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.

Preservation of residual hearing following cochlear implantation: comparison between three surgical techniques

2007 ◽  
Vol 122 (3) ◽  
pp. 246-252 ◽  
Author(s):  
S Berrettini ◽  
F Forli ◽  
S Passetti
Keyword(s):  
Cochlear Implant ◽  
Cochlear Implantation ◽  
Surgical Techniques ◽  
Electrode Array ◽  
Lateral Wall ◽  
Hearing Preservation ◽  
Acoustic Stimulation ◽  
Residual Hearing ◽  
Electrode Arrays ◽  
Electrode Insertion

AbstractThe preservation of residual hearing is becoming a high priority in cochlear implant surgery. It allows better speech understanding and ensures long-lasting and stable performance; it also allows the possibility, in selected cases, of combining electro-acoustic stimulation in the same ear.We present the results of a retrospective study of the conservation of residual hearing in three different groups of patients who had undergone cochlear implantation using three different cochlear implant electrode arrays, combined with three different surgical techniques for the cochleostomy. The study aimed to evaluate which approach allowed greater preservation of residual hearing.The best residual hearing preservation results (i.e. preservation in 81.8 per cent of patients) were achieved with the Contour Advance electrode array, using the Advance Off-Stylet technique and performing a modified anterior inferior cochleostomy; this combination enabled reduced trauma to the lateral wall of the cochlea during electrode insertion.

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.

Electrode design and insertional depth-dependent intra-cochlear pressure changes: a model experiment

2017 ◽  
Vol 132 (3) ◽  
pp. 224-229 ◽  
Author(s):  
P Mittmann ◽  
A Ernst ◽  
I Todt
Keyword(s):  
Cochlear Implant ◽  
Fluid Pressure ◽  
Electrode Array ◽  
Lateral Wall ◽  
Peak Frequency ◽  
Peak Amplitude ◽  
Residual Hearing ◽  
Electrode Arrays ◽  
Pressure Peak ◽  
Pressure Changes

AbstractBackground:Preservation of residual hearing is one of the major goals in modern cochlear implant surgery. Intra-cochlear fluid pressure changes influence residual hearing, and should be kept low before, during and after cochlear implant insertion.Methods:Experiments were performed in an artificial cochlear model. A pressure sensor was inserted in the apical part. Five insertions were performed on two electrode arrays. Each insertion was divided into three parts, and statistically evaluated in terms of pressure peak frequency and pressure peak amplitude.Results:The peak frequency over each third part of the electrode increased in both electrode arrays. A slight increase was seen in peak amplitude in the lateral wall electrode array, but not in the midscalar electrode array. Significant differences were found in the first third of both electrode arrays.Conclusion:The midscalar and lateral wall electrode arrays have different intra-cochlear fluid pressure changes associated with intra-cochlear placement, electrode characteristics and insertion.

Impact of Electric Stimulation on Residual Hearing

2015 ◽  
Vol 26 (08) ◽  
pp. 732-740 ◽  
Author(s):  
Margaret T. Dillon ◽  
Andrea L. Bucker ◽  
Marcia C. Adunka ◽  
English R. King ◽  
Oliver F. Adunka ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Electric Stimulation ◽  
Bone Conduction ◽  
Low Frequency ◽  
Electrode Array ◽  
Hearing Preservation ◽  
Acoustic Stimulation ◽  
First Year ◽  
Residual Hearing ◽  
Listening Experience

Background: Candidacy criteria for cochlear implantation are expanding to include patients with substantial low-to-mid frequency hearing sensitivity. Postoperative hearing preservation has been achieved in cochlear implant recipients, though with variable outcomes. Previous investigations on postoperative hearing preservation outcomes have evaluated intraoperative procedures. There has been limited review as to whether electric stimulation influences hearing preservation. Purpose: The purpose of this analysis was to evaluate whether charge levels associated with electric stimulation influence postoperative hearing preservation within the first year of listening experience. Research Design: Retrospective analysis of unaided residual hearing and charge levels. Study Sample: Twenty-eight cochlear implant recipients with postoperative residual hearing in the operative ear and at least 12 mo of listening experience with electric-acoustic stimulation (EAS). Data Collection and Analysis: Assessment intervals included initial cochlear implant activation, initial EAS activation, and 3-, 6-, and 12-mo postinitial EAS activation. A masked low-frequency bone-conduction (BC) pure-tone average (PTA) was calculated for all participants at each assessment interval. Charge levels for each electrode were determined using the most comfortable loudness level and pulse width values. Charge levels associated with different regions of the electrode array were compared to the change in the low-frequency BC PTA between two consecutive intervals. Results: Charge levels had little to no association with the postoperative change in low-frequency BC PTA within the first year of listening experience. Conclusions: Electric charge levels do not appear to be reliably related to the subsequent loss of residual low-frequency hearing in the implanted ear within the first year of EAS listening experience.

