An Alternative coupling method for DACS Implant in Patients with mobile footplate

Objective:

DACS is an Implant which uses mechanical power energy to directly stimulate the Cochlea. This Implant has been used in treating individuals with severe mixed hearing loss with Otosclerosis. Because of DACS mechanism of action and its high energy stimulation of the cochlea sudden postoperative (p/o) deafness can sometime be inevitable. Our objective was to present a novel surgical approach whereby the fixation of the DACS actuator will be on the Stapes Head (SH) with the help of angled Plester-prosthesis without the need to perform Stapedectomy.

Methods:

In our retrospective Study we compared the clinical outcome of four patients with severe mixed hearing loss without Otosclerosis and with mobile footplate. The average bone conduction of the Patients was (PTA4 51.2 dB). The DACS Actuator was placed on SH using the so-called angled Plester-prosthesis. The displacement of the actuator was measured intraoperative using Laser Doppler velocimetry (LDV). We measured the outcome in form of Audiological assessment involving aided hearing test, the Freiburg Monosyllabic word recognition Test and registration of any p/o complications.

Results:

The aided Hearing Test post-operative showed an average functional hearing gain of 40 dB (20 – 65 dB) compared to preoperative Air-conduction. The Freiburg Monosyllabic word recognition Test p/o at 65 dB showed an average improvement by 75% (60%-90%). The speech Test was not done by one of the patient because of language Barrier. All the patients have had no complication p/o especially reduction in Bone conduction.

Conclusion:

Our new surgical approach shows that coupling of the DACS-Actuator on the SH using angled Plester-prosthesis is a safe and reliable alternative for patients with no Otosclerosis and mobile footplate.

Publikationsverlauf

Publikationsdatum:
18. April 2018 (online)