Learning Objectives: We will show the safety of subtotal petrosectomy applied to cochlear implantation in cases chronic otitis media, to prevent future infections that might compromise the implant

Expanding indications for cochlear implantation require adaptation of surgical techniques in special cases.

The presence of chronic otitis media (relapsing acute otitis media, chronic supurative otitis media or cholesteatoma) require special protection in cases of cochlear implantation.

Subtotal petrosectomy offers the best protection option against future infection in these cases.

Cul di sac closure of the esternal auditory canal, sealing of the Eustachian tube orifice and elimination of middle ear mucosa provides a secure scenario to avoid infections and risk cochlear implant explantation in the future.

Out of 41 cases in which we have used this technique we have 17 cases that were applied to chronic otitis media of the above mentiones¡d cathegories. We will report on rationale, technique and complications.

Follow up is made with MRI techniques adapted to the type of implant.