Deeper insertion of electrode array result in better rehabilitation outcomes – Do we have evidence?

Nayak, Gyanaranjan; Panda, Naresh K.; Banumathy, N; Munjal, Sanjay; Khandelwal, N; Saxena, Akshay Kumar

doi:10.1016/j.ijporl.2015.12.028

Cited by 7 publications

(8 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Measuring cochleae was an active area of research among anatomists and physiologists in the 19th and early 20th centuries, who conducted their first studies in this area using histological methods 1,2 . However, the invention of cochlear implants has attracted the interest of otologists and neuroradiologists with knowledge of cochlear dimensions 7,9–11,26,27 . In one of the earlier studies, Retzius measured the average OC length as 33.5 mm ± 0.80 and believed it did not show many variations; however, it was observed over time that like fingerprints, the size, structure, and confluence of cochleae varied from individual to individual 1,2,6,19,23 .…”

Section: Discussionmentioning

confidence: 99%

“…Presently, the CDL is measured during preoperative imaging evaluation for patients being considered for cochlear implants, which have emerged as an appropriate management choice for patients with severe‐profound hearing loss 4–6 . The quantitative assessment of CDL allows selecting the cochlear implant most compatible with patients' specific anatomy and tonotopy 7,8 . Consequently, this reduces the risk of trauma during the implantation surgery and may preserve residual hearing 7,9–12 …”

Section: Introductionmentioning

confidence: 99%

“…The quantitative assessment of CDL allows selecting the cochlear implant most compatible with patients' specific anatomy and tonotopy 7,8 . Consequently, this reduces the risk of trauma during the implantation surgery and may preserve residual hearing 7,9–12 …”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Comprehensive Analysis of Factors Affecting Cochlear Size: A Systematic Review and Meta‐analysis

et al. 2021

View full text Add to dashboard Cite

Objectives To determine the cochlea's average size in humans and evaluate the relationships between certain covariates and cochlear size. Methods A systematic search on articles on cochlear size and published in English was conducted using Cochrane, PubMed, Web of Science, and Scopus databases up to September 15, 2020. Data were pooled using random‐effects with three models. The effect of demographic, clinical, and measurement‐related parameters was specifically analyzed. Meta‐regression and subgroup analyses were conducted. The overall effect estimation was made for outcomes. Results The meta‐analysis included 4,708 cochleae from 56 studies. The overall length of the organ of Corti was 32.94 mm (95% confidence interval [CI]: 32.51–33.38). The first and second models revealed that age, gender, country, continent, measurement method (direct, indirect), measured structure (“A” value, cochlear lateral wall), origin (in vivo, in vitro), and type (histology specimens, plastic casts, imaging) of the cochlear material did not affect the cochlear size. However, study populations (general population, patients with a cochlear implant, and patients with congenital sensorineural hearing loss [CSNHL]) were found to affect the outcomes. Compared to the other populations, patients with CSNHL had shorter cochleae. Therefore, we developed a third model and found that the general population and patients with cochlear implants did not differ in cochlear size. Conclusion This meta‐analysis investigated the factors that could affect the cochlear size and found that patients with CSNHL had significantly shorter cochleae, whereas other covariates had no significant effect. Laryngoscope, 132:188–197, 2022

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Comprehensive Analysis of Factors Affecting Cochlear Size: A Systematic Review and Meta‐analysis

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Lastly, the Stenvers view was not routinely available for our patients and was not assessed. However, this view is commonly used in cochlear implantation studies to assess insertion depth [12, 21, 22]. …”

Section: Discussionmentioning

confidence: 99%

“…Pelliccia et al suggested an insertion depth of 270° to optimize sound perception while minimizing cochlear trauma. Similarly, Nayak et al suggested in the pediatric population, optimal hearing outcomes are observed with insertion depths of 270° to 360° [21, 23]. Once optimal insertion depths are determined, techniques to intra-operatively assess and change electrode depth will become important.…”

