Factors affecting postoperative outcome in otosclerosis patients: Predictive role of audiological and clinical features

Factors Associated With Hearing Outcomes After Stapedotomy in Taiwanese Patients With Clinical Otosclerosis

OBJECTIVE

To examine the clinical factors associated with the effectiveness of stapedotomy in improving hearing sensitivity in Taiwanese patients with otosclerosis.

METHODS

In this retrospective study, we reviewed the medical records of 31 patients (36 ears) with otosclerosis undergoing stapedotomy performed by a single surgeon. Preoperative and postoperative hearing results were analyzed to identify factors associated with hearing outcomes after stapedotomy in the Taiwanese population with clinical otosclerosis.

RESULTS

Compared with preoperative pure tone averages (PTAs), stapedotomy significantly improved postoperative air conduction (AC) thresholds (P < .0001), bone conduction (BC) thresholds (P = .025), and air-bone gaps (ABGs; P < .0001). Postoperative closure of ABGs less than 10 or 20 dB was achieved in 16 (44.4%) and 33 (91.7%) of 36 surgical ears. Improvement in postoperative AC thresholds and ABGs and the size of preoperative ABGs were significantly correlated (r = .650, P < .001 and r = .745, P < .001, respectively). Gender-stratified analysis indicated a stronger correlation between improvement in postoperative AC thresholds and preoperative ABGs in male patients than in female patients (r = .893, P < .001 and r = .476, P = .014, respectively), and in postoperative and preoperative ABGs (r = .933, P < .001 and r = .626, P < .001, respectively). With the more stringent criteria for surgical success, factors including age (≤50 years), type (conductive, BC ≤25 dB), and degree (PTA ≤55 dB) of preoperative hearing loss led to more favorable outcomes.

CONCLUSIONS

We reported evidence supporting a potential gender difference on hearing outcomes after stapedotomy in Taiwanese patients with otosclerosis. Age, type, and degree of preoperative hearing loss may affect the surgical success rate.

The effect of female hormone in otosclerosis. A comparative study and speculation about their effect on the ossicular chain based on the clinical results

Purpose

This study aimed at identifying gender differences in the hearing thresholds in a sample of patients with otosclerosis before and after surgery to understand the impact of female hormones on auditory thresholds.

Methods

This retrospective study analyzed 184 patients (123 women and 61 men) affected by otosclerosis. All the patients were affected by conductive hearing loss and treated by stapedoplasty. Auditory thresholds at the baseline (T0) and one month after surgery (T30) were collected. Air and bone thresholds and Air Bone Gap (ABG) were compared between females and males using one-way ANOVA.

Results

Statistically significant differences were observed comparing the air threshold at T0 vs T30 both in women and men (p < 0.0001). No statistically significant differences were observed in the bone conduction thresholds before and after surgery. The comparison between females and males showed statistically significant differences both at T0 (p < 0.01) and T30 (p < 0.05) for air conduction thresholds and ABG at 4000 Hz.

Conclusion

Although stapedoplasty reduced the difference between females and males in the air conduction thresholds and ABG, women showed better recovery of their middle ear function with better auditory thresholds and ABG. The female hormones might positively impact the ligaments of the incudostapedial joint improving chain flexibility. This benefit might explain the statistically significant difference observed in women at 4000 Hz before and after surgery.

Stimulation efficiency of an actuator driven piston at the biological interface to the inner ear

Direct acoustic cochlear stimulation uses piston motion to substitute for stapes footplate (SFP) motion. The ratio of piston to stapes footplate motion amplitude, to generate the same loudness percept, is an indicator of stimulation efficiency. We determined the relationship between piston displacement to perceived loudness, the achieved maximum power output and investigated stapes fixation and obliteration as confounding factors. The electro-mechanical transfer function of the actuator was determined preoperatively on the bench and intraoperatively by laser Doppler vibrometry. Clinically, perceived loudness as a function of actuator input voltage was calculated from bone conduction thresholds and direct thresholds via the implant. The displacement of a 0.4 mm diameter piston required for a perception equivalent to 94 dB SPL at the tympanic membrane compared to normal SFP piston displacement was 27.6–35.9 dB larger, consistent with the hypothesis that the ratio between areas is responsible for stimulation efficiency. Actuator output was 110 ± 10 eq dB SPL_FF @1V_rms ≤ 3 kHz and decreased to 100 eq dB SPL_FF at 10 kHz. Output was significantly higher for mobile SFPs but independent from obliteration. Our findings from clinical data strongly support the assumption of a geometrical dependency on piston diameter at the biological interface to the cochlea.

