential for better scalar positioning and might improve long-term auditory outcome. Standard mastoidectomy size was enough for robot-assisted technique. This first study marks the arrival of the era of robotic CI for all ages.

scholarly journals Evaluation of the Relationship between the NRT-Ratio, Cochlear Anatomy, and Insertions Depth of Perimodiolar Cochlear Implant Electrodes

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Philipp Mittmann ◽  
Grit Rademacher ◽  
Sven Mutze ◽  
Frederike Hassepass ◽  
Arneborg Ernst ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Electrode Array ◽  
Scala Tympani ◽  
Flat Panel ◽  
Insertion Depth ◽  
Tomography System ◽  
Neural Response Telemetry ◽  
Auditory Performance ◽  
The Relationship ◽  
Scala Vestibuli

The position of the cochlear implant electrode array within the scala tympani is essential for an optimal postoperative hearing benefit. If the electrode array changes in between the scalae intracochlearly (i.e., from scala tympani to scala vestibuli), a reduced auditory performance can be assumed. We established a neural response telemetry-ratio (NRT-ratio) which corresponds with the scalar position of the electrodes but shows within its limits a variability. The aim of this study was to determine if insertion depth angle or cochlea size influences the NRT-ratio. The intraoperative electrophysiological NRT data of 26 patients were evaluated. Using a flat panel tomography system, the position of the electrode array was evaluated radiologically. The insertion depth angle of the electrode, the cochlea size, and the NRT-ratio were calculated postoperatively. The radiological results were compared with the intraoperatively obtained electrophysiological data (NRT-ratio) and statistically evaluated. In all patients the NRT-ratio, the insertion depth angle, and the cochlea size could be determined. A significant correlation between insertional depth, cochlear size, and the NRT-ratio was not found. The NRT-ratio is a reliable electrophysiological tool to determine the scalar position of a perimodiolar electrode array. The NRT-ratio can be applied independent from insertion depth and cochlear size.

In Vivo Measurements of the Insertion Depth of Cochlear Implant Arrays Using Flat-Panel Volume Computed Tomography

2011 ◽  
Vol 32 (1) ◽  
pp. 152-157 ◽  
Author(s):  
Annett Trieger ◽  
Anja Schulze ◽  
Matthias Schneider ◽  
Thomas Zahnert ◽  
Dirk Mürbe
Keyword(s):  
Computed Tomography ◽  
Cochlear Implant ◽  
Flat Panel ◽  
Insertion Depth ◽  
In Vivo Measurements ◽  
Volume Computed Tomography

scholarly journals MRI Pattern of Various Cochlear Implant Electrodes In Vivo

2019 ◽  
Vol 2 (02) ◽  
pp. 51-55
Author(s):  
Holger Sudhoff ◽  
Conrad Riemann ◽  
Hans Björn Gehl ◽  
Ingo Todt
Keyword(s):  
Cochlear Implant ◽  
Spin Echo ◽  
Lateral Wall ◽  
In Vivo Evaluation ◽  
Insertion Depth ◽  
Implant Positioning ◽  
Electrode Length ◽  
Recent Developments ◽  
Magnetic Resonance Imaging Mri

Abstract Introduction Recent developments regarding cochlear implant magnets (e.g., a bipolar diametral magnet) and refined surgical technique (e.g., implant positioning) have made a significant impact on the relation between a cochlear implant and magnetic resonance imaging (MRI). MRI scanning has changed from a contraindication to a diagnostic tool. For the first time, a pain-free in vivo evaluation of the cochlea’s fluid state, following the insertion of an electrode, has become possible via MRI scanning. The aim of this study was to evaluate various cochlear implant electrodes’ MRI-specific patterns. Materials and Methods In a retrospective study, we evaluated the MRI pattern of casting iron (CI) electrodes in a 3T T2 turbo spin echo (TSE) sequence after a surgery with Medel Flex 28, Flex 24, AB HFMS, and MRI at 1.5 T T2 TSE with the Oticon EVO array. Results A generally different axial MRI pattern between the “lateral wall” electrodes and the “modiolar” electrodes at the basal turn could be observed. A difference in terms of electrode length/insertion depth could not be found at the present scan resolution. Electrode contacts have an impact on the MRI signal-diminishing pattern. Conclusion At T2 sequences, an electrode design-specific MRI pattern can be observed.

