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 Intracochlear Pressure Changes due to Round Window Opening: A Model Experiment

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
P. Mittmann ◽  
A. Ernst ◽  
I. Todt
Keyword(s):  
Model Experiment ◽  
Round Window ◽  
Pressure Change ◽  
Intraluminal Pressure ◽  
Round Window Membrane ◽  
Electrode Design ◽  
Residual Hearing ◽  
Window Opening ◽  
Intracochlear Pressure ◽  
Pressure Changes

To preserve residual hearing in cochlea implantation, the electrode design has been refined and an atraumatic insertion of the cochlea electrode has become one aspect of cochlea implant research. The opening of the round window can be assumed to be a contributing factor in an atraumatic concept. The aim of our study was to observe intracochlear pressure changes due to different opening conditions of an artificial round window membrane. The experiments were performed in an artificial cochlea model. A round window was simulated with a polythene foil and a pressure sensor was placed in the helicotrema area to monitor intraluminal pressure changes. Openings of the artificial round window membrane were performed using different ways. Opening the artificial round window mechanically showed a biphasic behaviour of pressure change. Laser openings showed a unidirectional pressure change. The lowest pressure changes were observed when opening the artificial round window membrane using a diode laser. The highest pressure changes were seen when using a needle. The openings with the CO2laser showed a negative intracochlear pressure and a loss of fluid. In our model experiments, we could prove that the opening of the artificial round window membrane causes various intracochlear pressure changes.

Effects of Different Insertion Techniques of a Cochlear Implant Electrode on the Intracochlear Pressure

2016 ◽  
Vol 21 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Ingo Todt ◽  
Arneborg Ernst ◽  
Philipp Mittmann
Keyword(s):  
Cochlear Implant ◽  
Maximum Amplitude ◽  
Cochlear Model ◽  
Pressure Peak ◽  
Insertion Techniques ◽  
Intracochlear Pressure ◽  
Pressure Changes

To achieve a functional atraumatic insertion, low intracochlear pressure changes during the procedure are assumed to be important. The aim of this study was to observe intracochlear pressure changes due to different insertion techniques in a cochlear model. Cochlear implant electrode insertions were performed in an artificial cochlear model to record intracochlear pressure changes with a micropressure sensor to evaluate the maximum amplitude and frequency of pressure changes under different insertional conditions. We found statistically significant differences in the occurrence of intracochlear pressure peak changes comparing different techniques. Based on our model results, an insertion should be maximally supported to minimize micromovement-related pressure changes.

Effect of Round Window Opening Size on Residual Hearing Preservation in Cochlear Implantation

2020 ◽  
Vol 163 (2) ◽  
pp. 375-381
Author(s):  
Giselle L. Gotamco ◽  
Chuan-Hung Sun ◽  
Yi-Fan Chou ◽  
Chuan-Jen Hsu ◽  
Hung-Pin Wu
Keyword(s):  
Cochlear Implantation ◽  
Round Window ◽  
Hearing Preservation ◽  
Round Window Membrane ◽  
Tertiary Referral ◽  
Tertiary Referral Center ◽  
Window Technique ◽  
Cochlear Implant Surgery ◽  
Window Opening ◽  
Window Approach

Objectives This study aims to compare the hearing preservation outcomes in cochlear implant surgery following slit versus full opening of the round window membrane. Setting Tertiary referral center. Study Design Comparative study. Subjects and Methods Seventy patients (mean, 26.3 years; range, 2-69 years) who underwent cochlear implantation via the round window approach were included in the study. Thirty-five subjects were prospectively enrolled for cochlear implantation via the open round window technique between August 2018 and January 2019. Thirty-five patients who underwent cochlear implantation from January 2017 to July 2018 via the slit round window opening, frequency matched by sex and age, were retrospectively enrolled. Pre- and postoperative thresholds were obtained. The percentage of hearing preservation was computed with the HEARRING Network formula and classified into complete, partial, and minimal hearing preservation. The results between the groups were compared and analyzed at 6 months postoperatively. Results The rate of complete hearing preservation in the open group was statistically significant ( P = .030) at 71.4% (n = 25) as compared with 45.7% (n = 16) in the slit group. Conclusions The widely opened round window may be an optional technique that surgeons can utilize to improve hearing preservation outcomes.

