The First Active Transcutaneous Bone Conduction
Implant in Romania-Case Report of Permanent
Conductive Hearing Loss Due to Cleft Palate|crimson publishers.com
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The First Active Transcutaneous Bone Conduction
Implant in Romania-Case Report of Permanent
Conductive Hearing Loss Due to Cleft Palate
Madalina Georgescu1,2*, Baumgartner WD3, Anca Modan2 and Daniela Vrinceanu4
1 Institute of Phono Audiology and ENT Functional Surgery, Romania
2 Carol Davila University of Medicine and Pharmacy, Romania
3 Ear, Nose and Throat Department, University Clinic Vienna, Austria
4 ENT Department, Emergency University Hospital, Romania
*Corresponding author:Madalina Georgescu, ENT Consultant, Audiologist, Institute of Phono-Audiology and ENT Functional Surgery, University of
Medicine and Pharmacy, Bucharest, Romania
Submission:
September 16, 2018;Published: October 03, 2018
Since the introduction of bone conduction hearing implants in 1977, quality of life of the implantees have improved substantially. The first available
option were bone-anchored hearing devices, which improved sound quality, but had the major disadvantage of post-operative skin and wound infections.
Therefore, new technologies seeking intact skin solution have emerged lately. The BONEBRIDGE system (MED-EL, Medical Electronics, Innsbruck,
Austria) incorporates the first active bone conduction device, which especially aims to resolve abutment issues and still offers excellent audiological
benefit. The successful implantation of this system in the first Romanian patient suffering from congenital lip and hard palate cleft with recurrent
suppurative otitis media is presented. The authors report their experience with implantation, in terms of indications, selection assessment as well as
functional results with a critical review of advantages and disadvantages in comparison with classical methods.
Hearing implants employing bone conduction (BC) stimulation
have a long tradition (since 1977) and have become a standard care
for patients suffering with conductive- or mixed hearing loss who
cannot benefit from the conventional hearing aids. Since their development
40 years ago, there have been many improvements in
both, the surgical approach, the technology itself and the way of
fixation towards intact skin solutions of bone conduction hearing
systems.
Existing percutaneous bone conduction implants (BCI) provide
good audiological gain but are associated with a high rate of complications.
67 studies with a total of 6168 subjects were found reporting
on safety outcomes of the percutaneous BAHA Connect bone
conduction system since 2012 (date of first BONEBRIDGE implantation
was used for literature search (Figure 1)). Despite good audiological
rehabilitation results, the abutments of the BAHA percutaneous
systems are at risk of complications (75.3%), especially skin
related issues like infection and skin overgrowth as high as 46,7%
were found, as discussed elsewhere [1-67]. The Ponto system from
Oticon Medicals slightly differs from the Baha Connect system, as it
facilitates a longer abutment that does not require removal of the
muscles and subcutaneous tissue. Both have similar audiological
results, as discussed by Syms [68]. Safety issues in the Ponto System
were reported in twelve studies in a total of 314 subjects, as discussed
elsewhere [20,30,3,43,51,59,61-73]. Also, the Ponto system
due to its percutaneous nature reports a high incidence rate of complications
with 44.6% out of which the majority was related to skin
complications (37.3%). Thus, patients with the percutaneous kind
of device need to have a commitment to life with the care of the skin
where the device was placed, as discussed by Iseri [74].
In 2011 transcutaneous bone conduction implants, have become
available: The Alpha Hearing System and the BAHA Attract,
both conduct the sound through a titanium plate which is fixed
under the skin through surgery, differing only in size and shape
from each other. Despite the aesthetic and functional benefits, the
devices cause skin friction generated by the powerful magnet, necessary
to transfer the sound vibration to the skull efficiently, causing
discomfort, vascularization difficulties and local skin irritation
may lead to reduced wearing time [75]. Seventeen publications
evaluating data of 210 subjects reported a 40.6% rate of safety outcomes
for the Sophono Alpha 1 and Alpha 2, as discussed elsewhere
[21,61,65,75-88]. The Baha Attract system reported 56.9% safety
outcomes in nine studies with a total of 153 subjects, as discussed
elsewhere [47,75,83,89-94].
The BONEBRIDGE works differently from the Sophono Alpha
Hearing System and BAHA Attract in that the Implant generates vibrational
stimulation that is directly applied to the bone (“direct
drive bone conduction stimulation”). Active transcutaneous bone
conduction implants have the advantage over passive implants in
that the vibrating part of the device is located under the skin, directly
stimulating the bone through the screws, as discussed by Sprinzl
[95]. Several studies have shown that BONEBRIDGE implantation
offers an improvement of hearing thresholds and speech recognition,
as discussed by Sprinzl [95] and fourteen studies showed a
7.4% rate of complications, as discussed elsewhere [49,88,96-107].
All above mentioned devices and indications were carefully
considered before the here presented patient decided on the BONEBRIDGE
device. In this report, we present the first BONEBRIDGE
implantation performed in Bucharest, Romania. To the best of our
knowledge, there have been no previous reports of this kind of implantation.
A 25-years-old Caucasian male reported permanent hearing
loss in the left ear. The patient’s medical history included congenital
lip and hard palate cleft with recurrent suppurative otitis media
in the left ear. He underwent corrective procedures at the age of 3
for cleft closure and two surgeries in the left ear for otitis media,
leaving him with a permanent conductive hearing loss.
Figure 1:Search strategy used for searching PubMed databases (left) and flowchart of study selection (right).
Figure 2:Pure tone audiogram: Right ear – pre-op unaided mild conductive hearing loss (red); Left ear – pre-op moderate conductive
hearing loss, post-op BB-aided condition; (BB-BONEBRIDGE); [ - BC masked, right ear;] - BC masked, left ear.
