Transcript 2 - Department of Surgery, HKU

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
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
.
.
.
Moffat et al., 1998
n = 473
Expected symptom: 80.7 %
(progressive HL,tinnitus,unsteadiness)
Sudden hearing loss: 9.6 %
Atypical presentation: 10 %
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 neurinomas
Other lesions:
Most frequent:
Meningiomas
Cholesteatomas
Rare lesions :lipomas, metastases,
hemangiomas, medulloblastomas etc…..
Unilateral or asymetrical audio-vestibular signs :
Hearing loss, vestibular syndrome, tinnitus
Neurotological examination
Audiometry+ABR+VNG
Normal ABR and VNG
Abnormality
Age
< 60 years
> 60 years
MRI + Gadolinium
Follow-up
Audio-vestibular work-up
In 6 months
MRI + Gadolinium
Decisionnal factors
1. Tumor volume
2. Age
3. Hearing function
Therapeutic options
Varaiable tumor growth
• Conservative
managament
• Radiotherapy
• Surgery
According to age and tumor size < 1,5 cm
MRI in 6 months and then once a year
Gamma-knife, LINAC
Volume stabilisation
Hearing loss and facial paresis
Under evaluation
Goals of the surgery
1- Minimal vital and neurological risks
2- Total removal
3- Facial function preservation
4- Hearing preservation
Approaches
Middle cranial fossa (MCF)
Retrosigmoid (RS)
Translabyrinthine (TL)
Acoustic Neuromas
Intracanalar or CPA < 20 mm
> 70 years:
Conservative
management
< 70 years:
Surgery
CPA> 20 mm
Poor general condition:
Irradiation
Hearing
Serviceable
Unserviceable
MCF
retrosigmoid
translabyrinthine
Translabyrinthine or transotic
Population
•
•
•
•
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 %
I
II < 15 mm
III : 15-30 mm
IV > 30 mm
Approaches
•Translabyrinthine :
•Transotic:
•Retrosigmoid:
•Middle cranial fossa:
77 %
6%
12 %
5%
17% attempt to hearing preservation
Intraoperative monitoring
ABR
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
总计
Cases
83
1
31
Facial function
2
3
4
5
15 13 12
8
6
4
Hearing preservation
Hearing preservation attempts by middle cranial
fossa or retrosigmoid approach (n=17):
Class C: 24 %
Class B: 24 %
Class A: 12 %
Class A+B: 36%
Class D: 40 %
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.
Hearing rehabilitation in acoustic neuroma surgery
NF2 and Auditory Brainstem Implant
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
Aud ito ry c o rte x
Me d ia l g e nic ula te b o d y
Infe rio r c o llic ulus
La te ra l le m nisc us
Sup e rio r & a c c e sso ry o live a re a
Do rsa l c o c hle a r nuc le us
Ve ntra l c o c hle a r nuc le us
VIIIth ne rve
Co c hle a r
Aud ito ry
Bra inste m
Im pla nt
(Ad a p te d fro m "Ne uro to lo g y",Ja c kle r a nd Bra c kma nn)
Co c hle a r
Im pla nt
Auditory
pathway
Nucleus 21 Channel Auditory Brainstem
Implant
Removeable
magnet
CI22M receiver-stimulator
Monopolar
reference electrode
(plate)
Microcoiled electrode
wires
T-shaped
Dacron
mesh
Electrode array
(21 platinum disks
0.7mm diameter)
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