Current management of acoustic neuromas: review of surgical approaches andoutcomes

The management options for patients with acoustic neuromas is discussed wit h a review of 164 patients assessed and treated between 1944 and 1998. Twen ty-one patients have neurofibromatosis type II. In 33 cases initial observa tion was undertaken with repealed imaging. Surgical removal of 122 tumours was performed in 121 patients. Eleven of these patients have NF2, of whom t hree underwent Auditory Brainstem Implantation. Hearing preservation tumour removal was attempted in 37 and was successful in 20 (54%). The middle cra nial fossa approach was used in ten cases with 100% successful hearing pres ervation. The retrosigmoid approach was used in 27 cases with 36% successfu l hearing preservation. Non-hearing preservation tumour removal was perform ed in 85 cases where hearing was poor or the tumour measured more than 2 cm within the cerebellopontine angle. The translabyrinthine approach was used in 80 of these patients. Postoperative facial nerve outcome was dependent on tumour size. All 38 patients with tumours less than or equal to1.5 cm ha ve normal (Grade 1) facial function. For all sized tumours, 90% of patients have good facial function (82% Grade 1, 8% Grade 2), 7% of patients have m oderate function (6% Grade 3 and 1% Grade 4) and only 3% of patients have p oor function (2% Grade 5, 1% Grade 6), Lasting complications were minimal w ith no operative mortality and eight patients (6.4%) suffering CSF fistulae . Seven patients in this series have had stereotactic radiation with variab le outcome. The radiobiology of both single dose and fractionated stereotac tic radiation is described and the current role of stereotactic radiation i n the management of acoustic neuromas is discussed. Surgical tumour removal by an experienced multi-disciplinary team remains the primary treatment mo dality for acoustic neuromas. The middle cranial fossa approach is recommen ded for management of intracanalicular tumours. The translabyrinthine appro ach facilitates facial nerve preservation, particularly in patients with la rge tumours. (C) 2000 Harcourt Publishers Ltd.