Baha® Systems

FOR PROFESSIONALS
COCHLEAR
™
Baha Systems
®
SURGERY GUIDE
For Cochlear Baha®
DermaLock Surgical Procedure
™
™
This surgical guide sets forth detailed recommended procedures for using Cochlear ™
Baha® surgical components and instruments. It offers guidance needed for performing the
procedure but, as with any technical guide, the surgeon must consider the particular needs
of each patient and make appropriate adjustments when required. The techniques shown
in this guide are provided for your consideration only, and do not constitute direct medical
advice from Cochlear. This guide is not a substitute for actual medical education and
hands-on training.
Cochlear accepts no responsibility for any adverse outcomes if used with products not
recommended by Cochlear. Close cooperation in an interdisciplinary team is essential
for a successful outcome. Hands-on surgical workshops are available from Cochlear.
Contact your local Cochlear office for details.
 Acknowledgements
The protocol detailed in this manual originates from the clinical work carried out by:
Pete Weber, M.D., MBA, Chief Medical Officer, Cochlear Americas
2|
Contents
Introduction5
Preparations6
Baha FAST surgery
11
Baha two-stage surgery
17
Aftercare24
Complications26
References 29
Notes 30

NOTE:
Images in this guide are not to scale.
Not all products are available in all markets. Product availability
is subject to regulatory approval in the respective markets.
Baha FAST surgery is the same as one-stage surgery.
This guide is applicable for the DermaLock Implant with Abutment
(BIA400), and the BI300 Implants used with the DermaLock
Abutments (BA400). These products are used for Baha surgery
with soft tissue preservation.
Traditional Baha surgery with soft tissue removal is carried out using
BA210 Abutments, BA300 Abutments or previous generation Baha
abutments. For more information, see the Baha Surgery guide for the
BI300 Implant system (BUN004).
|3
4|
Introduction
Since 1977, the Cochlear Baha Bone Conduction Implant
has proven successful for thousands of patients worldwide.
The system – which combines a small titanium implant,
an abutment, and a sound processor – has yielded excellent
results for certain patient groups, particularly for those
individuals with single-sided sensorineural deafness,
conductive, and mixed hearing loss.1
The long-term predictability and success of Baha implants results from the creation
of an active bond between the titanium implant and the surrounding bone tissue –
a process known as osseointegration. The use of a precise implantation technique is
vital to successful, long-term osseointegration.
Since the introduction of the Baha System, the surgical procedure for implantation has
been modified by surgical teams worldwide to further improve the results and to shorten
the surgery time.
The Cochlear Baha DermaLock Abutments have been specifically designed to facilitate
a minimally invasive surgical technique that preserves soft tissue.
When selecting a surgical approach, the techniques in this guide provide the
recommended alternatives.
|5
Preparations
 Technique selection
Baha FAST surgery vs. two-stage surgery


The surgeon will decide to use either the FAST or two-stage procedure. This decision is
based on several factors, including the thickness and quality of the cortical bone as well as
the patient’s age. Generally, FAST surgery is recommended for patients with good bone
quality and thickness greater than 3mm. Two-stage surgery is generally recommended for
for patients with compromised or soft bone, irradiated bone, bone thickness less than 3mm,
special-needs patients (e.g. mentally or physically compromised) or in conjunction with
other surgery (e.g. Acoustic Neuroma removal).
Baha FAST surgery
Selection criteria
Good bone quality and
thickness greater than 3mm
Children

For children with bone thickness of 3-4mm, factors such as patient age, developmental delay
and bone quality may warrant the more conservative two-stage procedure. Children with
cortical bone thickness greater than 4mm (typically those older than nine years of age) could
be considered for FAST surgery.
Baha two-stage surgery
The timing of the second stage of surgery depends on the thickness and quality of the bone
encountered at stage one. With poorer bone quality, a longer interval between stage one
and two may be needed. As age and bone thickness increase, the inter-stage interval may
decrease. Children with a cortical bone thickness of less than 3mm may require more than
the usual 3–6 month inter-stage interval.
• Compromised or soft bone
• Irradiated bone
• Bone thickness less than
A key consideration for children with hearing loss is the importance of early auditory input
to avoid compromising their language development. Since there is a slightly higher rate of
implant loss in children,2,3 placing a sleeper implant is recommended.4 A sleeper implant
reduces the time between the potential implant loss and restoration of access to hearing.

NOTE:
In the United States and Canada, the placement of a bone-anchored
implant is indicated in children age five years and older.

