Surgery for sporadic vestibular schwannoma. Part III： Facial and auditory nerve function

摘要

OBJECTIVE The aim of this analysis was to assess short-term and long-term outcomes with respect to the preservation offacial and auditory nerve function following surgery for sporadic vestibularsehwannomas. MATERIAL AND METHODS The studyincluded 220 consecutive patients operated on with the retrosigmoid （217） or translabyrinthine （3） approach. The mean extrameataldiameter of the tumor was 30mm. In 217 patients, gross total resection was performed and near-total in 3. Before surgery, the facial nerve（CNVII） weakness was found in 18% of patients and only 20% had serviceable hearing. Intraoperative neurophysiological CNVIImonitoring was routinely used （the last 211 procedures）. Intraoperative monitoring of the cochlear nerve function was used when thepreservation of hearing was attempted （45 procedures ）. RESULTS The rate of CNVII continuity loss during surgery was 11%,however, this decreased to 6% in the second half of the series. Facial nerve function deteriorated, in 88% of the patients shortly aftersurgery. However, it improved in 87% in follow-up. Delayed CNVII palsy was found in 5% of the patients and had a good prognosis in88%. Final satisfactory CNVII function （CNVII-SF, HB grades Ⅰ -Ⅲ ） was achieved in 76% of the patients when excluding theanastomosis results, and 87% when including them. In recent years, the rate of CNVII-SF has risen to 94%. Non-serviceable hearingwas preserved in 49% of the patients, on whom it was attempted. CONCLUSION Considering the size of the tumors and extent of theresections, the preservation of CNVII function is currently very high. A close surveillance of CNVII function evolution following surgery ismandatory, as 2/3 of the patients discharged with deep paresis will need different face reanimation procedures. The preservation of usefulhearing is still problematic, especially in patients with large tumor.