scholarly journals Effects of Round Window Opening Size and Moisturized Electrodes on Intracochlear Pressure Related to the Insertion of a Cochlear Implant Electrode

2016 ◽  
Vol 6 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Ingo Todt ◽  
Arneborg Ernst ◽  
Philipp Mittmann
Keyword(s):  
Cochlear Implant ◽  
Round Window ◽  
Pressure Change ◽  
Hearing Preservation ◽  
Round Window Membrane ◽  
Cochlear Model ◽  
Window Opening ◽  
Hydrophilic Character ◽  
Intracochlear Pressure ◽  
Pressure Changes

Intracochlear pressure changes during the cochlear implant insertion are assumed to be an important contributor to hearing preservation. The aim was to observe intracochlear pressure changes by different round window opening sizes and different hydrophilic electrode conditions. The experiments were performed in a cochlear model with a micropressure sensor in the helicotrema area. Different artificial round window membrane and different moisturized electrode conditions were compared. A punctured round window causes a significantly higher and an indirect moisturized electrode condition a significantly lower intracochlear pressure change. The degree of round window opening and the hydrophilic character of an electrode during insertion affect the intracochlear pressure significantly in a model.

scholarly journals Frictional Behavior of Cochlear Electrode Array Is Dictated by Insertion Speed and Impacts Insertion Force

2021 ◽  
Vol 11 (11) ◽  
pp. 5162
Author(s):  
Dana Dohr ◽  
Nicklas Fiedler ◽  
Wolfram Schmidt ◽  
Niels Grabow ◽  
Robert Mlynski ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Cochlear Implant ◽  
Electrode Array ◽  
Mechanical Trauma ◽  
Electrode Arrays ◽  
Friction Behavior ◽  
Insertion Force ◽  
Friction Coefficients ◽  
Electrode Insertion ◽  
The Impact

Background: During cochlear implantation, the electrode array has significant friction with the sensitive endocochlear lining and causes mutual mechanical trauma while the array is being inserted. Both, the impact of insertion speed on electrode friction and the relationship of electrode insertion force and friction have not been adequately investigated to date. Methods: In this study, friction coefficients between a CI electrode array (31.5 mm) and a tissue simulating the endocochlear lining have been acquired, depending on different insertion speeds (0.1, 0.5, 1.0, 1.5, and 2.0 mm/s). Additionally, the electrode insertion forces during the placing into a scala tympani model were recorded and correlated with the friction coefficient. Results: It was shown that the friction coefficient reached the lowest value at an insertion speed of 0.1 mm/s (0.24 ± 0.13), a maximum occurred at 1.5 mm/s (0.59 ± 0.12), and dropped again at 2 mm/s (0.45 ± 0.11). Similar patterns were observed for the insertion forces. Consequently, a high correlation coefficient (0.9) was obtained between the insertion forces and friction coefficients. Conclusion: The present study reveals a non-linear increase in electrode array friction, when insertion speed raises and reports a high correlation between friction coefficient and electrode insertion force. This dependence is a relevant future parameter to evaluate and reduce cochlear implant insertion trauma. Significance statement: Here, we demonstrated a dependence between cochlear electrode insertion speed and its friction behavior and a high correlation to insertion force. Our study provides valuable information for the evaluation and prevention of cochlear implant insertion trauma and supports the optimization of cochlear electrode arrays regarding friction characteristics.

Anatomy of the round Window with Respect to Cochlear Implant Surgery

1987 ◽  
Vol 96 (1_suppl) ◽  
pp. 17-19 ◽  
Author(s):  
A. R. Clifford ◽  
W. P. R. Gibson
Keyword(s):  
Round Window ◽  
Electrode Array ◽  
Careful Analysis ◽  
Cochlear Duct ◽  
Video Recordings ◽  
Cochlear Implant Surgery ◽  
Electrode Insertion ◽  
Channel Electrode ◽  
Temporal Bones ◽  
Insertion Length

Twenty-three human temporal bones were dissected to study the anatomy of the round window with respect to cochlear implantation. Information was also gathered concerning the passage of a 22-channel electrode array along the cochlear duct by using cochlear surface dissection preparations. The insertion length and any insertion trauma were noted both by observation at the time of insertion and by careful analysis of video recordings. The crista semilunaris did not interfere with smooth electrode insertion. The recommendation is made that enlarging the round window anteroinferiorly is unnecessary and potentially hazardous in most cases.