Table 2: Technique selection for children
Bone thickness
FAST
Two-stage
Sleeper implants
•
•
•
•
Less than 3mm
3-4mm
±
Greater than 4mm
•
± Optional | • Recommended
Selection criteria
3mm In conjunction with
other surgery (e.g. Acoustic
Neuroma removal)
When children undergo Baha surgery, general anesthesia is often used. When selecting the
surgical technique, the potential to avoid a second anesthetic should be evaluated against
the safety profile for FAST surgery.
6|
Table 1:
Technique selection
±
 Treatment schedule
Baha FAST surgery
Baha two-stage surgery
Place implant with abutment.
First stage
Surgical follow-up
Time after surgery
Remove dressing and assess
the wound site. If healed, no
further dressing is required.
Instruct patient or their
family/caregivers on cleaning
and aftercare. If not healed,
place a new dressing and
healing cap.
5-7 days
If necessary, repeat relevant
steps as in the previous visit.
10-14 days
Fitting the sound
processor
Time after surgery
Ensure patients’ ability to
handle sound processor.
Surgical follow-up
Time after surgery
Remove sutures, if healed.
10-14 days
Osseointegration period.
3-6 months
Second stage
Remove cover screw and place abutment.
Check and clean abutment.
Fit the sound processor.
Place implant and cover screw.
12 weeks, given that the soft
tissue is sufficiently healed
Follow up
After the sound processor has been fitted, patients will return
for audiological assessment. At this time, the abutment and
tissue should be examined by the appropriate clinician(s).
Generally, patients will have annual or bi-annual check ups.
Surgical follow-up
Time after 2nd stage
Remove dressing and assess
the wound site. If healed, no
further dressing is required.
Instruct patient or their family/
caregivers on cleaning and
aftercare. If not healed, place a
new dressing and healing cap.
5-7 days
If necessary, repeat relevant
steps as in the previous visit.
10-14 days
Fitting of the sound
processor
Time after 2nd stage
Check and clean abutment.
Fit the sound processor.
Ensure patients’ ability to
handle sound processor.
Sound processor can be
attached when wound
healing has occurred.
Follow up
Following the fitting of the sound processor, patients will
return for audiological assessment. At this time the abutment
and tissue will also be examined by the appropriate clinician(s).
Generally, patients will have annual or bi-annual check ups.
|7

Selecting the implant site
Even though the surgeon will ultimately select the implant site, successful treatment relies
on an interdisciplinary approach that includes consultation with other clinicians involved
in the case, as well as the patient and/or the patient’s family/caregiver. Choosing the
appropriate implant site requires attention to the following factors and considerations:
• Audiological factors — Baha surgery is indicated as a treatment for patients with
with single-sided sensorineural deafness (SSD), as well as conductive or mixed hearing
loss. For patients with single-sided sensorineural deafness (SSD), place the implant
on the deaf side.
In patients with a bilateral hearing loss, bilateral fitting is recommended. Studies show
that the patient benefits from bilateral fitting in terms of greater stimulation level,
better directional hearing and space perception as well as overall better speech
understanding in noise.5
In case of unilateral fitting, place the implant on the side with the best cochlear
function (i.e. best bone conduction thresholds).
• Physiological factors — Incorrect implant placement too far from the cochlea can change
the audiological outcome.6 Estimate the site location in cases of complete aural atresia, or
place the Baha in the parietal cortex rather than the thicker mastoid bone in children with
craniofacial abnormalities. Move the site posteriorly (generally 60-65mm from ear canal)
for children who will undergo autogenous reconstruction.
• Manual dexterity — Ensure patients’ (or families’/caregivers’) ability to utilize controls
as well as remove and replace the sound processor.
• Head gear — Special consideration is warranted for patients who regularly wear a hat
or helmet for work or certain activities (e.g. construction workers and cyclists).
• For patients with mixed or conductive loss:
Driving habits — Patients that regularly drive with a passenger seated next to
or behind them usually prefer their implant on the side facing the passenger.
Telephone use — Patients that frequently use the telephone prefer the
implant on the side opposite to their writing hand.

Preparations for surgery
Prepare the patient as for any surgical procedure, i.e. sterilize the incision area. Local or
general anesthesia can be used for adult patients. When children undergo Baha surgery
general anesthesia is most often used.
1

NOTE:
All single-use products are delivered sterile (sterilized using irradiation)Do not use
products with damaged packaging or after the expiration date. Due to contamination
and efficacy risks, do not re-sterilize or reuse these single use products (Fig. 1).
The peel-open pack inside the sterile product box acts as the sterile barrier. The plastic
ampule is only a container for the sterile product. Inside the plastic ampule, a titanium
casing holds the product (Fig. 2). The product should not be touched but rather picked
up with the relevant instrument.
set of all components should always be available because FAST surgery may change
A
to two-stage surgery or a different implant or abutment size may be required. It is also
recommended that back-up components are available, in case a component is dropped.
8|
2

DermaLock abutments
The DermaLock Abutment is coated with a hydroxyapatite layer that is intended to be in
contact with the tissue. This coating is applied to the abutment, with 3mm of the upper
surface (2mm on 6mm abutments) remaining uncoated.
The abutment is available in four different heights (6mm, 8mm, 10mm and 12mm) to allow
selection of the abutment most appropriate for the patient’s skin thickness (Table 3). The
abutments are available pre-mounted on the 4mm BI300 implant for FAST procedures and
as separate abutment-only numbers, as listed below.