Revision Stapes Surgery: Hearing Symptoms and Associations With Intraoperative Findings and Outcomes

OBJECTIVE

Stapes surgery for otosclerosis occasionally requires revision due to recurrent or persistent conductive hearing loss (CHL). This study examines outcomes after revision stapes surgery.

STUDY DESIGN

Retrospective review.

SETTING

Single tertiary neurotology center.

METHODS

Patients undergoing revision stapes surgery for otosclerosis from 2008 to 2017 were reviewed. Postoperative air-bone gaps (ABGs) were the primary outcome measure.

RESULTS

During the study period, 150 patients underwent revision stapes surgery. One hundred patients (67%) had gradually progressive recurrent CHL; 16 (11%), sudden recurrent CHL; 13 (9%), persistent CHL; and 21 (14%), no CHL. For 129 patients with CHL, the mean ABG improved from 23.7 to 9.3 dB (P < .0005). The most common intraoperative findings for these patients were prosthesis displacement with incus necrosis (38%) or without it (43%), normal anatomy with seemingly good prosthesis placement (6%), and abundant scar tissue (6%). Patients with recurrent hearing loss achieved lower mean ABGs than patients with persistent hearing loss (8.8 vs 13.2 dB, P = .02). There were no associations between onset pattern of CHL or intraoperative findings and hearing outcomes (P > .05). Four patients (2.7%) developed sensorineural hearing loss after revision, defined as an increase in bone conduction pure tone average ≥15 dB, all of whom had previous replacement of a malpositioned prosthesis.

CONCLUSIONS

Revision stapes surgery confers significant improvement in hearing for patients with persistent and recurrent CHL, although patients with persistent CHL after initial surgery see less improvement with revision.

Association Between the Duration of Hearing Loss and Hearing Outcomes in Surgery for Otosclerosis

INTRODUCTION

Hearing loss due to otosclerosis is effectively treated with surgery. The association between duration of hearing loss and surgical outcomes is unknown.

STUDY DESIGN

Retrospective review.

SETTING

Large otology referral center.

METHODS

Patients undergoing primary stapes surgery for otosclerosis from 2005 to 2017 were evaluated according to their self-reported duration of hearing loss. Closure of the air-bone gap (ABG) was the primary outcome measure.

RESULTS

A total of 580 stapes operations were included. Sixteen percent of patients reported hearing loss for ≤1 year; 25%, >1 to ≤5 years; 24%, >5 to ≤10 years; 24%, >10 to ≤20 years; and 12%, >20 years, respectively. Average pre- and postoperative ABGs were 26.1 and 9.6 dB (P < .0005). Patients with longer duration of hearing loss had worse preoperative ABGs (P < .0005). After surgery, patients with longer duration of hearing loss had a greater reduction in their ABGs (P < .0005) such that the remaining ABG was not associated with duration of hearing loss (P > .05). There were no significant associations between the duration of hearing loss and complication rates or the need for revision surgery.

CONCLUSION

Otosclerosis is effectively treated with surgery even after a long duration of hearing loss, provided that sensorineural hearing and word recognition are favorable. Although far-advanced otosclerosis has known poorer hearing outcomes after stapes surgery, a long duration of hearing loss is an unreliable surrogate for this.

Fifteen-Year Follow-Up of Stapedotomy Patients: Audiological Outcomes and Associated Factors in a Middle Income Country

OBJECTIVE

To evaluate the short-term (postoperative), medium-term (5 years), and long-term (10 and 15 years) audiometric results of patients who underwent stapedotomy and to determine specific factors associated with better postoperative outcomes.

