# Visual Field Improvement and Electrode Extrusion Prevention by Extended Endaural Incision With Cavity Obliteration for Cochlear Implantation in Ears After Canal Wall-Down Mastoidectomy: Experience of Four Cases

## TL;DR

A new surgical technique for cochlear implantation in ears with open cavities after a specific mastoidectomy procedure is described, based on four case experiences.

## Contribution

The novel extended endaural incision technique prevents electrode extrusion and improves visual field access during cochlear implantation in post-CWD mastoidectomy ears.

## Key findings

- An extended endaural incision allowed effective cavity obliteration and electrode placement in four cases.
- The technique provided a clear view for flap pedicling and cavity closure without serious complications.
- This approach enabled successful cochlear implantation in ears previously modified by canal wall-down mastoidectomy.

## Abstract

There is no global consensus on the surgical technique of cochlear implantation (CI) in ears with an open cavity after canal wall-down (CWD) mastoidectomy. Here, we report CI surgery with an endaural incision for the ears after CWD mastoidectomy. The endaural incision was extended upward to obliterate the open cavity of the temporal fascial flap. The endaural incision was extended downward to close the open cavity inlet. After inserting the implanted electrode, the open cavity was obliterated using a temporal fascial flap, and the cavity was closed at the inlet. We performed this type of CI surgery in four ears in three patients. This extended endaural incision provided an excellent view for pedicling the temporal fascial flap with the superficial temporal artery and for open cavity closure without any serious complications. This technique allowed us to opt for CI surgery of the ears after CWD mastoidectomy.