Outcomes of large vestibular schwannomas following subtotal resection: early post-operative volume regression and facial nerve function
Subtotal resection (STR) of vestibular schwannoma (VS) tumors remains controversial and little is known regarding post-operative volume changes.
Authors retrospective reviewed the medical records from January 1st 2002 to January 1st 2018, for all patients who had undergone primary STR of large VS at a single tertiary academic institution.
Our series consists of 34 patients with a mean age of 53.9 (median 53; range 21–87) years that had STR of their VS tumor. The mean pre-operative tumor diameter and volume was 3.9 cm (median 3.0 cm; range 1.6–6.0 cm) and 11.7 cm3 (median 9.6 cm3; range 2.8–44.3 cm3), respectively, with a mean extent of resection of 86% (median 90%; range 53–99%). The mean radiographic and clinical follow-up was 40 months (range 6–120 months) and 51 months (range 7–141 months), respectively. 85% of patients had optimal House–Brackmann (HB) scores (Grade 1 & 2) immediately post-operatively, and 91% at 1 year; 94% of patients had normal (HB 1) at last follow-up. There was significant regression of residual tumor volume at 1 year (p = 0.006) and 2 years (p = 0.02), but not at 3 years (p = 0.08), when compared to the prior year. There was significant regression of size over time, with a mean slope estimate of − 0.70 units per year (p < 0.001).
Excellent clinical facial nerve outcomes can be obtained with STR of large VS tumors. Maximal reduction in tumor size occurs at 2-year post-operatively. Thus, in patients undergoing surgery for large VS, STR and a “watch and wait” strategy is a reasonable treatment option that may optimize facial nerve outcomes.
KeywordsAcoustic neuroma Vestibular schwannoma Subtotal resection Volume reduction Stereotactic radiosurgery
Magnetic resonance imaging
We thank David Hodge of the Mayo Clinic Florida statistics department for his assistance with analyzing this data.
Compliance with ethical standards
Conflict of interest
The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This article does not contain any studies with animals performed by any of the authors.
This study was approved by our institutional review board as minimal risk, thus negating need for written consent from each patient.
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