Examinations, otomicroscopy and audiological investigations
revealed a mastoidian cavity widely communicating with the external
auditory meatus in the left ear. The patient also presented
a nasal septum deviation, with severe obstruction of the left nasal
pathway. Pure tone audiometry revealed moderate conductive
hearing loss and a small perforation in the right eardrum with mild
conductive hearing loss (Figure 2).
Post-operative CT-scans in the left ear revealed 4mm bone dehiscence
of the lateral sinus and a dense deposit in the hypo-tympanum
which was in contact with the facial aqueduct (Figure 3a
& 3b). The lamellar deposit in the mezzo-tympanum, attached to
the promontory showed fibrous obstruction of the oval and round
windows. No density anomalies in the compact bone of the inner
ear were found, presenting normal permeability of the cochlea and
semi-circular canals, without dehiscence. The absence of the ossicular
chain led to moderate permanent conductive hearing loss.
Figure 3:High-resolution computed tomography temporal bone (a) axial section and (b) coronal section
(a) Right ear (axial view)
chronic otomastoiditis
sequelae (*) thick, retracted
eardrum with perforation in
the pars tensa); (#) punctual
erosion of the long incus arm
(b) Left ear (coronal view): post-mastoidectomy status,
(§) absence of the eardrum; ($) dense lamellae in hypoand
mezzo-tympanum, attached to the otic capsule,
obstructing completely the oval (OW) and round
windows (RW); complete absence of the ossicular chain
(OC)
Luckily for the patient, despite the congenital cleft and nasal
septum deviation, otitis media in the right ear was not so severe
and the sequelae minor–with small eardrum perforation and mild
conductive hearing loss. For this reason, language development of
the patient was not affected, and he therefore only opted in adult
age for a solution for his left ear hearing loss. No conventional
hearing aid was recommended due to the mastoid cavity communicating
widely with the external acoustic meatus. Recommended
treatment included nasal surgery and a bone conduction hearing
implant in the left ear. The candidate objected to the alternatives of
a conventional percutaneous and passive transcutaneous BCI because
of the stigmatization by the visible screw and the relatively
high complication rates. Secondary reason to opt for BONEBRIDGE
implantation was to avoid the need for life-long screw care [1-107].
Three months after nasal surgery, improved Eustachian tube
function was measured via impedancemetry and the patient was
scheduled for BONEBRIDGE implantation. Surgery was performed
at the Phono-Audiology and Functional ENT Surgery Institute, Bucharest,
Romania, under general anaesthesia. A presigmoid transmastoid
approach was used to place the internal component in the
drilled cavity, after removal of the chronic inflammatory mastoid
mucosa. Due to a relative high position of the sigmoid sinus, elevators
were used to ensure a proper position of the bone conduction
implant (BCI). This was fixated with two Titanium screws in the
normal density mastoid bone for best vibration transmission. The
internal coil of the BONEBRIDGE was placed in a subperiostal pocket.
Two layers closure of the muscular and skin layers was used,
with different directions of the incisions.
No intra- nor postoperative complications occurred.
At four weeks after surgery, the Samba audio processor was
switched on, and hearing evaluation was performed by pure tone
and speech audiometry, immediately after activation and one week
later. Results were similar at the two sessions: the PTA4 resulted
in an improvement of 58.8dB (pre-op unaided 68.8; post-op best
aided 10dB), with complete closure of the air-bone gap (ABG) on
PTA and 100%-word recognition score measured at 65dB SPL using
a Romanian language multisyllables-word test in quiet (post-op
best-aided condition) (Figure 2 aided condition and Figure 4b).
Recent literature suggests that implantation with the only active
transcutaneous bone conduction hearing implant, is safe and
effective for treating conductive and mixed hearing loss, as discussed
by Sprinzl [95]. The surgical technique for insertion is easier
than that of traditional surgeries, and there is no risk of inner
ear damage. Due to the intact skin solution, with the internal part
of the device being fully implanted without an abutment, the risk
of skin infections is minimal. Furthermore, the active vibration
without skin attenuation ensures more and better bone conduction
gains than that of passive bone conduction devices [95]. The
implantation of the BONEBRIDGE in this complex case due to its
specific pathological condition of lip and hard palate cleft, inducing
long-term dysfunction of the Eustachian tube and thus leading to
recurrent suppurative otitis media episodes, presents good longterm
solution with very satisfactory outcome. Postoperative audiological
evaluation showed very good pure tone thresholds, with
complete closure of the ABG and also excellent speech-recognition
score at 65dB SPL testing.
Figure 4:Word recognition score at 65dB after BONEBRIDGE implantation: (a) pre-op unaided (left and right ear (red) left ear (blue) (b)
post-operative aided condition (left, operated ear); Vppf - vocal pianissimo (very soft loudness); Vmf - vocal mezzoforte (half-loud); Vff -
vocal fortissimo (very loud).
For the treatment of conductive hearing loss with complex
underlying pathologies such as lip and hard palate cleft inducing
chronic otitis media, BONEBRIDGE implantation is a promising
option, offering a relatively easy surgical technique, very promising
audiological outcomes, and high patient satisfaction.
Professor, Chief Doctor, Director of Department of Pediatric Surgery, Associate Director of Department of Surgery, Doctoral Supervisor Tongji hospital, Tongji medical college, Huazhong University of Science and Technology
Senior Research Engineer and Professor, Center for Refining and Petrochemicals, Research Institute, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, Saudi Arabia
Interim Dean, College of Education and Health Sciences, Director of Biomechanics Laboratory, Sport Science Innovation Program, Bridgewater State University