Background: In most cases, intra-labyrinthine schwannoma (ILS) occurs in patients with unilateral hearing deterioration or neurofibromatosis type II (NF II). The pattern of localization of these tumors is various but affects mostly the cochlea. Extirpation of the ILS, if hidden by the cochlea modiolus, is difficult under the aspect of complete removal. Therefore, a tissue removal device (TRD) was designed and tested in temporal bones. The principle of handling the new device is a pushing and pipe cleaner handling inside the cochlea. This present study aimed to describe the first in vivo experience with the newly developed TRD for removing cochlear intra-labyrinthine schwannoma. Methods: In three patients, the TRD was used for the tumor removal of ILS. In two patients with a cochlear schwannoma in combination with a cochlea implantation and one patient suffering from NF II, a cochlear schwannoma was removed with the TRD. The access was performed with a posterior tympanotomy, an enlarged round window approach, and an additional second-turn access. The device was inserted and extracted gradually from the second turn access until the rings were visible in the second turn access. By pushing and pipe cleaner handling, the tumors were removed. An MRI control was performed on the day postoperatively with a T1 GAD sequence. Results: Tumor removal with the TRD was performed in a 15-minute procedure. MRI control confirmed a complete removal on the postoperative day in both cases. Conclusion: In vivo handling of the device confirmed a straightforward handling for tumor removal. MRI scanning showed a complete removal of the tumor by the TRD.

Introduction: Based on clinical practice guidelines, the application of corticosteroids as first-line therapy is common. Although SSHL's etiology is primarily idiopathic, hearing loss can result from perilymphatic fistula (PLF). Recent findings show evidence of a spe-cific rate of PLF based on a cochlin- tomoprotein (CTP) detection test. Based on this rate of PLF treatment, the concepts of SSNHL need to be re-evaluated. The present study aimed to evaluate CTP in SSNHL patients and compare pre-surgical and post-surgical pure tone hearing thresholds after round and oval window sealing as first-line treatment. Material and Methods: 30 patients with unilateral SSNHL with pure tone average (PTA) (4 Freq.) of 60 dB or more were enrolled in a prospective study. All patients underwent tympanoscopy for middle ear exploration as first-line treatment. After intraoperative obser-vation of possible PLF all patients obtained middle ear lavage to gain CTP samples for following ELISA-based CTP detection tests. All patients received round window and oval window sealing with fascia. PTA hearing thresholds were analyzed post-surgical 3 weeks after treatment based on 4-frequency bone conduction (BC). Results: Average preoperative pure-tone BC threshold was 97,7 dB compared with 69 dB postoperative BC threshold. Mean BC improved by 20,3 dB after middle ear explora-tion and window sealing. 56% (17 of 30) of patients recovered at least 10 dB. Middle ear cochlin-tomoprotein detection rate was in 70% positive. Conclusion: The combination of early tympanoscopy and inner ear-specific cochlin-tomoprotein as a detection tool for suspected perilymphatic fistula shows evidence of PLF as a key causative in SSNHL.