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.

Pamuk G., Pamuk A. E., Akgoz A., Ozturk E., Bajin M. D., Sennaroglu L.

The Journal of laryngology and otology, vol.133, no.9, pp.764-769, 2019 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 133 Issue: 9
  • Publication Date: 2019
  • Doi Number: 10.1017/s0022215119001671
  • Journal Name: The Journal of laryngology and otology
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.764-769
  • Keywords: Cochlear Duct, Cochlear Implantation, Electrodes, Implanted, Radiographic Image Interpretation, Computer-Assisted, Tomography, Spiral Computed, ELECTRODE POSITION
  • Hacettepe University Affiliated: Yes


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 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.