Download PDF

Outcomes Following Primary and Revision Auditory
Brainstem Implant Surgery in Children
Sidharth V. Puram, MD PhD1,2, Parth Shah1, Barbara S. Herrmann, PhD1,3,
Ann-Christine Duhaime, MD4,5, Fred G. Barker II, MD4,5, Daniel J. Lee, MD FACS1,2
1Dept.
of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, MA, USA; 2Dept. of Otology and Laryngology, Harvard Medical School, Boston, MA, USA;
3Dept. of Audiology, Massachusetts Eye and Ear Infirmary, Boston, MA, USA; 4Dept. of Neurosurgery, MassGeneral Hospital for Children, Boston, MA, USA;
5Department of Surgery (Neurosurgery), Harvard Medical School, Boston, MA, USA.
ABSTRACT
Objectives: The auditory brainstem implant (ABI) was developed for patients
with Neurofibromatosis Type 2 (NF2). Emerging data suggest a role for ABIs in
deaf non-NF2 children who are not candidates for the cochlear implant (CI).
However, experience in the U.S. with pediatric ABI surgery is limited. Here, we
review outcomes following three primary ABI surgeries and one revision ABI
surgery for device failure.
Study design: Retrospective single institution case series
Methods: Infants with congenital deafness who 1) were not candidates for CI
due to cochlear or auditory nerve hypoplasia/aplasia or 2) failed CI surgery and
3) underwent ABI surgery via retrosigmoid craniotomy were reviewed. Outcome
measures included perioperative complications, electrophysiologic and
behavioral audiologic responses, and speech development.
Results: Five pediatric ABI surgeries were performed (4 primary, 1 revision) in
children with profound hearing loss associated with cochlear and auditory nerve
hypoplasia. Mean age at primary ABI surgery was 18 months. Intraoperatively,
multiphasic Evoked Auditory Brainstem Responses (EABRs) were obtained on
multiple electrodes. There were no intraoperative complications, with an
average length of stay of four days. EABRs used to guide placement of the ABI
electrode were variable. Behavioral thresholds of 30-40 dB were attained in all
cases, including one patient who required revision surgery after device failure.
RESULTS
Pre-operative evaluation:
- Full developmental and birth history
- Otologic history
- Physical exam
- Audiologic evaluation
- Review of imaging, with repeat imaging if needed
- Developmental and psychosocial evaluation
Patient characteristics:
- Age at implantation ranged from 11 mo to 30 months, average age of
implantation of 18 months (not including the revision case at 24 months)
- One child born 32 weeks premature, the remainder were full terms
- CHARGE/developmental delay in 2 out of 4 patients (50%)
- Prior attempted CI in 1 out of 4 patients (25%)
- Four primary ABI surgeries, one revision; all right sided
- Etiology of hearing loss:
• 8 mo old F – bilateral nerve aplasia and cochlear dysplasia
• 13 mo old F – bilateral nerve aplasia w/ hypoplastic cochleae
• 16 mo old M –bilateral cochlear nerve aplasia and cochlear dysplasia
• 30 mo old M – bilateral nerve hypoplasia
RESULTS
RESULTS
B
Hospital course and complications:
- ICU stay ranged from 1-2 days, with an average stay of 1.2 days
- Total length of stay ranged from 2-4 days, with an average LOS of 3 days
- No CSF leak in any patients
- No facial nerve complications
- No surgical site infections
Post-operative device activation:
All patients were seen at 6 weeks post-operatively for otologic evaluation,
sedated EABR and awake live activation 24 hours later
Totals
Dur of Use (mo)
2.67 mo
(2-4)
5.25 mo
(1-10)
12.6 mo
(1-25)
8.6 mo
(2-17)
7.3 + 3.7
(1-25)
PTA
(500, 1, 2K)
NA
NA
NA
35
30
25
NA
26
35
35
45
NA
30
35
40
80
NA
37.8 + 14.4
dB
SDT (dB)
NA
NA
NA
55
25
NA
65
15
0
15
25
NA
15
20
40
80
NA
32.3 + 23.6
dB
1 ESP Cat 4
1 ESP Mono
58%
1 ESP Word
50%
Pre-activation
(17 months)
DISCUSSION
• ABI surgery is a reasonable and safe option in children who are deaf and
cannot receive a CI due to anatomical considerations.
