Objective: Review of postoperative morbidity and facial nerve outcomes of cystic vestibular schwannoma (CVS) patients compared with solid vestibular schwannoma (SVS) patients and a proposal for a new CVS classification system. Study Design: Retrospective review. Setting: Tertiary care facility. Patients: Ninety-six patients with surgically treated CVS (1998-2008). Outcomes were assessed in a subpopulation of 57 patients with greater than or equal to 1-year follow-up compared with 57 SVS patients. Intervention: Fifty-six CVS patients underwent the enlarged translabyrinthine approach with transapical extension (Type I), and 1 patient underwent a transcochlear/transzygomatic approach. Main Outcome Measure: Preoperative and postoperative (at least 1 yr) House-Brackmann facial nerve (HBFN) grade evaluation. Results: Favorable HBFN grades (I-III) were observed in 46 (81%) CVS patients, and unfavorable HBFN grades (IV-VI) were seen in 11 (19%) CVS patients. Comparison of tumor size and 1-year HBFN grades showed significant, moderate to strong, Pearson correlation (0.38). Comparison of long-term facial nerve outcomes with a sample of 57 matched SVS patients showed no significant difference (p = 0.74). When the tumor was adherent to the facial nerve and a dissection plane could not be developed between the cyst wall and the nerve, only subtotal resection could offer the CVS patients a normal facial nerve outcome. Conclusion: In most CVS cases, complete resection should be foreseen. Central and thick-walled tumors can be removed in almost all cases. However, when peripheral thin-walled, adherent, cystic tumors are confronted and the cysts are medially or anteriorly located, we recommend subtotal resection, leaving portions of the cyst walls on neurovascular structures and on the facial nerve. This surgical strategy allows us to improve facial nerve outcomes and to reduce complications.

Objective: The objective of this study was to examine the usefulness of intraoperative cochlear nerve monitoring (ICNM) in the preservation of normal and social hearing in vestibular schwannoma (VS) removal. Methods: A retrospective chart review was conducted. Of 1315 patients operated for VS between June 1988 and December 2005, 150 patients were subjected to hearing preservation surgery. Among these, 99 patients with preoperative normal and social hearing (class A and B in the modified Sanna classification) and with a small tumor <1.5 cm in size were included in the analysis. The difference in hearing preservation rates between patients operated with and without ICNM was statistically examined using Fisher’s exact test. An initial analysis was conducted for the total group. Patients were then divided into two subgroups according to the surgical approach (middle cranial fossa and retrosigmoid-retrolabyrinthine). The effectiveness of ICNM in each subgroup was analyzed. Results: The hearing preservation rate was 26.7% in cases operated with ICNM and 20.8% in cases without ICNM. The difference did not reach statistical significance (p = 0.79). In subgroup analyses, the ICNM did not prove to contribute to the significantly higher hearing preservation rate. Conclusions: ICNM did not increase the ratio of patients with postoperative normal and social hearing in VS surgery.

The ideal management of bilateral vestibular schwannomas (VSs) involves complete tumor resection with preservation of hearing in at least one ear. While auditory brainstem implants (ABIs) have represented a significant advance in the management of neurofibromatosis type 2 (NF-2) patients, hearing rehabilitation is far from ideal. More recently, cochlear implantation has been used in selected cases of NF-2, following tumor removal, where the patient is left with bilateral profound hearing loss but with anatomical continuity of the cochlear nerve. In selected cases, cochlear implant (CI) has given superior results to ABI. The Gruppo Otologico experience in managing NF-2 patients consists of 29 patients treated between December 1996 and December 2007 out of a total of 1723 VSs. Thirty-nine tumors have been removed, with 10 patients having had bilateral tumor removed. Ten ABIs have been implanted and 5 CIs placed. We present a case that illustrates some of the difficulties encountered in the management of NF-2 VS and provides a basis for discussion of a technique to assist intraoperative decision-making to achieve optimal hearing rehabilitation. In the setting of a negative fast auditory brainstem response (ABR), but preserved cochlear nerve action potential (CNAP), the option of a CI can be considered. However, where the fast ABR and the morphology and amplitude of the CNAP are significantly degraded at the brainstem, the placement of an ABI should be strongly considered at the time of tumor removal. This technique must be further evaluated, but it represents an adjunct in this difficult area for the neurotologist. To this end we propose that a multicenter trial be undertaken to further elucidate the role of intraoperative monitoring to determine the functional preservation of the cochlear nerve.

