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Individual Optimization of the Insertion of a Preformed Cochlear Implant Electrode Array.

Rau TS, Lenarz T, Majdani O - Int J Otolaryngol (2015)

Bottom Line: Conclusion.This finding leads to the conclusion that, in general, consideration of the specific curling behaviour of a CI electrode array is beneficial in terms of less traumatic insertion.Therefore, these results highlight an entirely novel aspect of clinical application of preformed perimodiolar electrode arrays in general.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany.

ABSTRACT
Purpose. The aim of this study was to show that individual adjustment of the curling behaviour of a preformed cochlear implant (CI) electrode array to the patient-specific shape of the cochlea can improve the insertion process in terms of reduced risk of insertion trauma. Methods. Geometry and curling behaviour of preformed, commercially available electrode arrays were modelled. Additionally, the anatomy of each small, medium-sized, and large human cochlea was modelled to consider anatomical variations. Finally, using a custom-made simulation tool, three different insertion strategies (conventional Advanced Off-Stylet (AOS) insertion technique, an automated implementation of the AOS technique, and a manually optimized insertion process) were simulated and compared with respect to the risk of insertion-related trauma. The risk of trauma was evaluated using a newly developed "trauma risk" rating scale. Results. Using this simulation-based approach, it was shown that an individually optimized insertion procedure is advantageous compared with the AOS insertion technique. Conclusion. This finding leads to the conclusion that, in general, consideration of the specific curling behaviour of a CI electrode array is beneficial in terms of less traumatic insertion. Therefore, these results highlight an entirely novel aspect of clinical application of preformed perimodiolar electrode arrays in general.

No MeSH data available.


Related in: MedlinePlus

Examples of different kinds of contour damage/intersection. (a) Without contact between electrode array and cochlear contour (grade 0). (b) Trauma risk grade II with both penetration of the electrode tip into the inner wall and overlapping of the silicone body with the outer wall. In fact, both lead to relevant contact forces inside the inner ear. (c) Extensive contour damage which results in the highest risk of causing an insertion trauma (grade IV).
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fig8: Examples of different kinds of contour damage/intersection. (a) Without contact between electrode array and cochlear contour (grade 0). (b) Trauma risk grade II with both penetration of the electrode tip into the inner wall and overlapping of the silicone body with the outer wall. In fact, both lead to relevant contact forces inside the inner ear. (c) Extensive contour damage which results in the highest risk of causing an insertion trauma (grade IV).

Mentions: Using this risk-rating method for each step of the modelled insertions, the degree of conformity of the implants' shape and the shape of the inner ear was rated (see Figures 8 and 9). Ideally, the electrode array lies fully inside the contours of the cochlea without any intersection. This means contact-free insertion with no insertion forces and, therefore, no insertion trauma. Mechanical contact between the implant and the inner ear (resulting in contact forces and thus a corresponding risk of insertion trauma) is visualized as an intersection (damage) of the contour of the electrode array and the cochlear contour. The extent of contour damage allows a qualitative valuation of the corresponding risk of intracochlear trauma and therefore loss of residual hearing. However, the “trauma risk” rating scale introduced is not, unlike Eshraghi et al.'s [40] “trauma grade,” a criterion for postexperimental evaluation. Rather, it is a method of estimating the risk of insertion trauma in advance (i.e., prospectively). Limitations of this evaluation method are discussed in detail in Section 4.3.


Individual Optimization of the Insertion of a Preformed Cochlear Implant Electrode Array.

Rau TS, Lenarz T, Majdani O - Int J Otolaryngol (2015)

Examples of different kinds of contour damage/intersection. (a) Without contact between electrode array and cochlear contour (grade 0). (b) Trauma risk grade II with both penetration of the electrode tip into the inner wall and overlapping of the silicone body with the outer wall. In fact, both lead to relevant contact forces inside the inner ear. (c) Extensive contour damage which results in the highest risk of causing an insertion trauma (grade IV).
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4581552&req=5

fig8: Examples of different kinds of contour damage/intersection. (a) Without contact between electrode array and cochlear contour (grade 0). (b) Trauma risk grade II with both penetration of the electrode tip into the inner wall and overlapping of the silicone body with the outer wall. In fact, both lead to relevant contact forces inside the inner ear. (c) Extensive contour damage which results in the highest risk of causing an insertion trauma (grade IV).
Mentions: Using this risk-rating method for each step of the modelled insertions, the degree of conformity of the implants' shape and the shape of the inner ear was rated (see Figures 8 and 9). Ideally, the electrode array lies fully inside the contours of the cochlea without any intersection. This means contact-free insertion with no insertion forces and, therefore, no insertion trauma. Mechanical contact between the implant and the inner ear (resulting in contact forces and thus a corresponding risk of insertion trauma) is visualized as an intersection (damage) of the contour of the electrode array and the cochlear contour. The extent of contour damage allows a qualitative valuation of the corresponding risk of intracochlear trauma and therefore loss of residual hearing. However, the “trauma risk” rating scale introduced is not, unlike Eshraghi et al.'s [40] “trauma grade,” a criterion for postexperimental evaluation. Rather, it is a method of estimating the risk of insertion trauma in advance (i.e., prospectively). Limitations of this evaluation method are discussed in detail in Section 4.3.

Bottom Line: Conclusion.This finding leads to the conclusion that, in general, consideration of the specific curling behaviour of a CI electrode array is beneficial in terms of less traumatic insertion.Therefore, these results highlight an entirely novel aspect of clinical application of preformed perimodiolar electrode arrays in general.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany.

ABSTRACT
Purpose. The aim of this study was to show that individual adjustment of the curling behaviour of a preformed cochlear implant (CI) electrode array to the patient-specific shape of the cochlea can improve the insertion process in terms of reduced risk of insertion trauma. Methods. Geometry and curling behaviour of preformed, commercially available electrode arrays were modelled. Additionally, the anatomy of each small, medium-sized, and large human cochlea was modelled to consider anatomical variations. Finally, using a custom-made simulation tool, three different insertion strategies (conventional Advanced Off-Stylet (AOS) insertion technique, an automated implementation of the AOS technique, and a manually optimized insertion process) were simulated and compared with respect to the risk of insertion-related trauma. The risk of trauma was evaluated using a newly developed "trauma risk" rating scale. Results. Using this simulation-based approach, it was shown that an individually optimized insertion procedure is advantageous compared with the AOS insertion technique. Conclusion. This finding leads to the conclusion that, in general, consideration of the specific curling behaviour of a CI electrode array is beneficial in terms of less traumatic insertion. Therefore, these results highlight an entirely novel aspect of clinical application of preformed perimodiolar electrode arrays in general.

No MeSH data available.


Related in: MedlinePlus