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The Mediterranean Journal of Otology
ORIGINAL ARTICLE
Stapes Surgery: A Review of 515 Operations Performed from 1988 to 2002
Costantino Simoncelli, M.D., Giampietro Ricci, M.D., Franco Trabalzini, M.D.,
Mario Gullà, M.D., Mario Faralli, M.D., Egisto Molini, M.D.
From the Department of MedicalSurgical Specialization, Division of
Otolaryngology and Cervico-Facial
Surgery, University of Perugia
(C. Simoncelli, G. Ricci, M. Gullà,
M. Faralli), Perugia; Department of
Otosurgery, Azienda OspedalieraUniversity (F. Trabalzini, E. Molini),
Padova, both in Italy.
Correspondence:
Giampietro Ricci, M.D.,
c/o Clinica Otorinolaringoiatrica,
Via Enrico Dal Pozzo
06126 Perugia, Italy.
Tel: +39 075 572 2906
Fax: +39 075 572 6886
e-mail: [email protected]
Submitted: December 11, 2004
Revised: January 06, 2005
Accepted: January 10, 2005
Mediterr J Otol 2005;1:00-00.
Copyright 2005 © The Mediterranean
Society of Otology and Audiology
OBJECTIVES: The object of this study was to review patients who underwent
stapes surgery during a 15-year period, together with an evaluation of techniques, results, and complications.
PATIENTS AND METHODS: Otosclerosis surgery was performed in 483 adult
patients (305 females, 178 males; mean age 46.3 years; range 24 to 74 years)
between 1988 and 2002. The disease was bilateral in 292 patients (60.5%) and
unilateral in 191 patients (39.5%). Operations were unilateral in 451 patients, and
bilateral in 32 patients, and included small fenestra stapedotomy with a perforation of 0.8 mm (442 ears, 85.8%), partial stapedectomy with removal of the posterior half of the footplate (30 ears, 5.8%), and total stapedectomy (43 ears, 8.4%).
A Teflon prosthesis, 0.6 mm in diameter and 4-4.5 mm length, was used nearly in
all the cases. In cases of stapedectomy, a perichondrial graft was placed over the
oval window. Preoperative and postoperative hearing levels (frequencies 500,
1000, 2000, and 3000 Hz) and air- and bone-conduction thresholds (frequencies
250, 500, 1000, 2000, and 4000 Hz) were measured. Postoperative closure of the
air-bone gap was evaluated in four groups: grade A (gap≤10 dB HL), grade B (1120 dB HL), grade C (21-30 dB HL), and grade D (>30 dB HL). The results were
evaluated in accordance with the guidelines of the Committee on Hearing and
Equilibrium-1995. Of 515 operations, 380 were evaluative (73.8%) with respect to
outcome. The mean follow-up period was 68 months (range 3 to 180 months).
RESULTS: Of 380 evaluative operations, 307 ears (80.8%) showed complete recovery with a postoperative air-bone gap less than 10 dB (grade A), whereas 10
ears (2.6%) showed no improvement in hearing thresholds and in the closure of
the air-bone gap. Together with partial recoveries (grade B and C), the overall
improvement in hearing thresholds was 97.3%. The mean preoperative and
postoperative air-conduction hearing thresholds at frequencies of 500, 1000,
2000, and 3000 Hz were 56.3±14.5 dB HL and 28.3±9.7 dB HL, respectively.
The mean gain for air conduction at the same frequencies was 25.3±11.7 dB HL.
Of 10 ears in which no hearing recovery was observed, two ears rapidly developed sensorineural hearing loss. Revision surgery was performed in six of the
remaining ears and resulted in complete response. Of these, air-bone gap closure was achieved in three ears, while one ear developed sensorineural hearing
loss a few days after revision surgery. The most common complications encountered intraoperatively, and in the immediate and late postoperative periods were
section of the chorda tympani (n=130, 25.2%), transient facial nerve paralysis
(n=13, 2.5%), and sensorineural hearing loss (n=2, 0.4%), respectively.
CONCLUSION: Our results show that stapes surgery yields very good functional results, with complete or partial closure of the air-bone gap in the great
majority of cases, and with very low rates of postoperative complications.
