Primary Treatment of Small to Medium (<3 cm) Sporadic Vestibular Schwannomas: A Systematic Review and Meta-Analysis on Hearing Preservation and Tumor Control Rates for Microsurgery versus Radiosurgery.

BACKGROUND: A meta-analysis of patients with sporadic vestibular schwannoma (VS) primarily treated with stereotactic radiosurgery (SRS) or microsurgery (MS) was performed, and hearing preservation outcome (HPO), tumor control (TC), and facial nerve dysfunction (FND) were analyzed. METHODS: A systematic review was conducted (Medline and Scopus database) for the period January 2010-June 2020 with appropriate MeSH. English language articles for small to medium sporadic VS (<3 cm) using SRS or MS as primary treatment modality, with minimum follow-up of 3 years, were included. Studies had to report an acceptable standardized hearing metric. RESULTS: Thirty-two studies met the inclusion criteria: 10 MS; 23 radiosurgery, and 1 comparative study included in both. HPO, at approximately 65 months follow-up, were comparable between MS group (10 studies; 809 patients) and SRS group (23 studies; 1234 patients) (56% vs. 59%; P = 0.1527). TC, at approximately 70 months follow-up, was significantly better in the MS group (9 studies; 1635 patients) versus the SRS group (19 studies; 2260 patients) (98% vs. 92%; P < 0.0001). FND, at approximately 12 months follow-up, was significantly higher in the MS group (8 studies; 1101 patients) versus the SRS group (17 studies; 2285 patients) (10% vs. 2%; P < 0.0001). CONCLUSIONS: MS and SRS are comparable primary treatments for small (<3 cm) sporadic VS with respect to HPO at 5-year follow-up in patients with serviceable hearing at presentation; approximately 50% of patients for both modalities likely lose serviceable hearing by that time point. High TC rates (>90%) were seen with both modalities; MS 98% versus SRS 92%. The posttreatment FND was significantly less with the SRS group (2%) versus the MS group (10%).

An update on unilateral sporadic small vestibular schwannoma.

Advances in neuroimaging have increased the detection rate of small vestibular schwannomas (VSs, maximum diameter < 25 mm). Current management modalities include observation with serial imaging, stereotactic radiosurgery, and microsurgical resection. Selecting one approach over another invites speculation, and no standard management consensus has been established. Moreover, there is a distinct clinical heterogeneity among patients harboring small VSs, making standardization of management difficult. The aim of this article is to guide treating physicians toward the most plausible therapeutic option based on etiopathogenesis and the highest level of existing evidence specific to the different cohorts of hypothetical case scenarios. Hypothetical cases were created to represent 5 commonly encountered scenarios involving patients with sporadic unilateral small VSs, and the literature was reviewed with a focus on small VS. The authors extrapolated from the data to the hypothetical case scenarios, and based on the level of evidence, they discuss the most suitable patient-specific treatment strategies. They conclude that observation and imaging, stereotactic radiosurgery, and microsurgery are all important components of the management strategy. Each has unique advantages and disadvantages best suited to certain clinical scenarios. The treatment of small VS should always be tailored to the clinical, personal, and social requirements of an individual patient, and a rigid treatment protocol is not practical.

Do cystic vestibular schwannomas have worse surgical outcomes? Systematic analysis of the literature.

OBJECT: The goal of this study was to perform a systematic quantitative comparison of the surgical outcomes between cystic vestibular schwannomas (CVSs) and solid vestibular schwannomas (SVSs). METHODS: A review of English-language literature published between 1990 and 2011 was performed using various search engines including PubMed, Google Scholar, and the Cochrane database. Only studies that reported surgical results of CVSs in comparison with SVSs were included in the analysis. The primary end point of this study was surgical outcomes, defined by the following: 1) facial nerve outcomes at latest follow-up; 2) mortality rates; or 3) non-facial nerve complication index. Secondary end points included extent of resection and brainstem adherence. RESULTS: Nine studies comprising 428 CVSs and 1287 SVSs were included in the study. The mean age of patients undergoing surgery was 48.3 ± 6.75 and 47.1 ± 9 years for CVSs and SVSs, respectively (p = 0.8). The mean tumor diameter for CVSs was 3.9 ± 0.84 cm and that for SVSs was 3.7 ± 1.2 cm (p = 0.7). There was no significant difference in the extent of resection among CVSs and SVSs (81.2% vs 80.7%, p = 0.87) Facial nerve outcomes were significantly better in the cohort of patients with SVSs than in those with CVSs (52.1% vs 39%, p = 0.0001). The perioperative mortality rates for CVSs and SVSs were not significantly different (3% and 3.8%, respectively; p = 0.6). No significant difference was noted between the cumulative non-facial nerve complication rate (including mortality) among patients with CVSs and SVSs (24.5% and 25.6%, respectively; p = 0.75) CONCLUSIONS: Facial nerve outcomes are worse in patients undergoing resection for CVSs than in patients undergoing resection for SVSs. There were no significant differences in the extent of resection or postoperative morbidity and mortality rates between the cohorts of patients with vestibular schwannomas.

Repair of middle fossa cerebrospinal fluid leaks using a novel combination of materials: technical note.

OBJECT: Methods for repairing middle fossa CSF (MFCSF) leaks have varied and yielded mixed results. The objective of this study was to evaluate the safety and durability of the authors' repair technique using a novel combination of 3 synthetic materials. METHODS: The authors performed a retrospective case review of patients treated for CSF leaks between January 2009 and September 2011. Eight patients were found to have undergone middle fossa craniotomies for CSF leaks. Inclusion criteria for the study included age greater than 18 years, neuroimaging-documented temporal bone defect, and symptoms consistent with CSF leaks or gross CSF otorrhea. Seven patients, 3 men and 4 women, met the inclusion criteria, and their charts were reviewed. Hydroxyapatite cement, collagen-based dural substitute matrix, and polyethylene glycol hydrogel sealant were used in all patients for the repair. RESULTS: In all patients the MFCSF leaks were successfully repaired. Initial presenting symptoms included CSF otorrhea in 4 patients (57.1%), hearing loss in 3 (42.9%), and CSF rhinorrhea in 1 (14.3%). The mean follow-up duration was 12 months (range 5-33 months). In 1 patient an epidural hematoma developed at the operative site on postoperative Day 2, and in another patient a superficial wound dehiscence occurred on postoperative Day 48. During the follow-up period, the authors found no evidence of wound infections, neurovascular damage, or CSF leakage requiring reoperation. CONCLUSIONS: The middle fossa approach involving a combination of hydroxyapatite cement, collagen-based dural substitute matrix, and polyethylene glycol hydrogel sealant is a safe, effective method for repairing MFCSF leaks. The combination of synthetic materials provides an alternative to existing materials for skull base surgeons.