Microsurgical Treatment of Intracanalicular Vestibular Schwannomas

Abstract

Early treatment of intracanalicular vestibular schwannomas (IVSs) may be advisable because their spontaneous course will show hearing loss in most cases. Advanced microsurgical techniques and continuous intraoperative monitoring of cranial nerves may allow hearing preservation (HP) without facial nerve damage. However, there are still controversies about the definition of HP and the best surgical approach that should be used. In this study, we reviewed the main data from the recent literature on IVS surgery and compared hearing, facial function and complication rates after the retrosigmoid and middle fossa approaches, respectively. The results showed that the average HP rate is approximately 45% after IVS surgery whatever the surgical route. HP varied widely depending on the audiometric criteria that were used for definition of serviceable hearing. There was a trend to show that middle fossa approach offered a better quality of postoperative hearing (not statistically significant), whereas the retrosigmoid approach offered a better facial nerve preservation and fewer complications (not statistically significant). We believe that the timing of treatment in the course of the disease and selection between radiosurgical versus microsurgical procedure are key issues in the management of IVS. Once open surgery has been decided, selection of the approach mainly depends on individual anatomical considerations and experience of the surgeon.

Risk Factors for Postoperative Recurrence of Acoustic Neuroma

“…Further comparison of surgical treatment effectiveness showed that the group who had conservative treatment after the first surgery preserved more auditory nerves than the nonsurgical treatment group, whereas no significant differences in facial and posterior cranial nerve retention were observed in this study. Similarly, a meta-analysis performed by Noudel et al (22) showed that the suboccipital sigmoid sinus approach is superior to the facial and auditory neuroprotection. Since the suboccipital retrosigmoid approach can not directly expose the internal auditory canal, the posterior wall of the internal auditory canal should be removed to expose the base of the internal auditory canal to the tumors invading the internal auditory canal, which can easily damage the posterior semicircular canal and facial nerve.…”