Objective: We present our series of surgically treated cystic vestibular schwannomas (CVSs), review postoperative morbidity and facial nerve outcomes, and propose a classification system for CVSs based on cyst location, which might be useful for guiding surgeons in the management of these tumors and for optimizing surgical results. Study Design: Retrospective chart review. Setting: Tertiary care facility. Patients: Patients were included in this study if they had a CVS and were surgically treated at our institution between January 1998 and May 2008 (96 patients). Facial nerve outcomes were assessed in a subpopulation of these patients (57) who had ≥1-year follow-up. Intervention: Fifty-six of the 57 patients underwent the enlarged translabyrinthine approach with transapical extension (type I), and 1 patient underwent a transcochlear/transzygomatic approach. Main Outcome Measure: Facial nerve function was assessed using the House-Brackmann facial nerve grading scale twice: (1) during preoperative evaluation and (2) at the most recent long-term follow-up appointment. Results: Of the 1416 patients who underwent vestibular schwannoma resection at our institution from January 1998 to May 2008, 96 (6.8%) underwent resection of some form of CVS. Among the 57 CVS patients with ≥1-year follow-up, 29 were men and 28 were women. The average age was 51 years (median, 50 years; range, 27–80 years), and the average length of follow-up was 23.8 months (median, 16 months; range, 12–66 months). Favorable House-Brackmann facial nerve grades (I–III) were observed in 46 (81%) CVS patients, and unfavorable grades (IV–VI) were seen in 11 (19%) patients. A comparison of tumor size and 1-year facial nerve grades showed a significant, moderate to strong Pearson's correlation (0.38). Although 2 patients who underwent subtotal resection had grade V facial nerve outcomes—because the tumor was adherent to the facial nerve and a dissection plane could not be developed between the cyst wall and the nerve—only subtotal resection could offer the CVS patients a normal facial nerve outcome. Conclusions: Complete resection should be anticipated in the majority of CVS cases. However, when thin-walled, adherent cystic tumors are confronted and the surgeon is unable to develop a sufficient dissection plane, we advocate subtotal resection, leaving cyst wall remnants anteriorly versus the facial nerve and/or medially versus the brainstem, and versus the posterior fossa vasculature to improve facial nerve results and reduce vascular complications.

Objective: To report on the results of intracanalicular vestibular schwannomas (ICVS) that were managed by wait and scan and to analyze the possible predictors of tumor growth and hearing deterioration throughout the observation period. Study Design: A retrospective case series. Setting: Quaternary referral center for skull base pathologies. Patients: Patients with sporadic ICVS managed by wait and scan. Intervention: Serial resonance imaging (MRI) with size measurement and serial audiological evaluation. Main Outcome Measure: Tumor growth defined as 2 mm increase of maximal tumor diameter, further treatment, and hearing preservation either maintain initial modified Sanna hearing class, or maintain initial serviceable hearing (class A/B). Results: 339 patients were enrolled. The mean follow-up was 36.5±31.7 months with a median of 24 months. Tumor growth occurred in 141 patients (40.6%) either as slow growth (SG) in 26.3% of cases or fast growth (FG) in 15.3% of cases. Intervention was performed in only 64 cases (18.8%). Out of 271 patients who underwent hearing analysis, 86 patients (33.5%) showed hearing deterioration to a lower hearing class of the modified Sanna classification. Tumor growth and older age were predictors of hearing deterioration. Of the 125 cases with initial serviceable hearing (Class A/B), 91 cases (72.8%) maintained serviceable hearing at last follow-up. Tumor growth and a worse initial pure tone average (PTA) were predictors of hearing deterioration. Conclusions: Wait and scan management of ICVS is a viable option and only 18.8% of patients needed further treatment. Hearing tends to deteriorate over time.