Transcript Vestibular Schwannoma Surgical management and outcomes

Vestibular Schwannoma
Surgical management and outcomes
Ching-Jen (Jared) Chen
Visiting Sub-Intern
University of Virginia
Patient MM
• 48yo M w/ L-sided tinnitus and dysequilibrium since 2009.
• MRI 2010 revealed 5mm L vestibular schwannoma (purely
intracanalicular).
– No intervention, followed with serial scans.
• MRI 2012 revealed schwannoma had extended to just outside
the IAC.
• Audiogram showed mild L sensorineural hearing loss.
• Referred to MGH for surgical consideration.
Patient MM (cont’d)
• PMH:
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Hx of Afib w/ spontaneous conversion to NSR
Viral pericarditis
S/p R knee surgery
S/p R shoulder surgery
SH: Denies tobacco and illicits, rare EtOH.
FH: Non-contributory, no hx of vestibular schwannomas.
MEDS: ASA 81 QDaily
ALL: NKDA
EXAM: NI, except slightly decreased hearing in L ear
Decided to undergo microsurgical resection via retrosigmoid
approach
T1-PostGad
2010
5mm L Vestibular
Schwannoma, purely
intracanalicular.
2012
Enlarging L Vestibular
Schwannoma, 11mm.
Projects just beyond
medial aspect of porous
acusticus.
2013
6 mo s/p microsurgical GTR,
via retrosigmoid approach.
W/o evidence of
residual/recurrent tumor.
Vestibular Schwannoma
• Usually arise from the superior division of
vestibular n.
• Histology: Antoni A, Antoni B, and Verocay
Bodies.
• Comprising 8-10% of intracranial tumors.
• Annual incidence ~1.5 cases/100,000.
• Typically become symptomatic after age 30.
– Most common symptoms: hearing loss, tinnitus, and
dysequilibrium.
B
• >95% are unilateral.
Wippold FJ et al.
A
Treatment options
• Microsurgery
– Middle Fossa approach
– Translabyrinthine approach
– Retrosigmoid approach
• Radiosurgery
Mayfield clinic
Middle Fossa Approach
• Usually selected for smaller (<25mm)
and laterally place tumors.
• Potential damage to temporal lobe w/
risk of seizures.
Gonzalez LF et al.
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Retrospective review; 46 patients, middle fossa approach.
Mean follow-up time: 1.8 yr.
Mean tumor size 8.3mm.
Facial n.
– Excellent/good (House-Brackmann Grade I-II) functional preservation: 89.1%.
– Not correlated w/ tumor size.
• Cochlear n.
– Functional hearing (AAO-HNS Class A-B) preservation: 63.2%
– Hearing preservation related to tumor size.
Translabyrinthine Approach
• Allows resection of tumors of
different sizes.
• Disadvantage:
– Sacrifices hearing
– Longer procedure
Gonzalez LF et al.
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Retrospective review, 1244 patients, translabyrinthine approach.
All patients at least 12mo of f/u.
Gross total resection 84%, near-total 13.7%, subtotal 2.2%.
Facial n.
– Excellent/good (House-Brackmann Grade I-II) functional preservation: 70.3%
– Tumor size significantly correlates w/ post-op facial n. function.
Retrosigmoid Approach
• Most commonly used approach.
• Allows resection of tumors of different
sizes and wide view of cisternal
component of tumor.
• Disadvantage:
Gonzalez LF et al.
– Cerebellar retraction (not a problem for
smaller tumors, <40mm)
– Less access to facial/cochlear n. in distal
IAC
– Headaches
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Retrospective review; 200 consecutive patients, retrosigmoid approach.
Mean follow-up time: 24 mo.
Gross total resection: 98%, Subtotal resection: 2%.
Tumor recurrence: 0.5%.
Facial n.
– Excellent/good (House-Brackmann Grade I-II) functional preservation: 62%.
– Tumor size significantly correlates w/ post-op facial n. function (p<0.05).
• Cochlear n.
– Functional hearing (New Hannover Classification Grade I-III) preservation: 51%.
– Hearing preservation related to tumor size and extension, and pre-op hearing level
(p<0.05).
Radiosurgery
• Alone or in conjunction with surgery.
• Usually reserved for small to medium sized tumors, or
patients who are poor surgical candidates.
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Retrospective review, 190 patients treated with GKRS.
Primary treatment 70.5% and adjunctive 29.5%.
Median margin dose 13Gy, tumor volume 3.6cm3, f/u 109mo.
Overall tumor control rate 89.5%.
– Estimated 3-, 5-, 10- and 15-year tumor control rates: 95%, 93%, 86%,
and 70%, respectively.
• Hearing preservation rate 75%.
– Estimated 3-, 5-, and 10-year tumor control rates:, 96%, 92%, and 70%
respectively.
• Facial n. function (House-Brackmann Grade I-II) preservation 98.6%.
• Tumor control was significantly affected by tumor volume.
Patient MM (cont’d)
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At 6mo f/u, pt has been doing well.
Stable tinnitus and hearing loss.
Exam unchanged, incision c/d/i.
No specific complaints.
F/u visit in 6mo w/ MRI and audiogram.
Conclusions
• Microsurgery appears to offer better tumor control rates,
whereas radiosurgery seems to have higher hearing
preservation.
• Treatment selection should be tailored to each individual
patient and tumor characteristics.
• Surgeon/institution experience should also be taken into
consideration.
Gonzalez LF et al.
Acknowledgements
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Mark E. Shaffrey, MD
John A. Jane Sr., MD PhD
Justin S. Smith, MD PhD
Christopher I. Shaffrey, MD
Jason P. Sheehan, MD PhD
– Robert L. Martuza, MD
– William T. Curry, MD
– Department of Neurosurgery
References
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Samii M, Gerganov V, Samii A: Improved preservation of hearing and facial nerve function in vestibular
schwannoma surgery via the retrosigmoid approach in a series of 200 patients. J Neurosurg 105: 527-535.
2006.
Gonzalez LF, Lekovic GP, Porter RW, Syms MJ, Daspit CP, Spetzler RF: Surgical approaches for resection of
acoustic neuromas. Barrow Quarterly 20(4): 22-32. 2004.
Wippold FJ, Lubner M, Perrin RJ, Lammle M, Perry A: Neuropathology for the neuroradiologist: antoni a
and antoni b tissue patterns. AJNR 28: 1633-1638. 2007.
Sun S, Liu A: Long-term follow-up studies of gamma knife surgery with a low margin dose for vestibular
schwannoma. J Neurosurg 117: 57-62. 2006.
Springborg JB, Fugleholm K, Poulsgaard L, Caye-Thomasen P, Thomsen J: Outcome after translabyrinthine
surgery for vestibular schwannomas: report on 1244 patients. J Neurol Surg B 73: 168-174. 2012.
Kutz JW, Scoresby T, Isaacson B, Mickey BE, Madden CJ, Barnett SL, Coimbra C, Hynan LS, Roland PS:
Hearing preservation using the middle fossa approach for the treatment of vestibular schwannoma.
Neurosurgery 70: 334-341. 2012.