Cochlear Implantation After Labyrinthectomy or a Translabyrinthine Surgical Approach
Phase: NA
Conditions: Unilateral Acoustic Neuroma, Meniere's Disease
Sponsor: University of North Carolina, Chapel Hill

 
Cochlear Implantation after Labyrinthectomy or a Translabyrinthine 
Surgical Approach 
 
 
 
NCT number NCT02309099 
Document Date 05/25/2015 
Most recent IRB approval Date  
(for this document version) 04/19/2018 
 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
Cochlear Implantation After Labyrinthectomy or a Translabyrinthine 
Surgical Approach 
Protocol, Version 5.0, Date: May 25, 2015 
 
 
I. 
Site Information: 
 
A. Investigators 
 
 
Kevin D Brown, MD, PhD (Principle Investigator and Sponsor) 
Associate Professor 
Department of Otolaryngology/Head and Neck Surgery 
University of North Carolina at Chapel Hill 
170 Manning Drive, Physician’s Office Building G190, CB 7070 
Chapel Hill, NC, 27599-7070 
Tel: 919-966-3344 Fax: 919-966-7941   Email: 
kevin_d_brown@med.unc.edu 
 
Craig A Buchman, MD, FACS (Co-Investigator) 
Professor 
Vice Chairman for Clinical Affairs 
Chief, Division of Otology/Neurotology and Skull Base Surgery 
Department of Otolaryngology/Head and Neck Surgery 
University of North Carolina at Chapel Hill 
170 Manning Drive, Physician’s Office Building G190, CB 7070 
Chapel Hill, NC, 27599-7070 
Tel: 919-843-4820 Fax: 919-966-7941 Email: buchman@med.unc.edu 
 
Emily Buss, PhD (Co-Investigator) 
Professor 
Department of Otolaryngology/Head and Neck Surgery 
University of North Carolina at Chapel Hill 
170 Manning Drive, Physician’s Office Building G190, CB 7070 
Chapel Hill, NC, 27599-7070 
Tel: 919-843-1963 Fax: 919-966-7941 Email: ebuss@med.unc.edu 
 
Margaret T Dillon, AuD (Co-Investigator) 
Assistant Professor 
Department of Otolaryngology/Head and Neck Surgery 
University of North Carolina at Chapel Hill 
170 Manning Drive, Physician’s Office Building G190, CB 7070 
Chapel Hill, NC, 27599-7070 
Tel: 919-966-5251 Fax: 919-966-7941 Email: mdillon@med.unc.edu 
 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
Meredith L Anderson, AuD (Co-Investigator) 
Research Instructor 
Department of Otolaryngology/Head and Neck Surgery 
University of North Carolina at Chapel Hill 
170 Manning Drive, Physician’s Office Building G190, CB 7070 
Chapel Hill, NC, 27599-7070 
Tel: 919-966-5251 Fax: 919-966-7941 Email: 
meredith_anderson@med.unc.edu 
 
Shuman He, MD, PhD (Co-Investigator) 
Assistant Professor 
Department of Otolaryngology/Head and Neck Surgery 
University of North Carolina at Chapel Hill 
170 Manning Drive, Physician’s Office Building G190, CB 7070 
Chapel Hill, NC, 27599-7070 
Tel: 919-966-8626  Fax: 919-966-7941 Email: shuman_he@med.unc.edu 
 
Douglas Fitzpatrick, PhD (Co-Investigator) 
Assistant Professor 
Department of Otolaryngology/Head and Neck Surgery 
University of North Carolina at Chapel Hill 
170 Manning Drive, Physician’s Office Building G190, CB 7070 
Chapel Hill, NC, 27599-7070 
Tel: 919-966-3254  Fax: 919-966-7941 Email: 
douglas_fitzpatrick@med.unc.edu 
 
 
B. IRB 
 
 
University of North Carolina Biomedical Institutional Review Board 
 
Co-Chairs: David Weber, Doug Mann, Kim Brownley, Herbert Patterson 
 
Medical School Building 52 
 
University of North Carolina at Chapel Hill 
 
105 Mason Farm Road, Chapel Hill, NC, 27599-7097 
 
Tel: 919-966-3113 Fax: 919-966-7879 
 
 
 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
II. 
Introduction 
 
The treatment for cases of vestibular schwannoma or Meniere’s disease may 
require a translabyrinthine surgical approach. This surgical approach results in a 
complete loss of hearing in the surgical ear, leaving the patient with a unilateral 
hearing loss. Though assistive hearing technologies exist to route signals from 
the poorer hearing ear to the better hearing ear, effected patients continue to 
have limitations with localization and speech perception in noise. An alternative 
hearing device is a cochlear implant, which would provide the signal to the 
affected ear. This could potentially offer binaural cues, thus improving 
localization and speech perception in noise. Since the surgical procedures for a 
translabyrinthine approach parallel those for cochlear implantation, insertion of 
the cochlear implant could occur within the same surgery. 
 
