Surgical management for large vestibular schwannomas: a systematic review, meta-analysis, and consensus statement on behalf of the EANS skull base section

Abstract

Background and objective The optimal management of large vestibular schwannomas continues to be debated. We constituted a task force comprising the members of the EANS skull base committee along with international experts to derive recommendations for the management of this problem from a European perspective. Material and methods A systematic review of MEDLINE database, in compliance with the PRISMA guidelines, was performed. A subgroup analysis screening all surgical series published within the last 20 years (January 2000 to March 2020) was performed. Weighted summary rates for tumor resection, oncological control, and facial nerve preservation were determined using meta-analysis models. This data along with contemporary practice patterns were discussed within the task force to generate consensual recommendations regarding preoperative evaluations, optimal surgical strategy, and follow-up management. Results Tumor classification grades should be systematically used in the perioperative management of patients, with large vestibular schwannomas (VS) defined as > 30 mm in the largest extrameatal diameter. Grading scales for pre- and postoperative hearing (AAO-HNS or GR) and facial nerve function (HB) are to be used for reporting functional outcome. There is a lack of consensus to support the superiority of any surgical strategy with respect to extent of resection and use of adjuvant radiosurgery. Intraoperative neuromonitoring needs to be routinely used to preserve neural function. Recommendations for postoperative clinico-radiological evaluations have been elucidated based on the surgical strategy employed. Conclusion The main goal of management of large vestibular schwannomas should focus on maintaining/improving quality of life (QoL), making every attempt at facial/cochlear nerve functional preservation while ensuring optimal oncological control, thereby allowing to meet patient expectations. Despite the fact that this analysis yielded only a few Class B evidences and mostly expert opinions, it will guide practitioners to manage these patients and form the basis for future clinical trials.

Gross-total versus near-total resection of large vestibular schwannomas. An institutional experience

“…This affirms previous research indicating that NTR allows the preservation of facial nerve function without significantly increasing the risk of recurrence. In many cases, it also assures a better postsurgical quality of life for the patient [ 25 ]. Furthermore, some authors have suggested that gamma knife radiosurgery is an efficient and safe adjuvant treatment, with a high tumor growth prevention rate, that can be used after total or partial tumor removal [ 45 , 46 , 47 ].…”

“…The surgical management of large VSs is controversial. Treatment options include gross-total resection (GTR), in one or multiple stages; near-total resection (NTR), followed by radiosurgical treatment; or NTR followed by observation with regular imaging follow-up [ 11 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ].…”

Koos Grade IV Vestibular Schwannomas: Considerations on a consecutive series of 60 cases. Searching for the Balance Between Preservation of Function and Maximal Tumor Removal

“…However, the postoperative facial function preservation rate is quite different in the two studies, being 45% in Silva et al (50) and 75% in Samii et al (45). The preservation of FN functional state is of paramount importance in VS surgery and it is accomplished, as reported in the literature, in 32,9-83,3% of cases (16,19,26,45,62,65), with a metaanalysis demonstrating FN preservation in 60% of cases (52). The highest value of FN function preservation rate was reported by Zhang et al (18) in a cohort of patient who underwent subtotal resection instead of radical extirpation.…”

“…Although hearing loss is one of the most common signs at presentation (41,7% of cases (1), as far as hearing is present preoperatively, attempts should be made -when possible-to accomplish hearing preservation (11,52). As far as large and giant VS are concerned, hearing has been reportedly preserved in 21,4-50% (11,31,60,61) and 66,7% (45) of cases, respectively.…”

“…Increasingly popular is the concept of the planned less-than-total resection performed for FN preservation (52). According to some authors (22,56,66) outcome might be improved in selected cases by a combined surgical and radiosurgical treatment.…”