The Behaviour of Residual Tumor after the Intentional Incomplete Excision of a Vestibular Schwannoma: Is it Such a Bad Thing to Leave Some behind?

Abstract

Objectives

To evaluate the biological behaviour of tumour remnants intentionally left in the surgical bed following the incomplete excision of vestibular schwannomas [VS] and to review the relation between extent of resection and preservation of facial nerve function.

Methods

A retrospective chart review of 450 patients that underwent surgery for resection of VS over 23 years [1992-2014]. Of these, 50 (11%) patients had residual tumor intentionally left on/around the facial nerve [near-total or subtotal excision] to preserve facial nerve function intra-operatively. The growth of residual tumour was evaluated using serial MRI scanning; pre- and post-operative facial nerve function was assessed using the House Brackmann grading scale.

Setting

Tertiary referral neurotology unit.

Results

Of the 42 non-NF2 cases where the tumour was intentionally incompletely excised, 28 (67%) patients underwent subtotal resection [mean follow up 68.5 ± 39.0 months] and 14 (33%) underwent near total resection [mean follow up 72.9± 48.3 months]. Three patients [all in subtotal resection group] showed regrowth. This was not statistically different from the near total resection group (χ2= 0.92, p = 0.31). The mean overall growth for these cases was 0.68mm ± 0.32 mm/year.

5 (1 near total, 4 subtotal) of the 8 NF2 patients (62.5%) were excluded from our analysis.

In the non-NF2 group, poor facial nerve outcomes [House-Brackmann scores of III-IV were seen in 2/14 and V-VI in 3/14 of the near total compared to 7/25 and 4/25 respectively in the subtotal group.

Conclusions

Given that the primary surgery for the VS was only for tumors that were relatively large or grew during conservative treatment, the low rate of tumor remnant growth [7%] is reassuring. It may be appropriate to have a lower threshold for leaving tumor on the facial nerve in non-NF2 patients where complete resection may jeopardize facial nerve function.

This article is protected by copyright. All rights reserved.

from #ORL via xlomafota13 on Inoreader http://ift.tt/1XhgnXi
via IFTTT