Insertion depth impacts speech perception and hearing preservation for lateral wall electrodes

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.

Download Full-text

Comparison of Insertion Depth and Hearing Preservation Results between HiFocus 1j and HiFocus Mid-Scala Electrodes in Pediatric Population

Annals of Otology and Neurotology ◽

10.1055/s-0038-1677053 ◽

2018 ◽

Vol 01 (02) ◽

pp. 068-076

Author(s):

Shweta Deshpande ◽

Neelam Vaid ◽

Dzemal Gazibegovic ◽

Ajimsha KM

Keyword(s):

Pediatric Population ◽

Round Window ◽

Lateral Wall ◽

Hearing Preservation ◽

Plain Radiography ◽

Residual Hearing ◽

Partial Loss ◽

Insertion Depth ◽

Prior Surgery ◽

Cover Up

Abstract Background Various electrodes are available with a range of features and designs to fulfil anatomical and geometrical variations of the cochlea. The HiFocus 1j (1j) electrode developed by Advanced Bionics LLC is a lateral wall electrode designed to cover up to 1.5 turns or approximately 540° of the cochlea. The HiFocus Mid-Scala (HFms) was recently introduced and designed for structure preservation with a target insertion depth of 420°. Objective To evaluate the average insertion depth and variation, and to assess the potential for hearing preservation with 1j and HFms electrodes in children. Method A group of prelingually deafened children with regular anatomy who received the HiRes90K implant (either 1j or HFms electrode) underwent a plain radiography investigation shortly after the surgery to determine the angular insertion depth. The median age in each group was 3.6 years (1j) and 4.3 years (HFms). The amount of residual hearing was measured through audiometry prior surgery and then monitored at device activation and 1,3, 6, and 12 months later. Results Seventeen subjects were included for calculation of insertion depth. The median insertion depth and the variation for the 1j electrode was higher than for the HFms electrode (1j 476°; 443°–540°, HFms 413°; 390°–468°). Only eleven subjects were assessed for hearing preservation. Complete hearing preservation was achieved in seven subjects (five HFms and two 1j) and partial loss was observed in two subjects (one HFms and one 1j). Conclusion Both 1j and HFms electrodes are suitable for young children. Their flexible design allows round window insertions. The HFms group showed higher rates of hearing preservation (HP) than the 1j group.

Download Full-text

Cochlear Implantation in Children with Postlingual Progressive Steeply Sloping High-Frequency Hearing Loss

Journal of the American Academy of Audiology ◽

10.3766/jaaa.16115 ◽

2017 ◽

Vol 28 (10) ◽

pp. 913-919 ◽

Cited By ~ 7

Author(s):

Margaret A. Meredith ◽

Jay T. Rubinstein ◽

Kathleen C. Y. Sie ◽

Susan J. Norton

Keyword(s):

Hearing Loss ◽

Speech Perception ◽

Hearing Aids ◽

Cochlear Implantation ◽

High Frequency ◽

Case Series ◽

Hearing Preservation ◽

Rapid Improvement ◽

Retrospective Case ◽

Monosyllabic Word

Background: Children with steeply sloping sensorineural hearing loss (SNHL) lack access to critical high-frequency cues despite the use of advanced hearing aid technology. In addition, their auditory-only aided speech perception abilities often meet Food and Drug Administration criteria for cochlear implantation. Purpose: The objective of this study was to describe hearing preservation and speech perception outcomes in a group of young children with steeply sloping SNHL who received a cochlear implant (CI). Research Design: Retrospective case series. Study Sample: Eight children with steeply sloping postlingual progressive SNHL who received a unilateral traditional CI at Seattle Children’s Hospital between 2009 and 2013 and had follow-up data available up to 24 mo postimplant were included. Data Collection and Analysis: A retrospective chart review was completed. Medical records were reviewed for demographic information, preoperative and postoperative behavioral hearing thresholds, and speech perception scores. Paired t tests were used to analyze speech perception data. Hearing preservation results are reported. Results: Rapid improvement of speech perception scores was observed within the first month postimplant for all participants. Mean monosyllabic word scores were 76% and mean phoneme scores were 86.7% at 1-mo postactivation compared to mean preimplant scores of 19.5% and 31.0%, respectively. Hearing preservation was observed in five participants out to 24-mo postactivation. Two participants lost hearing in both the implanted and unimplanted ear, and received a sequential bilateral CI in the other ear after progression of the hearing loss. One participant had a total loss of hearing in only the implanted ear. Results reported in this article are from the ear implanted first. Bilateral outcomes are not reported. Conclusions: CIs provided benefit for children with steeply sloping bilateral hearing loss for whom hearing aids did not provide adequate auditory access. In our cohort, significant improvements in speech understanding occurred rapidly postactivation. Preservation of residual hearing in children with a traditional CI electrode is possible.