Figure 4. Post-operative multiphasic EABRs, confirming adequate device
placement prior to ABI activation (subject #1).
Audiometric testing:
• ABI surgery can be performed reliably in pediatric patients for non-NF2
indications with reliable and reproducible outcomes.
• Pediatric ABI surgery requires a team-based approach to ensure
appropriate candidate selection and to optimize surgical outcomes
• Infants who are normal neurologically and are implanted below the age of 2
have better outcomes
• Revision surgery following device failure is possible and safe.
A major goal of clinical hearing research is the provision of meaningful sound
information to patients with severe to profound hearing loss. In patients who
are not candidates for cochlear implantation (CI), an auditory brainstem
implant (ABI) can provide direct electric stimulation to the cochlear nucleus in
the brainstem, bypassing the cochlea and cochlear nerve completely. Although
the vast majority of ABI patients have been adults with Neurofibromatosis Type
2 (NF2), there is growing interest in whether non-NF2 patients including adults
with severe cochlear ossification and traumatic avulsion of the cochlear nerve
as well as children with developmental inner ear abnormalities such as
cochlear and cochlear nerve hypoplasia or aplasia may also benefit from this
technology. Studies in Europe have focused on this latter population with good
clinical outcomes (Colletti et al., 2013; Sennaroglu et al., 2009).
• Continued development of better ABI devices will be essential to improving
auditory rehabilitation in the future. Further research into new technologies
such as optogenetics may greatly enhance the fidelity by which electrical
impulses are conducted to the cochlear nucleus and brainstem.
16 active
electrodes
Dynamic Range of 45
Sound Detection at 30 dB HL
Figure 5. Audiometric testing in subject #2 demonstrating 16 active electrodes
with good dynamic range and sound detection at 30 dB.
Figure 1. Pre-operative imaging in subject #1. Axial CT (left) and axial and
sagittal MRI (right) pre-operative scans of the right (top) and left (bottom)
temporal bone and IAC demonstrating bilateral cochlear defects and absence of
the cochlear nerves. Brainstem anatomy otherwise normal with normally
appearing lateral recesses bilaterally.
ABI surgery:
METHODS
IRB Approval: All aspects of this study were approved by the Human Studies
Committee, our institutional IRB.
UNC
Speech
Perception
Left:
Study design: A careful pre-operative assessment including imaging with MRI
and high resolution temporal bone CT scans is completed. The ABI device is
implanted using a craniotomy on the side opposite the child’s previous
cochlear implant (if present), assuming no obvious contraindications.
Depending on the anatomical and patient specific factors, a translabyrinthine
or retrosigmoid approach is utilized to obtain access to the cochlear nucleus of
the brainstem and place the electrode array, with intra-operative electrically
Evoked Auditory Brainstem Responses (EABRs) used to confirm positioning.
Patients are initially seen 1-2 weeks after surgery to confirm adequate healing,
and then 4-6 weeks after surgery, the ABI is activated and programmed in the
controlled setting of the audiologic clinic. Clinical and audiologic follow-up
occurs at 3 month intervals which are lengthened after one year. Postoperative evaluation includes both behavioral and audiometric testing with
developmentally appropriate measure of speech perception, speech
production, and language.
NYU
(16 months)
INTRODUCTION
Patient selection: Our clinical trial was reviewed and approved by the
Institutional Review Board as well as the FDA through an Investigational
Device Exemption (NCT01864291). Inclusion criteria for our study include both
pre- and post-lingually deafened children with severe to profound hearing loss.
