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Radiological measurement of cochlear dimensions in cochlear hypoplasia and its effect on cochlear implant selection

Published online by Cambridge University Press:  12 April 2021

G Pamuk ,
A E Pamuk Open the ORCID record for A E Pamuk [Opens in a new window] ,
A Akgöz ,
M D Bajin ,
B Özgen  and
L Sennaroğlu
G Pamuk
Affiliation:
Department of Otorhinolaryngology, Kırıkkale Yüksek İhtisas Hospital, Kırıkkale, Turkey
A E Pamuk*
Affiliation:
Department of Otorhinolaryngology, Kırıkkale Yüksek İhtisas Hospital, Kırıkkale, Turkey
A Akgöz
Affiliation:
Department of Radiology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
M D Bajin
Affiliation:
Department of Otorhinolaryngology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
B Özgen
Affiliation:
Department of Radiology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
L Sennaroğlu
Affiliation:
Department of Otorhinolaryngology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
*
Author for correspondence: Dr Ahmet Erim Pamuk, Department of Otorhinolaryngology, Kırıkkale Yüksek İhtisas Hospital, 71400 Kırıkkale, Turkey E-mail: dr_erim@hotmail.com Fax: +90 318 215 1195
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Abstract

Objective

To determine the effect of cochlear dimensions on cochlear implant selection in cochlear hypoplasia patients.

Methods

Temporal bone computed tomography images of 36 patients diagnosed with cochlear hypoplasia between 2010 and 2016 were retrospectively reviewed and compared with those of 40 controls without sensorineural hearing loss.

Results

Basal turn length and mid-modiolar height were significantly lower in the cochlear hypoplasia patients with subtypes I, II and III than in the control group (p < 0.001). Mid-scalar length was significantly shorter in subtype I–III patients as compared with the control group (p < 0.001). In addition, cochlear canal length (measured along the lateral wall) was significantly shorter in subtype I–IV patients than in the control group (subtypes I–III, p < 0.001; subtype IV, p = 0.002)

Conclusion

Cochlear hypoplasia should be considered if basal turn length is less than 7.5 mm and mid-modiolar height is less than 3.42 mm. The cochlear implant should be selected according to cochlear hypoplasia subgroup. It is critically important to differentiate subtype II from incomplete partition type I and subtype III from a normal cochlea, to ensure the most appropriate implant electrode selection so as to optimise cochlear implantation outcomes.

Keywords

Cochlear ImplantationHearing Loss, SensorineuralEar, InnerCochlear Diseases
Type
Main Articles
Information
The Journal of Laryngology & Otology , Volume 135 , Issue 6 , June 2021 , pp. 501 - 507
Copyright
Copyright © The Author(s), 2021. Published by Cambridge University Press

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Footnotes

Dr A E Pamuk takes responsibility for the integrity of the content of the paper

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