Simultaneous Translabyrinthine Removal of Acoustic Neuroma and Cochlear Implantation: A Case Report

Planned acoustic neuroma (AN) removal with preservation of the cochlear nerve (CN) and simultaneous or subsequent cochlear implantation (CI) has been suggested for hearing restoration.

Purpose: To report the outcome of CI in an elderly woman with profound SNHL due to long-standing bilateral Meniere's disease and an AN on the right side.

Material and Methods: Among 84 patients who underwent AN surgery at the ORL Department of the University of Brescia (1999 to 2006), one 70-year-old woman was affected by bilateral Meniere's disease with profound hearing loss. At preoperative MR imaging, an AN was observed in the right IAC, with limited extension into the CPA. The patient underwent translabyrinthine removal of the AN with sparing of the CN and concurrent ipsilateral CI (Nucleus Contour Advance device, Cochlear Ltd., Australia). Intraoperative recording of the neural response telemetry (NRT) assessed a sufficient nerve response.

Results: Complete removal of the AN was achieved without complications. All the electrodes had regular impedance telemetry values, and the NRT morphology was satisfactory. The patient's Freedom^® speech processor was activated and fitted 1 month after implantation using the ACE strategy at 1.200-Hz rate and 8 maxima. Speech perception and psychoacoustic and electrophysiologic tests were carried out at 1, 3, 6, and 12 months postoperatively. Narrow band audiometric thresholds via CI reached 30 dB on all frequencies. No acoustic residual hearing was detected on the operated side. The patient still used her contralateral hearing aid in daily activities. At 3 months after surgery the disyllabic words and sentences recognition and the speech comprehension reached 100% without lip reading. She only complained of a persistent mild dizziness, and underwent vestibular rehabilitation for 2 months, finally recovering. Postoperative NRT showed an improvement of the responses, and an E-ABR documented normal neural activity.

Conclusions: The possibility of CI after AN removal depends on survival of the CN and patency of the cochlea. Our experience confirms that CI achieves the best results if inserted at the time of tumor removal. An intraoperative promontory stimulation or an NRT after resection of the AN may help in determining the presence of neural elements. A translabyrinthine approach does not preclude a successful CI, provided the cochlear nerve is anatomically intact at the end of the procedure.