Pre-lingually deafened children include those under age 5 with deafness from
cochlear nerve deficiency, cochlear aplasia or severe hypoplasia, severe inner
ear malformations, or post-meningitis ossification. In patients with a cochlea
that is present and patent with a normally appearing cochlear nerve, there
must be a lack of significant benefit despite consistent use of a cochlear
implant for ≥ 6 months. Post-lingually deafened candidates must demonstrate
a lack of benefit from appropriate cochlear implantation without the possibility
for revision or contralateral implantation and previously have developed open
set speech perception and auditory-oral language skills. Major exclusion
criteria include pre- or post-linguistic children making progress with CI, MRI
demonstrating normal cochlear and cochlear nerves or NF2, surgical
contraindications, intractable seizures or neurological disorders, inability to
participate in device programing, and lack of potential for spoken language.
MEE
Intraoperative
Right:
Conclusions: Based on our early experience, primary and revision ABI surgery
can be a safe and effective means to provide auditory perception to infants who
are not candidates for the CI. Longterm follow-up is needed to determine the
speech and language outcomes with the ABI in this pediatric cohort.
We report our experience with out first five consecutive pediatric ABI surgeries
in four non-NF2 patients, including one revision surgery. All patients had
cochlear malformations/aplasia with cochlear nerve hypoplasia/aplasia. Some
had undergone prior attempted cochlear implant before presenting to our
center. We performed ABI surgery in all children using a retrosigmoid
carniotomy approach with successful placement of a Nucleus 24 ABI in all
cases. We subsequently assessed audiologic and safety outcomes. This report
demonstrates that this procedure can be safely tolerated and is feasible and
effective in children under the age of five.
HEI
Summary of MEEI patient outcomes::
Patient
ID
Duration of
ABI Use
Since
Activation
Active
Electrodes
Sound Field
Thresholds
dB HL
Report of Auditory Progress
S_01
4 months
15
25-45
•
•
•
•
Alerts to sound
More “in tune” with device
Parental report approximating “no”
Takes off device if told ‘no’
S_02
10 months
16
20-30
•
•
•
•
•
Looks for device
Babbles
Looks when name called
Follows some practiced auditory
play directions
Beginning to detect Ling sounds
S_03
6 months
11
25-30
•
•
•
Vocalic babbling and play
14 mo level for words understood
10-12 mo level for words produced
S_04
1 month
13
60-75
•
Alerts to environmental sounds
CONCLUSIONS
Our experience with ABI surgery in four pediatric ABI candidates with ages
ranging from a 11-30 months old and hearing loss caused by cochlear nerve
deficiency and/or cochlear hypoplasia/dysplasia suggests that ABI surgery is
well-tolerated at this age, with preliminary data suggesting benefits in terms of
hearing rehabilitation. Our experience with one revision surgery due to device
failure demonstrates that such a procedure can also be done safely. Although
additional studies are needed, our experience represents a detailed description
of pediatric ABI surgery in the United States. Based on our experience in
combination with the work of others internationally, it appears that ABI surgery
is feasible and safe in children under the age of five.
ACKNOWLEDGEMENTS
We thank each of the three other pediatric ABI centers including UNC (Dr. Crag
Buchman), House Ear Institute (Dr. Eric Wilkinson), and New York University
(Dr. Tom Roland). We specifically thank the UNC group for graciously sharing
their IDE protocol, upon which our IDE was based. We also thank Elliott Kozin,
Aaron Remenschneider, Aaron Tward and Dave Jung for review of aspects of
this study and helpful discussion. There are no conflicts of interest to disclose.