A vestibular schwannoma is a benign tumor on cranial nerve VIII that affects the 
vestibular and auditory systems. Hearing loss on the side of the vestibular 
schwannoma may result from degeneration of hair cells and spiral ganglia 
(Roosli et al, 2012) or growth of the schwannoma into the cochlear space 
(Falcioni et al, 2003). Treatment options include observation from routine 
imaging, radiation therapy, or surgical removal of the tumor. Despite treatment 
for the vestibular schwannoma, auditory sensitivity may be further reduced on 
the affected side as a result of the radiation therapy or compromises to the inner 
ear or cranial nerve VIII from surgical removal. Thus, in cases of unilateral 
vestibular schwannoma the patient is often left with a unilateral profound 
hearing loss. 
 
Patients who are scheduled to undergo labyrinthectomy for intractable 
Meniere’s disease are a second population with resulting unilateral profound 
hearing loss. These patients typically have non-functional hearing on the affected 
ear prior to the procedure. The main indication for the surgery is intractable 
vertigo and thus the loss of already non-functional hearing is typically well 
accepted. 
 
Though hearing on the contralateral ear may be within normal limits, unilateral 
hearing loss is known to result in reduced speech perception in noise (Welsh et 
al, 2004; Rothpletz, Wightman & Kistler, 2012), variable abilities on localization 
tasks (Slattery & Middlebrooks, 1994), increased report of hearing handicap 
(Iwasaki et al, 2013), and reduced quality of life (Wie, Pripp & Tvete, 2010). Due 
to the severity of the hearing loss, these patient populations cannot utilize 
conventional amplification that would offer auditory input to the affected ear. 
The current hearing device options for this patient population include CROS 
hearing aids and bone-conduction devices. With a CROS hearing aid, a 
microphone positioned near the affected ear picks up the signal and sends it to a 
hearing aid placed on the contralateral ear to present the signal to the unaffected 
side. Bone-conduction devices transmit the signal from the affected ear to the 
contralateral ear via transcutaneous vibrations. Though CROS hearing aids and 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
bone-conduction devices provide the patient with auditory information from 
both sides, the ability to use binaural cues for localization and speech perception 
in noise is variable (Kunst et al, 2007). 
 
It is of interest as to the potential benefit of cochlear implantation in these 
populations considering the profound hearing loss resulting from surgical 
intervention. A cochlear implant is a two-part system, including the internal 
electrode array and external speech processor. The internal electrode array is 
surgically implanted into the affected cochlea. The external speech processor 
receives sounds and transmits this signal to the internal portion. The electrode 
array presents the signal via electrical pulses within the cochlear space, which is 
interpreted by the brain as sound.  
 
Cochlear implantation has been reported as a viable treatment option in other 
cases of unilateral hearing loss, including sudden sensorineural hearing loss 
(Firszt et al, 2012), and severe tinnitus (Vermiere & Van de Heyning, 2009; Van 
de Heyning et al, 2008). Further, cochlear implantation has been shown to offer 
superior speech perception in noise, localization abilities, and subjective report 
in cases of unilateral sensorineural hearing loss as compared to CROS hearing 
aids and bone-conduction devices (Arndt et al, 2011).  
 
There is limited evidence as to the success of cochlear implantation in patients 
with unilateral profound hearing loss resulting from vestibular schwannoma. Pai 
et al (2013) reported variable speech perception outcomes in five cochlear 
implant recipients with a history of vestibular schwannoma due to NF2 or 
sporadic growth. Limitations of this study are the subjects underwent a range of 
treatments prior to cochlear implantation and the cases reviewed had profound 
hearing loss in both ears. Zanetti et al (2008) reported on a case study of 
unilateral vestibular schwannoma removal and simultaneous cochlear 
implantation. This subject reportedly experienced an improvement in speech 
perception abilities and quality of life postoperatively. Determining the 
preferred treatment option for patients suffering from unilateral vestibular 
schwannoma is still needed. 
 
Further, there is limited evidence of the preferred treatment option for patients 
suffering from unilateral profound hearing loss after undergoing a 
labyrinthectomy for intractable Meniere’s disease. Osborn, Yeung and Lin (2012) 
reported on a patient who underwent bilateral labyrinthectomies for Meniere’s 
disease. They reported an improvement in speech perception abilities and 
subjective benefit; however, there was a delay between the two surgeries. 
Allowing for a waiting period between the two surgeries is not ideal as cochlear 
ossification may occur (Wareing & O’Connor, 1997), limiting the ability to 
successfully insert the electrode array. Lustig et al (2003) also reported 
successful outcomes from cochlear implantation in subjects with bilateral 
Meniere’s disease. However, there is no published report investigating whether 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
cochlear implantation improves speech perception and/or localization abilities 
in unilateral cases of Meniere’s disease. 
 