Baha FAST surgery (4mm)
93329
DermaLock 4mm
Implant with
6mm Abutment

93331
DermaLock 4mm
Implant with
10mm Abutment
93332
DermaLock 4mm
Implant with
12mm Abutment
93334
DermaLock
8mm Abutment
93335
DermaLock
10mm Abutment
93336
DermaLock
12mm Abutment
Baha two-stage surgery
93333
DermaLock
6mm Abutment

93330
DermaLock 4mm
Implant with
8mm Abutment
Table 3: Abutment selection
Tissue thickness should be measured prior to injecting local anesthetic.
Tissue thickness (mm)
Abutment length (mm)
Corresponding part number
One stage
Two stage
3 or less
6
93329
93333
4-5
8
93330
93334
6-7
10
93331
93335
8-9
12
93332
93336
10 or more*
12
93332
93336
* With soft tissue reduction.
|9
10 |
Baha FAST surgery
Generally, FAST surgery is recommended for patients with
good bone quality and thickness. FAST surgery is performed
in one stage and the procedure involves placing an implant
with a pre-mounted abutment.
This section provides step-by-step instructions for Baha FAST surgery with soft tissue
preservation, or minimal soft tissue removal where required. Because a FAST surgery
may need to be converted to a two-stage surgery intra-operatively, it is recommended
to keep a 3mm implant and a 3mm widening drill in the OR.
| 11
Baha FAST surgery
 STEP 1 Prepare the site
Mark the site
1
• Use the indicator for Baha to carefully mark the location of the planned implant site,
generally 50–55mm from the ear canal and with the indicator in line with the top of the
pinna. Anatomical landmarks, such as the zygomatic line are useful guides. Avoid the
sound processor touching the pinna (Fig. 1).
• Mark the incision line approximately 10mm anterior to the abutment site. The incision
length is generally 20-30mm long, following the direction of the hair line. The implant/
abutment should be placed at least 10mm from the incision line.
Measure soft tissue
2
• Measure the tissue thickness before local anesthesia is infiltrated. A hypodermic needle,
a clamp and a ruler may be used (Fig. 3).
• Select an abutment depending on the tissue thickness (Table 3). The tissue should cover
the coated part of the abutment. The coating is applied 3mm below the top surface
(2mm below the top surface on 6mm abutments) (Fig. 4).

Table 3: Abutment selection
Tissue thickness (mm)
3
Abutment length (mm)
Corresponding part number
One Stage
Two Stage
3 or less
6
93329
93333
4-5
8
93330
93334
6-7
10
93331
93335
8-9
12
93332
93336
10 or more*
12
93332
93336
* With soft tissue reduction.
4

NOTE:
If it is not possible to use a 12mm abutment due to excessive tissue
thickness, remove subcutaneous tissue to achieve a thickness of
approximately 10mm and 40x60mm across.
5
 STEP 2 Make the incision
• Use a scalpel to make an incision down to the periosteum (Fig. 5).
• Open up the incision and identify the implant placement, at least
10mm posterior to the incision line.
• Make a cruciate incision (6mm square) in the periosteum to expose enough
bone for the implant flange, and raise the edges with a raspatorium (Fig. 6).
6
TIP: DermaLock abutments
deliver better results when
incisions are made with a scalpel
vs. electrocautery. If cautery is
needed, use low power bipolar or
“spot” monopolar cautery.
12 |
 STEP 3 Drill with the conical guide drill
Be certain to drill at an angle perpendicular to the patient and bone surface. The drill indicator
facilitates correct drill orientation and should be used during drilling and implant placement.
7
• Set the drill unit to the high-speed setting, 2000 rpm (program 2 for the Osscora
surgical set) (Fig. 7).
• Begin drilling with the guide drill with 3mm spacer (Fig. 8).
• While drilling, move the burr up and down and slightly enlarge the hole to visualize the site and
to ensure that coolant reaches the tip of the drill, using abundant irrigation while drilling. Cooling
is critical to preserve osteocytes, which are crucial for the osseointegration process.
• Check the bottom of the implant site repeatedly for bone, both visually and with the dissector (Fig. 9)
to ensure that the implant site has bone at its base.
8
• If there is adequate bone thickness, remove the white spacer on the conical guide drill
and continue drilling to a depth of 4mm (Fig. 10).

NOTE:
The DermaLock Abutments are delivered pre-mounted on 4mm implants. A 3mm implant can
be considered for a one-stage procedure when there is sufficient bone quality and thickness.
In that case, the abutment should be manually attached after having placed the implant
(for more information about how to attach an abutment, see page 24).
9
Observe the quality and quantity of the cortical bone and spongiosa air cells during initial
penetration. Proceed with care to avoid penetrating the wall of the sigmoid sinus or
damaging the dura mater.
10
 STEP 4 Drill with the widening drill
• Keep the drill unit on the high-speed setting, 2000 rpm (program 2 for the
Osscora surgical set).
• Use either a 3 or 4mm widening drill, depending on the depth reached with the guide drill
(Fig 11). Because bone thickness varies, it is recommended to keep a 3mm implant and a
3mm widening drill in the OR.
11
• Move the widening drill up and down during drilling to ensure that coolant reaches the tip of the drill.
Only use up and down movements, do not make the hole larger than the actual drill size.
• If necessary, use the dissector to remove bone chips frequently from the drill flutes.
• When reaching the bone surface, use the widening drill to create a small countersink in the
bone (maximum 0.5mm) (Fig. 12). The widening drill has been designed to allow early recognition
of when countersinking is complete. However, take care not to press too hard, especially in soft
bone, to avoid excessive countersinking.
12

