Hearing preservation in cochlear implantation for electric acoustic stimulation.
OBJECTIVE
To evaluate the possibility of preservation of low-frequency hearing in atraumatic cochlear implant electrode insertion procedures for combined, ipsilateral electric and acoustic stimulation.


METHODS
A total of 21 patients were implanted with a MED EL C40+ cochlear implant using an atraumatic electrode insertion technique to preserve residual low-frequency hearing. Pure-tone audiometric thresholds were measured pre- and postoperatively to evaluate the degree of preserved hearing. Speech discrimination tests in quiet and with background noise were performed in a patient with successful hearing preservation.


RESULTS
Using the atraumatic electrode insertion procedure with an insertion depth of 360 degrees (18-24 mm), hearing preservation could be achieved in 18/21 patients (85.7%). Three patients (14.3%) lost their residual low-frequency hearing after the implantation. Residual hearing was preserved completely in 13 patients (61.9%) and partial hearing preservation was possible in 5 (23.8%). Preliminary speech discrimination tests showed a dramatic benefit for the combined electric and acoustic stimulation mode compared to cochlear implantation alone.


CONCLUSIONS
Preservation of low-frequency hearing in cochlear implantation is possible in patients implanted because of profound high-frequency deafness. With the development of new, more atraumatic electrode designs, preservation of residual hearing should be further improved.
Gstoettner
Wolfgang
W
ENT Department, Head and Neck Surgery, Johann Wolfgang Goethe University, Frankfurt am Main, Germany. gstoettner@em.uni-frankfurt.de
Kiefer
Jan
J
Baumgartner
Wolf-Dieter
WD
Pok
Stefan
S
Peters
Silke
S
Adunka
Oliver
O
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone; D002675:Child, Preschool; D019929:Cochlear Implantation; D004558:Electric Stimulation; D005260:Female; D006309:Hearing; D006316:Hearing Loss, High-Frequency / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013067:Speech Perception