Morphological Anatomy of Round Window for Electrode Insertion through Facial Recess Approach: A Soft Surgical Technique

A refined electrode insertion technique is presented for the multichannel cochlear implant. It comprises two basic steps. The first step is the removal of the anteroinferior overhang of the round window and crista fenestrae, or alternatively an opening drilled into the scala tympani anteroinferior to the round window. The second is rotation of the electrode during insertion, counterclockwise in the right ear and clockwise in the left ear.

Download Full-text

Surgical considerations during cochlear implantation: the utility of temporal bone computed tomography

The Journal of Laryngology & Otology ◽

10.1017/s0022215121000232 ◽

2021 ◽

pp. 1-8

Author(s):

Beomcho Jun ◽

Sunwha Song

Keyword(s):

Computed Tomography ◽

Temporal Bone ◽

Cochlear Implantation ◽

Round Window ◽

Three Dimensional ◽

Electrode Placement ◽

Posterior Tympanotomy ◽

Electrode Insertion ◽

Window Approach ◽

Bone Structures

Abstract Objective This paper describes the construction of portals for electrode placement during cochlear implantation and emphasises the utility of pre-operative temporal bone three-dimensional computed tomography. Methods Temporal bone three-dimensional computed tomography was used to plan portal creation for electrode insertion. Results Pre-operative temporal bone three-dimensional computed tomography can be used to determine the orientation of temporal bone structures, which is important for mastoidectomy, posterior tympanotomy and cochleostomy, and when using the round window approach. Conclusion It is essential to create appropriate portals (from the mastoid cortex to the cochlea) in a step-by-step manner, to ensure the safe insertion of electrodes into the scala tympani. Pre-operative three-dimensional temporal bone computed tomography is invaluable in this respect.

Download Full-text

Extracochlear Implantation: Technique and Results

Annals of Otology Rhinology & Laryngology ◽

10.1177/00034894870960s159 ◽

1987 ◽

Vol 96 (1_suppl) ◽

pp. 111-113 ◽

Cited By ~ 2

Author(s):

B. Fraysse ◽

M. J. Soulier ◽

H. Urgell ◽

P. Levy ◽

F. Furia ◽

...

Keyword(s):

Signal Processing ◽

Single Channel ◽

Round Window ◽

Pectoral Muscle ◽

Rehabilitation Program ◽

Implantation Technique ◽

Facial Recess ◽

Deaf Adults ◽

Channel Electrode

The authors present an overview of the technique and results in the rehabilitation of totally deaf adults by an extracochlear single-channel electrode. Eight patients were implanted with a follow-up of at least 6 months. Sound signal processing, the receiver, and the electrode are described. The access to the round window is through the facial recess. The internal coil is placed over the pectoral muscle. The rehabilitation program consists of training patients to recognize background sounds up to more discriminating exercises. The results are discussed.

Download Full-text

The role of high-resolution Computer Tomography in prediction of the round window membrane visibility and the feasibility of the round window electrode insertion

European Archives of Oto-Rhino-Laryngology ◽

10.1007/s00405-020-06417-6 ◽

2020 ◽

Author(s):

Saad Elzayat ◽

Islam Soltan ◽

Mona Talaat ◽

Yasser Ahmed Fouad

Keyword(s):

High Resolution ◽

Computer Tomography ◽

Round Window ◽

Round Window Membrane ◽

Electrode Insertion

Download Full-text

Cochlear Implant Revision: Effects of Reimplantation on the Cochlea

Annals of Otology Rhinology & Laryngology ◽

10.1177/000348948909801012 ◽

1989 ◽

Vol 98 (10) ◽

pp. 813-820 ◽

Cited By ~ 31

Author(s):

Robert K. Jackler ◽

Patricia A. Leake ◽

William S. McKerrow

Keyword(s):

Adverse Effects ◽

Cochlear Implant ◽

Round Window ◽

Neural Population ◽

Scala Tympani ◽

New Device ◽

Adult Cats ◽

Electrode Insertion ◽

Window Area ◽

Reimplantation Procedure

The removal of an indwelling cochlear implant electrode followed by reinsertion of a new device has been a maneuver of uncertain cosequences to the cochlea and its surviving neural population. The present study was conducted in an attempt to elucidate the factors at determine whether a reimplantation procedure will be successful. Cochlear implantation followed by explanation and subsequent implantation was performed in eight adult cats. Evaluation of cochlear histopathology suggested a significant increase in electrode insertion trauma when there was proliferation of granulation tissue in the round window area and scala tympani. In other cases, atraumatic insertion was achieved without apparent injury to the cochlea. The results of a survey of cochlear implant manufacturers and surgeons indicate that electrode replacement can usually be accomplished without adverse effects. Difficulties have been encountered, however, in moving implants with protuberant electrodes and when reimplantation was attempted on a delayed basis following explanation.

Download Full-text

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

Otolaryngology ◽

10.1177/0194599817739837 ◽

2017 ◽

Vol 158 (2) ◽

pp. 350-357 ◽

Cited By ~ 2

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.

Download Full-text

The evaluation of a slim perimodiolar electrode: surgical technique in relation to intracochlear position and cochlear implant outcomes

European Archives of Oto-Rhino-Laryngology ◽

10.1007/s00405-019-05696-y ◽

2019 ◽

Vol 277 (2) ◽

pp. 343-350 ◽

Cited By ~ 1

Author(s):

Floris Heutink ◽

Berit M. Verbist ◽

Lucas H. M. Mens ◽

Wendy J. Huinck ◽

Emmanuel A. M. Mylanus

Keyword(s):

Speech Perception ◽

Surgical Technique ◽

Round Window ◽

Hearing Preservation ◽

Electrode Position ◽

Residual Hearing ◽

High Resolution Computed Tomography ◽

Absolute Increase ◽

Window Approach

Abstract Purpose In cochlear implantation (CI), the two factors that are determined by the surgeon with a potential significant impact on the position of the electrode within the cochlea and the potential outcome, are the surgical technique and electrode type. The objective of this prospective study was to evaluate the position of the slim, perimodiolar electrode (SPE), and to study the influence of the SPE position on CI outcome. Methods Twenty-three consecutively implanted, adult SPE candidates were included in this prospective cohort study conducted between December 2016 and April 2019. Mean age at surgery was 59.5 years. Mean preoperative residual hearing was 92.2 dB. Intra-operative fluoroscopy and high-resolution computed tomography scans were performed to evaluate electrode position after insertion using a cochleostomy (CS) approach. Follow-up was 12 months after implantation; residual hearing (6–8 weeks) and speech perception (6–8 weeks and 12 months) were evaluated in relation to the intracochlear SPE position. Results In most patients in whom the SPE was positioned in the scala tympani residual hearing was preserved [mean absolute increase in PTA of 4.4 dB and 77.2% relative hearing preservation (RHP%)]. Translocation into the scala vestibuli occurred in 36% of the insertions, resulting in a mean absolute increase in PTA of 17.9 dB, and a RHP% of 19.2%. Participants with a translocation had poorer speech perception scores at 12-month follow-up. Conclusion Given the incidence of CS-associated translocations with the SPE and the negative effect on outcome, it is advised to insert the SPE using the (extended) round window approach.

Download Full-text

Effect of Underwater Insertion on Intracochlear Pressure

Frontiers in Surgery ◽

10.3389/fsurg.2020.546779 ◽

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.

Download Full-text