NOTE:
Do not use the guide drill after the widening drill since the guide drill stop
diameter is smaller than the site.
The blunt tip of the widening drill minimizes the risk of damage to tissue at the
bottom of the implant site.
Be very careful not to over-widen the section that will contain the implant
threads or you risk losing initial implant stability.
| 13
 STEP 5 Place the implant and abutment
• Set the drill to the torque setting (program Implant Installation for the Osscora
surgical set) (Fig. 13).
• Set the torque limit to suit the quality of the bone.
13
Bone quality
Suggested Torque
Compact bone
40 –50 Ncm
• Open the ampule upright by unscrewing the lid so the bottom section can be placed
in the holder on the tray (Fig. 14).
14
• Pick up the implant and the abutment using the abutment inserter (Fig. 15).
• Place the implant without irrigation until the first threads of the implant are well within
the bone (approximately two rotations). Irrigation at this time would result in cooling
solution being compressed into the marrow spaces in the bone by the implant (Fig. 16).
• Once in the bone, continue implant placement with irrigation.
• The Osscora surgical set stops automatically and beeps when the preset torque is reached.
15
• Carefully lift up the handpiece to remove the abutment inserter from the abutment (Fig. 17).

NOTE:
The implant must not come in contact with anything other than
the ampule and abutment inserter before being placed in the bone.
The surface must be kept free from contamination for successful
osseointegration.
16
When placing the implant in hard bone, slight pressure may need to be
applied during the initial insertion.
If the implant enters the implant site incorrectly, put the drill in reverse
and unscrew the implant. Then find the correct angle and re-insert the
implant. This should only be attempted once.
16
17
14 |
If the drill stops prematurely – before the flange of the implant is seated
in the countersunk bone – reverse one thread and increase the torque by
5 Ncm on the control panel of the drill system.
Be very careful not to loosen the implant through a lever arm effect.
The risk of this occurring is higher if implanting a patient with thin or
compromised bone.
 STEP 6 Prepare to close the surgical site
• Remove the retractors (Fig. 18).
• Using a Ø 5mm biopsy punch, make a hole in the skin exactly over the abutment,
ensuring 10mm of tissue remains between the punch site and incision line (Fig 19).
18
• Carefully ease the skin over the abutment, ensuring the approximated skin
edges evert around the abutment, and are not inverted.
 STEP 7 Suture and attach the healing cap
19
• Close and suture the incision (Fig 20). Ensure that the suture goes through
periosteum to maximize soft tissue stability.
• A non-adherent dressing should be applied around the abutment and the healing cap
placed to keep soft tissue immobile during the initial 7-10 day healing phase (Fig 21).

NOTE:
The dressing should be kept in place during the healing period to protect
the wound and the coating and to stabilize the integration process.
20
TIP: This incision should be closed
such that the suture goes from
the skin through the periosteum
to the skin on the opposite side to
minimize soft tissue movement.
If a silver dressing is used and the coating of the abutment is protruding
from the skin, the coated part of the abutment will be discolored by the
silver in the dressing. This is not harmful to the abutment or tissue.
Cleaning around the abutment site is very important. Non-alcoholic wet
wipes work very well and may be better for some patients than the soft
abutment brush. Either method will keep the site clean.
TIP: A non-adherent dressing
should be applied with the
healing cap in place to keep
soft tissue immobile during the
initial healing phase.
| 15
16 |
Baha two-stage surgery
Generally, two-stage surgery is recommended for patients
with compromised or soft bone with a bone thickness
less than 3mm. For children with bone thickness 3-4mm,
factors such as patient age, developmental delay and
bone quality may warrant the more conservative twostage procedure.* The bone quality and thickness may
also influence the length of the inter-stage interval and
placement of a sleeper implant.

NOTE:
This section illustrates two-stage surgery with a straight incision.
However, a skin flap may also be used.
 When FAST surgery
becomes a two-stage procedure
Because a FAST surgery may have to be converted to a two-stage surgery
intra-operatively, it is recommended to keep a 3mm implant and a 3mm widening
drill in the OR.
If a 4mm FAST system is being converted to a two stage procedure, disconnect the
abutment from the implant by using the counter torque wrench and the 95mm
Unigrip screwdriver. Place a cover screw into the implant at this time.
* In the U.S. and Canada, Baha surgery is indicated for children age five years and older.
| 17
Baha two-stage surgery: Stage 1
 STEP 1 Prepare the site
• Use the indicator for Baha to carefully mark the location of the planned implant site,
generally 50–55mm from the ear canal and with the indicator in line with the top of the
pinna. Anatomical landmarks, such as the zygomatic line are useful guides. Avoid the
sound processor touching the pinna (Fig. 1).
1
• Mark the incision line approximately 10mm anterior to the abutment site. The incision
length is generally 20-30mm long,following the direction of the hair line (Fig 2). The
implant/abutment should be placed at least 10mm from the incision line.
 STEP 2 Make the incision
2
• Use a scalpel to make an incision down to the periosteum. (Fig. 3).
• Open up the incision and identify the implant placement, at least 10mm
posterior to the incision line.
• Make a cruciate incision (6mm square) in the periosteum to expose enough
bone for the implant flange, and raise the edges with a raspatorium (Fig. 4).
3
4
TIP: DermaLock abutments
deliver better results when
incisions are made with a scalpel
vs. electrocautery. If cautery is
needed, use low power bipolar or
“spot” monopolar cautery.
18 |
 STEP 3 Drill with the conical guide drill
Be certain to drill at an angle perpendicular to the patient and bone surface. The drill
indicator facilitates correct drill orientation and should be used during drilling and
implant placement.
5
• Set the drill unit to the high-speed setting, 2000 rpm (program 2 for the Osscora
surgical set)(Fig. 5).
• Begin drilling with the guide drill with 3mm spacer (Fig. 6).
• While drilling, move the burr up and down and slightly enlarge the hole to ensure
visual inspection and that coolant reaches the tip of the drill, using abundant irrigation
while drilling. Cooling is critical to preserve osteocytes, which are crucial for the
osseointegration process.
6
• Check the bottom of the implant site repeatedly for bone, both visually and with the
dissector (Fig. 9) to ensure that the implant site has bone at its base.
• If there is adequate bone thickness, remove the white spacer on the conical guide drill
and continue drilling to a depth of 4mm (Fig. 8).

