What are the advantages of perimodiolar electrodes? How has this advantage been emphasized with the introduction of Slim Modiolar?
First, perimodiolar arrays reduce the distance to the modiolus to improve performance1,2 and allow for more focused stimulation.3,4 A study conducted at Washington University in St.Louis showed a correlation between the position of the electrode with respect to the modiolus (often referred to as the “wrapping factor”) and CNC word score.5 The group showed that those electrodes with proper perimodiolar placement had a lower wrapping factor, meaning tighter to the modiolus, and improved performance.
While the benefits of a perimodiolar array are well understood, the introduction of Slim Modiolar has redefined how we think of perimodiolar electrodes in four areas:
While the performance benefits of a perimodiolar electrode are well understood, a recent publication demonstrated that in a matched population (post-lingual patients with all electrodes in scala tympani), the phoneme score at 12 months was significantly better with Slim Modiolar reporting a 79.5% mean and 14% standard deviation (SD) 1-5. This was compared to Contour Advance’s 69.4% mean and 17% SD.6
Placement in Scala Tympani:
In multiple published surgical papers on the Slim Modiolar electrode successful Scala Tympani location was seen in 90 to 100% of the patients.6-9 The Slim Modiolar presents an opportunity to combine the benefits of being close to the hearing nerve with consistent scala tympani location.
Preservation of structures:
The Slim Modiolar electrode is designed to preserve the delicate inner ear structure, using a sheath-based delivery stystem which allows for a 60% reduction in volume compared to Contour Advance.10 Moreover, in a temporal bone study, 98% of the bones that were implanted experienced “no trauma” through the smooth insertion and sheath-based system.11
Preference of insertion technique:
Another benefit of the Slim Modiolar electrode is the ability to use the preferred surgical approach including round window, extended round window and cochleostomy. A 2017 study showed that 44% of the Slim Modiolar cases were performed with round window insertion, 22% with extended round window and 34% with cochleostomy.7 The study demonstrated that Slim Modiolar could be implanted with all surgical approaches, while still maintaining consistent Scala Tympani location.
1. Lazard D. S, et al. Pre-, per- and postoperative factors affecting performance of postlinguistically deaf adults using cochlear implants: a new conceptual model over time. PloS one. 2012; 7:e48739
2. Blamey P, et al. Factors affecting auditory performance of postlinguistically deaf adults using cochlear implants: An update with 2251 patients. Audiology & neuro-otology. 2013; 18:36-47.
3. Hughes, ML, Abbas, PJ. Electrophysiological channel interaction, electrode pitch ranking, and behavioral threshold in straight versus perimodiolar cochlear implant electrode arrays. J Acoustic Soc Am. 2006; 119(3):1538-47.
4. Cohen L., Richardson L., Saunders E., Cowan R. Spatial spread of neural excitation in cochlear implant recipients: comparison of improved ECAP method and psychophysical forward masking. Hearing Research. 2003; 179 (1-2):72-87.
5. Holden LK, Finley CC, Firszt JB, Holden TA, Brenner C, Potts LG, et al. Factors affecting open-set word recognition in adults with cochlear implants. Ear Hear. 2013; 34(3):342-60
6. Shaul C, Dragovic AS, Stringer AK, O’Leary SJ, Briggs RJ. Scalar localization of peri-modiolar electrodes and speech perception outcomes. J Laryngol Otol 2018; 1-7. https://doi.org/10.1017/S0022215118001871
7. Aschendorff et al. Clinical investigation of the Nucleus Slim Modiolar Electrode. Audiology & Neurotology. 2017; 22:169-179. https://www.ncbi.nlm.nih.gov/pubmed/29059669
8. Data on File: US Multicenter CI532 Study. 2018.
9. Cuda, D, Murri, A. Cochlear Implantation with the nucleus slim modiolar electrode (CI532): a preliminary experience. European Archives of Oto-Rhino-Laryngology. 20017; 12:4141. https://www.ncbi.nlm.nih.gov/pubmed/29032420
10. Friedmann et al. Surgical Experience and Early Outcomes With a Slim Perimodiolar Electrode. NYU Cochlear Implant Center. Otology & Neurotology, Vol 40, No. 3,2019.
11. EA32 Electrode Insertion Safety and Performance Study Report Data on File (Document Number: 473386)
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