Send to

Choose Destination
Acta Otorhinolaryngol Ital. 2018 Oct;38(5):468-475. doi: 10.14639/0392-100X-1579.

Radiologic measurement of cochlea and hearing preservation rate using slim straight electrode (CI422) and round window approach.

Author information

Institute of Physiology and Pathology of Hearing, Mochnackiego, Warsaw, Poland.
World Hearing Center, Mokra, Kajetany, Poland.
Department of Heart Failure and Cardiac Rehabilitation, Medical University of Warsaw, Kondratowicza, Warszawa, Poland.
Institute of Sensory Organs, Mokra, Kajetany, Poland.


in English, Italian

Hearing preservation surgery constitutes a considerable branch of cochlear implantation surgery and is being steadily developed and perfected. The aim of the study was to verify if insertion of a cochlear implant electrode according to individually calculated linear insertion depth improves hearing preservation. We evaluated the relations between the size of a cochlea, insertion depth angle, linear insertion depth and hearing preservation rate (HP) according to Hearing Preservation Classification in a retrospective case review of 54 patients implanted with a slim straight electrode Nucleus CI422 in 2008-2011. Group HP was 0.75 at activation, 0.67 at 12 months (for 53 patients) and 0.60 at 24 months. In 53 cases, the mean insertion depth angle was 375° (SD 17°); mean calculated cochlear duct length 35.87 mm (SD 1.95); mean calculated linear insertion depth 23.14 mm (SD 1.68). There was no significantly relevant relation between HP values and angular insertion depth or insertion depth. Preoperative measurements of cochlea and specific parameters such as linear insertion depth have no effect on hearing preservation. Poor hearing preservation in some deep insertion cases cannot be explained entirely by the electrode position.


Cochlear implant; Electrode insertion depth; Hearing preservation; Partial deafness; Round window

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for PubMed Central
Loading ...
Support Center