Download Policy and procedures for Bone Conduction Implantable Devices

Policy and procedures for Bone Conduction
Implantable Devices Pilot Program
Description
Bone conduction implantable devices are used in cases of conductive hearing loss, mixed hearing loss and
single sided deafness, when conventional hearing aids do not provide sufficient access to sound or are
contraindicated due to anatomical or chronic middle ear conditions. Information generated through the bone
conduction implantable devices enables the recipients to access sound across the speech spectrum at levels
required for audition of soft speech sounds.
Bone conduction implantable devices traditionally used a percutaneous titanium abutment, which through
osseointegration technology enables vibration created through an externally worn transducer to conduct
information through the bone to the cochlea. Transcutaneous devices are available that are implanted and
magnetically coupled to the sound transducer worn externally.
The scheduling and procedures of post-operative management of the recipients is determined by the device
they receive. Osseointegration occurs over a period of 2- 12 weeks, depending on recipient age, bone
quality and device choice, therefore fitting of the external components should be at the direction of the
surgeon. In some cases there is a two-stage procedure in finalising osseointegration due to soft, irradiated
or thin bone (<3mm) or where the implantation is combined with another surgery, such as tumour removal.
Transcutaneous devices can have external components fitted within 2-4 weeks after surgery, even earlier in
some cases.
Table 1. Devices available include:
System
Oticon
medical
Cochlear Baha®
Connect
Cochlear Baha®
Attract
Sophono
MedEl Bonebridge
Type
Percutaneous
Percutaneous
Transcutaneous
Transcutane
ous
Transcutaneous
Processor
Ponto
Ponto Pro
Ponto Pro
power
Baha 5
Baha BP110 Power
Baha 5 SuperPower
Baha 5
Baha BP110 Power
Baha 5 Super Power
Alpha 2
Samba
Bone conduction
requirements at
0.5,1,2,3 kHz
0-55dB
0-65dB
0-55dB
0-45dB
0-45dB
Osseo-integration
yes
yes
yes
no
no
Device fitting
4-12 weeks *
2-4 weeks*
4 weeks *
4 weeks
2 weeks
yes
Yes to 3.0 Tesla
Yes to 1.5 Tesla
(magnet insitu) to 3.0
Tesla (magnet removed)
Yes to 3.0
Tesla
Yes to 1.5 Tesla
(not SSD cases)
(time after surgery)
MRI compatibility
*Device fitting guide based on healthy adult bone and normal wound healing. Surgeon may recommend
longer time to fitting for individual patient criteria based on recipient age, bone quality and device choice.
Referral
Potential recipients of bone conduction implantable devices can be referred by GP’s, ENT’s, audiologists or
other hearing health professionals.
Completion of the Preoperative Evaluation and completion of the Clinical Results Form at the time of referral
is needed to facilitate consideration of allocation of funding.
Referrals should be made to the Medical Director SCIC Cochlear Implant Program.
Preoperative Evaluation
(Clinical results form completed)
A battery of audiological procedures include:
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Otoscopy
Tympanometry
Pure tone audiogram for individual ears with bone conduction and masking where required
Speech perception using recorded materials in individual ears, performance on single syllable
words, no better than 60% in the poorer ear
Speech perception sentences in quiet
Speech perception in noise using recorded materials presented at 1 metre at 50dB HL (65dB
SPL)
Noise configuration to be specified as either S0:N0 – speech and noise both at 180°; Speech
270° Noise 90° with noise facing the better ear)
Speech Spatial Quality Scale v5
Categories of Auditory Perception 9 (CAP 9)
Soft band trial
CROS aid trial for SSD patients
Selection criteria
Conductive Hearing Loss
Audiometry indicating an air-bone gap of more than 30dB
(however may be smaller in cases where air conduction aids
cannot be worn or exacerbate other medical conditions.
Bone conduction thresholds up to 65dB (see Table 1)
Tympanometry may be consistent with a conductive
component (eg Type B or C tympanogram. However in some
permanent conductive conditions, Type A tympanogram may
be evident.
Evidence of benefit with preoperative device trial compared to
existing condition (ie unaided AC aid)
SSQ no better than an average of 7 on at least one of the
scales presented.
Mixed Hearing Loss
Audiometry indicating an air bone gap of 30dB (however may
be smaller in some cases where air conduction aids cannot
be worn or exacerbate other medical conditions).
Bone conduction thresholds up 55 dB (see table 1)
Tympanometry consistent with a conductive component (eg
Type B or C tympanogram).
However in some permanent conductive conditions, Type A
tympanogram may be evident.
Evidence of benefit with preoperative device trial compared to
existing condition (eg unaided AC aid).
SSQ no better than an average of 7 on at least one of the
scales presented.
Single Sided Deafness (SSD)
Audiometry: Normal hearing to mild hearing loss in the good
ear.
Tympanometry: Type A, B or C.SSQ no better than an
average of 7 on at least one of the scales presented.
Cros/BiCros trial.
Cochlear implant option discussed.
Realistic expectations needed.
Transcranial attenuation: presence of great attenuation may
impact on BCID ability to provide sufficient gain overall or at a
particular frequency area.