The goal of this project is to determine whether subjects who have undergone 
labyrinthectomy or a translabyrinthine surgical approach as the treatment for 
vestibular schwannoma or Meniere’s disease with intractable vertigo benefit 
from cochlear implantation on speech perception and localization tasks. If the 
auditory nerve is able to transmit this signal effectively, then these two 
populations may be able to utilize the combination of electric (in the affected 
ear) and acoustic (in the non-affected ear) information for improved speech 
perception in noise and localization as reportedly experienced in other 
unilateral sensorineural hearing loss populations.  
 
III. 
Objectives 
 
A. The purpose of this study is to demonstrate the safety and effectiveness of 
cochlear implantation in subjects with unilateral deafness resulting from 
either a labyrinthectomy or a translabyrinthine surgical approach. 
Postoperative results will be evaluated with speech perception measures, 
localization tasks, and subjective reports. 
 
IV. 
Investigational Device 
 
A. Subjects will be implanted with the commercially available MED-EL 
SYNHRONY cochlear implant with either the standard or Flex28 electrode 
array (MED-EL Corporation, Innsbruck, Austria). The device consists of a 
stimulator, a coil with a magnet within its center, a reference electrode, an 
EAP reference electrode and an active electrode permanently attached to the 
stimulator. The electrode is made of medical grade silicone, platinum 
(electrode contacts) and platinum/iridium (90/10) wires and nitinol. 
 
The purpose of the device is perception of environmental sound and 
potential for improvement in communication abilities. 
 
For the adult population, the MED-EL SYNCHRONY cochlear implant is 
indicated for those 18 years of age or older, who have bilateral sensorineural 
hearing impairment and obtain limited benefit from appropriately fitted 
binaural hearing aids. Additional information regarding this device is 
provided in Appendix A. 
 
The standard electrode array is 31.5 mm long, with 12 pairs of contacts 
spaced over 26.4 mm with 2.4 mm spacing between each contact pair. The 
electrode’s length allows insertion into the scala tympani and stimulation of 
the cochlear canal to the fullest extent possible. The array features a marker 
ring 31.5 mm from the apex that is used to seal the cochleostomy and to 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
indicate maximum electrode insertion. The diameter of the array increases to 
1.3 mm at the proximal thicker part of array just before the marker ring. 
 
The Flex28 electrode array is 28 mm long featuring FLEX tip technology. The 
contacts for the 12 channels are arranged as 5 single contacts at the apical 
array end and 7 contact pairs at the base with 2.1 mm spacing between each 
channel. The specially designed electrode tip offers increased mechanical 
flexibility for reduced insertion force. The marker ring is located 28 mm from 
the electrode tip and indicates the deepest insertion.  Near the marker ring, 
the electrode lead features an additional marker on the same side of the 
array as the single apical contacts. The marker allows the surgeon to ensure 
appropriate alignment of the single contacts toward the modiolus. 
 
Subjects will be fit with the SONNET speech processor. The SONNET speech 
processor is an external component of the MAESTRO Cochlear Implant 
System and is indicated for use on patients who have been implanted with a 
MED-EL cochlear implant.  The SONNET audio processor consists of the 
control unit with the earhook attached, the battery pack frame and cover, the 
connecting piece, the coil and the coil cable.  The audio processor uses 
batteries that provide sufficient power for both the external and the 
implanted electronics. 
 
The MAESTRO Fitting Software will be used to program the SONNET speech 
processor. The MAESTRO software is used for different intraoperative and 
postoperative purposes for the MED-EL Cochlear Implant System. Currently, 
it contains the implant Telemetry and Fitting of the SONNET, OPUS 2, 
RONDO, OPUS 1, or TEMPO+ processors, EABR (Electrical Auditory 
Brainstem Response), ART (Auditory nerve Response Telemetry) and ESRT 
(Electrically Evoked Stapedius Reflex Threshold), and Audiogram 
functions.  The MAESTRO software is an external component of the MED-EL 
Cochlear Implant System and is intended to be used in a clinical or office 
environment by persons adequately skilled and trained to perform all 
intended tasks and with patients who received one of the intended MED-EL 
Cochlear implants. 
 
V. 
Study Duration 
 
A. Enrollment Period 
1. 4 years 
 
B. Study Timeline 
1. Candidacy evaluation, preoperative evaluation, surgery, initial 
postoperative follow-up, initial activation, and post-initial activation 
evaluations (1, 3, 6, 9, and 12-months post-initial activation) 
 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
C. The study endpoint for each subject will be the 12-months post-initial 
activation follow-up interval. 
 
 
VI. 
Methods 
All procedures will be conducted by UNC investigators, including board-certified 
otologists and an audiologist. Fully informed consent will be obtained from all 
subjects. 
 
