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Video

Otology/Neurotology

(A841) Long Term Outcomes of Cochlear Implantation in Inner Ear Malformations – Surgical and Auditory Perspectives

Monday, October 13, 2025
12:00 PM - 1:00 PM EDT
Location: OTO EXPO, Posters

    Presenting Author(s)

  • PS

    POONAM SAGAR, MD

    Assistant Professor
    All India Institute of Medical Sciences New Delhi
    Delhi, Delhi, India

    • Co-Author(s)

  • KS

    Kapil Sikka, MD

    Professor
    All India Institute of Medical Sciences, New Delhi
    New Delhi, Delhi, India

  • PS

    Prem Sagar, MD

    Additional Professor
    All India Institute of Medical Sciences, Delhi, India

    • Senior Author(s)

  • RK

    Rakesh Kumar, MD

    Professor
    All India Institue of Medical Sciences, New Delhi, Delhi, India

    • Co-Author(s)

  • Alok Thakar, MD, FRCS

    Professor
    All India Institute of Medical Sciences, New Delhi
    New Delhi, Delhi, India

Disclosure(s):
POONAM SAGAR, MD: No relevant relationships to disclose.
Alok Thakar, MD, FRCS: No relevant relationships to disclose.


Introduction: The objective of present study is to determine surgical challenges and auditory outcomes of cochlear implantation in patients with inner ear malformation.

Methods: Retrospective study. Medical records of patients undergone cochlear implantation for bilateral severe to profound sensorineural hearing loss during 2018-2023 at tertiary care center were reviewed. Group I included inner ear malformation (n=37); group II included normal inner ear (n=33). Data was analyzed for demography, outcomes; electrode insertion, intra-operative neural response telemetry (NRT), complications auditory outcomes with Categories of auditory performance (CAP) score and speech intelligibility rating (SIR) using Stata 18.0 (StataCorp LP) software. Chi square/Fischer’s Exact and t- test were used for categorical and quantitative variables respectively. Probability of auditory improvement was compared between two groups using Kaplan Meier survival analysis followed by Log rank test. Inner ear malformation, normal inner ear anatomy were independent variables.

Results: Statistically significant difference was found between two groups in terms of insertion site i.e. cochleostomy Vs round window, (p= 0.026), complications (p=0.000), intraoperative NRT (p =0.001). Probability of getting better auditory perception at 48 months is less (24%) in group I as compared to group II (28%) which was statistically not significant (p=0.63). Types of cochlear malformation included incomplete partition (IP)-2 (n=15), IP-1 (n=4), cochlear hypoplasia (n=3). Most common complication was CSF leak (7/37) occurred most often in IP-2 (5/7).

Conclusions: Cochlear implantation in inner ear malformation has significant complications rate. CSF gusher is more often encountered in IP-2 in the present study. Probability of getting better auditory perception is less in inner ear malformation group at 48 months which was statistically not significant. Future research should investigate overall impact of cochlear implantation on auditory and speech outcomes.