Trial Outcomes & Findings for Cochlear Response Telemetry and Hearing Preservation (NCT NCT03134989)

Last Updated: 2021-09-24

Results Overview

Average low-frequency (LF) hearing thresholds (average thresholds at 500, 750, and 1000 Hz) will be measured for the implanted ear 4 to 6 weeks following surgery and compared with average LF hearing thresholds measured relative to the pre-operative baseline measured within 90 days of CI surgery. The outcome measure of interest is the change in average LF hearing thresholds pre- to postoperative for each subject. The average change observed for individual subjects will then be compared with individual electrophysiological cochlear microphonic (CM) measures made during the surgery using the Cochlear Response Telemetry System. Of specific interest is whether or not compromised CM measures relate to pre-to-postoperative changes in low-frequency hearing. In other words, are larger changes in average LF hearing thresholds observed in subjects with compromised CM measures made intraoperative versus those with uncompromised CM response?

Recruitment status

TERMINATED

Target enrollment

80 participants

Primary outcome timeframe

Baseline measurement (pre-operatively) compared to 4 to 6 weeks post-surgery

Results posted on

2021-09-24

Participant Flow

Participant milestones

Participant milestones
Measure	Adults Implanted With CI522, CI532, CI622, CI632 or Hybrid-L24 (US Only) Adults (≥ 18 years of age) implanted with CI522, CI532, CI622, CI632 or Hybrid-L24 (US only) with pre-operative audiometric threshold in the ear to be implanted of better than or equal to 80 dB HL at the frequency of 500 Hz.
Overall Study STARTED	80
Overall Study COMPLETED	80
Overall Study NOT COMPLETED	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Adults Implanted With CI522, CI532, CI622, CI632 or Hybrid-L24 (US Only) n=61 Participants Adults (≥ 18 years of age) implanted with CI522, CI532, CI622, CI632 or Hybrid-L24 (US only) with pre-operative audiometric threshold in the ear to be implanted of better than or equal to 80 dB HL at the frequency of 500 Hz.
Age, Categorical <=18 years	0 Participants n=61 Participants
Age, Categorical Between 18 and 65 years	36 Participants n=61 Participants
Age, Categorical >=65 years	25 Participants n=61 Participants
Age, Continuous	59.7 Years n=61 Participants
Sex: Female, Male Female	35 Participants n=61 Participants
Sex: Female, Male Male	26 Participants n=61 Participants
Device CI522/522	52 participants n=61 Participants
Device CI532	9 participants n=61 Participants
AETIOLOGY Unknown	39 participants n=61 Participants
AETIOLOGY Otosclerosis	2 participants n=61 Participants
AETIOLOGY Genetic	8 participants n=61 Participants
AETIOLOGY Meniere's Disease	1 participants n=61 Participants
AETIOLOGY Sudden Hearing Loss	2 participants n=61 Participants
AETIOLOGY Chronic Otitis Media	1 participants n=61 Participants
AETIOLOGY Usher's Syndrome	3 participants n=61 Participants
AETIOLOGY DeaFNess Autosomal Dominant 9 (DFNA9)	1 participants n=61 Participants
AETIOLOGY Noise Exposure	4 participants n=61 Participants
EAR (Left/Right Left Ear	31 participants n=61 Participants
EAR (Left/Right Right Ear	30 participants n=61 Participants
Nature of Hearing loss PROGRESSIVE	47 participants n=61 Participants
Nature of Hearing loss CONGENITAL WITH PROGRESSION	8 participants n=61 Participants
Nature of Hearing loss SUDDEN	4 participants n=61 Participants
Nature of Hearing loss PROGRESSION WITH SUDDEN	1 participants n=61 Participants
Nature of Hearing loss No Data	1 participants n=61 Participants
Age of onset of hearing loss	30.75 Years n=60 Participants • No data from one patient in this study
Age of diagnosis Severe -Profound Hearing Loss	46.98 Years n=51 Participants • Total Analysis population=61 Subjects with No diagnosis=9 Subjects with No data =1 Hence, Measure Analysis Population=51

PRIMARY outcome

Timeframe: Baseline measurement (pre-operatively) compared to 4 to 6 weeks post-surgery

Population: 19 of the 80 ECochG intro-operative responses were excluded from the analysis (reasons are outlined in the CIR). A further 18 of the remaining 61 data points were excluded due to an unclear CM response resulting in N=43 responses categorized as either preserved or compromised. Further, two subjects were excluded from the primary endpoint analysis as there were no FUV1 thresholds collected. Thereby N=41.

Outcome measures

Outcome measures
Measure	Cochlear Implant Recipients n=41 Participants Study group is comprised of cochlear implant patients already identified as candidates and undergoing surgery. Cochlear implant: Study involves using Electrocochleography to measure the CM response in patients undergoing cochlear implant surgery
Change in Low-frequency Hearing Thresholds Assessed Audiometrically Pre- and Post-operatively.	26.9 dB Interval 15.0 to 60.0

SECONDARY outcome

Timeframe: Baseline (pre-operative) compared to 3 months post cochlear implant activation

Population: 5 data points were excluded from this analysis due to post-operative thresholds not being measured at FUV2 (43 - 5 = 38).

Average low-frequency (LF) hearing thresholds (average thresholds at 500, 750, and 1000 Hz) will be measured for the implanted ear 3 months following cochlear implant activation and compared with average LF hearing thresholds measured preoperatively. The outcome measure of interest is the change in average LF hearing thresholds pre- to postoperative for each subject. The average change observed for individual subjects will then be compared with individual electrophysiological cochlear microphonic (CM) measures made during the surgery using the Cochlear Response Telemetry System. Of specific interest is whether or not compromised CM measures relate to pre-to-postoperative changes in low-frequency hearing. In other words, are larger changes in average LF hearing thresholds observed in subjects with compromised CM measures made intraoperative versus those with uncompromised CM response.