A. Participants 
Subjects must meet the following inclusion criteria and not exhibit any of the 
exclusion criteria. 
 
1. Inclusion Criteria 
a. Scheduled to undergo a surgical procedure that will result in profound 
hearing loss in the surgical ear 
i. 
Unilateral, vestibular schwannoma with planned 
translabyrinthine surgery or unilateral Meniere’s disease with 
planned labyrinthectomy 
ii. 
Diagnosed by UNC investigators 
b. PTA ≤ 35 dB HL in the contralateral ear 
i. 
No evidence of retrocochlear dysfunction 
c. Unaided CNC word score ≥ 80% in the contralateral ear 
d. Greater than 18 years of age at implantation 
e. Realistic expectations 
f. Willing to obtain appropriate meningitis vaccinations 
g. No reported cognitive issues  
i. 
Pass the Mini Mental State Examination (MMSE) screener 
h. Able and willing to comply with study requirements, including travel 
to investigational site 
i. Obtain CDC recommended meningitis vaccinations prior to surgery 
 
2. Exclusion Criteria 
a. History of implantable technology in either ear, such as a bone-
conduction implant 
b. Non-native English speaker 
i. 
Speech perception materials are presented in English 
c. Inability to participate in follow-up procedures (i.e., unwillingness, 
geographic location) 
 
3. Enrollment 
a. This study seeks to enroll ten (10) subjects. 
 
B. Timeline 
Appendix B graphically depicts the timeline and associated measures. 
 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
1. Candidacy Evaluation 
a. Medical Evaluation 
i. 
Diagnosis of unilateral vestibular schwannoma with planned 
translabyrinthine surgery or unilateral Meniere’s disease with 
planned labyrinthectomy 
ii. 
Associated imaging studies 
a. This is standard of care for these patient populations 
b. May also be completed at Preoperative Evaluation 
iii. 
Discussion of current treatment options (surgical approach and 
associated hearing loss, and hearing device options for use 
postoperatively) 
iv. 
Determine if potential subject meets candidacy criteria 
 
b. Audiologic Evaluation 
i. 
Unaided air- and bone-conduction thresholds in both ears 
a. Air-conduction assessed with insert phones 
ii. 
Unaided word recognition with CNC words in both ears 
a. Unaided word recognition testing is conducted in quiet in the 
effected ear 
b. Masking will be presented to the contralateral ear if indicated 
iii. 
Tympanometry in both ears 
iv. 
Determine if potential subject meets candidacy criteria 
 
c. Informed Consent 
i. 
Review and discussion of consent form 
ii. 
Provide time for subject to review consent form and ask questions 
iii. 
Provide subject with a signed copy of the completed consent form 
 
2. Preoperative Evaluation 
a. Medical Evaluation 
i. 
Subjects will undergo a medical assessment  
ii. 
Associated imaging studies 
a. This is standard of care for these patient populations. 
b. May have been completed at Candidacy Evaluation. 
iii. 
Counseling on cochlear implantation surgical procedure and 
postoperative considerations, including MRI limitations due to 
internal magnet 
a. MED-EL SYNCHRONY cochlear implant is approved up to 3 Tesla 
with magnet in place (magnet can be removed to eliminate 
shadow if necessary). 
 
b. Audiologic Evaluation 
i. 
Obtain a case history, including but not limited to: 
a. Onset of hearing loss 
b. Resulting impairments from vestibular schwannoma or 
Meniere’s disease (i.e., dizziness) 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
ii. 
Unaided air- and bone-conduction thresholds in both ears 
a. Air-conduction assessed with insert phones 
iii. 
Unaided word recognition with CNC words in both ears 
iv. 
Tympanometry in both ears 
v. 
Counseling on cochlear implant external technology, test battery, 
and postoperative timeline 
 
3. Surgery 
Two surgical scenarios are considered dependent on the subjects’ 
etiology (i.e. vestibular schwannoma or unilateral Meniere’s Disease with 
intractable vertigo). Due to the etiology of the impairment, subjects will 
be scheduled to undergo these surgical approaches whether or not they 
elect to participate in the study. Both surgical approaches, however, 
result in profound hearing loss in the surgical ear. Both surgical 
approaches also include steps taken during a cochlear implantation 
procedure, thus limiting the additional operative time needed for 
cochlear implant placement. 
 
Risk factors associated with cochlear implantation are listed in Section X 
“Risk Analysis.”  
 
All surgical procedures will take place at the UNC Memorial Hospital or 
UNC ACC operating rooms. All procedures will be completed by board-
certified otologists. 
 
a. Vestibular Schwannoma Subjects: Translabyrinthine Approach 
i. 
This surgical approach allows wide access to various parts of the 
ear. As such, most surgical steps required for cochlear 
implantation have already been drilled. Thus, implantation will 
only take an additional 5 minutes or less. The overall operative 
times for vestibular schwannoma removal with a 
translabyrinthine approach range from 6-12 hours. 
 
It is pertinent to note that the auditory nerve will have to be 
preserved for these procedures. For tumors of less than 2 cm in 
size this appears to be a reasonable goal. For larger growths, 
however, this might be impossible. Hence, intraoperative 
preservation of the structural integrity of the nerve will be a 
prerequisite for implantation, which will be performed once 
resection of the schwannoma has been completed. 
 
