Comparable Electrode Impedance and Speech Perception at 12 Months after Cochlear Implantation Using Round Window versus Cochleostomy: An Analysis of 40 Patients

Objective: The objective of this study was to examine whether cochlear implantation using the round window (RW) route versus cochleostomy achieves comparable electrode impedance and hearing results. Methods: This retrospective analysis included 40 patients receiving a cochlear implant (REZ-1): 20 using the RW approach and the remaining 20 using cochleostomy. Electrode impedance and tone, vowel, consonant, disyllable and sentence perception were measured during and after the implantation. Results: Electrode impedance did not differ significantly between the 2 groups at any time points [F(1, 38) = 1.84; p = 0.184]: 1.87, 5.16, 6.47 and 6.70 k Omega in the RW group versus 2.86, 5.33, 6.92 and 8.16 k Omega in the cochleostomy group at 0, 1, 3 and 12 months, respectively. There was no significant difference between the RW and cochleostomy groups for tone (77.50 vs. 80.50%; p = 0.472), vowel (77.70 vs. 78.65%; p = 0.760), consonant (75.50 vs. 78.25%; p = 0.443), disyllable (78.60 vs. 81.50%; p = 0.317) and sentence (50.90 vs. 52.50%; p = 0.684) perception at 12 months. Conclusion: The RW approach is comparable to cochleostomy in electrode placement as reflected by impedance and function as reflected by tone, vowel, consonant, disyllable and sentence perception. (C) 2018 The Author(s) Published by S. Karger AG, Basel