NOTE:
7
Observe the quality and quantity of the cortical bone and spongiosa air
cells during initial penetration. Proceed with care to avoid penetrating
the wall of the sigmoid sinus or damaging the dura mater.
 STEP 4 Drill with the widening drill
8
• Keep the drill unit on the high-speed setting, 2000 rpm (program 2 for the Osscora
surgical set).
• Use either a 3 or 4mm widening drill, depending on the depth reached with the guide drill
(Fig 11). Because bone thickness varies, it is recommended to keep a 3mm implant and a
3mm widening drill in the OR.
• Move the widening drill up and down during drilling to ensure that coolant reaches
the tip of the drill. Only use up and down movements, do not make the implant site
larger than the actual drill size.
9
• Use the dissector to remove bone chips frequently from the drill flutes.
• When reaching the bone surface, use the widening drill to create a small countersink in
the bone (maximum 0.5mm) (Fig. 10). The widening drill has been designed to allow early
recognition of when countersinking is complete. However, take care not to press too hard,
especially in soft bone to avoid excessive countersinking. For patients with bone less than
3mm countersinking risks diminishing the bone available for osseointegration.
10

NOTE:
Do not use the guide drill after the widening drill since the guide drill
stop diameter is smaller than the site.
The blunt tip of the widening drill minimizes the risk of damage to tissue
at the bottom of the implant site.
Be very careful not to over-widen the section that will contain the
implant threads or you risk losing initial implant stability.
| 19
 STEP 5 Place the implant
• Set the drill to the torque setting (program Implant Installation for the
Osscora surgical set) (Fig. 11).
11
Bone quality
Suggested Torque
Compromised or soft bone
20 –30 Ncm
• Set the torque limit to suit the quality of the bone.
• Open the ampule upright by unscrewing the lid so the bottom section can be placed
in the holder on the tray (Fig. 12).
12
• Pick up the implant using the implant inserter. It is easier to fit the implant inserter in the
implant if the drill motor is running. A click will indicate when the implant inserter
is correctly positioned (Fig. 13).
• Place the implant without irrigation until the first threads of the implant are well within
the bone (two rotations). Irrigation at this time would result in cooling solution being
compressed into the marrow spaces in the bone by the implant (Fig. 14).
• Once in the bone, continue implant placement with irrigation.
13
• The Osscora surgical set stops automatically and beeps when the preset torque is reached.
• Carefully lift up the handpiece to remove the implant inserter from the implant.

NOTE:
14
The implant must not come in contact with anything other than
the ampule and implant inserter before being placed in the bone.
The surface must be kept free from contamination for successful
osseointegration.
If the implant enters the implant site incorrectly, put the drill in reverse
and unscrew the implant. Then find the correct angle and re-insert the
implant. This should only be attempted once.
If the drill stops prematurely – before the flange of the implant is seated
in the countersunk bone – reverse one thread and increase the torque by
5 Ncm on the control panel of the drill system.
15
Be very careful not to loosen the implant through a lever arm effect.
The risk of this occurring is quite high if implanting a patient with thin or
compromised bone.
For patients with bone <3mm countersinking risks diminishing the bone
available for osseointegration. Instead place the implant flush with the
calvarial surface even if it slightly abuts or depresses the dura mater
(A). Alternatively, make an incomplete insertion and leave the implant
protruding with bone chips, collected from the widening drill, placed
under the flange (B)(Fig. 15).
16
20 |
The implant can be inserted manually with the multi wrench and the
implant inserter. Rotate the whole multi wrench shaft clockwise
(“IN” facing upwards) until the implant is fully seated (Fig. 16). The
multi wrench is not intended to be used as a torque wrench for implant
placement as the torque limit is 25 Ncm.
Placing a sleeper implant

• Since there is a slightly higher rate of implant loss in children 2,3, placing a sleeper
implant is recommended4 in order to reduce the time between the potential loss
of an implant and access to hearing being restored.
17
• Leave at least 10mm between the centers of the two implants (Fig. 17). However,
the thickness of the cortical bone must be considered. Insert a cover screw to protect
the internal threads of the implant from tissue and bone overgrowth during the
healing phase.

NOTE:
In cases of bilateral hearing loss, contralateral placement of a
sleeper implant may also be considered.
18
 STEP 6 Place the cover screw
Inserting a cover screw protects the internal threads of the implant from tissue and
bone overgrowth during the healing phase.
• Place and hand tighten the cover screw using the 95mm Unigrip screwdriver (Fig. 18).
• Suture down and through the periosteum with resorbable sutures over the implant.
• Suture the incision.
• Apply a suitable dressing.
| 21
Baha two-stage surgery: Stage 2
 STEP 1 Make the incision
• Locate the implant position.
• Measure the tissue thickness before local anesthesia is infiltrated. A hypodermic needle,
a clamp and a ruler may be used (Fig. 19).
19
• Select an abutment depending on the tissue thickness. The tissue should cover the coated
part of the abutment. The coating is applied 3mm below the top surface (2mm below the
top surface on 6mm abutments) (Fig. 20).

