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

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.

2020 ◽  
Vol 7 ◽  
Author(s):  
Conrad Riemann ◽  
Holger Sudhoff ◽  
Ingo Todt

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.


2016 ◽  
Vol 6 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Ingo Todt ◽  
Arneborg Ernst ◽  
Philipp Mittmann

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.


2017 ◽  
Vol 132 (3) ◽  
pp. 224-229 ◽  
Author(s):  
P Mittmann ◽  
A Ernst ◽  
I Todt

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.


2021 ◽  
pp. 1-6
Author(s):  
Ceyhun Ucta ◽  
Philipp Mittmann ◽  
Arneborg Ernst ◽  
Rainer Seidl ◽  
Gina Lauer

Objective: Atraumatic cochlear implantation (CI) and insertion of the electrode in particular are major goals of recent CI surgery. Perimodiolar electrode arrays need a stylet or exosheath for insertion. The sheath can influence the intracochlear pressure changes during insertion of the electrode. The aim of this study was to modify the insertion sheath to optimize intracochlear pressure changes. Methods: In an artifical cochlear model, 7 different modified insertion sheaths were used. The intracochlear pressure was measured with a micro-optical sensor in the apical part of the model cochlea. Results: Significant lower intracochlear pressure changes were observed when the apical part of the insertion sheath was either shortened or tapered. Modification of the stopper does influence the intracochlear pressure significantly. Conclusion: Modification of the insertion sheath leads to lower intracochlear pressure gain. The differences and impact on intracochlear pressure changes found in this study underline the importance of even subtle modifications of the electrode insertion technique.


Author(s):  
Ingo Todt ◽  
Julica Utca ◽  
Dania Karimi ◽  
Arne Ernst ◽  
Philipp Mittmann

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
I. Todt ◽  
P. Mittmann ◽  
A. Ernst

Introduction. To preserve residual hearing the atraumaticity of the cochlea electrode insertion has become a focus of cochlear implant research. In addition to other factors, the speed of insertion is thought to be a contributing factor in the concept of atraumatic implantation. The aim of our study was to observe intracochlear fluid pressure changes due to different insertional speeds of an implant electrode in a cochlear model.Materials and Methods. The experiments were performed using an artificial cochlear model. A linear actuator was mounted on an Advanced Bionics IJ insertional tool. The intracochlear fluid pressure was recorded through a pressure sensor which was placed in the helicotrema area. Defined insertions were randomly performed with speeds of 0.1 mm/sec, 0.25 mm/sec, 0.5 mm/sec, 1 mm/sec, and 2 mm/sec.Results. A direct correlation between speed and pressure was observed. Mean maximum values of intracochlear fluid pressure varied between 0.41 mm Hg and 1.27 mm Hg.Conclusion. We provide the first results of fluid pressure changes due to insertional speeds of CI electrodes in a cochlear model. A relationship between the insertional speed and intracochlear fluid pressure was observed. Further experiments are needed to apply these results to the in vivo situation.


2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
I. Todt ◽  
D. Karimi ◽  
J. Luger ◽  
A. Ernst ◽  
P. Mittmann

Introduction.To achieve a functional atraumatic cochlear implantation, intracochlear pressure changes during the procedure should be minimized. Postinsertional cable movements are assumed to induce intracochlear pressure changes. The aim of this study was to observe intracochlear pressure changes due to postinsertional cable movements.Materials and Methods.Intracochlear pressure changes were recorded in a cochlear model with a micro-pressure sensor positioned in the apical region of the cochlea model to follow the maximum amplitude and pressure gain velocity in intracochlear pressure. A temporal bone mastoid cavity was attached to the model to simulate cable positioning. The compared conditions were (1) touching the unsealed electrode, (2) touching the sealed electrode, (3) cable storage with an unfixed cable, and (4) cable storage with a fixed cable.Results.We found statistically significant differences in the occurrence of maximum amplitude and pressure gain velocity in intracochlear pressure changes under the compared conditions. Comparing the cable storage conditions, a cable fixed mode offers significantly lower maximum pressure amplitude and pressure gain velocity than the nonfixed mode.Conclusion.Postinsertional cable movement led to a significant pressure transfer into the cochlea. Before positioning the electrode cable in the mastoid cavity, fixation of the cable is recommended.


2018 ◽  
Vol 275 (12) ◽  
pp. 2947-2956 ◽  
Author(s):  
Silke Hügl ◽  
Katharina Rülander ◽  
Thomas Lenarz ◽  
Omid Majdani ◽  
Thomas S. Rau

2019 ◽  
Vol 4 (4) ◽  
pp. 441-445 ◽  
Author(s):  
Gina Lauer ◽  
Julica Uçta ◽  
Lars Decker ◽  
Arneborg Ernst ◽  
Philipp Mittmann

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