Related Experiment Video
Updated: Jun 28, 2026
Performing Repeated Intraoperative Impedance Telemetry Measurements during Cochlear Implantation
Published on: August 4, 2023
Intra-operative monitoring of cochlear function during cochlear implantation
John S Oghalai1, Ross Tonini, Jamie Rasmus
1The Hearing Center at Texas Children's Hospital, Houston, Texas, USA. jso@bcm.edu
Insights
Intra-operative auditory monitoring during cochlear implantation is feasible and improves residual hearing preservation. Real-time feedback helps surgeons modify techniques, leading to better long-term hearing outcomes in pediatric patients.
Area of Science:
- Otolaryngology
- Audiology
- Neurosurgery
Background:
- Cochlear implantation is a common procedure for profound hearing loss.
- Preservation of residual hearing is a key goal during cochlear implantation.
- Real-time feedback during surgery may enhance surgical precision and outcomes.
Purpose of the Study:
- To assess the feasibility of intra-operative auditory monitoring in pediatric cochlear implantation.
- To determine if this monitoring can provide feedback to surgeons for improved residual hearing preservation.
- To evaluate the impact of monitoring on long-term auditory thresholds.
Main Methods:
- Prospective, non-randomized study of 38 pediatric patients undergoing cochlear implantation.
- Division into an unmonitored (n=22) and a monitored (n=16) cohort.
- Auditory steady-state response audiometry used to measure thresholds pre-operatively, intra-operatively, and post-operatively (≥1 month).
Main Results:
- No significant difference in pre-operative thresholds between cohorts.
- In the monitored cohort, auditory thresholds increased minimally during electrode insertion (average 4.6 dB).
- Post-operative thresholds were significantly better in the monitored cohort (98.8 dB HL) compared to the unmonitored cohort (114.0 dB HL) (p < 0.001).
Conclusions:
- Intra-operative auditory monitoring is a viable tool during cochlear implantation.
- Real-time auditory feedback allows surgeons to adjust techniques, improving residual hearing preservation.
- This technique is associated with better long-term hearing outcomes in pediatric cochlear implant recipients.
Abstract:
The objective of this study was to determine if intra-operative auditory monitoring is feasible during cochlear implantation and whether this can be used as feedback to the surgeon to improve the preservation of residual hearing. This prospective non-randomised study was set in a paediatric tertiary referral hospital. Thirty eight consecutive paediatric patients undergoing cochlear implantation who had measurable auditory thresholds pre-operatively were divided into two cohorts. The unmonitored cohort included the first 22 patients and the monitored cohort included the last 16 patients. The main outcome measure(s) were pre-operative, intra-operative and more than one month post-operative average auditory thresholds at 500, 1000 and 2000 Hz measured using auditory steady-state response audiometry. The average pre-operative thresholds were 103.5 dB HL and 99.7 dB HL in the unmonitored and monitored cohorts, respectively. These were not statistically different (p > 0.3). In the monitored cohort, we measured auditory thresholds to assess cochlear function at multiple time points during the operation. Compared to baseline, thresholds were increased 0.7 dB after drilling the mastoidectomy and well, 0.2 dB after opening the cochlea and 4.6 dB after inserting the electrode array. One month post-operatively, the average thresholds were 114.0 dB HL in the unmonitored cohort but only 98.8 dB HL in the monitored cohort (p < 0.001). Both the use of intra-operative auditory monitoring and higher pre-operative thresholds were associated with improved preservation of residual hearing (p