Table 3: Abutment selection
Tissue thickness should be measured prior to injecting local anesthetic.
20
21
Tissue thickness (mm)
Abutment length (mm)
Corresponding part number
One stage
Two stage
3 or less
6
93329
93333
4-5
8
93330
93334
6-7
10
93331
93335
8-9
12
93332
93336
10 or more*
12
93332
93336
* With soft tissue reduction.

NOTE: If it is not possible to use a 12mm abutment due to excessive soft
tissue thickness, remove subcutaneous tissue to achieve a thickness of
approximately 10mm and 40x60mm across.
22
• Make an incision in the same incision line as in Stage 1 (Fig. 21).
• Open up the incision to expose the periosteum using a self retaining
retractor (Fig. 22). Any other retractor may also be used.
23
 STEP 2 Remove the cover screw
• Remove the cover screw using the 95mm Unigrip screwdriver (Fig. 23).
22 |
 STEP 3 Connect the abutment
• Pick up the abutment with the counter torque wrench and place it into
the implant (Fig. 24).
• Ensure the tri-lobe connection is locked together and then gently pre-tighten
the abutment screw with the 95mm Unigrip screwdriver (Fig. 25).
24
• Set the drill to the torque setting (program Implant Installation for the Osscora
surgical set) and set the torque limit to 25 Ncm.
• Finalize the tightening of the abutment screw to 25 Ncm with the 25mm machine
screwdriver Unigrip and the counter torque wrench (Fig. 26).
• For manual tightening, tighten the abutment screw to 25 Ncm using the multi wrench
(“IN” facing upwards), with the 25mm machine screwdriver Unigrip. (Fig. 27).
25

NOTE:
The counter torque wrench should always be used to avoid rotational
forces on the implant.
26
24
25 Ncm
 STEP 4 Close and suture
• Using a Ø 5mm biopsy punch, make a hole in the skin exactly over the abutment,
ensuring 10mm of tissue remains between the punch site and incision line (Fig 28).
If needed, remove excessive tissue at the skin edges with a scalpel to allow for better
adaption of the skin to the abutment.
25 Ncm
27
• Carefully ease the skin over the abutment, ensuring the approximated skin edges evert
around the abutment, and are not inverted.
• Suture the incision (Fig. 29).
• Ensure that the abutment is free of blood and clotted debris above the skin level.
• Apply a suitable non-adherent wound dressing.
• The healing cap can be placed either before or after the dressing depending on
the type of dressing used (Fig. 30).
28

NOTE:
The dressing should be kept in place during the healing period to protect
the wound and the coating and to stabilize the integration process.
If a silver dressing is used and the coating of the abutment is protruding
from the skin, the coated part of the abutment will be discolored by the
silver in the dressing. This is not harmful to the abutment or tissue.
29
30
| 23
Aftercare
 Dressing guidelines
1 day post-op
5-7 days post-op
1. Remove the mastoid dressing.
1. Remove and discard the healing cap.
2. Leave the dressing and healing cap
in situ.
2. Carefully remove the dressing.
3. Ensure that the patient does not
allow any water to come in contact
with the site before complete
healing of the wound.
4. Gently clean the wound with normal saline
and gauze.
3. Remove the sutures (if applicable).
5. Gently remove any dried blood or debris.
6. Assess the wound site and treat accordingly.
7. If healed, no further dressing is required.
8. Provide the patient with aftercare instructions
and emphasize the importance of daily
cleaning. For the first few weeks, a skinfriendly shampoo should be used.
Patient aftercare instructions

Start daily cleaning with an alcohol-free wet wipe after dressing removal. Be careful not
interfere with the tissue integration during the healing phase.
After the initial healing phase (up to 12 weeks), continue to clean once a day with an alcoholfree wet wipe or the cleaning brush available from Cochlear. The cleaning brush needs to be
changed regularly.

NOTE:
The cleaning should, independent on the method selected, be light.
After the wound has healed, half yearly or yearly checkups at the
outpatient clinic are recommended.
For detailed cleaning instructions, please refer to patient user manuals or the ”Living with
your Baha” Aftercare kit. The Aftercare kit consists of a brochure and a DVD together with
useful cleaning tools.
In case of infection, the patient’s cleaning routine should be assessed.

NOTE:
When healed, a small part of the coating may protrude above the skin.
The coating is sensitive to low pH-solutions (such as certain soaps) and
will in acidic environment partly dissolve into its ionic components.
These ions are found abundantly in the human body (e.g. blood and
bone) and are not considered harmful. Underneath the coating
is blasted titanium.
24 |
7-10 days post-op
1.If necessary, repeat relevant steps as
in the previous visit.
2. If the wound site has not healed
consult a wound care specialist.

