Revision surgery in otosclerosis--an investigation of the factors which influence the hearing result

Vertigo Associated with Otosclerosis and Stapes Surgery-A Narrative Review

Otosclerosis is a pathological condition affecting the temporal bone, and is characterized by remodelling of the labyrinthine bone tissue through a dynamic process of osteolysis and osteogenesis. This condition progressively leads to hearing loss, tinnitus, and vertigo. Stapedotomy, a surgical procedure involving the removal of the stapes superstructure and its replacement with a prosthesis, is the treatment of choice to improve hearing in individuals with otosclerosis. However, vestibular dysfunction is a significant complication associated with this procedure, which can occur intraoperatively or postoperatively, ranging from the immediate postoperative period to weeks, months, or even years after surgery. This paper aims to provide a comprehensive review of the most important causes of vertigo associated with otosclerosis and stapes surgery with the goal of minimizing the incidence of this complication. Understanding the underlying factors contributing to vertigo in this context is crucial for the prevention and effective management of vertigo in patients undergoing stapedotomy.

Fixed vs Measured Length of Stapes Prosthesis in Stapes Surgery

Aims The aim of this study is to assess the relationship between the prosthesis length and the outcome of the primary stapes surgery in patients with otosclerosis. Material and Methods This was a retrospective cohort study. We reviewed medical records of 218 patients between January 2015 and August 2020 in two different referral centers. It was conducted in two hospitals by two different well experienced otologic surgeons that one of them believes in fixed length (4.75 mm) of stapes prosthesis (group A) and, the other one believes in measuring the distance between the footplate and incus long process to choose the proper length of prosthesis (group B). The surgery success rates and complications between these two groups were compared 3 months postoperatively. Results Mean age, preoperative bone conduction (BC) audiometric threshold and air-bone gap, postoperative BC and air-bone gap were similar in both groups (All p > 0.05). Vertigo frequency was not significantly different between the two groups (p = 0.303). There were no significant differences regarding the number of favorable postoperative outcomes between group A and B (70 (97.2%) vs. 142(97.3%) respectively) (p = 0.632). Conclusion This study found no significant difference regarding the hearing outcomes between fixed length vs measured length of stapes prosthesis.

Revision Stapedotomies: the Role of Periprosthetic Scar Tissue Formation in the Development of Unsatisfactory Hearing Results after Stapedotomy

Introduction  Revision stapes surgeries are difficult to perform, and their audiological results are inferior to primary surgeries.

Objective  Our goal was to identify the most common and most influential postoperative reasons that cause persistent air-bone gap (ABG) after the primary surgery. Our focus was concentrated on the mechanical dysfunctions in the middle ear, with special regard to postoperative adhesion formation.

Methods  We performed a retrospective case series study with 23 cases that underwent revision stapedotomies.

Results  A significant improvement was seen in ABG and air conduction levels after surgery. The periprosthetic adhesion formation was seen in 65% of the cases, and it was the primary cause behind the unsatisfactory hearing result in 30% of cases. There was no significant difference in the level of persistent ABGs after the primary surgery, in case of the intratympanic adhesion presence, compared with the presence of other surgical failures. Concerning hearing and ABG gain after revision surgery, the non-inferiority of the negative effect associated with adhesion was shown compared with the other reasons.

Conclusion  The revision stapedotomy is an efficient treatment option in case of persistent ABG. Periprosthetic adhesions are the most common intratympanic reasons for compromised audiological outcomes after stapedotomy.

Adhesion formations have the same negative effect on ABG development as any other surgical failure, and the revision could be more challenging in these cases. These findings highlight the use of the most atraumatic surgical technique and preservation of intact intratympanic mucosa during middle ear surgery.

The Relationship between Stapes Prosthesis Length and Rate of Stapedectomy Success

OBJECTIVES

To identify whether measurement of the prosthesis length is mandatory in patients requiring otosclerosis surgeries and to assess their postoperative audiometric outcomes. In addition, evaluation of prosthesis length used in revision compared to primary stapedectomy was carried out.

STUDY DESIGN

Case series with chart review.

METHODS

Chart review of 393 patients undergoing primary (321) versus revision stapedectomy (72) was performed in a tertiary referral center. The indication for surgery was the presence or persistence/recurrence of an air-bone gap (ABG) greater than 20 dB. Air and bone conduction thresholds (ACT and BCT, respectively), ABG as well as pure tone averages (PTAs) were determined for all patients, and the results were compared preoperatively and postoperatively.

RESULTS

Prosthesis length used ranged from 3.0 to 6.0 mm without differences between primary and revision groups. Of the revision surgeries, 62.5% were stapedectomies versus stapedotomies (P < 0.001). Patients showed significant decrease in speech discrimination score, with increased air and bone conduction thresholds as well as mean ABG and PTA before the revision surgeries as a first procedure failure. Prosthesis length changes occurred in 73.5% of the cases, with an average absolute change of 0.55 mm. Prosthesis length did not affect postoperative audiometric results between primary and revision groups, in all surgeries combined. When grouping stapes surgery into accurately versus inaccurately measured incus-footplate distance, significant differences were observed in prosthesis length employed (P < 0.01). Hearing outcomes were also better in the group in which an accurately measured prosthesis was chosen, as opposed to “standard-length” prosthesis.

CONCLUSIONS

This study corroborates postoperative success rates of revision surgeries, which show smaller improvements in hearing compared to a primary intervention. Accurate intra-operative measurement of prosthesis length was correlated with better audiometric results postoperatively.

Revision surgery for otosclerosis: An overview

Stapes surgery for otosclerosis has been proved to be a very satisfying procedure. However, the condition is difficult for the patients with no or little hearing gain after surgery and for those who had sudden or gradual hearing loss after a successful air-bone gap closure in the follow-up period. The issue of re-exploring the middle ear is challenging. A general review of this subject from several points of view remains lacking. In this study, articles related with the revision surgery for otosclerosis have been reviewed after a PubMed research and common and/or contradictory points were documented. The aim of this study is to give an insight to diagnostic and therapeutic approaches for the clinicians in patients who need a revision surgery. In conclusion, prosthesis problems, loose prosthesis in stapedotomy and migrated prosthesis in stapedectomy are the most common causes for revision surgery. Most important indicators which effect better hearing outcome following revision surgery are those ears with the presence of incus, with no obliteration of oval window, with small fenestra stapedotomy and the experience of surgeon. The risk of neurosensorial hearing loss in revision cases is not high but the hearing gain is limited as compared to primary cases. The rate of 10 dB air-bone gap closure is around 60%-70% at most and even less promising results have been reported. Patient’s demands and expectations have to be clarified in a realistic way.

Persistent and recurrent conductive deafness following stapedotomy

Background:

Stapedotomy produces the best hearing results of any otological operation. However, in a small number of cases the air–bone gap is not successfully closed, or conductive hearing loss recurs.

Objective:

To investigate the proportion of cases in the senior author's series which required revision surgery and to determine the medium to long term success rate of surgery, taking into account the results of revision surgery.

Methods:

Review of a series of 233 primary stapedotomy operations and 100 revision procedures carried out by one surgeon over a 20-year period.

Results:

Closure of the air–bone gap to within 10 dB was achieved in 80 per cent of cases following the primary procedure. Fifteen per cent of patients developed a recurrence of conductive hearing loss. When the results of revision surgery were taken into account, the proportion of ears with a mean air–bone gap of less than 10 dB was 86 per cent. However, of the patients undergoing revision surgery, air–bone gap closure to within 10 dB was only achieved in 52 per cent of cases.

Conclusion:

The best chance of obtaining a successful outcome in stapedotomy is to achieve this for the first procedure. However, revision surgery does increase the medium to long term success rate.

Revision Stapedectomy

Revision stapedectomy can be a technically demanding operation. The surgeon must be prepared for many pathologic conditions before revision stapes surgery. Appropriate preoperative patient counseling is a must. The best chance for hearing improvement is in those cases that have a delayed conductive hearing loss after primary stapedectomy. This article serves as a guideline for discussing the myriad possibilities that may be encountered during this type of revision stapedectomy. Indications for revision stapedectomy and general surgical guidelines for management of specific pathologic conditions are discussed. The material presented is based on literature review, the authors' personal experience, and a review of temporal bone studies relative to stapes surgery.

Malleostapedotomy in revision surgery for otosclerosis

PURPOSE

The purpose of this study was to analyze the results of malleostapedotomy and to compare them with those of a conventional incus stapedotomy in a series of 82 consecutive surgical revisions in otosclerotic patients.

MATERIALS AND METHODS

82 consecutive revision stapes surgery cases over 5 years were evaluated. The preoperative and postoperative audiometric data of 80 (97.5%) of the patients were obtained.

RESULTS

71 of the patients underwent a functional revision procedure as malleostapedotomy (56, 79%) or as incus stapedotomy (15, 21%). The most common cause of failure of primary surgery was a displaced or malfunctioning prosthesis (86.2%). Pathologic changes of the oval window were found in 80% of the cases. Problems of the incus were identified in 80% and abnormality of the malleus in 48.6% of the cases. The functional success rate of malleostapedotomy (closure within 10 dB) was found to be higher than that of traditional incus stapedotomy (p < 0.05). Overclosure was seen in 12 patients (17%) and a significant sensorineural hearing loss in 2 patients (3%). There were no dead ears in this series. The postoperative hearing results after first revision surgery were better than those after multiple surgical procedures (p < 0.05).

CONCLUSIONS

Malleostapedotomy yields better functional hearing results than incus stapedotomy in revision surgery for otosclerosis. The detection of many malleus fixations was the result of the systematic exposure of the anterior malleal process and ligament through an endaural approach with superior canaloplasty.

Laser stapedotomy

Thirty-four ears with conductive hearing loss due to otosclerosis were operated upon using the laser stapedotomy technique. Audiological results were compared with the results of 316 non-laser stapedotomies. The post-operative air-bone gap, calculated as the difference between the post-operative air and bone conduction levels, was smaller with the laser stapedotomy group. Also, the bone conduction showed significant improvement with the use of laser. Significant sensorineural hearing loss was not found in any of the laser-treated patients. According to our results, we concluded that laser is of benefit in stapes surgery for improving the hearing results and minimizing the inner ear trauma.

Effect of penicillin on formation of fibrous adhesions in acute otitis media

Fibrous middle ear adhesions are occasionally encountered in middle ear surgery and may cause a hearing impairment. Although usually associated with chronic otitis media, adhesions are also found following a single episode of experimental acute suppurative otitis media, suggesting a pathogenesis based on the inflammatory process engaging acute infection. In a well-established rat model of pneumococcal acute otitis media, we report on the effect of penicillin V on formation of fibrous middle ear adhesions. Previous studies have shown marked impact of penicillin on mucosal goblet cell density and other histopathologic features. Number, anatomic localization, and histopathologic morphology of adhesions were assessed in a longitudinal study of 25 normal, 25 untreated, and 25 treated rats. Although penicillin administration induced a slight tendency toward fewer ears with adhesions and fewer adhesions per ear, these changes were nonsignificant. Histomorphology and the general pattern of anatomic localization of adhesions were unaffected by penicillin administration. We conclude that administration of penicillin has an inconspicuous effect on the formation of fibrous adhesions in experimental acute otitis media caused by Streptococcus pneumoniae.