Summary of North American experience with pediatric ABI:
HEI
MEE
NYU
UNC
Totals
Number
3
4
5
5
17
Previous CI
2
0
3
3
8
Age at ABI
27-36
11-30
21-17 yrs
26-66
39 + 26*
Gender
1M & 2F
2M & 2 F
1M & 4 F
2M & 3 F
6 M & 11 F
Side
2R&1L
4R
5R
3R & 2 L
14 R & 3 L
3 CND
4 CND
4 CND
5 CND
16 of 17 CND
2 Michel
1 PMO
1 Severe
inner ear
2 CHARGE
1 CC
2 CND alone
1 PMO
Etiology
Figure 2. Retrosigmoid craniotomy for ABI surgery. (A) Patient is prepped and
draped. (B) Flaps are raised and a pocket is created for the implanted receiverstimulator. (C) Dummy device is used to confirm an adequately sized periosteal
pocket. (D) Inferiorly based periosteal flap exposes underlying calvarium to allow
an approximately 3 x 3 cm retrosigmoid craniotomy.
A
B
HEI
MEE
NYU
UNC
Totals
3 of 3
5 of 5
4 of 5
4 of 5
16 of 18
Other CN Stim
0
0
0
0
0
Complications
CSF Leak
Device
Failure
CSF Leak
CSF Leak
Aseptic
Meningitis
3 CSF Leaks
1 Meningitis
1 Device
Failure
None
None
None
None
None
OR Repeat
Stim
3
5
4
5
17 of 18
Aversive
Behavioral
Stimulation
1 of 3
Unsteadyresolved
0 of 5
2 of 5
Leg
Leg,throat
3 of 5
2 vestibular
1 cough
6 of 18
Outcome
Resolved
Resolved
Resolved
Resolved
Resolved
eABR +
Sequelae
Figure 3. (A) Intra-operative multiphasic EABRs that includes P3 which is
associated with stimulation of the auditory pathway for several bipolar stimulation
electrode pairs. (B) Non-contrast head CT confirming positioning of the array.
Correspondence: Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, 243 Charles St, Boston, MA 02115; [email protected]
REFERENCES
Colletti V, Shannon RV, Carner M, et al. Complications in auditory brainstem implant
surgery in adults and children. Otol Neurotol. 2010; 31(4):558-64.
Colletti V, Shannon R, Carner M, et al. Outcomes in nontumor adults fitted with the
auditory brainstem implant: 10 years' experience. Otol Neurotol 2009; 30:614-618.
Colletti L, Wilkinson EP, Colletti V. Auditory brainstem implantation after unsuccessful
cochlear implantation of children with clinical diagnosis of cochlear nerve deficiency.
Ann Otol Rhinol Laryngol. 2013; 122(10):605-12.
Eisenberg LS, Johnson KC, Martinez AS, et al. Comprehensive evaluation of a child
with an auditory brainstem implant. Otol Neurotol. 2008; 29(2):251-7.
House WF and Hitselberger WE. Twenty-year report of the first auditory brain stem
nucleus implant. Annals of otology, rhinology, and laryngology 2001; 110:103-104.
Kaplan AB, Kozin ED, Puram SV, et al. Auditory brainstem implant candidacy in the
United States in children 0-17 years old. Int J Pedi Otorhinolaryngol. 2015;79(3):310-5.
Lin HW, Herrmann BS, Lee DJ. Cochlear Implants and Other Implantable Hearing
Devices. Cochlear implants and other implantable hearing devices 2013: 317-348.
Noji KS, Remenschneider AK, Kozin ED et all. “Direct parasagittal MRI of the internal
auditory canal in pediatric auditory implant candidates,” Laryngoscope (in press).
Sennaroglu L, Colletti V, Manrique M, et al. Auditory brainstem implantation in children
and non-neurofibromatosis type 2 patients: a consensus statement. Otol Neurotol.
2011; 32(2):187-91.
Sennaroglu L, Ziyal I, Atas A, et al. Preliminary results of auditory brainstem
implantation in prelingually deaf children with inner ear malformations including severe
stenosis of the cochlear aperture and aplasia of the cochlear nerve. Otol Neurotol.
2009; 30(6):708-15.
Varni JW, Seid M, Rode CA. The PedsQL: measurement model for the pediatric quality
of life inventory. Med Care. 1999; 37(2):126-39.