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Acoustic neuroma surgery —Shanghai experience. Hao Wu Department of Otolaryngology-Head and Neck Surgery Xinhua Hospital, Shanghai Second Medical University. McBumey (1891): unsuccessful Balance (1894): first successful. Cushing Era Surgical mortality: 80% Cushing –partial removal. - PowerPoint PPT Presentation
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Acoustic neuroma surgery—Shanghai experience
Hao WuDepartment of Otolaryngology-Head and Neck Surgery
Xinhua Hospital, Shanghai Second Medical University
• McBumey (1891): unsuccessful
• Balance (1894): first successful
Cushing Era
• Surgical mortality: 80%
• Cushing –partial removal
Dandy Era( 1917–1961)• Total removal: mortality↓(22.1%)
• Atkinson (1949): AICA
• Total facial paralysis
1960
• Mortality rate in California: 43.5%
• Olivecrona (Sweden): 414 cases– small tumors: 4.5%
– large tumors: 22.5%
– Facial paralysis: 50%
Dr. W. House ( 1961-)
•Middle fossa approach (1961)
•Traslab approach (1962)
Origin
Development in the internal acoustic meatus from the schwann cells of the vestibular ganglion (Sterkers JM et al., Acta Otolaryngol., 1987)
Arachnoid sheet enveloping the tumour during its expansion to the CPA.
Epidemiology• 6 to 8 % of all intracranial tumours• The most frequent (80 to 90%) of the
CPA tumours• Sporadic, and solitary in 95 % of cases• Associated with NF2 in 5 % of cases• Estimated incidence in USA and
Western Europe: 1 for 100,000 individuals per year (Kurlan et al., J neurosurg, 1958 ; Nestor JJ et al., Arch Otlaryngol Head Neck Surg, 1988)
REASON FOR CONSULTATION
Expected symptom: 80.7 %(progressive HL,tinnitus,unsteadiness) Sudden hearing loss: 9.6 %Atypical presentation: 10 %
.
..
Moffat et al., 1998n = 473
MRI diagnosis
Isosignal on T1, and variable aspect en T2 views
Constant gadolinium enhancement
Intratumoral cysts in large neurinomes
No adjascent meningeal enhancement
Enlarged IAM
Extension predominantly posterior to IAM
Differential diagnosis
Other neurinomas in the CPA: 5th, 7th, or caudal cranial nerve neurinomasOther lesions:
Most frequent:MeningiomasCholesteatomas
Rare lesions :lipomas, metastases, hemangiomas, medulloblastomas etc…..
Unilateral or asymetrical audio-vestibular signs :Hearing loss, vestibular syndrome, tinnitus
MRI + GadoliniumMRI + Gadolinium Follow-upAudio-vestibular work-up
In 6 months
Neurotological examinationAudiometry+ABR+VNG
Age
< 60 years > 60 years
Abnormality Normal ABR and VNG
Decisionnal factors
1. Tumor volume
2. Age
3. Hearing function
Therapeutic options
Varaiable tumor growth
According to age and tumor size < 1,5 cm
MRI in 6 months and then once a year
Gamma-knife, LINACVolume stabilisationHearing loss and facial paresisUnder evaluation
• Conservative managament
• Surgery
• Radiotherapy
Goals of the surgery
1- Minimal vital and neurological risks
2- Total removal
3- Facial function preservation
4- Hearing preservation
Approaches
Retrosigmoid (RS)
Translabyrinthine (TL)
Middle cranial fossa (MCF)
Acoustic Neuromas
Intracanalar or CPA < 20 mm
> 70 years:Conservativemanagement
< 70 years:Surgery
Poor general condition:Irradiation
CPA> 20 mm
Translabyrinthine or transotictranslabyrinthineMCFretrosigmoid
Hearing
Serviceable Unserviceable
II < 15 mmIII : 15-30 mm
IV > 30 mm
I
• 1999.1-2004.3: 100 VS operated on • Mean age: 49 years (range: 20-79)• Sex ratio: 0.8• Tumor stages :
– Stage 1: 3 %
– Stage 2: 11 %
– Stage 3 : 71 %
– Stage 4 : 15 %
Population
Approaches
•Translabyrinthine : 77 %
•Transotic: 6 %
•Retrosigmoid: 12 %
•Middle cranial fossa: 5 %
17% attempt to hearing preservation
ABRIntraoperative monitoring
Direct cochlear nerve potential
Resection quality
Complete removal in 98 cases Subtotal removal in 1 cases (1 %)
In cases with subtotal removal :1 MRI images demonstrate to be stable (1 %)1 case surgically revised (1 %)
Postoperative facial function in translabyrinthine or transotic
approach
Stages Cases Facial function
1 2 3 4 5 6
总计 83 31 15 13 12 8 4
Hearing preservation
Hearing preservation attempts by middle cranial fossa or retrosigmoid approach (n=17):
Class D: 40 %
Class A: 12 %
Class C: 24 %
Class B: 24 %
Class A+B: 36%
Complications
• CSF leaks: 6%(all in first 39 cases)
Neurological: 3%
Infectious: 1 %
Miscellaneous: 3 %
Translabyrinthine approach
Translabyrinthine removal of VS after radiosurgery
• 5 cases;• Difficult in facial nerve dissection;• Results: total removal in all cases
facial function: grade II in 1 case
grade III in 2 cases
grade IV in 2 cases
grade VI in 1 case
Transotic removal of VS with chronic middle ear infection
• 3 cases;• Results: total removal in all cases
facial function: all with gradeI-II
no postoperative infection
Fallopian bridge technique
Middle fossa approach
Retrosigmoid-IAM approach
Facial nerve repair after interruption
• end-to-ent anastomosis
• Reroute technique
• Bridge technique
• Facial-hypolingual ana.
NF2 and Auditory Brainstem Implant
Hearing rehabilitation in acoustic neuroma surgery
NF2 DIAGNOSIS
• Bilateral vestibular schwannoma (VS)
• NF2 familial history
and
- unilateral VS
- or 2 among : meningioma, glioma, neurofibroma,schwannoma,subcapsular lens opacity
NF2
• NF2 gene on chromosome 22 (1993)
• Tumor suppressor gene
Auditory pathway
Me dia l g e nic ula te bo dy
Infe rio r c o llic ulus
La te ra l le mnisc us
Supe rio r & a c c e sso ry o live a re a
Do rsa l c o c hle a r nuc le usVe ntra l c o c hle a r nuc le us
(Ada pte d fro m "Ne uro to lo g y",Ja c kle r a nd Bra c kma nn)
Co c hle a r
Audito ry c o rte x
VIIIth ne rve
Co c hle a rImpla nt
Audito ryBra inste m
Impla nt
Nucleus 21 Channel Auditory Brainstem Implant
CI22M receiver-stimulator
Monopolarreference electrode
(plate)
Microcoiled electrodewires
Electrode array(21 platinum disks0.7mm diameter)
T-shapedDacronmesh
Removeablemagnet
Bone anchored hearing aide (BAHA)
• Single sided deafness;• FDA approval;
Conclusions 1• In spite of modern image techniques, large VS acounts for most diagnosed cases in China.
•The translabyrinthine app. could be used in even largest VS with minival invasion.
Conclusions 2• The facial function is aceptable in most patients.•The hearing preservation result should still be improved.•Hearing rehabilitation techniques are available after tumor removal.
Thanks
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