The Round Window: Is it the "Cochleostomy" of Choice? Experience in 130 Consecutive Cochlear Implants

Objective: To demonstrate that the round window insertion (RWI) for cochlear implantation with multichannel electrodes is a reliable, safe, and effective technique. Study Design: Retrospective case review. Setting: Academic tertiary referral center. Patients: One hundred thirty consecutive cochlear implants (72 female and 58 male subjects) performed from August 2009 to August 2011. Devices included 83 Cochlear, 40 Med El, and 7 Advanced Bionics (AB) cochlear implants. Intervention: Subsequent to a full audiometric assessment, patients underwent a mastoidectomy with facial recess approach whereby the primary surgical objective was to perform a RWI. When the surgeon was unable to access the round window safely, a cochleostomy was performed anterior and inferior to the round window. Postoperative performance was measured with Hearing in Noise Test, the Consonant-Nucleus-Consonant test, and/or the Arizona Biomedical Sentences test. Main Outcome Measures: Surgical feasibility of reliably performing a RWI, reason for cochleostomy, postoperative complications, and audiometric performance. Results: In 111 (85.4%) of 130 procedures, a RWI was performed; in 19 (14.6%), a cochleostomy was readily performed by the same approach. Reasons for creating a cochleostomy included facial nerve and jugular bulb location. There were no major postoperative complications in either group and 13 total minor complications. There was no statistically significant difference in postoperative complications or in audiometric performance between the 2 groups. Conclusion: The RWI may offer several advantages over a cochleostomy, and it seems to be a reliable, safe, and effective technique for cochlear implantation with today's cochlear implant electrodes. Further studies would be necessary to verify these findings for broad application to the cochlear implant patient population.