Outcome measures

Outcome measures
Measure	Cochlear Implant Recipients n=38 Participants Study group is comprised of cochlear implant patients already identified as candidates and undergoing surgery. Cochlear implant: Study involves using Electrocochleography to measure the CM response in patients undergoing cochlear implant surgery
Change in Low-frequency Hearing Thresholds Assessed Audiometrically Pre- and Post-operatively.	31.52 dB Interval 0.0 to 60.0

SECONDARY outcome

Timeframe: Intraoperative

Population: 40 data points with a CM response were eligible to be analysed for this outcome. Those excluded were due to an absence of CM under visual inspection (n =16), an absence of the impedance measurement used to calculate depth (n = 4), or an array that was withdrawn or reinserted at any time (n = 5).

The onset of the cochlear microphonic (CM) response will be measured intraoperative to determine if there is a relationship between the onset of the CM response during electrode insertion and the preoperative high-frequency acoustic hearing thresholds. The onset of the CM response will be tracked by impedance measures that are interleaved with the CM recordings. As each electrode in the array enters the perilymph in the cochlea there will be a measured reduction in impedance. CM onset will be defined in terms of the nth electrode (out of the 22 electrodes) to enter the cochlea. Preoperative high-frequency hearing will be defined as the average of preoperative thresholds at frequencies of 2 kHz, 3 kHz and 4 kHz for each individual subject.

Outcome measures

Outcome measures
Measure	Cochlear Implant Recipients n=40 Participants Study group is comprised of cochlear implant patients already identified as candidates and undergoing surgery. Cochlear implant: Study involves using Electrocochleography to measure the CM response in patients undergoing cochlear implant surgery
Correlation of Preoperative High-frequency Hearing Thresholds and Cochlear Microphonic Response (Number of Electrodes Inserted When CM Detected).	0.78 Pearson correlation coefficient

Adverse Events

Cochlear Implant Recipients

Serious events: 2 serious events

Other events: 15 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Cochlear Implant Recipients n=61 participants at risk Study group is comprised of cochlear implant patients already identified as candidates and undergoing surgery. Cochlear implant: Study involves measuring cochlear response electrophysiologically during surgery to place a cochlear implant in patients already identified as candidates.
Surgical and medical procedures SUDDEN ONSET ROTARY VERTIGO	3.3% 2/61 • 5 months Adverse events were collected for the subjects duration of involvement in the study - which was expected to be 5 months

Other adverse events

Other adverse events
Measure	Cochlear Implant Recipients n=61 participants at risk Study group is comprised of cochlear implant patients already identified as candidates and undergoing surgery. Cochlear implant: Study involves measuring cochlear response electrophysiologically during surgery to place a cochlear implant in patients already identified as candidates.
General disorders COLD	1.6% 1/61 • Number of events 1 • 5 months Adverse events were collected for the subjects duration of involvement in the study - which was expected to be 5 months
Musculoskeletal and connective tissue disorders UNDISPLACED FRACTURE OF THE MEDIAL FEMORAL CONDYLE	1.6% 1/61 • Number of events 1 • 5 months Adverse events were collected for the subjects duration of involvement in the study - which was expected to be 5 months
Musculoskeletal and connective tissue disorders DELAYED FACIAL PARALYSIS	1.6% 1/61 • Number of events 1 • 5 months Adverse events were collected for the subjects duration of involvement in the study - which was expected to be 5 months
General disorders VERTIGO AND NAUSEA	6.6% 4/61 • Number of events 4 • 5 months Adverse events were collected for the subjects duration of involvement in the study - which was expected to be 5 months
Respiratory, thoracic and mediastinal disorders BRONCHITIS	1.6% 1/61 • Number of events 1 • 5 months Adverse events were collected for the subjects duration of involvement in the study - which was expected to be 5 months
Ear and labyrinth disorders OTITIS MEDIA WITH EFFUSION	1.6% 1/61 • Number of events 1 • 5 months Adverse events were collected for the subjects duration of involvement in the study - which was expected to be 5 months
Ear and labyrinth disorders OTITIS EXTERNA DURING SURGERY	1.6% 1/61 • Number of events 1 • 5 months Adverse events were collected for the subjects duration of involvement in the study - which was expected to be 5 months
General disorders INTRAOPERATIVE HORIZONTAL CANAL DEFECT resulted in 'SEVERE VERTIGO EXPERIENCED DURING AUDIOMETRY, TY	1.6% 1/61 • Number of events 1 • 5 months Adverse events were collected for the subjects duration of involvement in the study - which was expected to be 5 months
Ear and labyrinth disorders PULSATILE TINNITUS	1.6% 1/61 • Number of events 1 • 5 months Adverse events were collected for the subjects duration of involvement in the study - which was expected to be 5 months
Ear and labyrinth disorders PAIN AND INFLAMATION POST SURGERY	1.6% 1/61 • Number of events 1 • 5 months Adverse events were collected for the subjects duration of involvement in the study - which was expected to be 5 months
Ear and labyrinth disorders EXACERBATION MENIERE'S DISEASE	1.6% 1/61 • Number of events 1 • 5 months Adverse events were collected for the subjects duration of involvement in the study - which was expected to be 5 months
Ear and labyrinth disorders BLOOD/FLUID STILL BEHIND EAR; NO PAIN REPORTED BY PATIENT	1.6% 1/61 • Number of events 1 • 5 months Adverse events were collected for the subjects duration of involvement in the study - which was expected to be 5 months

Additional Information

Ruth English

Cochlear

Phone: 0386633105

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place