Download Full-text

Cone beam CT for perioperative imaging in hearing preservation Cochlear implantation – a human cadaveric study

Journal of Otolaryngology - Head and Neck Surgery ◽

10.1186/s40463-019-0388-x ◽

2019 ◽

Vol 48 (1) ◽

Cited By ~ 2

Author(s):

Kayvan Nateghifard ◽

David Low ◽

Lola Awofala ◽

Dilakshan Srikanthan ◽

Jafri Kuthubutheen ◽

...

Keyword(s):

Radiation Dose ◽

Cochlear Implantation ◽

Lateral Wall ◽

Cone Beam ◽

Insertion Depth ◽

Cochlear Duct ◽

Low Radiation Dose ◽

A Value ◽

Cochlear Duct Length ◽

Temporal Bones

Abstract Background Knowledge of the cochlear implant array’s precise position is important because of the correlation between electrode position and speech understanding. Several groups have provided recent image processing evidence to determine scalar translocation, angular insertion depth, and cochlear duct length (CDL); all of which are being used for patient-specific programming. Cone beam computed tomography (CBCT) is increasingly used in otology due to its superior resolution and low radiation dose. Our objectives are as followed: Validate CBCT by measuring cochlear metrics, including basal turn diameter (A-value) and lateral wall cochlear duct length at different angular intervals and comparing it against microcomputed CT (uCT).Explore the relationship between measured lateral wall cochlear duct length at different angular intervals and insertion depth among 3 different length electrodes using CBCT. Methods The study was performed using fixed human cadaveric temporal bones in a tertiary academic centre. Ten temporal bones were subjected to the standard facial recess approach for cochlear implantation and imaged by CBCT followed by uCT. Measurements were performed on a three-dimensional reconstructed model of the cochlea. Sequential insertion of 3 electrodes (Med-El Flex24, 28 and Soft) was then performed in 5 bones and reimaged by CBCT. Statistical analysis was performed using Pearson’s correlation. Results There was good agreement between CBCT and uCT for cochlear metrics, validating the precision of CBCT against the current gold standard uCT in imaging. The A-value recorded by both modalities showed a high degree of linear correlation and did not differ by more than 0.23 mm in absolute values. For the measurement of lateral wall CDL at various points along the cochlea, there was a good correlation between both modalities at 360 deg and 720 deg (r = 0.85, p < 0.01 and r = 0.79, p < 0.01). The Flex24 electrode displayed consistent insertion depth across different bones. Conclusions CBCT reliably performs cochlear metrics and measures electrode insertion depth. The low radiation dose, fast acquisition time, diminished metallic artifacts and portability of CBCT make it a valid option for imaging in cochlear implant surgery.

Download Full-text

Angular Electrode Insertion Depth and Speech Perception in Adults With a Cochlear Implant

Otology & Neurotology ◽

10.1097/mao.0000000000002298 ◽

2019 ◽

Vol 40 (7) ◽

pp. 900-910 ◽

Cited By ~ 2

Author(s):

Floris Heutink ◽

Simone R. de Rijk ◽

Berit M. Verbist ◽

Wendy J. Huinck ◽

Emmanuel A. M. Mylanus

Keyword(s):

Speech Perception ◽

Cochlear Implant ◽

Insertion Depth ◽

Electrode Insertion

Download Full-text

Preservation of residual hearing after cochlear implant surgery with slim modiolar electrode

European Archives of Oto-Rhino-Laryngology ◽

10.1007/s00405-019-05708-x ◽

2019 ◽

Vol 277 (2) ◽

pp. 367-375 ◽

Cited By ~ 2

Author(s):

Matti Iso-Mustajärvi ◽

Sini Sipari ◽

Heikki Löppönen ◽

Aarno Dietz

Keyword(s):

