Cochlear size variation among the Argentinian population

Area of Science:

• Otolaryngology
• Medical Imaging
• Anatomy

Background:

• Cochlear anatomy exhibits considerable variation across individuals.
• Accurate cochlear dimensions are crucial for selecting appropriate cochlear implant electrode lengths.

Purpose of the Study:

• To evaluate variations in cochlear size and shape within the Argentine population.
• To provide data for optimizing cochlear implant fitting in this demographic.

Main Methods:

• Computed Tomography (CT) scans of 247 ears were analyzed.
• Key parameters measured included basal turn diameter (A-value), width (B-value), and height (H-value).
• Cochlear Duct Length (CDL) and basal turn shape were also assessed using OTOPLAN® software.

Main Results:

• Mean A-value was 8.7 ± 0.61 mm (range 6.7-10.1 mm) and mean B-value was 6.4 ± 0.57 mm (range 4.5-8.1 mm).
• Mean cochlear height was 3.78 ± 0.57 mm.
• 83.5% of cochleas had an elliptical basal turn shape (B/A ratio <0.75), while 16.5% were rounder (B/A ratio ≥0.75).
• Cochlear Duct Length (CDL) ranged from 24.5 mm to 41.2 mm, with a median of 33.6 mm.

Conclusions:

• The Argentine population exhibits a slightly smaller mean cochlear size compared to other reported populations.
• These findings are important for tailoring cochlear implant device selection and surgical planning.