Download Device Failures, Complications, and Reoperation in a Cochlear

P96
Conclusions: The present study is the first to report depiction of
the labyrinthine artery by 7-T MRI. Our preliminary results
indicate occlusion of the labyrinthine artery would be rare in
the pathogenesis of ISSNHL and also demonstrate the labyrinthine artery could be detected by ultra-high field MRI.
Device Failures, Complications, and
Reoperation in a Cochlear Implant
Program
Kaitlin F. Brill (presenter); Peter G.Volsky,
MD; Stephanie M. Antonio, MD
Objectives: 1) Determine the incidence of complications of
cochlear implants (CIs) in our small program; 2) Compare
device failures and medical failures between types of implants;
3) Describe minor and major complications and patterns of CI
device malfunction/failure.
Methods: A chart review of CI patients in an academic medical
center was performed in January 2013. Major complications
included infections, tissue breakdown, or device failure requiring
surgical management, including explantation. Device failure was
determined by the CI surgeon, audiologist, or both. Minor complications included infections managed medically or with office
procedures. Preliminary review included known patients with
complications, device failures, and revision surgery and
non-users.
OTOL/NEUROTOL
Results: Between 1990 and 2012, 232 CI patients received care at
our institution, including 16 implanted elsewhere. Nine patients
(4%) experienced only minor complications, and 28 patients
(12%) experienced a major complication. There were 20 cases of
device failure in 19 patients (8%). Twenty-three explants were
performed in 22 patients (9%), indicated for device malfunction
in 18 cases (17 patients, 7%); infection and extrusion in 2 patients
(1%); headache in 2 patients (1%), and facial nerve stimulation in
1 patient. Magnet extrusion without acute infection occurred in 2
patients (1%), requiring 3 surgeries with the device in vivo. There
were 3 non-users (1%), one of whom was explanted for headache. Three patients (1%) had more than 1 revision surgery.
Conclusions: Our complication rates are similar to those
reported in the literature. Device testing post-explantation is
rarely received by the manufacturer; device failure appears to
be a clinical diagnosis.
Direct-Drive Acoustic Amplification
Using a Tympanostomy Tube
Yuk Y. A.Yau, MD (presenter); Hossein
Mahboubi, MD, MPH; Melinda J. D. Malley;
Christian P. Conderman, MD; Peyton
Paulick; Mark Bachman, MD; Hamid R.
Djalilian, MD
Objectives: Determine whether a tympanostomy tube with a
ferromagnetic cap can be actuated to deliver sound to the
cochlea.
Otolaryngology–Head and Neck Surgery 149(2S)
Methods: A ferromagnetic mixture of nickel powder and epoxy
was glued to the outer flange of an Armstrong V Grommet
tympanostomy tube. The tube was then placed into the pars
tensa portion of a cadaveric temporal bone. The Direct-Drive
Hearing Device (DHD), a completely-in-the-canal hearing aid
prototype developed in our lab, was coupled to the nickelepoxy flange and fixed inside the ear canal. The displacements
of the posterior crus of the stapes were then measured using a
Laser Doppler Vibrometer. The range of displacements
induced by the device was compared to those of natural sound.
Results: A 200 mV input to the device produced a range of displacements equivalent to those of sound at 70 dB sound pressure
level (SPL; mean 0.44 nm; range 0.01-2.80). A 400 mV input
produced a range of displacements equivalent to those of sound at
80 dB SPL (mean 1.34 nm; range 0.02-8.87).
Conclusions: DHD, a small completely-in-the-canal hearing aid
prototype, is capable of actuating the TM through a ferromagnetic tympanostomy tube and producing range of displacements equivalent to moderate to severe levels of hearing loss.
Direct Monitoring of ABIs Evoked
Potentials on the Cochlear Nuclei
and Neighboring Cranial Nerves
Vittorio Colletti, MD (presenter); Marco
Mandala, MD; Liliana Colletti
Objectives: The potentials evoked with Auditory Brainstem
Implant (ABI) on the cochlear nuclei (CN) and on the neighboring cranial nerves are traditionally evaluated with Electrical
Auditory Brainstem Response (E-ABR) and electromyography (EMG). To obtain a more precise evaluation of ABI insertion, a near field monitoring procedure that records electrical
compound action potentials (E-CNAPs) directly from the CN
and from each individual cranial nerve is presented.
Methods: Between January 1997 and September 2012, 184
patients were fitted with ABI by the Verona team, 155 in
Verona and 29 (13 children and 16 adults) elsewhere. The
E-CNAPs utilizes a cotton-wick recording electrode locate on
different anatomical structures: CN, root entry zone of the cranial nerve VII, IX, X, XI, and V. All subjects were monitored
with E-ABR and 18 of them underwent also E-CNAPs
recording.
Results: Systematic significant lower E-CNAPs thresholds
were observed compared with E-ABRs. The evaluation of the
threshold for inducing extra-auditory effects with E-CNAPs
on the neighboring cranial nerves allowed a more precise
selection of the active electrodes to be used in the fitting. For
the same electrical intensity value utilized for obtaining ABI
responses, E-ABRs and E-CNAPs showed potentials of neighboring cranial nerves respectively on 4 and 10 electrodes.
Conclusions: The adoption of near-field recordings offered the
chance to improve the correct placement of the array and postoperative outcomes. E-CNAPs recorded on neighboring cranial nerves can replace EMG giving an on line demonstration