01
Stapes Surgery: A Review of 515 Operations Performed from 1988 to 2002
Perkins,[17] introduced the use of laser to vaporize
the stapes without instrumentation, which has then
become popular.[18,19]
Otosclerosis is a dystrophic disorder of the labyrinthine
capsule, with characteristic localization. Its most typical clinical manifestation is hearing loss due to progressive fixation of the stapes. The prevalence of clinical otosclerosis is 0.3-0.4% among whites,[1] and there
is a 2:1 female preponderance in the general population.[2]
The object of this study was to review patients
who underwent stapes surgery during a 15-year
period (1988 to 2002), together with an evaluation
of techniques, results, and complications, and to
draw a comparison with the relevant literature
reports.
In 40-54% of cases, otosclerosis has a hereditary
basis,[3,4] and manifests characteristics of an autosomal dominant disease with incomplete penetrance
(25-40%).[5,6] The clinical expressiveness of the gene
may be conditioned by biochemical or hormonal
factors.[4] Maurizi et al.[7] could not locate receptor
sites for calcitonin in otosclerotic bone cell cultures,
but found alterations in calcium metabolism. This
discovery was further confirmed by Lim.[8]
According to the autoimmune theory, the disorder is
likely to stem from the production of autoantibodies
to certain types of collagen, particularly type II,
which is present in the enchondral layer and in
residual embryonic cartilage of the auditory capsule.[9] More recent studies have addressed the possible role of measles virus in initiating the otosclerotic process.[10-14]
MATERIALS AND METHODS
Otosclerosis surgery was performed in 483 adult
patients (305 females, 178 males; mean age 46.3
years; range 24 to 74 years) between 1988 and 2002
by the same surgeon. Otosclerosis was bilateral in
292 patients (60.5%) and unilateral in 191 patients
(39.5%). Preoperatively, all the patients underwent
liminar pure tone audiometry, speech audiometry,
tympanometry, and vestibular examinations.
Unilateral operation was performed in 451
patients, while 32 patients underwent surgery in both
ears, making up a total of 515 operations. The operations were assessed in three categories according to
the type of stapes manipulation: small fenestra stapedotomy resulting in a perforation of 0.8 mm (442
ears, 85.8%); partial stapedectomy with removal of
the posterior half of the footplate (30 ears, 5.8%); and
total stapedectomy with complete removal of the
footplate (43 ears, 8.4%).[20]
Treatment of otosclerosis dates back to the late
nineteenth century, with numerous attempts for surgical remedy. Finally, in 1958, Shea[15] proposed the
so-called stapedectomy, which included the removal
of the stapes under an operation microscope, closure
of the oval window with a thin slice of connective tissue, and implantation of a prosthesis from the incus
to the oval window. Since then, many modifications
of stapedectomy have been developed, all of which
adhered to the principles of Shea, involving the closure of the oval window and the restoration of ossicular continuity.
A Teflon prosthesis with a diameter of 0.6 mm
and a length of 4-4.5 mm was applied nearly in all the
cases, and a 0.8 mm piston in some. A small amount
of blood was left around the prosthesis to create a
seal. In cases of stapedectomy, a perichondrial graft
was placed over the oval window.
One of these modifications is stapedotomy,
which is based on the principle of restoring sound
transmission by creating a partial opening in the
stapes footplate. In this technique, manipulation of
the stapes footplate is restricted to the small area of
fenestration, reducing potential risks for any injury
to the membranous labyrinth within the vestibule.[16]
The size of the new fenestra can be from 0.3 to 0.8
mm, with the hearing results being comparable. In
addition, differences both between the types of
prostheses and between the techniques used to create the fenestra are slight. Many surgeons use a
microdrill or perforator to fenestrate the footplate.
Preoperative and postoperative hearing levels
(frequencies 500, 1000, 2000, and 3000 Hz) and airand bone-conduction thresholds (frequencies 250,
500, 1000, 2000, and 4000 Hz) were measured.
Postoperative closure of the air-bone gap was evaluated in four groups: grade A (gap≤10 dB HL), grade
B (11-20 dB HL), grade C (21-30 dB HL), and grade
D (>30 dB HL).
The results were evaluated in accordance with the
guidelines recommended by the Committee on
Hearing and Equilibrium of the American Academy
of Otology (1995).[21]
02
The Mediterranean Journal of Otology
Table 1. Postoperative closure of the air-bone gap in
380 evaluative ears
Of 515 operations, 380 were evaluative (73.8%)
with respect to outcome. The mean follow-up period
was 68 months (range 3 to 180 months).
Grade[*]
A
B
C
D
RESULTS
Of 380 evaluative operations, 307 ears (80.8%)
showed complete recovery with a postoperative airbone gap less than 10 dB (grade A), whereas 10 ears
(2.6%) showed no improvement in hearing thresholds and in the closure of the air-bone gap (Table 1).
[*]
Air-bone gap (dB)
No. of ears
%
<10
11-20
21-30
>30
307
45
18
10
80.8
11.8
4.7
2.6
Based on the guidelines of the Committee on Hearing and Equilibrium.
Together with partial recoveries (grade B and C),
the overall improvement in hearing thresholds
accounted for 97.3%.
The mean preoperative and postoperative air-conduction hearing thresholds at frequencies of 500, 1000,
2000, and 3000 Hz were 56.3±14.5 dB HL and
28.3±9.7 dB HL, respectively. The mean gain for air
conduction at the same frequencies was 25.3±11.7 dB
HL. The mean preoperative and postoperative air- and
bone-conduction thresholds measured at frequencies of
500, 1000, 2000 and 4000 Hz are tabulated in Table 2.
The success rates reported in the literature following
surgery for otosclerosis are tabulated in Table 4.[22-31] The
variability in the improvement rates of hearing thresholds ranging from 78% to 96% can be attributed to the
use of varying criteria to evaluate the results, different
surgical techniques, and, last but not least, the variable
lengths of postoperative follow-up periods.[32]
The rates of intraoperative and postoperative complications were similar to those reported in other studies. Our rate for sensorineural hearing loss (0.4%) was
comparable to those reported as 0.4% and 3%.[27,33]
Compared to reported rates of 08%,[31] 1%,[27] and
1.9%,[34] perforation of the tympanic membrane
occurred in 0.7% in our study. The rate of postoperative vertigo (1.0%) was also similar to 0.7% reported
by Glasscock et al.[27] The occurrence a floating footplate in nine ears (1.8%) had no effect whatsoever on
the final results. This complication showed a significant decrease upon inverting the order of surgical
applications, i.e. placing the prosthesis before removing the superstructure of the stapes.
Of 10 ears in which no hearing recovery was
observed, two ears rapidly developed sensorineural
hearing loss. Revision surgery which was performed
in six of the remaining eight ears resulted in complete
response. Of these, air-bone gap closure was achieved
in three ears, while one ear developed sensorineural
hearing loss a few days after revision surgery.
Complications encountered intraoperatively, and
in the immediate and late postoperative periods are
shown in Table 3.
DISCUSSION
This study examines a series of 515 operations performed by the same surgeon for otosclerosis over a
15-year period. The analysis of the results reveals
the indubitable effectiveness of the operations in
providing major improvements in air-conduction
hearing levels of the majority of patients. Indeed,
the rate of air-bone gap of less than 10 dB HL
(grade A) was 80.8% in 380 evaluative operations.
With regard to the type of the operation, the common opinion in the literature is that small fenestra
stapedotomy furnishes similar results to those of
stapedectomy, but with fewer complications. In
1978, Smyth and Hassard[24] reported better performance rates with small fenestra operations (diameter
0.4 mm) in a study of 800 ears. In 1981, McGee[25]
Table 2. The mean preoperative and postoperative air- and bone-conduction thresholds
Frequencies (Hz)
Air-conduction
Bone-conduction
250
500
1000
2000
4000
Preoperative
61.2±11.7
58.9±12.8
57.1±12.8
52.3±15.3
55.1±20.63
Postoperative
26.4±10.6
27.5±10.4
27.1±11.8
30.0±14
40.0±18.4
Preoperative
15.1± 6.9
19.7±10.0
22.1±10.1
30.4±12.6
29.7±16.4
Postoperative
14.8±6.3
17.3±8.1
18.3±9.4
23.2±12.7
27.9±16.3
03
Stapes Surgery: A Review of 515 Operations Performed from 1988 to 2002
Table 3. Intraoperative, immediate postoperative and late postoperative complications
Complication
No. of ears
%
Intraoperative complications/
anatomical variations
Section of the chorda tympani
Presence of the overhanging facial nerve
Presence of “biscuit” footplate
Floating footplate
Tympanic membrane perforation
Local hemorrhage
Fixed malleus
Perilymph gusher
130
15
13
9
4
4
2
1
25.2
2.9
2.5
1.8
0.8
0.8
0.4
0.2
Immediate postoperative
Acute vertigo
Transient facial nerve paralysis
5
13
1.0
2.5
Late postoperative
Sensorineural hearing loss
Alteration in gustatory sensitivity
2
1
0.4
0.2
fenestra operations. Rizer and Lippy[41] reported that
partial or total stapedectomies yielded better results,
compared with small fenestra operations, in the
range of frequencies involved in language comprehension. Ferrario et al.[42] compared the merits of
stapedectomy and small fenestra stapedotomy:
while the former resulted in better improvement in
air conduction, the latter was found more reliable in
controlling the postoperative course of bone conduction for acute tones, probably due to the fact that
it involved a more limited vestibular exposure and
lower potential risks to the labyrinth; hence, far
more fewer problems of dizziness in the postoperative clinical course.
pointed out an inversely proportional relationship
between the size of the fenestra and auditory
improvement. In 1982, Fisch[35] compared the results
of stapedectomies and stapedotomies, indicating that
the latter yielded better gap closure at 4000 Hz. Other
studies also reported better air-bone gap closure following stapedotomy operations, particularly at higher frequencies and with lower complication rates.[36-38]
Moreover, Persson et al.[38] found that long-term
results of stapedectomy involved a higher rate of
deterioration in hearing thresholds. Spandow et al.[39]
demonstrated better improvement in air-conduction
thresholds with small fenestra stapedotomy in the
frequency range of 4-6 kHz. Finally, Gjuric[40] pointed
out that it would be safer to create a small opening in
the visible part of the footplate in patients with an
overhanging facial nerve, so that removal of the prosthesis could be easier and less hazardous for the inner
ear, if revision surgery might be necessary.
In our study, we could not draw statistical interpretations concerning the effectiveness of the techniques employed because of the small size of
stapedectomy operations. Yet, taking into account
both our results and the growing number of reports in
favor of small fenestra operations, we are of the opinion that stapedotomy offers more advantageous
However, there are some authors that favor the
use of partial or total stapedectomies over small
Table 4. Literature data on case studies concerning the improvement in the
closure of the air-bone gap
Author(s)
Moon (1968)
House (1967)[23]
Smyth and Hassard (1978)[24]
McGee (1981)[25]
Moller (1992)[26]
Glasscock et al. (1995)[27]
Sedwick et al. (1997)[28]
Frias et al. (2000)[29]
Kos et al. (2001)[30]
Agrawal and Parnes (2002)[31]
Simoncelli et al. (2005)
[22]
No. of ears
Duration
Success rate (%)
460
140
584
255
215
600
550
183
604
112
380
–
4 mo
4 mo
6 mo
3-6 mo
1-243 mo
4 mo
1 yr
1-21 yr
2.5 mo
3-180 mo
96.0
92.0
94.0
91.1
95.0
91.3
78.2
79.0
79.0
85.7
80.8
04
The Mediterranean Journal of Otology
results in terms of inner ear performance, particularly in clinically advanced forms of otosclerosis.[18,37,43]
Stapes surgery is generally performed under local
anesthesia and can be considered for elderly patients
or those presenting with an advanced impairment of
the cochlear reserve.[42,44,45]
10.
The data provided by this study and by relevant
literature reports clearly indicate that, in experienced
hands, stapes surgery yields very good functional
results, with complete or partial closure of the conduction gap in the great majority of cases, and with
extremely low rates of intraoperative and postoperative complications. Moreover, improvement
achieved surgically does not exclude the use of hearing aids that may be required to promote communication and socialization needs of the patient.
11.
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