During the surgical procedure there will be nerve monitoring as 
well as visual confirmation of auditory nerve integrity. Once the 
cochlear implant is in place, integrity testing will be performed 
(including but not limited to EABR, ART, and telemetry). 
 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
b. Unilateral Meniere’s Disease with intractable vertigo Subjects: 
Labyrinthectomy  
i. 
A labyrinthectomy in this population is curative; however, a 
labyrinthectomy will render the subject profoundly hearing 
impaired in the operated ear. The routine surgical approach for 
this procedure is approximately 2 hours and includes all steps 
typically drilled for cochlear implantation. Thus, cochlear 
implantation will only take an additional 5 minutes or less. 
 
4. Postoperative Evaluations 
a. Initial Follow-Up (approximately 1-2 weeks postoperatively) 
i. 
Medical Evaluation 
a. This is standard of care. 
b. Subject will be seen by the physician  
 
ii. 
Audiologic Evaluation 
a. Unaided air and bone conduction thresholds  
i. 
Air-conduction assessed with insert phones 
 
b. Initial Activation of External Speech Processor (approximately 2-4 
weeks postoperatively)  
i. 
Unaided air and bone conduction thresholds 
a. Air-conduction assessed with insert phones 
ii. 
Unaided word recognition with CNC words in both ears 
a. Unaided word recognition testing is conducted in quiet in the 
effected ear 
b. Masking will be presented to the contralateral ear if indicated 
iii. 
Initial activation of external speech processor 
a. Subjects will be fit with the commercially available MED-EL 
SONNET external speech processor (MED-EL Corporation, 
Innsbruck, Austria). Speech perception and localization 
measures will be conducted with the subject listening with the 
SONNET external speech processor for the aided conditions. 
iv. 
Counseling on the external device and use 
 
c. 1-month Post-Initial Activation 
i. 
Completion of test battery listed in VI.C. 
 
d. 3-months Post-Initial Activation 
i. 
Completion of test battery listed in VI.C. 
 
e. 6-months Post-Initial Activation 
i. 
Completion of test battery listed in VI.C. 
 
f. 9-months Post-Initial Activation 
i. 
Completion of test battery listed in VI.C. 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
 
g. 12-months Post-Initial Activation (study endpoint) 
i. 
Completion of test battery listed in VI.C 
 
C. Test Battery 
The following test battery will be completed at each post-initial activation 
interval (1, 3, 6, 9 and 12 months). All assessment and mapping will be 
conducted at the Carolina Crossing research lab by a board-certified 
audiologist.  
 
1. Unaided Diagnostic Assessment 
 
a. Air- and bone-conduction thresholds in both ears  
i. 
Air-conduction assessed with insert phones 
b. Unaided word recognition with CNC words in both ears 
a. Unaided word recognition testing is conducted in quiet in the 
effected ear 
b. Masking will be presented to the contralateral ear if indicated 
 
2. Tympanometry for each ear 
 
3. Sound Field Measures 
The Carolina Crossing research lab features a 180° arc with 11 speakers 
spaced 18° apart. This arc will be utilized during the speech perception 
and localization measures. 
 
a. Aided thresholds with the external speech processor on and masking 
applied to the contralateral ear will be measured using pulsed, warble 
tones 
i. 
Frequencies assessed: 250-8000 Hz, including all inter-octaves 
 
b. Speech Perception Measures 
Speech perception will be assessed in an aided (cochlear implant 
speech processor on) and unaided (cochlear implant speech 
processor off) condition.  
Recorded materials will be presented at 60 dB SPL. 
 
i. 
Speech Perception in Quiet 
a. Listening condition 
i. 
Speech 0° azimuth 
b. Speech perception materials 
i. 
CNC words  
ii. 
CID sentences  
iii. 
HINT sentences (if >50% correct on CID sentences) 
iv. 
AzBio sentences (if >50% correct on HINT sentences) 
 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
ii. 
Speech Perception in Noise 
a. Listening conditions 
i. 
Speech and noise 0° azimuth 
ii. 
Speech 0° azimuth and noise to implanted side 
iii. 
Speech 0° azimuth and noise to contralateral ear 
b. Speech perception materials 
i. 
HINT sentences 
a. If >50% at SNR+10, then SNR+5 
b. If >50% at SNR+5, then SNR+0 
ii. 
AzBio sentences 
a. If >50% at SNR+10, then SNR+5 
b. If >50% at SNR+5, then SNR+0 
iii. 
BKB-SIN sentences with adaptive SNR 
 
iii. 
Listening Conditions 
a. Cochlear implant only (contralateral ear masked) 
b. Contralateral ear only (cochlear implant speech processor off) 
c. Combined (Cochlear implant on + contralateral ear 
unmasked) 
 
c. Localization 
Localization will be assessed in an aided (cochlear implant speech 
processor on) and unaided (cochlear implant speech processor off) 
condition. 
i. 
The stimulus is a 200-ms speech-shaped noise, presented at 70-
dB-SPL from one of the 11 speakers (evenly spaced -180 to 180 
degrees), selected at random. 
ii. 
The listener will be facing the center speaker during stimulus 
presentation.  The task is to identify the source of the noise via a 
touchscreen monitor.  No feedback is provided. 
iii. 
Data will be analyzed in terms of error and adjusted constant 
error, as described by Grantham et al (2007). 
iv. 
Listening Conditions 
a. Contralateral ear only (cochlear implant speech processor off) 
b. Combined (Cochlear implant on + contralateral ear 
unmasked) 
 
