Usefulness of Endoscope-Assisted Microsurgery for Removal of Vestibular Schwannomas^[*]

Abstract

The usefulness of endoscope-assisted microsurgical removal of vestibular schwannomas in the internal auditory canal (IAC) was evaluated. Microsurgical removal using the endoscope was done in 28 procedures and microsurgical removal without an endoscope was done in 43 procedures. A retrosigmoid approach was used. The tumor location in the IAC was classified as grade 1 (located up to the mid-portion), 2, 3, or 4 (located up to the fundus with bony destruction) according to the tumor extent, and residual tumor in the IAC was evaluated as grade A (remnant tumor was not observed), B, C, or D (remnant tumor was observed over the mid-portion) according to the extent of remnant tumor. The residual tumor in the IAC was less in the endoscope-assisted group than in the microsurgery group. There was a significant difference only in grade 2, that is, tumor located beyond the mid-portion of the IAC. There was no significant difference in the results of preservation of useful hearing, facial nerve function, and tumor recurrence between the two groups. The benefit of endoscope-assistance microsurgery was shown for those patients whose tumors extended beyond the mid-portion of the IAC but did not reach the fundus.

Keywords

vestibular schwannoma - endoscopy - retrosigmoid approach - internal auditory canal

^* This article was originally Published online in Skull Base on December 1, 2011 (DOI:10.1055/s-0031-1296035)

• References

• 1 Gerganov VM, Giordano M, Herold C, Samii A, Samii M. An electrophysiological study on the safety of the endoscope-assisted microsurgical removal of vestibular schwannomas. Eur J Surg Oncol 2010; 36 (4) 422-427
• 2 Gerganov VM, Romansky KV, Bussarsky VA, Noutchev LT, Iliev IN. Endoscope-assisted microsurgery of large vestibular schwannomas. Minim Invasive Neurosurg 2005; 48 (1) 39-43
• 3 Göksu N, Bayazit Y, Kemaloğlu Y. Endoscopy of the posterior fossa and dissection of acoustic neuroma. J Neurosurg 1999; 91 (5) 776-780
• 4 Hori T, Okada Y, Maruyama T, Chernov M, Attia W. Endoscope-controlled removal of intrameatal vestibular schwannomas. Minim Invasive Neurosurg 2006; 49 (1) 25-29
• 5 King WA, Wackym PA. Endoscope-assisted surgery for acoustic neuromas (vestibular schwannomas): early experience using the rigid Hopkins telescope. Neurosurgery 1999; 44 (5) 1095-1100, discussion 1100–1102
• 6 McKennan KX. Endoscopy of the internal auditory canal during hearing conservation acoustic tumor surgery. Am J Otol 1993; 14 (3) 259-262
• 7 Miyazaki H, Deveze A, Magnan J. Neuro-otologic surgery through minimally invasive retrosigmoid approach: endoscope assisted microvascular decompression, vestibular neurotomy, and tumor removal. Laryngoscope 2005; 115 (9) 1612-1617
• 8 Tatagiba M, Matthies C, Samii M. Microendoscopy of the internal auditory canal in vestibular schwannoma surgery. Neurosurgery 1996; 38 (4) 737-740
• 9 Valtonen HJ, Poe DS, Heilman CB, Tarlov EC. Endoscopically assisted prevention of cerebrospinal fluid leak in suboccipital acoustic neuroma surgery. Am J Otol 1997; 18 (3) 381-385
• 10 Wackym PA, King WA, Poe DS , et al. Adjunctive use of endoscopy during acoustic neuroma surgery. Laryngoscope 1999; 109 (8) 1193-1201
• 11 Gardner G, Robertson JH. Hearing preservation in unilateral acoustic neuroma surgery. Ann Otol Rhinol Laryngol 1988; 97 (1) 55-66
• 12 Yanagihara N. Grading of facial palsy. In: Fisch U, ed. Facial Nerve Surgery. Amstelveen, The Netherlands: Kugler Medical Publications; 1977: 533-554
• 13 Roland PS, Meyerhoff WL, Wright CG, Mickey B. Anatomic considerations in the posterior approach to the internal auditory canal. Ann Otol Rhinol Laryngol 1988; 97 (6 Pt 1) 621-625
• 14 Kumon Y, Sakaki S, Kohno K , et al. Selection of surgical approaches for small acoustic neurinomas. Surg Neurol 2000; 53 (1) 52-59, discussion 59–60