Tumour Resection Volumes and Facial Nerve Outcomes for Vestibular Schwannomas

Abstract

The objective of this study is to correlate tumour volume relationship with surgical outcomes in subtotal resections and accepted nomenclature through a retrospective study at Charing Cross Hospital, London, a tertiary referral centre. The participants were 16 patients with vestibular schwannoma managed with subtotal resection between 2002 and 2011. The main outcome measures were surgical technique; tumour volume; recurrence and post-operative facial nerve function. Mean preoperative and post-operative volumes for all patients were 14.7 and 3.7 cm 3 respectively. Tumour volumes do not correlate with diameter (p \ 0.05). Mean reduction in volume of these subtotal resections was 75 %. Long term facial nerve outcome was good in the majority of patients: House-Brackmann Grade I/II in 12 (75 %), Grade III/IV in 2 (12.5 %) and Grade V/VI in 2 patients (12.5 %). Notably, two patients with Grade I/II House-Brackmann grading later developed Grade V/VI palsy following adjunctive radiotherapy. Seven of the 16 subtotal resections had subsequent radiotherapy or microsurgery. Mean follow up was 26.5 months. In conclusion, subtotal resections lead to good facial nerve outcomes but may require further treatments. Radiation treatment can worsen facial nerve function. There is no standardised use of tumour volumes or accepted guidelines for resection terminology. We propose the use of tumour volumes to define this further.

Subtotal resection of vestibular schwannoma: Evaluation with Ki-67 measurement, magnetic resonance imaging, and long-term observation

“…If regrowth is demonstrated, the patients should be monitored by MRI for residual tumor growth postoperatively and eventually treated with revision microsurgery or radiation therapy if regrowth is demonstrated. 1 , 10 – 14 , 25 , 26 …”

“…In accordance with published results, patients who underwent NTR had a lower tumor regrowth rate (5.8%) than did patients who underwent STR (17.6%). 1 , 8 – 15 …”

“…Reviews of the literature have revealed that in the event of partial removal, the residual VS in patients who had undergone near total resection (NTR) versus subtotal resection (STR) showed an incidence of regrowth ranging from 0.0% to 3.5% versus 18.4% to 73.9%, respectively. 1,[8][9][10][11][12][13][14][15] The ability to monitor the residual tumor with magnetic resonance imaging (MRI), advances in revision microsurgery, and the development of stereotactic radiosurgery allow for adequate management when a VS regrows after partial resection. 1,10,15 The molecular mechanisms associated with the formation of a VS secondary to impaired growth regulation remain unclear.…”

Advanced Vestibular Schwannoma: A Case of Optic Disc Oedema without Hydrocephalus

“…1 Management options include watchful observation with serial scanning, radiosurgery, or surgery. 4 We report an unusual case of large VS presenting with optic disc oedema with no evidence of obstructive hydrocephalus.…”

“…3 The predominant presenting symptoms are unilateral hearing loss and tinnitus. 1,2,4 Ophthalmic symptoms are less common and include diplopia, blurred vision, obscurations, and tunnel vision.…”