Abstract

The passed published literature concerning postoperative results of cystic vestibular schwannoma show no clear results.
In our work we compare the outcome of the function of the facial nerve and the hearing function in cystic vestibular schwannoma versus non-cystic vestibular schwannoma after total resection by a lateral subocciptal approach.

Study

1000 vestibular schwannoma have been operated by Prof. A.S. The sampled data due to clinical notes, audiogram, MRI, surgery reports, discharge letters, histology, follow-up notes and pre-and postoperative facial nerve and hearing test.

We analyzed the data retrospectively. Exclusion criteria have been patients with NF-2, recurrent tumours and recurrence after Gammaknife treatment.
All patients received transesophageal echocardiography to exclude a persistent foramen ovale to be operated in semi-sitting position. Facial nerve test and hearing function have been examined pre-and postoperatively. The used classification is the House-Brackmann and Gardner Robertson classification.
The operated patients received one day postoperatively MRI for resection control or to detect bleedings.

54% were female patients. The average age was higher in the female (46,7yrs) than male (44,2 yrs) group of patients.
In our study patients with radiologically proved cystic tumor parts and confirmed by the surgeon within the surgery have been defined as doubtless cystic.
11% have been cystic vestibular schwannoma.
21, 6% of had a persistent foramen ovale.

No air embolisation, one patient suffered from Pneumocephalon. Here extubation phase prolonged, without respiratory deficits.
The rest of the patients have been extubated in the operation theatre. In all operations neurophysiologic monitoring was applied.

The good function of the facial nerve was classified as sum of H&B I and II compared within cystic (c) versus non-cystic (nc) acoustic neurinoma. The results are: 1-2cm 95% v 97, in 2-3cm 90%-94% in 3-4cm 80%-82%.
The hearing function classified in Gardner & Robertson I and II,(III) show in the postoperative results: 1-2cm 53% v 51%, 2-3cm 36% v 33% and 3-4cm 26% v 28%. Our results show no explicit and significant differences in both groups.