Section: Discussionmentioning

confidence: 99%

Effectiveness of skull X-RAY to determine cochlear implant insertion depth

Fernandes

Wang

Yeung

et al. 2018

Journal of Otolaryngology - Head & Neck Surgery

View full text Add to dashboard Cite

BackgroundCochlear implant (CI) insertion depth can affect residual hearing preservation, tonotopic range coverage, and Mapping. Therefore, determining insertion depth has the potential to maximize CI performance. A post-op skull X-RAY is commonly used to assess insertion depth, however its effectiveness has not been well established. Our primary objective was to assess the accuracy of post-op skull X-RAYs to determine insertion depth, compared to CT as the gold standard. Secondary objectives were to compare experience level of raters and different skull X-RAY views.MethodsThirteen patients with Advanced Bionic HiRes 90 K implants, and post-operative temporal bone CT scans were selected from the CI database at Sunnybrook Health Sciences Centre. Medical students, otology fellows, and CI surgeons evaluated insertion depths on post-op skull X-RAYs, while neuroradiologists evaluated CT scans. Descriptive statistics, regression analysis, and paired t-tests were used to compare the two types of imaging.ResultsX-RAYs and CTs provided an equivalent mean insertion depth of 337 degrees (p = 0.93), a mean difference of − 0.9 degrees and a standard deviation of paired differences of 43 degrees. Although means were similar across rater groups, CI surgeons (45 degrees) had the lowest standard deviation of paired differences. Comparing X-RAY views, Caldwell (29 degrees) had less variation than Towne (59 degrees) for standard deviation of paired differences.ConclusionsSkull X-RAYs provide accurate and reliable measurements for CI insertion depth. The Caldwell view alone may be sufficient for evaluations of insertion depth, and experience has a minor impact on the variability of estimates.Electronic supplementary materialThe online version of this article (10.1186/s40463-018-0304-9) contains supplementary material, which is available to authorized users.

show abstract

An overview of cochlear implant electrode array designs

2017

View full text Add to dashboard Cite

Cochlear implant electrode arrays are designed with specific characteristics that allow for the preservation of intra-cochlear structures during the insertion process, as well as during explantation. Straight lateral wall (LW) electrode arrays and pre-curved modiolar hugging (MH) electrode arrays are the two types that are commercially available. Although there is a third type of electrode array called the mid-scala (MS), which is positioned in the middle of the scala tympani (ST), and is usually considered as an MH type of electrode. Different lengths of straight LW electrode arrays are currently available which allow for insertion across a range of different sized cochleae; however, due to manufacturing limitations, pre-curved MH electrodes are generally only available to cover the basal turn of the cochlea, while the spiral ganglion cells are distributed in the Rosenthal's canal that extends into 1.75 turns of the cochlea. Both straight LW and pre-curved MH electrodes can cause a certain degree of intra-cochlear trauma, but pre-curved MH electrodes tend to deviate into the scala vestibuli from the scala tympani more often than the straight LW electrodes, resulting in damage to the osseous spiral lamina/spiral ligament which could initiate new bone formation and eventually affect the cochlear implant users' hearing performance. Structural damage to the cochlea could also affect the vestibular function. With pre-curved MH electrodes, higher degrees of trauma are related to the fixed curling geometry of the electrode in relation to the variable coiling pattern of individual cochleae, the orientation of the electrode contacts in relation to the modiolus wall, and how effectively the stylet was handled by the surgeon during the procedure. Wire management, metal density, and the shore hardness of the silicone elastomer all contribute to the stiffness/flexibility of the electrode. It is important to acknowledge the impact of bringing the stimulating contacts closer to the modiolus wall with an MH electrode type in terms of the resultant damage to intra-cochlear structures. The presence of malformed cochleae should be identified and appropriate electrodes should be chosen for each specific cochlea, irrespective of the cochlear implant brand. In order to utilize drug therapy, the cochlea should be free from any trauma.

show abstract

Deeper insertion of electrode array result in better rehabilitation outcomes – Do we have evidence?

Cited by 7 publications

References 19 publications

Comprehensive Analysis of Factors Affecting Cochlear Size: A Systematic Review and Meta‐analysis

Comprehensive Analysis of Factors Affecting Cochlear Size: A Systematic Review and Meta‐analysis

Effectiveness of skull X-RAY to determine cochlear implant insertion depth

An overview of cochlear implant electrode array designs

Contact Info

Product

Resources

About