Intracochlear electrode array position and cochlear implant outcomes using the nucleus slim modiolar electrode and the extended round window approach: a follow-up study

European Archives of Oto-Rhino-Laryngology, vol. 279, pp. 4735–4743

Abstract

PURPOSE: The aim of this study was to evaluate the intracochlear position of the Slim Modiolar Electrode (SME) after insertion via the extended Round Window (eRW) approach, and to correlate this with residual hearing preservation and speech perception outcomes. METHODS: Twenty-three adult participants, consecutively implanted with the SME via the eRW approach, were included in this prospective, single-center, observational study. Electrode position was evaluated intra-operatively using X-ray fluoroscopy and TIM measurement, and post-operatively using ultra-high resolution CT. Residual hearing [threshold shift in PTA between pre- and post-operative measurement, relative hearing preservation (RHP%)] and speech perception were evaluated at 2 and 12 months after surgery. RESULTS: In each of the 23 participants, complete scala tympani positioning of the electrode array could be achieved. In one participant, an initial tip fold-over was corrected during surgery. Average age at implantation was 63.3 years (SD 13.3, range 28-76) and mean preoperative residual hearing was 81.5 dB. The average post-operative PTA threshold shift was 16.2 dB (SD 10.8) at 2 months post-operatively, corresponding with a RHP% score of 44% (SD 34.9). At 12 months, the average RHP% score decreased to 37%. Postoperative phoneme scores improved from 27.1% preoperatively, to 72.1% and 82.1% at 2 and 12 months after surgery, respectively. CONCLUSION: Use of the eRW approach results in an increased likelihood of complete scala tympani insertion when inserting the SME, with subsequent excellent levels of speech perception. However, residual hearing preservation was found to be moderate, possibly as a result of the extended round window approach, emphasizing that it is not an all-purpose approach for inserting this particular electrode array.

Authors 6

1. Tim M. Klabbers corresponding

   Radboud University Nijmegen · Radboud University Medical Center · Donders Institute for Brain, Cognition and Behaviour

   Affiliation as printed

   Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Philips Van Leydenlaan 15, 6525 EX, Nijmegen, The Netherlands. tim.klabbers@radboudumc.nl

   Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands. tim.klabbers@radboudumc.nl

   Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Philips Van Leydenlaan 15, 6525 EX, Nijmegen, The Netherlands

2. Floris Heutink

   Radboud University Nijmegen · Radboud University Medical Center · Donders Institute for Brain, Cognition and Behaviour

   Affiliation as printed

   Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Philips Van Leydenlaan 15, 6525 EX, Nijmegen, The Netherlands

   Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands

3. Wendy J. Huinck

   Radboud University Nijmegen · Radboud University Medical Center · Donders Institute for Brain, Cognition and Behaviour

   Affiliation as printed

   Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Philips Van Leydenlaan 15, 6525 EX, Nijmegen, The Netherlands

   Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands

4. Willem-Jan van der Woude

   Radboud University Medical Center

   Affiliation as printed

   Department of Radiology, Radboud University Medical Center, Nijmegen, The Netherlands

5. Berit M. Verbist Aachen Department of Radiology, Leiden University Medical Center

   Leiden University Medical Center · Radboud University Medical Center

   Affiliation as printed

   Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands

   Department of Radiology, Radboud University Medical Center, Nijmegen, The Netherlands

6. Emmanuel A. M. Mylanus

   Radboud University Nijmegen · Radboud University Medical Center · Donders Institute for Brain, Cognition and Behaviour

   Affiliation as printed

   Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Philips Van Leydenlaan 15, 6525 EX, Nijmegen, The Netherlands

   Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands