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Prospects of Simultaneous Bilateral Stapedoplasty

Y. Yanov, V. Sitnikov, V. Babiyak, An. Vavilova, M. Levinina

St. Petersburg Scientific Research Institute of Ear, Throat, Nose and Speech, St. Petersburg, Russia

ABSTRACT

Objective: The objective of this study was to evaluate clinical and audiological results of surgical treatment in patients with otosclerosis after simultaneousbilateral stapedoplastyin comparison with patients operated unilaterally.
Study Design: The study design was a retrospective review.
Setting: This study was performed at the Ear Pathology and Physiology Department of St. Petersburg Scientific Research Institute of Ear, Throat, Nose and Speech, St. Petersburg.
Patients: The study included 104 patients with otosclerosis.
Intervention: 32 patients with otosclerosis had underwent simultaneous bilateral stapedoplasty and in 72 patients stapedoplasty was performed unilaterally.
Main Outcome Measures: The patients passed precise otorhinolaryngological, audiometry and vestibular examination before and after the operation.
Results: Hearing improvement on both ears after simultaneous bilateral stapedoplastywas estimated in 16 % patients as high (the air-bone gap less than 10 dB), in 50 % as good (the air-bone gap from 10 to 15 dB) and in 25 % as satisfactory (the air-bone gap more than 15 dB). There were no labyrinth complications in all cases. Besides, there was no significant difference in postoperative vestibular reaction after simultaneousbilateral stapedoplastyand after stapedoplasty only on one ear.
Conclusions: The results of the complex examinations led us to the conclusion that simultaneous bilateral stapedoplastyis the efficient method of hearing improvement allowing to attain simultaneous restoration of hearing in both ears, that is, binaural hearing.
Key words: Otosclerosis surgery,Bilateral stapedoplasty, Postoperative outcome, Computerized electronystagmography.
Pro Otology 1:42—46, 2004

INTRODUCTION

The proper functioning of the human hearing analyzer is determined, to a large extent, by the state of binaural hearing. It is just owing to binaural hearing that the essential property of the hearing system – the ability to localize where from a sound is coming – is realized, thus enabling the humans to be oriented adequately in the space.

Otosclerosis is considered to be a focal pathology of the labyrinth osseous capsule resulting in progressive hearing loss. Generally this pathology is emerging as a bilateral process; nevertheless developing hearing loss is often of the asymmetrical nature. In the case of asymmetrical hearing loss or after unilateral surgical treatment undertaken to improve hearing, this disease could be accompanied by the Stenger symptom – sounds are perceived predominantly by the better-hearing ear. This phenomenon is most likely caused by contralateral cortical inhibition in the result of more active excitation of central sections of the hearing analyzer on the surgery side.

Development of inhibition processes in the auditory cortex in the case of otosclerosis was proven by a number of researchers (6,4). Physiological and clinical observations mentioned above support the concept that the optimum solution of the problem of surgical rehabilitation of patients with otosclerosis would be restoration of bilateral hearing ability.

However, no unanimous opinion exists now as to the term of performance of the hearing improvement surgery on the other ear. Some researchers recommended to be confined to unilateral stapedoplasty only, in order to prevent the possible risk of postoperative complications, which may emerge in the inner ear (8). At the same time, many authors think it expedient to perform surgery on the second ear, in order to provide for binaural hearing (2,7,9). It is customary to perform surgery on the other ear, on the contralateral side, in 6, 12 months and more after the first operation of stapedoplasty (3,7). At the same time, results of generalization of the world experience in surgical treatment of otosclerosis and the up-to-date practice based on the modern level of technological support allow to revise some orthodox concepts concerning, in particular, the terms of surgery on the second ear. In the present state of the art of otosclerosis surgery, it is reasonable to assume that simultaneous, maximally sparing operations on both ears will be instrumental to earlier and more effective rehabilitation of patients both in medical and social sense.

PATIENTS AND METHODS

In the Ear Pathology and Physiology Department of the St. Peterburg Scientific-Research Institute of Ear, Throat, Nose and Speech we arranged close surveillance of the group of 32 patients with otosclerosis aged from 30 to 70 (9 men and 23 women), who had undergone simultaneous bilateral stapedoplasty (SBS) on both ears. 12 patients had been affected by tympanic form of otosclerosis, 18 – by mixed form and 2 – by cochlear form of otosclerosis. Results of examination of these 32 patients after SBS surgery were analyzed as compared with data determining the condition of patients with otosclerosis, who had undergone traditional stapedoplastic surgery – on the one ear only (72 patients).

In addition to standard otorhinolaryngological examination, all patients were subjected to comprehensive examination of the vestibular function and audiologic examination prior to surgery and after it.

In the framework of the audiologic examination, there were carried on: acumetry using conventional tuning fork tests, threshold pure tone audiometry, speech audiometry, noise level metering, recruitment determination, tympanometry (measurements of the acoustic impedance and the acoustic reflex), determination of spontaneous electroacoustic emission, investigation of noise interference immunity under conditions of the free acoustic field.

The comprehensive examination of the vestibular function was carried on twice – prior to surgery and after it, in 5 to 9 days, and included tests as follows: investigation of the spontaneous and positional nystagmus, assessment of the smooth pursuit eye movements, air bithermal caloric test (to be carried on only prior to surgery), optokinetic tests. For registration and quantitative analysis of obtained eye movement responses, the method of computerized electronystagmography was applied.

On the basis of audiological, vestibular function metering and somatic criteria, there were elaborated indications and contraindications for SBS surgery.

Indications for SBS surgery

1. Absence of sound lateralization during the Weber tuning fork test, negative results of the Rinne test on both sides.

2. Comparatively symmetrical bilateral hearing impairment of II – III grade (with the hearing loss difference between the right and left ear by air conduction no more than 15 dB).

3. Existence of the bone-air interval of more than 20 dB in the range of speech frequencies, on both sides.

4. High percent of speech discrimination on both sides, typical for the conductive hearing loss.

5. Absence of the acoustic reflex (contralateral and ipsilateral), the tympanogram of the type A.

6. Data of vestibulometry showing absence of spontaneous vestibular disorders.

Contraindications for SBS surgery

Pre-surgery contraindications

1. Symptoms of the active otosclerotic process obvious on evidence derived from data of microotoscopy (the positive Schwartze sign).

2. Pronounced sensoryneural component of hearing loss on the one or both sides (the bone conduction threshold lower than 40 dB in the range of middle and high frequencies), in the presence of recruitment, on evidence of above-threshold tests results.

3. Asymmetrical hearing loss with the air conductance difference between the right and left ears no more than 15 dB.

4. Low percentage of speech discrimination by the one or both ears.

5. Symptoms of vestibular disorders (vertigo or imbalance complaints) and signs of the vestibular dysfunction on evidence derived from data of vestibulometry.

6. Too young (under 20) or too old (above 70) age of a patient.

7. Severe somatic diseases (diabetes mellitus, blood diseases, hypertensive disease, severe forms of cervical spondiloartrosis or vertebrobasilar insufficiency, severe allergic or autoimmune diseases, diseases of the central nervous system.

Considering that in the course of operating on the first ear some unforeseen circumstances can emerge unfavorable for the operation result, we deemed it worthwhile to single out a number of intraoperative contraindications for surgery to be performed on the other side.

Intraoperative contraindications

1. Pronounced vestibular reaction emerging after stapes footplate perforation of the first ear (severe vertigo, nausea, vomiting, spontaneous nystagmus III degree as determined by visual inspection).

2. Inadequately large extent of surgical intervention on the first ear (traumatic stapedectomy, perilymph flooding).

3. Specific technical problems and errors emerging in the course of surgery (obliterating form of otosclerosis, gross hemorrhage, incus luxation, facial canal overhang, some damage of the facial nerve, general habitus deterioration of the patient).

4. Failure to attain any hearing gain in the first ear on evidence derived from data of spoken voice examination.

The method of simultaneous
bilateral stapedoplasty

All patients’ ears were operated using the unified method of piston stapedoplasty and local anesthesia. The first ear to be operated was the one that caused the most subjective anxiety to the patient (with greater hearing loss and/or tinnitus).

Surgery was performed using transcanal approach to the middle ear. There were used titan prostheses manufactured by Kurz company or original Teflon prostheses designed in the Institute. To seal an excess of the oval hole in the base of stapes, a blood clot was used (5). When necessary, the posterior wall of the external acoustic meatus was strengthened by an autogenic cartilage, to prevent scarring and subsequent dislocation of the prosthesis.

In the case of moderate vestibular reaction after perforation of the base of stapes and the sufficient hearing gain in the first ear, the operation of the second ear might be performed. The total duration of the operation on both ears generally was not exceeding 1.5 h.


FIG. 1. The spontaneous nystagmus testing (with eyes closed) in patient A. - with otosclerosis, on the 6-th day after bilateral simultaneous stapedoplasty. Bidirectional spontaneous nystagmus: A - in straight eyes position – spontaneous nystagmus is absent; B - in right eyes position - horizontal spontaneous nystagmus, directed to the right; C - in left eyes position - horizontal spontaneous nystagmus, directed to the left.

RESULTS

Postoperative care of patients

During the early postoperative period, patients must have been kept in a fixed position lying in bed on their backs over the time interval of 3 days. Antibiotic prophylaxis was given to all patients using broad spectrum medications. For purposes of prophylaxis of the postoperative vestibular reaction, the patients were given Betaserk. Tampons were pulled out of the ear on the 7th – 8th day after operation. Usually the patients were discharged from the clinic on the 10th – 12th day.

Results of postoperative vestibulometry

The intensity of the postoperative vestibular reaction (PVR), determined by the period when the patients complained of vertigo, nausea and imbalance, was assessed in three degrees: high, moderate and mild (1). In the case of the mild vestibular reaction (degree I) vestibular disorders – vertigo, nausea, imbalance – were observed only for the first three days after surgery. In the case of the moderate vestibular reaction (degree II) complaints mentioned above continued the next three days. The degree of intensity of the vestibular reaction was considered as high (degree III) in case all complaints – of vertigo, nausea and imbalance – continued more than six days after surgery.

The PVR after SBS surgery was assessed as mild one (degree I) in 32% of the patients and as moderate one (degree II) – in 52%. The intensive PVR (degree III) was noted in 16% of the patients. Thus, the patients subjected to SBS surgery showed predominantly the moderate or mild postoperative reactions. These data are in sufficiently strong correlation with the data of examination of patients undergone unilateral stapedoplasty surgery: the most part of them showed the mild (44%) or moderate (25%) postoperative vestibular reaction.

The objective examination 5 to 9 days after surgery showed that the majority of the patients (56%) had the horizontal spontaneous nystagmus. It seems to be important to note the peculiar bidirectional character of the spontaneous nystagmus we observed in the most patients after SBS surgery. The spontaneous nystagmus was directed to the right side with glance moved to the right, and to the left side with glance moved to the left (FIG. 1); probably, it reflects the continuing irritation response to stimuli coming simultaneously from both labyrinths. In patients with unilateral surgery the spontaneous nystagmus was registered (also without visual fixation) in 34 patients out of 72 (47%), but always the nystagmus was unidirectional.

Results of audiological examination after surgery

In all cases there was achieved the sufficient hearing gain in both ears. There were no postoperative labyrinth complications in all cases. Hearing gain in the result of surgery was estimated as high (the value of the air-bone gap less than 5 dB) in 16% of the patients, as good in 50% (the air-bone gap 5 to 10 dB) and as satisfactory in 25% of the patients (the air-bone gap more than 10 dB). FIG. 2 shows the results of audiological examination of the patient before and after SBS.

As compared with patients undergone unilateral-sided stapedoplasty, the patients undergone SBS surgery noted that their acoustic perception became more volumetric, more distinct even in the noisy environment. In 19 cases out of 32 the patents noted disappearance of permanent tinnitus; one patient declared the lower intensity of tinnitus. It was noted that maximum symmetrical hearing improvement, not exceeding 5 to 10 dB, was achieved in patients having had practically symmetrical initial hearing loss.

 

  

A: Before bilateral simultaneous stapedoplasty
 

B: One month after bilateral simultaneous stapedoplasty

FIG. 2 A,B. Pure-tone audiograms of patient B. - 47 years old, with otosclerosis.

 

DISCUSSION

As presented data of simultaneous bilateral stapedoplasty are showing, the satisfactory functional results of surgery were achieved in the majority of cases. The duration and intensity of the postoperative vestibular reaction appeared to be of the moderate to mild degree, therefore approximately identical to those of the vestibular reaction in patients undergone unilateral stapedoplasty.

Thus, advantages of simultaneous bilateral stapedoplasty are as follows:

1. Binaural hearing is attained, resulting in improvement of speech discrimination, noise immunity and ototopics.

2. The overall time required for auditory and social rehabilitation of patients is reduced; the necessity of repeated admission of the patient to the hospital is eliminated.

3. The psychological trauma caused by awaiting for the second operation is prevented.

4. The economic efficiency (both immediate and circumstantial) is achieved due to saving of medication costs, hospitalization expenses and transport costs.

5. The subjective social and psychological self-esteem of patients, as well as their quality of life may be greatly improved.

6. Successful treatment gives great countenance both to the surgeon and the patient.

Its drawbacks are at present as follows:

1. Too long time and too great invasiveness of the surgical operation.

2. Certain risk of emerging of intraoperative and postoperative complications on both sides (vestibular dysfunction, sensoryneural hearing loss).

3. Greater difficulties arising in the postoperative period (restricted motion activity, temporary difficulties in contacts with other people, because both ears are obstructed simultaneously).

4. More sudden transition from the “world of silence” to the “world of sounds” (though the short-time discomfort is generally of temporary nature and is soon compensated by the positive emotional response of the patient).

CONCLUSION

We think that simultaneous bilateral stapedoplasty surely offers new prospects in surgical treatment of otosclerosis and restoration of patient’s socially acceptable hearing. Primarily, it is determined by specific features of the human auditory apparatus, because it is based on the principle of binaural hearing, with its potential properties that are much more wide and rich than those of monaural hearing. In additional, simultaneous activation of both auditory receptors allows to eliminate the risk of emerging of the Stenger symptom in the patient, with subsequent development of the “cortex hearing loss” (6).

At the same time, bilateral stapedoplasty cannot be considered to be a standard unified intervention; on the contrary, it must be adapted to specific conditions every time it is used. As in the case of unilateral stapes surgery, bilateral stapedoplasty surgery must be performed by a specialist having high qualification and long-time experience in the field of ear surgery. The other condition as important as this is the careful selection of patients and their pre-operative examination.

We think that the subsequent conceptual investigation of the issue of expediency and prospects of simultaneous bilateral stapedoplasty will contribute to development of the necessary theoretical and methodological base allowing to modify and improve some traditional concepts of otosclerosis surgery.

REFERENCES

  1. Vavilova AA. The function of the vestibular system in patients with otosclerosis before and after stapedoplasty. St. Peterburg, 2000.

  2. Kolomichenko AI, Gukovich VA, Hurshak EM, et al. Operations on the stapes in otosclerosis. Kiev, 1962.

  3. Nikitina VF. Using the external ear autocartilage in otosclerosis surgery. Vestnik Otorhinolar 2000;5:35-8.

  4. Rozenblum AS. Short term hearing adaptation in patients with otosclerosis. In: Actual problems of hearing loss. Moscow, 1981;24?:14-20.

  5. Sitnikov VP. Methods of the improving of the stapedoplasty. The 3-rd Congress of Otorhinolaryngologists of Byelorussia. Minsk, 1992:57-8.

  6. Hilov KL. Otosclerosis. Moscow: Medgiz, 1958.

  7. de Bruijn AJ, Tange RA, Dreschler WA, et al. Bilateral stapedotomy in patients with otosclerosis: a disability-oriented evaluation of the benefit of second ear surgery. Clin Otolaryngol 1998;23:123-27.

  8. Ludman H, Grant H. The case against bilateral stapedectomy and problems of post-operative follow-up from the Kings College Hospital series. J Laryngol Otol 1976;87:833-43.

  9. Lundman L, Mendel L, Bagger-Sjoback D, et al. Hearing in patients operated unilaterally for otosclerosis. Self-assessment of hearing and audiometric results. Acta Otolaryng (Stockh) 1999;119:453-58.

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