Adjusting the abutment
Occasionally the abutment may need to be tightened or replaced. The multi wrench with
ISO adapter, the 25mm machine screwdriver Unigrip and the counter torque wrench are
required (Fig. 1). Insert the ISO adapter in the multi wrench and then insert the 25mm
machine screwdriver Unigrip in the ISO adapter (Fig. 2).
The counter torque wrench should always be used to avoid rotational forces on the implant.
Tighten the abutment

1
• Tighten the abutment screw to 25 Ncm using the multi wrench (“IN” facing upwards) with
machine screwdriver Unigrip 25mm (Fig. 4).
Replacing the abutment

CLICK
• Loosen the abutment screw using the multi wrench (“OUT” facing upwards) with the
25mm machine screwdriver Unigrip. If the abutment is difficult to remove from the
implant, gently rock the counter torque wrench side to side to loosen the abutment.
You may have to excise the soft tissue from the abutment.
2
• Clean the skin thoroughly. If needed, allow the area to heal before placing a new
abutment. A cover screw can be used to cover the implant during healing.
• A fresh wound may be created with a small incision. A biopsy punch Ø 5mm
may also be used.
• Pick up the new abutment with the counter torque wrench (Fig. 3) and place it into
the implant (Fig. 3).
3
• Ensure the tri-lobe connection is locked together and then gently pre-tighten the
abutment screw with the 95mm Unigrip screwdriver.
• Finalize the tightening of the abutment screw to 25 Ncm using the multi wrench
(“IN” facing upwards) with 25mm machine screwdriver Unigrip (Fig. 4).
• Ensure that the approximated skin edges evert around the abutment, and are not inverted.
25 Ncm

4
NOTE:
DermaLock Abutments
93336
93335
93334
The DermaLock Abutments are only compatible with
BI300 Implants (Fig. 5).
93333
92128 / 92129
93336
93335
5
90430 / 90432 / 90434 /
90480 / 92134 / 92135
93334
93333
| 25
Complications
The success rate for Baha surgery is very high. However,
unexpected situations, both intra-operatively and
postoperatively, may occur. Below is a list of potential
complications and recommendations for handling
them. Importantly, the patient must be informed of
all possible complications related to safety and
effectiveness prior to surgery.
The regulation of medical devices requires the manufacturer to report adverse events to the
appropriate authority. Should such an incident occur, notify your local Cochlear office or its
official distributor as soon as possible.


Complications during surgery
Implant becomes stuck during insertion
This can occur if the implant alignment is incorrect. Set the drill unit to reverse mode. Then
unscrew the implant. Find the correct alignment and re-insert the implant. If the same
happens again, prepare a new implant site at least 10mm from the first site.

Implant continues to rotate when seated
This may occur when drilling in compromised and soft bone, and when the torque is set too
high in relation to the quality of the bone. Prepare a new implant site at least 10mm from
the first site and then place the implant with a lower torque.

Exposure of dura mater or perforation of the sigmoid sinus
Although rare, a mild CSF or blood leak can occur during guide hole drilling. If this occurs,
it is a low pressure system that can be sealed easily. If there is good bone volume, place the
implant to seal the leak. If the bone is too thin, seal the leak with soft tissue of bone wax.
Then choose a new implant site at least 10mm from the original site (as close as possible
without intersecting).

Subdural hematoma
This condition, caused by venous bleeding under the dura, is rare and typically slow
developing. It is not often identified during surgery, but is more likely caused by direct
trauma and will develop gradually over time and display general neurological symptoms.
Should this occur, a CT or MRI can be used to verify the diagnosis. Treat this condition
according to general practice.
26 |


Post-operative soft tissue complications
Inflammation and infection around the abutment
Poor or excessive personal hygiene is the most common cause of irritation. It could also
be due to a loose abutment or insufficient osseointegration.
If the skin around the abutment becomes inflamed /infected, thoroughly clean the entire
implant site and, if appropriate, apply antimicrobial cream. Provide the patient with the
appropriate aftercare instructions.
If further treatment is needed, an antibiotic/steroid injection might be considered.

Persistent soft tissue complications
When medical therapy has failed and the patient has a persistent problem, remove the
abutment. You may have to excise the soft tissue from the abutment. Clean the skin
thoroughly. Perform a culture before providing the appropriate antimicrobial and antiinflammatory treatment. Place a cover screw and allow the area to heal before placing
a new abutment. Ensure the approximated skin edges evert around the abutment,
and are not inverted.

Skin overgrowth
In some patients (predominantly male teenagers) an inflammatory reaction may occur
and result in soft tissue thickening or complete overgrowth of the abutment by soft tissue.
Treatment with a longer abutment, topical steroid cream or a steroid injection may be
consideared. 7,8

Keloids
In the case of keloids that do not subside over time, an injection with Kenalog might be
considered. Another option is to place a silicone disc9 over the keloid and keep pressure
on the silicone disc for 7-10 days.

Post-operative numbness-parasthesia
Postoperative numbness may occur. Usually this will subside after a few months.
| 27


Post-operative bone complications
Implant loss
Potential causes for failure of osseointegration include lack of adequate bone quantity/
quality, trauma, infection, generalized diseases and surgical complications.

Bony overgrowth
The potential for a bony overgrowth around the implant is highest in children implanted at
a very young age. Removal of some bone will allow sufficient clearance between the skin and
the Baha sound processor.

