New Cochlear Implant Method Is Easy, Fast, Safe

From: Doctor's Guide, Canada - 24 Dec 2002

A DGReview of :"Cochlear implantation without mastoidectomy: the pericanal electrode insertion technique."
Acta Oto-Laryngologica

12/24/2002
By David Loshak

A new method of cochlear implantation, using direct pericanal electrode insertion, minimises the risk of facial nerve damage and cuts operating time in half.

The technique is also simple and particularly safe in both adults and older children, says a report from the University of Berne, Switzerland.

Functional results were comparable to those with the classical method, cochlear implantation via mastoidectomy, and might replace it.

There were no surgical complications, infections or electrode extrusions during post-operative observation periods of 6 to 24 months and beyond, the author said.

The new method had so far been applied to 15 adults and pre-adolescent patients who were deaf (m=7, f=8). Pericanal electrode insertion was easy, with depths into the cochlea of 30 mm or more using a MED-EL Combi 40+ device in 14 patients and of 20 mm with a Nucleus CI24M used in one patient.

Surgery began with a retroauricular skin incision. The bony surface of the mastoid plane behind the ear was dissected free and the skin of the external auditory canal elevated together with the posterior part of the tympanic membrane.

Cochleostomy was performed through the external auditory canal with a microdrill anterior to the round window. A rim was drilled into the postero-superior region of the bony external auditory canal immediately above the incus towards the outer border of the external auditory canal and connected to the retroauricular surface by a short tunnel.

The implant device was placed in the usual retroauricular area. The electrode was inserted through the tunnel and rim into the tympanic cavity and pushed into the cochleostomy hole. The electrode was immobilised in the rim using glass ionomer cement and covered with bone dust.

After the ground electrode was in place, the retroauricular incision was closed. The tympano-meatal flap was replaced and a dressing put into the external auditory canal.
Acta Oto-Laryngologica 2002;122(7):715-719. "Cochlear implantation without mastoidectomy: the pericanal electrode insertion technique."

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