Acoustic neuromas: results of current surgical management

In this article, we review the surgical outcomes of 179 patients with acoustic neuromas.

Most of the tumors (84%) were operated on using a retrosigmoid, transmeatal approach. A transpetrosal, retrosigmoid approach was used in 10% of the patients, most of whom had large tumors. The translabyrinthine (4%) and transmastoid, transpetrosal, partial labyrinthectomy approaches (2%) were used selectively. The operative approaches are discussed. Tumors were categorized according to their cerebellopontine angle dimensions as small (< 2 cm), medium (2.0-3.9 cm), and large (> or = 4 cm).

House-Brackmann evaluation of postoperative facial nerve function revealed excellent results (Grade I or II) in 96% of small tumors, 74% of medium tumors, and 38% of large tumors. A fair postoperative function (Grade III or IV) was achieved in 4% of small tumors, 26% of medium tumors, and 58% of large tumors. Functional hearing preservation, defined as Gardner-Robertson Class I or II, was achieved in 48% of small tumors and 25% of medium tumors. Hearing was not preserved in any of the three patients with large tumors in whom hearing preservation was attempted. Treatment complications consisted mainly of cerebrospinal fluid leakage (15% of the patients). The majority of the patients who experienced cerebrospinal fluid leakage were treated successfully with lumbar spinal drainage; only four patients (2% of the total group) required subsequent surgery for correction of cerebrospinal fluid leakage. There were two deaths (1%) in this series. One death occurred as the result of myocardial infarction and the other as the result of severe obstructive lung disease. One patient sustained disability because of cerebellar and brain stem injury. Complete tumor resection was accomplished in 99% of the patients, and there was no evidence of recurrence in this group. Only 1 of the 179 patients underwent incomplete tumor resection; he required subsequent surgery for symptomatic tumor regrowth. Our patient follow-up had a mean duration of 70 months and a median of 65 months (range, 3-171 mo).

Our results are similar to those of other large microsurgical series of acoustic neuromas. Unless a patient has major medical problems, microsurgery by an experienced team of surgeons is preferred over radiosurgery.