Contraindications for a bone conduction implantable device
 Individuals who fall out of the selection criteria indicated above
 Presence of bone disease that renders the skull too thin to support implant (eg osteogenesis
imperfecta)
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 Conditions that may prevent the recipient from adequately maintaining their bone conduction
implantable device eg psychological conditions
 Suitability for surgery /anaesthetic
Prioritisation of candidates for surgery
Priority 1 (high)
Highest priority for first ear for candidates with bilateral maximum conductive losses/ mixed losses who are
unable to wear conventional aids and/or are not considered good candidates for surgical/medical
intervention for the cause of hearing loss.
Also included in this group are candidates with conductive / mixed loss in their only hearing ear even if
conventional aiding is possible.
Priority 2 (mid)
Second highest priority for first ear for candidates with bilateral conductive / mixed losses who demonstrate
improved performance with Baha over conventional aiding but don't fall into category 1.
Priority 3 (low)
Third priority category for the following indications:
- second ear on candidates that fall into category 1 or 2
- unilateral conductive / mixed loss candidates
- single sided deafness
Allocation of BCID – consents and agreements
The allocation of the BCID is under a NSW Health program that requires careful evaluation and
measurement of outcomes and commitment to attend scheduled appointments. Consents and agreements
need to be finalised prior to surgery.
Clients who are eligible for Australian Hearing funding of external components will be considered for BCID
surgery through this pilot scheme.
Surgery
Surgery for percutaneous devices may be one step where implant and abutment or magnet is placed; or two
step for clients who have thin bone. Two step procedures require a 3-6 month interval for osseointegration to
occur before fitting of the abutment.
Device activation and follow up
Device activation should only occur after a medical review from surgeon
Each session should involve a close check of the abutment (where appropriate) or magnet site to detect for
skin/tissue complications and ensure no debris is present (which can reduce sound level and quality)
Session 1: Device is programmed and activated for the first time
 Client is counselled on external components
 Aided audiogram
 Phoneme detection to check access to speech spectrum
Session 2: (4 weeks later – 2 weeks for Baha attract recipients):
 Device program refined
 Review of magnet selection and strength (Bonebridge and Baha Attract)
 Client is further counselled on external components & accessories
 Aided audiogram
 Phoneme detection and word test speech perception
Session 3: (12 weeks post device activation)
(Clinical results form completed)
 Evaluation of device and management Device review
 Review of implant site
 Otoscopy
 Tympanometry
 Pure tone audiogram for individual ears with bone conduction and masking where required
 Speech perception using recorded materials for single syllable words,
 Speech perception sentences in quiet
 Speech perception in noise using recorded materials presented at 1 metre at 50dB HL (65dB SPL).
Noise configuration to be specified as either S0:N0 – speech and noise both at 180°;Speech 270° Noise
90° with noise facing the better ear). Noise level to be specified as +10dB SNR; +5dB SNR or 0dB SNR
 Functional listening questionnaires including the Speech Spatial Quality Scale C v5
 Categories of Auditory Perception 9 (CAP 9 )
Session 4: (6 months post device activation)
(Clinical results form completed)
 Device program and review
 Review of device site
 Otoscopy
 Tympanometry
 Pure tone audiogram for individual ears with bone conduction and masking where required
 Speech perception individual ears, performance on single syllable words
 Speech perception sentences in quiet
 Speech perception in noise using recorded materials presented at 1 metre at 50dB HL (65dB
SPL). Noise configuration to be specified as either S0:N0 – speech and noise both at
180°;Speech 270° Noise 90° with noise facing the better ear). Noise level to be specified as
+10dB SNR; +5dB SNR or 0dB SNR
 Functional listening questionnaires including the Speech Spatial Quality Scale C v5
 Categories of Auditory Perception 9 (CAP 9)
Ongoing management
Recipients will attend regular review appointments as indicated. Reviews are required to verify device
integrity through direct check of equipment and performance based procedures.
Earlier appointment times should be scheduled if recipients have any concerns
Review appointments will include:
 Check device site
 Check device program
 Unaided audiogram
 Aided audiogram
 Tympanometry
 Speech perception testing (words and sentences in quiet and in noise)
Functional evaluation (SSQ)
Expected outcomes
Conductive hearing loss
Studies suggest that recipients with an air bone gap of greater than 30dB will experience significant benefit
from the Baha compared to air conduction hearing aids.
Mixed losses
Those with mild to moderate sensorineural component. Most powerful Bone conduction implantable device
processor can compensate for a sensorineural element of up to 65dB HL (measured at 0.5, 1, 2, & 3 kHz) on
a percutaneous abutment.
SSD
Those with normal to mild hearing loss in their good ear can benefit. Limited or no benefit if greater hearing
loss. Benefits over a CROS aid include no occlusion of the hearing ear, and no need to wear hearing devices
on both ears. Bone conduction implantable device recipients reported quality of life improvements and
improvements in difficult listening situations such as conversation in background noise. Bone conduction
implantable device cannot provide localisation improvements. (Flynn & Sammeth, et.al., 2010)
References
NHSCB/DO9/P/a
Cochlear Baha systems guide
Flynn MC, Sammeth CA, Sadeghi A, Halvarsson G (2010) “Baha for single sided sensorineural deafness:
Review and recent technology innovations” Seminars in Hearing 31 4 326-349
MSAC draft protocol Jan 2015
Appendix
Clinical Reference Forms