Surgical methods and postoperative results of cochlear implantation in 79 cases of ossified cochlea

Abstract

Conclusion: A man-made bone tunnel of 1.5 turns around the modiolus can be created in cases of total cochlear ossification. Patients with ossified cochlea types I and II achieved satisfactory hearing results after cochlear implantation (CI). Patients with ossified cochlea type III, in which the modiolus is damaged by the ossification, showed poor hearing results after CI. Objectives: To introduce a new CI surgical technique for ossified cochlea and to summarize postoperative hearing results. Methods: A total of 79 patients with ossified cochlea who underwent CI were analyzed. Cases were divided into three types: type I, round window ossification; type II, partial cochlear ossification; and type III, complete cochlear ossification. Four surgical methods were used: method A, applicable to type I; methods B and C, applicable to type II; and method D, applicable to type III. Sound field audiometric and speech tests were performed 6 months postoperatively. Results: All surgeries were successful. The average hearing thresholds for warble tone were 35 dB hearing level (HL) in types I and II and 75 dB HL in type III. The average recognition rates of Mandarin speech were 100% (single finals) and 91% (single initials) in types I and II and 20% (single finals) and 0% (single initials) in type III.

Keywords::

• Cochlea ossification
• cochlear implant
• operation
• hearing results

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.