4. Subjective questionnaires 
a. Speech, Spatial and Qualities of Hearing Scale (SSQ) Gatehouse & 
Noble (2004) 
b. Abbreviated Profile of Hearing Aid Benefit (APHAB) Cox & Alexander 
(1995) 
 
VII. 
Proposed Claims 
 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
A. Demonstrate the safety and effectiveness of cochlear implantation in 
populations suffering from unilateral profound hearing loss after 
labyrinthectomy or translabyrinthine surgical approaches.  
 
1. Demonstrate an improvement in speech perception abilities in an aided 
(cochlear implant on) versus an unaided (cochlear implant off) condition 
 
2. Demonstrate an improvement in localization abilities in an aided 
(cochlear implant on) versus an unaided (cochlear implant off) condition 
 
3. Demonstrate an improvement in subjective report in an aided (cochlear 
implant on) versus an unaided (cochlear implant off) condition 
 
VIII. 
Statistical Analysis 
 
A. Descriptive summaries will be provided for the following: subject 
demographics, and frequency of major and minor complications/adverse 
events. 
 
B. A single-subject design will be utilized, where each subject serves as his or 
her own control, for analysis of objective and subjective results. A single-
subject design was chosen in order to accommodate the heterogeneity that is 
well known to characterize auditory prosthesis research. Repeated-measures 
ANOVA will be calculated with a p-value of ≤ 0.05 for statistical significance. 
Statistical analysis will be conducted with SPSS software. 
1. Comparison in aided speech perception performance on word and 
sentence materials in the post-initial activation intervals 
a. Also compare the difference between the aided and unaided 
conditions at each follow-up interval 
2. Comparison in localization abilities in the post-initial activation intervals 
a. Also compare the difference between the aided and unaided 
conditions for each follow-up interval 
3. Comparison in subjective report in the post-initial activation intervals 
 
If needed, statistical consultation will be sought from the North Carolina 
Translational and Clinical Sciences Institute (TraCS) or UNC Odum Institute. 
 
IX. 
Endpoints 
 
A. Safety endpoint 
1. The primary safety endpoint is the evaluation of Adverse Events. All 
Adverse Events will be reported to the UNC IRB. If the UNC IRB or study 
investigators deem an Adverse Event unacceptable, then this would be 
sufficient terms to terminate the study. 
 
B. Primary effectiveness endpoint 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
1. The primary effectiveness endpoint is the comparison of speech 
perception (VII.A.1), localization abilities (VII.A.2) and/or subjective 
report (VII.A.3) when the cochlear implant is on versus off. 
 
X. 
Risk Analysis 
 
A. Potential risks 
The following are potential risks associated with this protocol. There are 
other risks associated with the surgical procedure and follow-up care that 
the subject would experience as a result of the surgical procedure for the 
treatment of their vestibular schwannoma or Meniere’s Disease with 
intractable vertigo. The following are potential risks the subject may 
experience related to the study procedure. 
 
1. Surgical 
a. The risks associated with this surgery are the same as those 
associated with the surgical procedures the subject would already 
undergo as part of their treatment for vestibular schwannoma or 
Meniere’s Disease with intractable vertigo. There are no further risks 
anticipated from placement of the cochlear implant. 
i. 
Risks associated with translabyrinthine surgical approach  
a. Facial nerve injury   
b. Incomplete tumor removal 
c. CSF leak 
d. Hemorrhage 
e. Infection 
ii. 
Risks associated with labyrinthectomy 
a. Bleeding 
b. Infection 
c. Persistent disequilibrium 
d. Facial nerve injury 
 
2. Postoperative 
a. Swelling around the incision and/or coil site. 
b. Pain 
c. Reduced or loss of pinna sensitivity on the surgical side 
i. 
Typically resolves 1-2 months postoperatively. 
d. The cochlear implant may not provide any auditory stimulation. 
e. The cochlear implant may provide auditory stimulation, but with a 
sound quality too poor to aid in the perception of speech. 
f. The cochlear implant may provide auditory stimulation, but with a 
sound quality too poor to aid in localization. 
g. Pain associated with the coil and/or placement of the external speech 
processor on the subject’s ear. 
h. Discomfort from electric stimulation 
i. Facial nerve stimulation 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
j. Headache 
k. Dizziness 
l. Altered taste (i.e. reports of metallic tastes on the same side of the 
tongue as the surgical ear) 
m. Fatigue during follow-up assessment (completion of the test battery 
and/or mapping) 
n. The internal device may fail, requiring revision cochlear implantation 
 
