The Association of Vestibular Schwannoma Volume With Facial Nerve Outcomes After Surgical Resection

Abstract

Objective: To explore the relationship between tumor size and facial nerve outcomes following vestibular schwannoma (VS) resection. Study Design: Single institutional retrospective chart review of all adult patients with untreated sporadic VS who underwent surgical resection from 2008 to 2018 with preoperative magnetic resonance imaging (MRI) and 1 year of follow-up. The primary outcome measure was facial nerve outcome as assessed by the House-Brackmann facial nerve grading system. Results: One hundred sixty-seven patients, 54.5% female, with a median age of 49 years (20-76 years), were identified who underwent VS resection. Surgical resection was performed by translabyrinthine (76.7%), middle cranial fossa (14.4%), retrosigmoid (7.2%), and transpromontorial (1.8%) approaches. The median tumor diameter and volume were 25.3 mm (range: 4.1-47.1 mm) and 3.17 cm 3 (range: 0.01-30.6 cm 3), respectively. The median follow-up was 24.2 months (range: 12-114.2 months). Gross total resection was performed in 79% of cases, with residual tumor identified on MRI in 17% of cases. For patients with tumors <3 cm 3 , 92.7% had grade 1 or 2 facial function after at least 1 year follow-up, compared to 81.2% for those with tumors >3 cm 3 (univariate logistic regression OR = 2.9, P = .03). Tumor volume >3 cm 3 was predictive of facial weakness on multivariate regression analysis (OR = 7.4, P = .02) when controlling for surgical approach, internal auditory canal extension, anterior extension, age, gender, and extent of resection. Conclusions: Tumor volume >3 cm 3 is associated with worse facial nerve outcomes 12 months following surgical resection.

The Influence of Extent of Resection and Tumor Morphology on Facial Nerve Outcomes Following Vestibular Schwannoma Surgery

“…Many tumor parameters have been investigated as potential predictors of FN outcome. Larger tumor volume has consistently been associated with poor FN outcomes (3,5,7,12,19,23). Similarly, our analysis found that larger tumor volume was associated with poor short- and long-term FN function.…”

“…Microsurgical resection remains a favorable option for large tumors with brainstem compression, hydrocephalus, growing tumors, or symptomatic patients. Recent literature suggests management of VS has increasingly favored observation or radiation in place of microsurgery, likely reflecting a lower tolerance for cranial neuropathy, particularly facial nerve paralysis in VS treatment outcomes (2)(3)(4)(5)(6).…”

How to Precisely Open the Internal Auditory Canal for Resection of Vestibular Schwannoma via the Retrosigmoid Approach

“…The goal of VS surgery is complete resection while preserving neurological function, which is challenging ( 1 , 4 , 5 , 25 , 26 ). For large VSs, the RS approach is preferred when hearing preservation is required.…”

Clinical Staging to Estimate the Probability of Severe Postoperative Complications in Patients With Vestibular Schwannoma

“…The decision to pursue surgical management instead of radiotherapy or active surveillance is multifactorial and largely depends on features including age, comorbidity, initial tumor size, rate of growth, hearing status, and patient preference. The mortality rate in patients surgically managed is very low and affords the opportunity to shift focus to other relevant clinical outcomes, such as recurrence-free survival, growth-free survival, surgical complications, facial nerve functioning, hearing preservation, and quality of life …”

“…The mortality rate in patients sur-gically managed is very low and affords the opportunity to shift focus to other relevant clinical outcomes, such as recurrencefree survival, growth-free survival, surgical complications, facial nerve functioning, hearing preservation, and quality of life. [4][5][6] Patient symptom presentation is a fundamental characteristic of the patient with VS and likely relates to the pathophysiologic characteristics of the tumor. Symptoms at presentation include cardinal symptoms, such as hearing loss, vestibular dysfunction, facial numbness, tinnitus, and headaches.…”