Low Frequency ◽

Hearing Preservation ◽

Acoustic Stimulation ◽

Residual Hearing ◽

Insertion Depth ◽

Cochlear Implant Surgery ◽

Computed Tomography Scans ◽

Electric Acoustic Stimulation ◽

Speech Recognition In Noise

Abstract Purpose To evaluate the insertion results and hearing preservation of a novel slim modiolar electrode (SME) in patients with residual hearing. Methods We retrospectively collected the data from the medical files of 17 patients (18 ears) implanted with a SME. All patients had functional low frequency hearing (PTA (0.125–0.5 kHz) ≤ 80 dB HL). The insertion results were re-examined from the postoperative cone-beam computed tomography scans. Postoperative thresholds were obtained at the time of switch-on of the sound processors (mean 43 days) and at latest follow-up (mean 582 days). The speech recognition in noise was measured with the Finnish matrix sentence test preoperatively and at follow-up. Results The mean insertion depth angle (IDA) was 395°. Neither scala dislocations nor tip fold over were detected. There were no total hearing losses. Functional low-frequency hearing was preserved in 15/18 (83%) ears at switch-on and in 14/17 (82%) ears at follow-up. According to HEARRING classification, 55% (10/18) had complete HP at switch-on and 41% (7/17) still at follow-up. Thirteen patients (14 ears) were initially fitted with electric–acoustic stimulation and seven patients (8 ears) continued to use it after follow-up. Conclusions The preliminary hearing preservation results with the SME were more favorable than reported for other perimodiolar electrodes. The results show that the array may also be feasible for electro-acoustic stimulation; it is beneficial in that it provides adequate cochlear coverage for pure electrical stimulation in the event of postoperative or progressive hearing loss.

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

Intracochlear Position of Cochlear Implants Determined Using CT Scanning versus Fitting Levels: Higher Threshold Levels at Basal Turn

Audiology and Neurotology ◽

10.1159/000442513 ◽

2016 ◽

Vol 21 (1) ◽

pp. 54-67 ◽

Cited By ~ 8

Author(s):

Feddo B. van der Beek ◽

Jeroen J. Briaire ◽

Kim S. van der Marel ◽

Berit M. Verbist ◽

Johan H.M. Frijns

Keyword(s):

Speech Perception ◽

Cochlear Implants ◽

Dynamic Range ◽

Ct Scanning ◽

Electrode Position ◽

Insertion Depth ◽

Threshold Levels ◽

Lower Amplitude ◽

Standard Profile

Objectives: In this study, the effects of the intracochlear position of cochlear implants on the clinical fitting levels were analyzed. Design: A total of 130 adult subjects who used a CII/HiRes 90K cochlear implant with a HiFocus 1/1J electrode were included in the study. The insertion angle and the distance to the modiolus of each electrode contact were determined using high-resolution CT scanning. The threshold levels (T-levels) and maximum comfort levels (M-levels) at 1 year of follow-up were determined. The degree of speech perception of the subjects was evaluated during routine clinical follow-up. Results: The depths of insertion of all the electrode contacts were determined. The distance to the modiolus was significantly smaller at the basal and apical cochlear parts compared with that at the middle of the cochlea (p < 0.05). The T-levels increased toward the basal end of the cochlea (3.4 dB). Additionally, the M-levels, which were fitted in our clinic using a standard profile, also increased toward the basal end, although with a lower amplitude (1.3 dB). Accordingly, the dynamic range decreased toward the basal end (2.1 dB). No correlation was found between the distance to the modiolus and the T-level or the M-level. Furthermore, the correlation between the insertion depth and stimulation levels was not affected by the duration of deafness, age at implantation or the time since implantation. Additionally, the T-levels showed a significant correlation with the speech perception scores (p < 0.05). Conclusions: The stimulation levels of the cochlear implants were affected by the intracochlear position of the electrode contacts, which were determined using postoperative CT scanning. Interestingly, these levels depended on the insertion depth, whereas the distance to the modiolus did not affect the stimulation levels. The T-levels increased toward the basal end of the cochlea. The level profiles were independent of the overall stimulation levels and were not affected by the biographical data of the patients, such as the duration of deafness, age at implantation or time since implantation. Further research is required to elucidate how fitting using level profiles with an increase toward the basal end of the cochlea benefits speech perception. Future investigations may elucidate an explanation for the effects of the intracochlear electrode position on the stimulation levels and might facilitate future improvements in electrode design.

Download Full-text

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

Frontiers in Surgery ◽

10.3389/fsurg.2021.695728 ◽

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.

Download Full-text