Facial Nerve Outcomes After Vestibular Schwannoma Microsurgical Resection in Neurofibromatosis Type 2

Abstract

Objective The aim of this study is to investigate facial nerve outcomes after microsurgical resection in neurofibromatosis type 2 (NF2) compared to sporadic tumors. Study Design Single institutional retrospective chart review. Setting Tertiary referral center. Methods All adult patients with NF2 vestibular schwannoma (VS) or sporadic VS who underwent microsurgical resection from 2008 to 2019 with preoperative magnetic resonance imaging (MRI) and 1 year of postsurgical follow-up were included. The primary outcome measure was postoperative House-Brackmann (HB) facial nerve score measured at first postoperative visit and after at least 10 months. Results In total, 161 sporadic VSs and 14 NF2 VSs met inclusion criteria. Both median tumor diameter (NF2, 33.5 mm vs sporadic, 24 mm, P = .0011) and median tumor volume (NF2, 12.4 cm3 vs sporadic, 2.9 cm3, P = .0005) were significantly greater in patients with NF2. The median follow-up was 24.9 months (range, 12-130.1). Median facial nerve function after 1 year for patients with NF2 was HB 3 (range, 1-6) compared to HB 1 (range, 1-6) for sporadic VS ( P = .001). With multivariate logistic regression, NF2 tumors (odds ratio [OR] = 13.9, P = .001) and tumor volume ≥3 cm3 (OR = 3.6, P = .025) were significantly associated with HB ≥3 when controlling for age, sex, extent of tumor resection, translabyrinthine approach, and prior radiation. Conclusion Tumor volume >3 cm3 and NF2 tumors are associated with poorer facial nerve outcomes 1 year following microsurgical resection.

Analysis of the effect of neuroendoscopy-assisted microscopy in the treatment of Large (Koos grade IV) vestibular schwannoma

“…However, the anatomical preservation of the facial nerve is not an indicator of the integrity of the facial nerve function. Sobieski reported that a preservation rate of facial nerve function (H-B grade I to II) in of 53.4%, but for tumors with a diameter greater than 3 cm only 35.7% ( 15 ). Zhao et al.…”

Neuro-Ophthalmic Complications of Vestibular Schwannoma Resection: Current Perspectives

“…[14][15][16][17][18][19][20] Patients with VSs associated with neurofibromatosis type-2 also seem to be at risk of adverse VII nerve outcomes following surgical resection. 21 With smaller tumors (<20mm), rates of VII nerve palsy following VS resection are less than 10%, 16,19 but for larger tumors (>30mm) VII nerve function is affected in more than half of patients undergoing surgical resection. 22,23 A large study, including over 4000 patients from approximately 20% of all the hospitals in the United States of America, found that VII nerve palsy occurred in 14% of patients who had undergone VS surgical resection between 2002 and 2010.…”

Commentary: Surgical Management of Peripheral Nerve Pathology in Patients With Neurofibromatosis Type 2

“…Several studies have shown that NF2-associated vestibular schwannomas progress at a faster rate compared with sporadic cases and that resection of NF-2associated vestibular schwannomas is associated with greater risk of facial nerve complications. [13][14][15] The study provides excellent baseline data for peripheral nerve schwannoma outcomes in patients with NF2 and shows that patients with NF2 can often have good outcomes after surgical resection of conventional schwannomas. Note that these authors found that most of the patients who had a motor deficit after surgery in their cohort had multinodular/plexiform lesions.…”

“…Several studies have shown that NF2-associated vestibular schwannomas progress at a faster rate compared with sporadic cases and that resection of NF-2–associated vestibular schwannomas is associated with greater risk of facial nerve complications. 13-15…”