Presented in part at the 10th European Symposium on Pediatric Cochlear Implantation, Athens, Greece, May 12–15, 2011.
Article first published online: 30 MAY 2012
Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.
Volume 122, Issue 9, pages 2057–2063, September 2012
How to Cite
Kontorinis, G., Scheper, V., Wissel, K., Stöver, T., Lenarz, T. and Paasche, G. (2012), In vitro modifications of the scala tympani environment and the cochlear implant array surface. The Laryngoscope, 122: 2057–2063. doi: 10.1002/lary.23408
The authors have no funding, financial relationships, or conflicts of interest to disclose.
- Issue published online: 23 AUG 2012
- Article first published online: 30 MAY 2012
- Manuscript Accepted: 12 APR 2012
- Manuscript Revised: 21 MAR 2012
- Manuscript Received: 17 JAN 2012
- cochlear implant;
- hyaluronic acid;
- insertion forces;
- neurotrophic factors;
- Level of Evidence: N/A.
To investigate the influence of alterations of the scala tympani environment and modifications of the surface of cochlear implant electrode arrays on insertion forces in vitro.
Research experimental study.
Fibroblasts producing neurotrophic factors were cultivated on the surface of Nucleus 24 Contour Advance electrodes. Forces were recorded by an Instron 5542 Force Measurement System as three modified arrays were inserted into an artificial scala tympani model filled with phosphate-buffered saline (PBS). The recorded forces were compared to control groups including three unmodified electrodes inserted into a model filled with PBS (unmodified environment) or Healon (current practice). Fluorescence microscopy was used before and after the insertions to identify any remaining fibroblasts. Additionally, three Contour Advance electrodes were inserted into an artificial model, filled with alginate/barium chloride solution at different concentrations, while insertion forces were recorded.
Modification of the scala tympani environment with 50% to 75% alginate gel resulted in a significant decrease in the insertion forces. The fibroblast-coated arrays also led to decreased forces comparable to those recorded with Healon. Fluorescence microscopy revealed fully cell-covered arrays before and partially covered arrays after the insertion; the fibroblasts on the arrays' modiolar surface remained intact.
Modifications of the scala tympani's environment with 50% to 75% alginate/barium chloride and of the cochlear implant electrode surface with neurotrophic factor–producing fibroblasts drastically reduce the insertion forces. As both modifications may serve future intracochlear therapies, it is expected that these might additionally reduce possible insertion trauma.