Revision operations after previous stapes surgery for persisting hearing loss.

OBJECTIVES: The aim of the study was to find out the reasons of the recurrent or persisting hearing loss after previous stapes surgery indicated for otosclerosis. BACKGROUND: Revision stapes surgery is a relatively safe surgical method. Recurrent or persisting conductive hearing loss is commonly caused by prosthesis dislocation and adhesions in the oval window. Hearing loss is directly proportional to the number of previous operations. METHOD: Retrospective analysis of 48 patients after revision stapes surgery was done over a period of 4 years (2005-2008). Improvement of the hearing and the reasons of a previous surgery failure were studied. RESULTS: RESULTS were compared to the other studies. The main reason of the failed surgery was adhesions and dislocation of the prosthesis. The mean postoperative air-bone gap was 12.0 dB. A mean postoperative air-bone gap closure within 10 dB occurred in 24 cases (55.8 %), between 11-20 dB occurred in 11 cases (25.6 %) and above 20 dB in 8 cases (18.6 %). The original prosthesis was replaced with a new one in 41 (95.3 %) cases. In 2 cases (4.7 %), previous prostheses were left in place and fixed by a ionomer glass cement to the long process of incus. CONCLUSION: Revision stapes surgery is a relatively safe surgical procedure allowing to improve hearing. The number of previous stapes surgery deteriorates hearing (p < 0.05) (Tab. 4, Ref. 20).

Our experience with surgical treatment of tympanojugular pragangliomas.

Tympanojugular paragangliomas are benign and slow growing lesions of the lateral skull base. Due to their localization and vascularity, they represent a surgical challenge. Treatment modalities include preoperative embolization of feeding vessels and tumour itself, surgical removal and irradiation. In our group, 16 patients with large tympanojugular paragangliomas have been operated in the period of 10 years. Surgical radicality has been achieved in 62.5%, in the rest of patients the tumour remnants were either irradiated with a Leksell gamma knife, or left without treatment in a wait-end-rescan approach. According to the benign character of the tumour, radicality is not always the highest goal, since a radical removal may be compromised by a high postoperative morbidity.

Our surgical experience with large vestibular schwannomas.

Our aim is to remove large vestibular schwannomas (VS) radically with minimal morbidity. Usually, these tumours cannot not be treated by irradiation. In the years 1997-2003, 69 VS were operated in the Department of Otorhinolaryngology, Head and Neck Surgery of the First Medical Faculty in Prague, Czech Republic. Prevailing majority of these tumours were of the 4th grade (House classification), compressing the brainstem. Six patients in the group suffered from neurofibromatosis 2, in five cases the patients were indicated for neurosurgery due to rapid tumour growth after previous irradiation. All tumours were radically removed using a retromastoid osteoplastic and translab approach with an intraoperative nerve monitoring. Good function of the facial nerve was achieved in 90%. The nerve had to be resutured in 4 cases with consequent satisfactory results, cross anatomosis was not performed. Hearing function was preserved in 8% of patients only. In 6 patients with neurofibromatosis 2, the auditory brainstem implant (ABI) was used to preserve hearing. This study demonstrates that a radical removal of large vestibular schwannomas is possible using a minimally invasive surgical technique and peroperative nerve monitoring with a good impact on quality of life. Auditory brainstem implants bring a new chance of hearing after tumour removal in patients with NF2.

[Use of the auditory brainstem neuroprosthesis in the Czech Republic]. / Sluchová kmenová neuroprotéza v Ceské republice.

BACKGROUND: Auditory brainstem implant (ABI) is an electroprosthetic device enabling sound sensations in deaf persons with a bilateral lesion of auditory nerves. Stimulation of auditory nuclei in the floor of the IVth ventricle is realized by an electrode array introduced during surgery in the lateral recess of the IVth ventricle. METHODS AND RESULTS: The main indication group for ABI is represented by patients with neurofibromatosis 2 (NF2) suffering from bilateral vestibular schwannomas. During surgery aimed at tumour removal, auditory nerve function and integrity are almost always destroyed, therefore, an ABI can be introduced as an one stage procedure. Implantees use the device mainly as the aid in lipreading, only very rarely they can comprehend speech without visual cues. Auditory brainstem implant programme has been introduced in the Czech Republic in the year 1999. It was the very first ABI surgery in the Central Europe. Since that time, 5 patients had received the auditory brainstem implant, from which the first four use the device for a longer time. CONCLUSIONS: The last operated patient has not been activated yet. It may be said, that ABI represents a benefit to all our patients, in one implanted this benefit is significant, since he can understand speech without lipreading, the other implantees use the device as an aid in lipreading. In one female patient, the device benefit is severely limited by a motoric handicap after partial cerebellar resection during surgery. Nevertheless, she uses the implant on a daily basis, but contact with her is limited and difficult.