Hostname: page-component-848d4c4894-xm8r8 Total loading time: 0 Render date: 2024-06-18T05:42:49.166Z Has data issue: false hasContentIssue false
  • English
  • Français

A study on modelling cochlear duct mid-scalar length based on high-resolution computed tomography, and its effect on peri-modiolar and mid-scalar implant selection

Published online by Cambridge University Press:  19 August 2019

G Pamuk ,
A E Pamuk ,
A Akgöz ,
E Öztürk ,
M D Bajin  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
E Öztürk
Affiliation:
Department of Biostatistics, Faculty of Medicine, Hacettepe University, Ankara, Turkey
M D Bajin
Affiliation:
Department of Otorhinolaryngology, 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, Kırıkkale 71400, Turkey E-mail: dr_erim@hotmail.com Fax: +90 318 215 1195
Get access Rights & Permissions [Opens in a new window]

Abstract

Objective

To determine cochlear duct mid-scalar length in normal cochleae and its role in selecting the correct peri-modiolar and mid-scalar implant length.

Methods

The study included 40 patients with chronic otitis media who underwent high-resolution computed tomography of the temporal bone. The length and height of the basal turn, mid-modiolar height of the cochlea, mid-scalar and lateral wall length of the cochlear duct, and the ‘X’ line (the largest distance from mid-point of the round window to the mid-scalar point of the cochlear canal) were measured.

Results

Cochlear duct lateral wall length (28.88 mm) was higher than cochlear duct mid-scalar length (20.08 mm) (p < 0.001). The simple linear regression equation for estimating complete cochlear duct length was: cochlear duct length = 0.2 + 2.85 × X line.

Conclusion

Using the mid-scalar point as the reference point (rather than the lateral wall) for measuring cochlear duct mid-scalar length, when deciding on the length of mid-scalar or peri-modiolar electrode, increases measurement accuracy. Mean cochlear duct mid-scalar length was compatible with peri-modiolar and mid-scalar implant lengths. The measurement method described herein may be useful for pre-operative peri-modiolar or mid-scalar implant selection.

Keywords

Cochlear DuctCochlear ImplantationElectrodes, ImplantedRadiographic Image Interpretation, Computer-AssistedTomography, Spiral Computed
Type
Main Articles
Information
The Journal of Laryngology & Otology , Volume 133 , Issue 9 , September 2019 , pp. 764 - 769
Copyright
Copyright © JLO (1984) Limited, 2019 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

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

References

1Erixon, E, Hogstorp, H, Wadin, K, Rask-Andersen, H. Variational anatomy of the human cochlea: implications for cochlear implantation. Otol Neurotol 2009;30:14–2210.1097/MAO.0b013e31818a08e8Google Scholar
2Alexiades, G, Dhanasingh, A, Jolly, C. Method to estimate the complete and two turn cochlear duct length. Otol Neurotol 2014;36:904–710.1097/MAO.0000000000000620Google Scholar
3Gulya, AJ. Anatomy of the Temporal Bone with Surgical Implications, 3rd edn. New York: CRC Press, 2007;251–31010.3109/9780849375989-10Google Scholar
4Würfel, W, Lanfermann, H, Lenarz, T, Majdani, O. Cochlear length determination using cone beam computed tomography in a clinical setting. Hear Res 2014;316:65–7210.1016/j.heares.2014.07.013Google Scholar
5Angeli, SI, Goncalves, S. Predicting depth of electrode insertion by cochlear measurements on computed tomography scans. Laryngoscope 2016;126:1656–6110.1002/lary.25742Google Scholar
6Jiam, N, Jiradejvong, P, Pearl, MS, Limb, C. The effect of round window vs cochleostomy surgical approaches on cochlear implant electrode position. JAMA Otolaryngol Head Neck Surg 2016;142:873–8010.1001/jamaoto.2016.1512Google Scholar
7Adunka, O, Gstoettner, W, Hambek, M, Unkelbach, MH, Radeloff, A, Kiefer, J. Preservation of basal inner ear structures in cochlear implantation. ORL J Otorhinolaryngol Relat Spec 2004;66:306–1210.1159/000081887Google Scholar
8Meng, J, Li, S, Zhang, F, Li, Q, Qin, Z. Cochlear size and shape variability and implications in cochlear implantation surgery. Otol Neurotol 2016;37:1307–1310.1097/MAO.0000000000001189Google Scholar
9Escude, B, James, C, Deguine, O, Cochard, N, Eter, E, Fraysse, B. The size of the cochlea and predictions of insertion depth angles for cochlear implant electrodes. Audiol Neurootol 2006;11:27–3310.1159/000095611Google Scholar
10Shepherd, RK, Hatsushika, S, Clark, GM. Electrical stimulation of the auditory nerve: the effect of electrode position on neural excitation. Hear Res 1993;66:108–2010.1016/0378-5955(93)90265-3Google Scholar
11Eshraghi, AA, Yang, NW, Balkany, TJ. Comparative study of cochlear damage with three perimodiolar electrode designs. Laryngoscope 2003;113:415–1910.1097/00005537-200303000-00005Google Scholar
12Koch, RW, Ladak, HM, Elfarnawany, M, Agrawal, SK. Measuring cochlear duct length – a historical analysis of methods and results. J Otolaryngol Head Neck Surg 2017;46:1910.1186/s40463-017-0194-2Google Scholar