Stage II vestibular schwannoma: predictive factors for postoperative hearing loss and facial palsy.
OBJECTIVE
To assess predictive factors for deafness and facial palsy after vestibular schwannoma surgery on a translabyrinthine or retrolabyrinthine approach, and to compare sequela results to those for gamma knife radiosurgery.


METHODS
A retrospective study included 70 patients operated on for stage II vestibular schwannoma (Koos classification). Postoperative hearing was assessed on pure-tone average and speech discrimination score, and facial palsy on the House and Brackmann classification, preoperatively and at 1 year postoperatively. Various predictive factors were assessed for both. Statistical analysis used the Fischer exact test, with a significance threshold of P<0.05.


RESULTS
Hearing was conserved in 18.9% of patients operated on with a retrolabyrinthine approach, with 8.1% conserving useful hearing. Facial function was conserved in 91.4%. Predictive factors for hearing conservation did not achieve statistical significance, but showed trends for: preoperative pure-tone average threshold≤30dB and speech discrimination score≥ 70%, age less than 55 years, tinnitus, nearly normal auditory brainstem response (ABR) latency, and homogeneous tumor on MRI. Predictive factors for conserved facial function likewise did not achieve statistical significance, but showed trends for: age less than 55 years, deafness of progressive onset, absence of cardiovascular risk factors, nearly normal ABR latency and tumor size<13.5mm on MRI.


CONCLUSIONS
Facial nerve risk is largely the same with surgery or gamma knife radiosurgery. Concerning hearing, gamma knife radiosurgery seems to provide better hearing conservation, but only over the short term.
Service d'otorhinolaryngologie et de chirurgie de la base du crâne, CHU Pellegrin, université Victor-Segalen Bordeaux-2, place Amélie-Raba-Léon, Bordeaux cedex, France.
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S
Milhe de Saint Victor
D
D
Bonnard
V
V
Darrouzet
O
O
Bellec
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V
Franco-Vidal
D000328:Adult; D000368:Aged; D003638:Deafness / Q000453:epidemiology* / Q000209:etiology; D018450:Disease Progression; D005158:Facial Paralysis / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000601:surgery*; D013506:Otologic Surgical Procedures / Q000009:adverse effects / Q000379:methods; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors