71 / 264
even after ITG. The remaining 8 (8.4%) patients were
class F (Table I). Six patients received ETG after failure
of ITG. Vestibular function on a caloric test was not suf-
ficiently attenuated in four of six patients after ITG
(patients 3, 4, 6, and 7 in Table II), whereas it was atte-
nuated substantially but vertigo attacks were not con-
trolled in two patients (patients 2 and 5 in Table II).
After ETG, five of seven (71.4%) patients whose caloric
function was attenuated substantially achieved class A,
and the remaining two patients (patients 6 and 7),
whose caloric functions were not sufficiently attenuated
even after ETG, needed subsequent labyrinthectomies.
We tried to determine any possible anatomical prob-
lems that might obscure the passage of gentamicin.
Prominent bony overhang over the round window niche
was remarkable in two patients; otherwise, there was no
definite suspected barrier such as mucosal thickening,
thickening of the round window membrane, or bone
chips (Table II). Including one patient administered gen-
tamicin during a tympanomastoidectomy due to chronic
otitis media after trial use of the Meniett device, a total
of seven patients underwent ETG. Although the bone
conduction threshold was aggravated by 12.5 dB in one
of the seven (14.3%) patients, the hearing level was
already more than 55 dB in each patient who received
ETG.
Three patients finally underwent labyrinthectomies
after the failure of ITG, including two patients whose
vertigo was not controlled by ITG or ETG. The two did
improve after the labyrinthectomy, up to class A. An
intralabyrinthine schwannoma was found incidentally
during the labyrinthectomy (patient 2 in Table III), and
tumor removal was completed via translabyrinthine
approach.
TABLE I.
Additional Interventions Performed to Control Intractable Vertigo.
Treatment
Class*
No.
Comments
ITG (n
5
95)
A
73
s/p ELSD (n
5
3)
B
12
C
2
s/p ELSD (n
5
1)
F
8
Subsequently ETG (n
5
6), labyrinthectomy (n
5
1),
vestibular neurectomy (n
5
1)
ELSD (n
5
11)
A
5
C
2
F
4
Subsequently ITG (n
5
4)
Meniette (n
5
3)
A
2
F
1
Subsequently ETG (n
5
1)
ETG (n
5
7)
A
5
s/p Meniett, then chronic draining ear (n
5
1)
F
2
Subsequently labyrinthectomy (n
5
2)
Labyrinthectomy (n
5
4)
A
4
Labyrinthectomy
1
STP
†
(n
5
1),
intralabyrinthine tumor removal
‡
(n
5
1)
Vestibular neurectomy (n
5
1)
A
1
*Functional classification according to the 1995 American Academy of Otolaryngology–Head and Neck Surgery guideline.
†
Surgery to control chronic otitis media.
‡
Translabyrinthine approach and tumor removal for incidentally detected intralabyrinthine schwannoma.
ITG
5
intratympanic gentamicin injection; ELSD
5
endolymphatic sac decompression; ETG
5
exploratory tympanotomy and gentamicin application;
n
5
number of patient(s); s/p
5
status post; STP
5
subtotal petrosectomy.
TABLE II.
Changes in Vestibular Function Before ITG, After ITG, and After ETG.
Pt
CP (%) Before ITG
CP (%) After ITG
CP (%) After ETG
Class*
Dx
Comments
1
21%
–
HIT(
1
)
†
A
MD s/p Meniett, then chronic draining ear
2
35%
62% (7 inj
‡
)
56%
A
MD
3
10%
25% (3 inj
‡
)
66%
A
MD Persistent unsteadiness
4
46%
44% (2 inj
‡
)
97%
A
MD Prominent bony overhang
5
32%
90% (3 inj
‡
)
90%
A
MD
6
15%
28% (3 inj
‡
)
32%
F
EH
7
4%
31% (3 inj
‡
)
29%
F
MD Prominent bony overhang
*Functional classification according to the 1995 American Academy of Otolaryngology–Head and Neck Surgery guideline.
†
Positive head impulse sign indicates attenuation of ipsilateral canal function after ETG.
‡
Number of intratympanic injections of gentamicin.
CP
5
canal paresis bithermal caloric test; Dx
5
diagnosis; EH
5
secondary endolymphatic hydrops; ETG
5
exploratory tympanotomy and gentamicin
application; HIT
5
head impulse test; inj
5
injection; ITG
5
intratympanic gentamicin injection; MD
5
definite Menie` re’s disease; Pt
5
patient; s/p
5
status post.
Laryngoscope 125: April 2015
Rah et al.: Intractable Menie` re’s Disease
50