B. Risk Mitigation 
1. Current hearing device options, including CROS hearing aids and bone-
conduction devices, would still be available to the subject in the future if 
the subject does not benefit from the cochlear implant or elects to no 
longer use the cochlear implant. 
2. Magnet strength will be assessed at each interval to ensure comfort at the 
coil site. 
3. Reports of pain from the external speech processor placement will be 
addressed by different wearing options (i.e. moleskin between the 
external speech processor and the subject’s ear, or different battery-
wearing options to lighten weight on the pinna). 
4. Mapping will be conducted at each post-initial activation interval to 
improve audibility and comfort of the sound quality from electric 
stimulation. 
5. The MED-EL cochlear implant has MRI limitations*. Subjects may have CT 
scans or x-ray imaging postoperatively. 
a. *The MED-EL SYNCHRONY cochlear implant is approved for MRI up 
to 3 Tesla with the magnet in place (magnet can be removed to 
eliminate shadow if necessary). 
6. An otologist will conduct medical follow-up evaluations at the 3, 6 and 
12-month intervals which is standard of care for cochlear implant 
recipients. 
 
XI. 
Potential Benefits 
 
A. Improvement in speech perception abilities in noise with the cochlear 
implant due to utilization of auditory cues from both ears. 
 
B. Improvement in localization abilities with the cochlear implant due to 
utilization of auditory cues from both ears. 
 
C. Improvement in subjective benefit with the cochlear implant as compared to 
an unaided condition.  
 
XII. 
Adverse Events 
 
A. Anticipated versus Unanticipated Events 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
1. Anticipated Events: those events described as potential risks (section 
X.A.) of the protocol.  
 
2. Unanticipated Events: events not reported as potential risks (section 
X.A.). 
a. Unanticipated serious adverse events are defined as any serious 
adverse event related to the health or safety or any life-threatening 
problem or death caused by, or associated with, a device, if that event, 
problem, or death that was not previously defined in nature, severity, 
or degree of incidence in the literature or investigational plan. It can 
also include any other unanticipated serious problem associated with 
a device that relates to the rights, safety or welfare of subjects. 
 
B. Reporting adverse events 
1. Anticipated events will be reported to the FDA in the annual report 
 
2. Unanticipated events will be reported to the FDA and UNC IRB within 10 
days of the investigator becoming aware of the event, as required by 
21CFR 812.150. 
 
XIII. 
Monitoring 
 
A. Subjects will be monitored on a case-by-case basis for ongoing or 
unanticipated medical complications. Adverse events will be tracked on a 
case-by-case basis and recorded in study binders at the time of occurrence 
and followed up at resolution. Any adverse event will be reported to the UNC 
IRB. Should there be concern for the safety of subjects because of their 
participation in the study by the investigators or the UNC IRB, the study 
would be halted at least temporarily and a detailed discussion with the 
investigators and UNC IRB would be undertaken to evaluate the viability of 
the study. 
 
B. Subjects can withdraw from the study at any time by notifying the Primary 
Investigator. If the investigator identifies the need to withdraw a subject 
from the study for any reason, this will be discussed in person during a 
scheduled evaluation. In either scenario, the subject will continue to receive 
care irrespective of their participation in the study. Should a subject not be 
able to receive auditory stimulation from the cochlear implant, or develops a 
complication related to participation in the study, their participation in the 
study will end when their study related morbidity has resolved or is no 
longer active. Again, this will not affect the medical care for the subject. 
 
XIV. 
Confidentiality 
 
A. Subjects will be assigned a specific, anonymous subject number that will be 
associated with his or her data. Database entry will be by subject number 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
only. All personal identifiers will be kept in a separate, secure data file that 
will be password protected and not associated with the study data. Only 
investigators will have access to the subject numbers. 
 
B. Subject specific binders will be maintained in a locked cabinet in the 
Carolina Crossing research lab. Individual data collection sheets will be 
coded with the subject number and placed in the subject specific binder at 
each interval. For analysis, the data will not included identifiable 
information. 
 
C. Data will not be shared outside the investigative team except during 
reporting of anonymous results. 
 
D. After the closure of the study, subject data will be retained for seven years. 
At that time, paper data will be shredded and destroyed in a HIPAA 
compliant manner. Electronic data will be destroyed following UNC policy. 
 
E. A description of the clinical trial will be available on 
http://ClinicalTrials.gov. This web site will not include information that can 
identify research subjects. 
 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
XV. 
References 
 
Arndt S, Aschendorff A, Laszig R, Beck R, Schild C, Kroeger S, Ihorst G, Wesarg T 
(2011). Comparison of pseudo binaural hearing to real binaural hearing 
rehabilitation after cochlear implantation in patients with unilateral deafness 
and tinnitus. Otol Neurotol, 32(1):39-47. 
 
Cox RM & Alexander GC (1995). The abbreviated profile of hearing aid benefit. 
Ear Hear, 16(2):176-86. 
 