Cochlear implant placement: round window approach

2014 ◽  
Vol 36 (v1supplement) ◽  
pp. 1 ◽  
Author(s):  
Douglas D. Backous
Keyword(s):  
Clinical Trials ◽  
Surgical Technique ◽  
Cochlear Implant ◽  
Cochlear Implantation ◽  
Round Window ◽  
Hearing Preservation ◽  
Residual Hearing ◽  
Implant Placement ◽  
Single Sided Deafness ◽  
Window Approach

The indications for cochlear implantation continue to extend to patients with increased levels of residual hearing. Single-sided deafness and tinnitus are currently under various clinical trials as even further expansion of the application of cochlear implant device and programming technology is underway. This video details a round window and hearing preservation approach for cochlear implant placement, and incorporates the most recent advances in surgical technique.The video can be found here: http://youtu.be/bDqkbboXrU4.

Hearing Preservation with the Slim Modiolar Electrode Nucleus CI532® Cochlear Implant: A Preliminary Experience

2017 ◽  
Vol 22 (6) ◽  
pp. 317-325 ◽  
Author(s):  
Angel Ramos-Macías ◽  
S.A. Borkoski-Barreiro ◽  
J.C. Falcón-González ◽  
A. Ramos-de Miguel
Keyword(s):  
Cochlear Implant ◽  
Randomized Study ◽  
Electrode Array ◽  
Hearing Preservation ◽  
Residual Hearing ◽  
Flexible Electrode ◽  
And Performance ◽  
The Impact ◽  
Sydney Australia

As the indications for cochlear implant have expanded to include younger patients and individuals with greater degrees of residual hearing, increasing emphasis has been placed on atraumatic surgery and the preservation of the cochlear structure. Here, a descriptive prospective randomized study was performed. It was shown that residual hearing preservation is possible 12 months postoperatively with an atraumatic perimodiolar flexible electrode array CI532® (Cochlear Ltd, Sydney, Australia). Residual hearing preservation, considered as < 15 dB, was obtained in 70% of the cases. Better clinical outcomes and performance could be obtained compared with the previous perimodiolar CI512®, but further research and a longer follow-up are necessary to verify the impact of outcomes.

scholarly journals Comparison of residual hearing preservation and auditory based performance after paediatric cochlear implantation by round window insertion versus cochleostomy technique: an ambispective cohort study

2021 ◽  
Vol 7 (9) ◽  
pp. 1455
Author(s):  
Dayana Antony ◽  
Aneena Chacko ◽  
Ravi A.
Keyword(s):  
Cohort Study ◽  
Cochlear Implant ◽  
Cochlear Implantation ◽  
Round Window ◽  
Tertiary Care ◽  
Sensorineural Deafness ◽  
Hearing Preservation ◽  
Care Hospital ◽  
Residual Hearing ◽  
Round Window Insertion

<p class="abstract"><strong>Background:</strong> Cochlear implantation (CI) has revolutionized the treatment of sensorineural deafness. The aim of the study was to compare auditory based performance in cochlear implants who underwent round window insertion and cochleostomy.</p><p class="abstract"><strong>Methods:</strong> Ambispective cohort study was done among the children who underwent perilingual cochlear implant in a tertiary care hospital for period of 1 year. Children who satisfied the inclusion criteria were selected and randomly subdivided into 2 groups: group A- round window insertion and group B-cochleostomy. Pre- and post-operative pure tone average (PTA) and residual hearing preserved were evaluated among the cochleostomy and round window insertion groups separately. Post-operatively, children were evaluated, from three months to 1 year from the activation of cochlear implant, with the use of scores such as Category of Auditory Performance (CAP), Meaningful Auditory Integration Scale (MAIS), Speech Intelligibility rating (SIR) and Meaningful use of speech scale (MUSS score) to measure speech production skills by auditory verbal therapist.   </p><p class="abstract"><strong>Results:</strong> A total of 80 patients were included in the study. Complete hearing preservation (within 10 dB) was significantly high in round window insertion group compared to   cochleostomy technique (p&lt;0.001). None the subjects had complete loss of residual hearing. On evaluating the post CI performance, MAIS score in the round window insertion group (9.34, 18.21, 27.79) were significantly better compared to cochleostomy group during the 3 months, 6 months and 12 months follow-up.</p><p class="abstract"><strong>Conclusions:</strong> Round window insertion technique is significantly more successful in complete hearing preservation at low frequencies compared to cochleostomy technique. Among the auditory scores, only MAIS in the round window insertion group was found to be significantly better compared to cochleostomy group.</p>

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