Pain when touching the abutment
If the patient experiences pain when touching the abutment, there may be an increased risk
of implant loss. In most cases, the loose implant can be removed and another one placed
in adjacent bone. In others, the implant must be removed and the defect then carefully
curetted and filled with blood coagulates. In most cases adjacent bone is available and
suitable for the placement of another implant.


Special considerations
MRI and magnetic fields
Be certain to caution patients about procedures that could be harmful to the sound processor,
such as MRI and other magnetic fields. Always remove the sound processor before an MRI
procedure. The implant itself and the abutment are not ferromagnetic and will not cause any
damage to the patient during an MRI.10 The resulting artifacts are minor.

Radiation therapy
If a patient already has an implant, and is scheduled for radiation therapy around the implant
area, the abutment should be removed but the implant could be left in place to allow
healing of the site before radiation is performed. A cover screw can be used to cover the
implant until the abutment is replaced.

Sporting activities
It is important to educate the parents and caregivers about the need for helmets and other
safety precautions during sporting activities to minimize traumatic events. Traumatic implant
loss can still occur across all age groups.
28 |
References
1. Snik AF, Mylanus EA, Proops DW, Wolfaardt JF, Hodgetts WE, Somers T, Niparko JK,
Wazen JJ, Sterkers O, Cremers CW, Tjellström A. Consensus statements on the
BAHA system: where do we stand at present? Ann Otol Rhinol Laryngol Suppl.
2005 Dec;195:2-12.
2. de Wolf MJ et al. Nijmegen results with application of a Bone-Anchored Hearing Aid in
children: Simplified Surgical Technique Ann Otol Rhinol Laryngol. 2008;117(11):805-14.
3. McDermott AL, Williams J, Kuo M, Reid A, Proops D, The Birmingham paediatric bone
anchored hearing aid programme: A 15 year experience . Otol Neurotol.
2009;30(2):178-83.
4. Durvasula VS, Patel H, Mahendran S, Gray RF. Bone anchored hearing aids: a second
fixture reduces auditory deprivation in Cambridge. Eur Arch Otorhinolaryngol. 2007
Sep;264(9):991-4.
5. Priwin C, Stenfelt S, Granström G, Tjellström A, Håkansson B. Bilateral Bone-Anchored
Hearing Aids (BAHAs): an audiometric evaluation. The Laryngoscope 2004;114(1):77-84.
6. Eeg-Olofsson M, Stenfelt S, Tjellström A, Granström G. Transmission of boneconducted sound in the human skull measured by cochlear vibrations. Int J Audiol. 2008
Dec;47(12):761-9.
7. Falcone MT, Kaylie DM, Labadie RF, Haynes DS. Bone-anchored hearing aid abutment
skin overgrowth reduction with clobetasol. Otolaryngol Head Neck Surg. 2008
Dec;139(6):829-32.
8. Ghossaini SN, Spitzer JB. Local steroid injections in the management of skin growth over
the abutment in Baha patients. Otolaryngol Head Neck Surg. 2009 Oct;141(4):530-2.
9. Wiseman S, Tapia G, Schaaf N, Sullivan M, Loree T. Utilization of a plastic washer to
prevent auricular prosthesis abutment overgrowth report of a case and description of a
technique. International Journal of Oraland Maxillofacial
Implants 2001 Nov-Dec;16(6):880-82
10. Arndt S, Kromeier J, Berlis A, Maier W, Laszig R, Aschendorff, A. Imaging procedures after
bone-anchored hearing aid, implantation. Laryngoscope; 2007, Oct;117(10):1815–8
Products in this manual are protected by the following patents: US 5 735 790, US 5 935
170, EP 0715839, EP 0715838, US 07074222, WO 02/09622, US 7409070, EB 01633284,
US 27009853, WO 04105650 , US 2010249784 (A1) and corresponding patents in
other countries and pending patent applications. All products can be subject to change
without notice. No part of this publication may be replaced, stored in a retrieval system,
or transmitted, in any form by means, electronic, mechanical, photocopying, recording or
otherwise, without the prior written permission of the publisher.
| 29
Notes
30 |
Notes
| 31
As the leading global expert in implantable hearing solutions,
Cochlear is dedicated to bringing the gift of sound to people
all over the world. For thirty years, Cochlear has pioneered this
technology, helping more than a quarter of a million people
reconnect to their families and friends.
Along with the industry’s largest investment in research and
development, we continue to partner with leading international
researchers and hearing professionals, ensuring that we are at
the forefront of hearing science.
For our customers, that means access to our latest technologies
throughout their lives, and the ongoing support they need.
That is why seven out of ten people worldwide who choose a
cochlear implant choose Cochlear as their hearing partner.*
Not everyone with hearing loss is a candidate for a Baha. All surgical procedures include an
element of risk, and it is impossible to guarantee success. For complete information regarding
the risks and benefits of a Baha procedure, please refer to the Instructions for use for the Baha
implant available at www.Cochlear.com/US/BahaIndications
*Cochlear Americas [Data on file] 2012 March.
www.Cochlear.com/US
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Centennial, CO 80111 USA
Telephone: 1 303 790 9010
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Telephone: 1 416 972 5082
Fax: 1 416 972 5083
©Cochlear Limited 2014. All rights reserved. Hear now. And always and other trademarks and registered
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actual companies and products mentioned herein may be the trademarks of their respective owners.
BUN128 ISS2 AUG14
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