Falcioni M, Taibah A, Di Trapani G, Khrais T, Sanna M (2003). Inner ear extension 
of vestibular schwannomas. Laryngoscope, 113(9):1605-8. 
 
Firszt JB, Holden LK, Reeder RM, Waltzman SB, Arndt S (2012). Auditory abilities 
after cochlear implantation in adults with unilateral deafness: a pilot study. Otol 
Neurotol, 33(8):1339-46. 
 
Gatehouse S & Noble W (2004). The speech, spatial and qualities of hearing scale. 
Int J Audiol, 43(2):85-99. 
 
Grantham, DW, Ashmead, DH, Ricketts, TA, Labadie, RF, and Haynes, DS (2007). 
Horizontal-plane localization of noise and speech signals by postlingually 
deafened adults fitted with bilateral cochlear implants Ear Hear, 28(4): 524:541. 
 
Iwasaki S, Sano H, Nishio S, Takumi Y, Okamoto M, Usami S, Ogawa K (2013). 
Hearing handicap in adults with unilateral deafness and bilateral hearing loss. 
Otol Neurotol, 34(4):644-9. 
 
Kunst SJW, Leijendeckers JM, Mylanus EAM, Hol MKS, Snik FM, Cremers WRJ 
(2007). Bone-anchored hearing aid system application for unilateral congenital 
conductive hearing impairment: audiometric results. Otol Neurotol, 29(1):2-7. 
 
Lustig LR, Yeagle J, Niparko JK, Minor LB (2003). Cochlear implantation in 
patients with bilateral Meniere’s syndrome. Otol Neurotol, 24(3):397-403. 
 
Osborn HA, Yeung R, Lin VY (2012). Delayed cochlear implantation after surgical 
labyrinthectomy. J Laryngol Otol, 126(1):63-5. 
 
Pai I, Dhar V, Kelleher C, Nunn T, Connor S, Jiang D, O’Connor AF (2013). 
Cochlear implantation in patients with vestibular schwannoma: a single United 
Kingdom center experience. Laryngoscope, 24 
 
Roosli C, Linthicum FM Jr, Cureoglu S, Merhcant SN (2012). Dysfunction of the 
cochlea contributing to hearing loss in acoustic neuromas: a underappreciated 
entity. Otol Neurotol, 33(3):473-80. 
 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
Rothpletz AM, Wightman FL, Kistler DJ (2012). Informational masking and 
spatial hearing in listeners with and without unilateral hearing loss. J Speech 
Lang Hear Res, 55(2):511-31. 
 
Slattery WH 3rd, Middlebrooks JC (1994). Monaural sound localization: acute 
versus chronic unilateral impairment. Hear Res, 75(1-2):38-46. 
 
Van de Heyning P, Vermiere K, Diebl M, Nopp P, Anderson I, De Ridder D (2008). 
Incapacitating tinnitus in single-sided deafness treated by cochlear implantation. 
Ann Otol Rhinol Laryngol, 117(9):645-52. 
 
Vermiere K, Van de Heyning P (2009). Binaural hearing after cochlear 
implantation in subjects with unilateral sensorineural deafness and tinnitus. 
Audiol Neurootol, 14(3):163-71. 
 
Wareing MJ, O’Connor AF (1997). The role of labyrinthectomy and cochlear 
implantation in Meniere’s disease. Ear Nose Throat J, 76(9):664-6. 
 
Welsh LW, Welsh JJ, Rosen LF, Dragonette JE (2004). Functional impairments 
due to unilateral deafness. Ann Otol Rhinol Laryngol, 113(12):987-93. 
 
Wie OB, Pripp AH, Tvete O (2010). Unilateral deafness in adults: effects on 
communication and social interaction. Ann Otol Rhinol Laryngol, 119(11):772-81. 
 
 
 

CI after Labyrinthectomy or a Translabyrinthine Surgical Approach 
Appendix A: Device Information 
 
 
 
Appendix B: Procedure Timeline 
 
 
 
 
  
Candidacy 
Evaluation 
Preoperative 
Evaluation 
Surgery 
Initial 
Follow-
Up 
Initial 
Activation 
Post-Initial Activation 
Intervals (months) 
1 
3 
6 
9 
12 
Informed Consent 
X 
  
  
  
  
  
  
  
  
  
Medical Assessment 
X 
X 
X 
X 
  
  
 X X  
  
X  
Imaging Studies 
  
X 
  
  
  
  
  
  
  
  
Unaided Diagnostic 
Assessment 
X 
X 
  
X 
X 
X 
X 
X 
X 
X 
Tympanometry 
X 
X 
  
  
X 
X 
X 
X 
X 
X 
Sound Field 
Measures 
Aided 
Thresholds 
  
  
  
  
  
X 
X 
X 
X 
X 
Speech 
Perception 
  
  
  
  
  
X 
X 
X 
X 
X 
Localization 
  
  
  
  
  
X 
X 
X 
X 
X 
Subjective Questionnaires 
  
  
  
  
  
X 
X 
X 
X 
X