Incidence of Complete Insertion in Cochlear Implant Recipients of Long Lateral Wall Arrays

2021 ◽  
pp. 019459982098745
Author(s):  
Michael W. Canfarotta ◽  
Margaret T. Dillon ◽  
Kevin D. Brown ◽  
Harold C. Pillsbury ◽  
Matthew M. Dedmon ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Electrode Array ◽  
Lateral Wall ◽  
Electrode Arrays ◽  
Tertiary Referral ◽  
Insertion Depth ◽  
Future Studies ◽  
Tertiary Referral Center ◽  
Cochlear Duct Length ◽  
Cochlear Morphology

Objective High rates of partial insertion have been reported for cochlear implant (CI) recipients of long lateral wall electrode arrays, presumably caused by resistance encountered during insertion due to cochlear morphology. With recent advances in long-electrode array design, we sought to investigate (1) the incidence of complete insertions among patients implanted with 31.5-mm flexible arrays and (2) whether complete insertion is limited by cochlear duct length (CDL). Study Design Retrospective review. Setting Tertiary referral center. Methods Fifty-one adult CI recipients implanted with 31.5-mm flexible lateral wall arrays underwent postoperative computed tomography to determine the rate of complete insertion, defined as all contacts being intracochlear. CDL and angular insertion depth (AID) were compared between complete and partial insertion cohorts. Results Most cases had a complete insertion (96.1%, n = 49). Among the complete insertion cohort, the median CDL was 33.6 mm (range, 30.3-37.9 mm), and median AID was 641° (range, 533-751°). Two cases of partial insertion had relatively short CDL (31.8 mm and 32.3 mm) and shallow AID (542° and 575°). Relatively shallow AID for the 2 cases of partial insertion fails to support the idea that CDL alone prevents a complete insertion. Conclusion Complete insertion of a 31.5-mm flexible array is feasible in most cases and does not appear to be limited by the range of CDL observed in this cohort. Future studies are needed to estimate other variations in cochlear morphology that could predict resistance and failure to achieve complete insertion with long arrays.

Comparison of the HiFocus Mid-Scala and HiFocus 1J Electrode Array: Angular Insertion Depths and Speech Perception Outcomes

2016 ◽  
Vol 21 (5) ◽  
pp. 316-325 ◽  
Author(s):  
M. Annerie van der Jagt ◽  
Jeroen J. Briaire ◽  
Berit M. Verbist ◽  
Johan H.M. Frijns
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Electrode Array ◽  
Lateral Wall ◽  
Neural Stimulation ◽  
Insertion Depth ◽  
Optimal Distance ◽  
Frequency Mismatch ◽  
The Mean

The HiFocus Mid-Scala (MS) electrode array has recently been introduced onto the market. This precurved design with a targeted mid-scalar intracochlear position pursues an atraumatic insertion and optimal distance for neural stimulation. In this study we prospectively examined the angular insertion depth achieved and speech perception outcomes resulting from the HiFocus MS electrode array for 6 months after implantation, and retrospectively compared these with the HiFocus 1J lateral wall electrode array. The mean angular insertion depth within the MS population (n = 96) was found at 470°. This was 50° shallower but more consistent than the 1J electrode array (n = 110). Audiological evaluation within a subgroup, including only postlingual, unilaterally implanted, adult cochlear implant recipients who were matched on preoperative speech perception scores and the duration of deafness (MS = 32, 1J = 32), showed no difference in speech perception outcomes between the MS and 1J groups. Furthermore, speech perception outcome was not affected by the angular insertion depth or frequency mismatch.

scholarly journals Evaluation of Intracochlear Trauma Caused by Insertion of Cochlear Implant Electrode Arrays through Different Quadrants of the Round Window

