[Trans-petrous surgery in acoustic neuroma. Value of preoperative audiovestibular and facial investigation in the risk evaluation of facial nerve function].

Between 1987 and february 1994, 162 consecutive patients with acoustic neuroma were operated on by an otoneurosurgery team, using transpetrous approaches (89% translabyrinthine, 8% middle fossa and 3% retrosigmoid). The relationship between the clinical, audiometric and vestibulographic characteristics and the post-operative facial nerve function were evaluated. In acoustic neuromas with cerebello-pontine component inferior to 3 cm without central neurologic signs (ic: central controlateral auditory and/or ipsilateral vestibular pathway alteration), good post-operative facial nerve function was achieved in 80% of cases. In acoustic neuromas superior to 3 cm with alteration of the central vestibular and auditory pathways, a good result was obtained in only 30% of cases which correlated negatively with preoperative facial dysfunction. These results underline the value of preoperative facial and audiovestibular examinations in predicting the postoperative facial nerve function following surgery for acoustic neuroma.