Various Surgical Techniques for Cochlear Implantation in an Ossified Cochlea: A Systematic Review

Cochlear ossification, otherwise known as labyrinthitis ossificans, is not an uncommon encounter in candidates for cochlear implantation (CI) that may necessitate alternative surgical approaches due to the insertion difficulties. We aimed to review the literature for the documented approaches for CI in cases with cochlear ossification.

This review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines on articles that described their surgical approach for CI in cases with cochlear ossification. A comprehensive search of the electronic medical databases was conducted through Feb 2025.

A total of 31 reports on 492 patients were included. The following approaches were documented: the facial recess approach, facial recess approach with removal of the incus buttress, combined facial recess and transcanal approach, subtotal petrosectomy/or radical mastoidectomy approach. The insertion was carried out through round window (RW), extended RW, scala tympani (ST) cochleostomy, scala vestibuli (SV) cochleostomy, double cochleostomy (basal turn with apical or middle turn cochleostomies), retrograde array insertion (through middle or apical turn cochleostomy) and partial or complete drill-out procedure. Alternative electrode designs used were short, double/split, triple, and stiff electrode arrays. In some instances, there was a need for alternative techniques to enable CI, including partial insertion technique, retrograde insertion, and robotic-assisted cochlear implant surgery.

This review suggests numerous approaches and techniques for CI in an ossified cochlea, providing alternative approaches when the RW is inaccessible through the standard facial recess approach.