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Graziela de Souza Queiroz Martins ◽  
Rubens Vuono Brito Neto ◽  
Robinson Koji Tsuji ◽  
Eloisa Maria Mello Santiago Gebrim ◽  
Ricardo Ferreira Bento
Keyword(s):  
Cochlear Implant ◽  
Round Window ◽  
Electrode Array ◽  
Hearing Preservation ◽  
Round Window Membrane ◽  
Residual Hearing ◽  
Electrode Arrays ◽  
Minimal Trauma ◽  
Electrode Insertion ◽  
Temporal Bones

Hypothesis. This study aimed to evaluate whether there is a difference in the degree of intracochlear trauma when the cochlear implant electrode arrays is inserted through different quadrants of the round window membrane.Background. The benefits of residual hearing preservation in cochlear implant recipients have promoted the development of atraumatic surgeries. Minimal trauma during electrode insertion is crucial for residual hearing preservation.Methods. In total, 25 fresh human temporal bones were subjected to mastoidectomy and posterior tympanotomy. The cochlear implant electrode array was inserted through the anterosuperior quadrant of the round window membrane in 50% of the bones and through the anteroinferior quadrant in the remaining 50%. The temporal bones were dehydrated, embedded in epoxy, serially polished, stained, viewed through a stereomicroscope, and photographed with the electrode arraysin situ. The resulting images were analyzed for signs of intracochlear trauma.Results. Histological examinations revealed varying degrees of damage to the intracochlear structures, although the incidence and severity of intracochlear trauma were not influenced by the quadrant of insertion.Conclusions. The incidence and severity of intracochlear trauma were similar in all samples, irrespective of electrode array insertion through the anterosuperior or anteroinferior quadrant of the round window membrane.

scholarly journals Clinical investigation of the Nucleus Slim Modiolar Electrode

2017 ◽  
Vol 22 (3) ◽  
pp. 169-179 ◽  
Author(s):  
Antje Aschendorff ◽  
Robert Briggs ◽  
Goetz Brademann ◽  
Silke Helbig ◽  
Joachim Hornung ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cochlear Implant ◽  
Temporal Bone ◽  
Clinical Investigation ◽  
Round Window ◽  
Electrode Array ◽  
Lateral Wall ◽  
Scala Tympani ◽  
Flat Panel ◽  
Insertion Depth

Aims: The Nucleus CI532 cochlear implant incorporates a new precurved electrode array, i.e., the Slim Modiolar electrode (SME), which is designed to bring electrode contacts close to the medial wall of the cochlea while avoiding trauma due to scalar dislocation or contact with the lateral wall during insertion. The primary aim of this prospective study was to determine the final position of the electrode array in clinical cases as evaluated using flat-panel volume computed tomography. Methods: Forty-five adult candidates for unilateral cochlear implantation were recruited from 8 centers. Eleven surgeons attended a temporal bone workshop and received further training with a transparent plastic cochlear model just prior to the first surgery. Feedback on the surgical approach and use of the SME was collected via a questionnaire for each case. Computed tomography of the temporal bone was performed postoperatively using flat-panel digital volume tomography or cone beam systems. The primary measure was the final scalar position of the SME (completely in scala tympani or not). Secondly, medial-lateral position and insertion depth were evaluated. Results: Forty-four subjects received a CI532. The SME was located completely in scala tympani for all subjects. Pure round window (44% of the cases), extended round window (22%), and inferior and/or anterior cochleostomy (34%) approaches were successful across surgeons and cases. The SME was generally positioned close to the modiolus. Overinsertion of the array past the first marker tended to push the basal contacts towards the lateral wall and served only to increase the insertion depth of the first electrode contact without increasing the insertion depth of the most apical electrode. Complications were limited to tip fold-overs encountered in 2 subjects; both were attributed to surgical error, with both reimplanted successfully. Conclusions: The new Nucleus CI532 cochlear implant with SME achieved the design goal of producing little or no trauma as indicated by consistent scala tympani placement. Surgeons should be carefully trained to use the new deployment method such that tip fold-overs and over insertion may be avoided.

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