Resection of Intracochlear Schwannomas With Immediate Cochlear Implantation

Abstract

Introduction: Intralabyrinthine schwannomas, including the intracochlear variety, are rare benign tumors. They can cause a number of symptoms and have the potential to grow to involve other critical structures of the inner ear and skull base. While surgical resection is feasible, there is typically permanent hearing dysfunction as a result of resection and subsequent fibrosis. Here, we present 2 cases of intracochlear schwannomas (ICS) that were successfully resected with simultaneous cochlear implant placement. Methods: Patient 1 presented with an intravestibulocochlear schwannoma. This patient underwent a translabyrinthine approach. Endoscopic assistance was used to dissect the tumor from the vestibule and basal turn of the cochlea, through an enlarged round window approach. A cochlear implant was placed via a round window cochleostomy. Patient 2 presented with an intracochlear schwannoma involving the basal and middle turns of the cochlea. The patient underwent a trans-otic approach for resection. A large portion of the cochlear promontory required unroofing for complete exposure of the tumor. A cochlear implant was then placed via a round window cochleostomy. Results: Upon cochlear implant activation, Patient 1’s sound field thresholds using the implant were near the normal range of hearing, ranging from 25 to 50 dB HL from 250 to 6000 Hz. Patient 2’s 6-month post-operative cochlear implant sound field testing ranged from 20 to 30 dB HL from 250 to 6000 Hz and speech recognition testing revealed 59% on AZ Bio sentences compared to 0% pre-operatively. Conclusion: Simultaneous cochlear implantation after resection of intracochlear schwannomas is safe and successful in restoring hearing. Attention to adequate exposure and endoscopic assistance, when required, allow for gross total resection while minimizing trauma to cochlear structures. In such cases, immediate cochlear implantation allows for hearing rehabilitation before likely cochlear fibrosis can occur.

Audiological Outcome of the Simultaneous Tumor Resection and Cochlear Implantation in Two Cases of Sporadic and Two Cases of Neurofibromatosis Type 2-Associated Intracochlear Schwannoma

“…Intralabyrinthine schwannoma (ILS) is a specific subtype of vestibular schwannoma that originates exclusively in the membranous labyrinth from peripheral branches of the cochlear or vestibular nerves [ 4 ]. The enhanced capabilities of modern imaging modalities have increased the diagnosis rate of ILS, whereas, previously, the incidence was 0.81 per 100,000 persons–year [ 5 ].…”

Simultaneous Cochlear Implantation and Salvage Translabyrinthine Resection of Vestibular Schwannoma after Radiotherapy

“…Available management options for patients with single-sided deafness (SSD) have recently expanded to include cochlear implantation (CI) (1)(2)(3)(4). Simultaneous CI with translabyrinthine microsurgical resection of vestibular schwannoma (VS) has also emerged as an innovative option for hearing rehabilitation (5)(6)(7)(8). Nonserviceable hearing in VS cases may be due to several distinct etiologies including previous stereotactic radiosurgery (SRS).…”