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 The Effects of Round Window Membrane Injury and the Use of a Model Electrode Application on Hearing in Rats

2021 ◽  
pp. 014556132199018
Author(s):  
Murat Koc ◽  
Abdullah Dalgic ◽  
Mehmet Ziya Ozuer
Keyword(s):  
Hearing Loss ◽  
Cochlear Implant ◽  
Round Window ◽  
Mechanical Trauma ◽  
Round Window Membrane ◽  
Albino Rats ◽  
Topical Steroids ◽  
Distortion Product ◽  
Significant Difference ◽  
Group 3

Objective: To investigate the effects of the mechanical trauma to the round window, a model electrode inserted into the scala tympani on the cochlear reserve, and the efficacy of topical steroids in preventing hearing loss. Materials and Methods: 21 male Wistar Albino rats were equally categorized into three groups. In all groups an initial mechanical injury to round window was created. Only subsequent dexamethasone injection was administrated into the cochlea in the subjects of group 2 while a multichannel cochlear implant guide inserted into the cochlea prior to dexamethasone administration for group 3. Distortion product otoacoustic emissions (DPOAEs) were obtained prior to and immediately after the surgical injury, eventually on postoperative seventh day (d 7). Mean signal/noise ratios (S/Ns) obtained at 2000, 3000, and 4000 Hz were calculated. Data sets were compared with non-parametric statistical tests. Results: The early intraoperative mean S/Ns were significantly less than preoperative measurements for group 1 and 2; however, preoperative and postoperative d 7 average S/Ns did not differ. There was statistically significant difference between preoperative, intraoperative and postoperative d 7 average S/Ns for group 3. Conclusion: We observed that hearing was restored approximately to the preoperative levels following early postoperative repair. However, an electrode insertion into the cochlea via round window subsequent to mechanical trauma seems to cause a progressive hearing loss. Therefore, a special care must be taken to avoid the injury to the round window membrane in the course of the placement of a cochlear implant electrode and surgery for the chronic otitis media.

Impact of the round window membrane accessibility on hearing preservation in adult cochlear implantation

2017 ◽  
Vol 274 (8) ◽  
pp. 3049-3056 ◽  
Author(s):  
Marjan Mirsalehi ◽  
Saleh Mohebbi ◽  
Mahsa Ghajarzadeh ◽  
Thomas Lenarz ◽  
Omid Majdani
Keyword(s):  
Cochlear Implantation ◽  
Round Window ◽  
Hearing Preservation ◽  
Round Window Membrane

scholarly journals Effect of Underwater Insertion on Intracochlear Pressure

2020 ◽  
Vol 7 ◽  
Author(s):  
Conrad Riemann ◽  
Holger Sudhoff ◽  
Ingo Todt
Keyword(s):  
Hyaluronic Acid ◽  
Cochlear Implant ◽  
Middle Ear ◽  
Round Window ◽  
Maximum Amplitude ◽  
Influential Factor ◽  
Fluid State ◽  
Insertion Techniques ◽  
Electrode Insertion ◽  
Intracochlear Pressure

Background: The importance of intracochlear pressure during cochlear electrode insertion for the preservation of residual hearing has been widely discussed. Various aspects of pre-insertional, intra-insertional, and post-insertional relevant conditions affect intracochlear pressure. The fluid situation at the round window during electrode insertion has been shown to be an influential factor.Aims/Objectives: The aim of the study was to compare various insertion techniques in terms of the fluid situation at the round window.Material and Methods: We performed insertion of cochlear implant electrodes in a curled artificial cochlear model. We placed and fixed the pressure sensor at the tip of the cochlea. In parallel to the insertions, we evaluated the maximum amplitude of intracochlear pressure under four different fluid conditions at the round window: (1) hyaluronic acid; (2) moisturized electrode, dry middle ear; (3) middle ear filled with fluid (underwater); and (4) moisturized electrode, wet middle ear, indirectly inserted.Results: We observed that the insertional intracochlear pressure is dependent on the fluid situation in front of the round window. The lowest amplitude changes were observed for the moisturized electrode indirectly inserted in a wet middle ear (0.13 mmHg ± 0.07), and the highest values were observed for insertion through hyaluronic acid in front of the round window (0.64 mmHg ± 0.31).Conclusions: The fluid state in front of the round window influences the intracochlear pressure value during cochlear implant electrode insertion in our model. Indirect insertion of a moisturized electrode through a wet middle ear experimentally generated the lowest pressure values. Hyaluronic acid in front of the round window leads to high intracochlear pressure in our non-validated artificial model.

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