METHODS

This study is a retrospective case review of 486 ears with surgically confirmed stapes fixation who underwent microscopic small fenestra stapedotomy. Preoperative, postoperative, and medium- and long-term air conduction (AC), bone conduction (BC), and air-bone gap (ABG) were assessed. Postoperative factors associated with better postoperative outcomes were evaluated.

RESULTS

At 10- and 15-year follow-ups, ABG, AC, and BC were significantly deteriorated but clinically preserved in comparison with postoperative results. According to a multiple quantile regression, younger age was associated with better postoperative results at 0.25 kHz (p = 0.003) and 4 kHz (p = 0.028) and a smaller preoperative ABG was associated with better audiometric results at 0.25 kHz (p = 0.048), 0.5 kHz (p = 0.001), and 4 kHz (p = 0.001). In addition, younger age (p = 0.001 for AC and p < 0.001 for BC) and preoperative AC PTA (p < 0.001 for AC) were significantly associated with better postoperative AC and BC PTA.

CONCLUSIONS

Stapedotomy surgery provides short-, medium-, and long-term hearing benefits in our studied cohort. ABG, AC, and BC thresholds obtained after the surgery are clinically preserved in 5-, 10-, and 15-year follow-ups, with an age-expected BC deterioration. Smaller preoperative ABG and younger age were positive predictors for better postoperative ABG. Future research should address long-term subjective and quality of life outcomes.

Involvement of the Internal Auditory Canal in Subjects With Cochlear Otosclerosis: A Less Acknowledged Third Window That Affects Surgical Outcome

OBJECTIVE

To investigate the effects of cavitating lesions involving the internal auditory canal (IAC) in subjects with cochlear otosclerosis with regard to poststapedotomy hearing outcome.

STUDY DESIGN

Retrospective study.

SETTING

Tertiary referral center.

PATIENTS

A retrospective chart review of 134 subjects with otosclerosis treated from January 2011 to June 2017 at Seoul National University Bundang Hospital was conducted. Sixteen subjects (23 ears) with temporal bone computed tomography (TBCT)-confirmed cochlear otosclerosis who underwent stapedotomy were included in the study.

MAIN OUTCOME MEASURES

Pure tone audiometry (PTA) (i.e., air and bone conduction; AC and BC, respectively) thresholds and air-bone gap (ABG), measured at 6 months postoperatively were compared between cochlear otosclerosis with and without IAC involvement (IAC group and non-IAC group, respectively).

RESULTS

A total of 14 of 23 ears showed involvement of the IAC. There were no significant differences in age, side of otosclerosis, or preoperative hearing threshold between the two groups. The mean postoperative AC and BC thresholds and ABG of the IAC group were significantly poorer (45.7 dB, 33.8 dB, and 11.8 dB, respectively) than those of the nonIAC group (24.1 dB, 20.0 dB, and 4.1 dB, respectively).

CONCLUSIONS

Cochlear otosclerosis with cavitating lesions involving the IAC showed significantly poorer postoperative audiological outcomes than those without any cavitating lesion. Cavitation extending to the IAC may act as a third window providing a route for sound energy shunting, and thus precluding successful hearing outcome in some subjects with cavitating otosclerosis after stapedotomy.

Hearing Aid Treatment in Patients with Mixed Hearing Loss. Part I: Expected Benefit and Limitations after Stapes Surgery

OBJECTIVE

The purpose of the present study was to determine the fraction of patients with mixed hearing loss who can or cannot expect benefit from power hearing aids (HAs) after stapes surgery.

DESIGN

The audiological outcome of 374 stapes surgeries was used to calculate the patients' individual postoperative requirements in terms of gain and output of HAs. These requirements were compared to the available gain and output provided by state-of-the-art power HAs at 0.5, 1.0, 2.0, and 4.0 kHz. According to these comparisons, ears were divided into three groups. For G0, required gain and output lay within the corresponding technical limits of the HAs at all frequencies. In G1, one or both requirements could not be fulfilled at 1 frequency. G2 combined all ears where the requirements lay beyond the HA's technical limitations at 2 or more frequencies.

RESULTS

Stapes surgery resulted in an improvement of air-bone gap (ABG) in 84.5% of the cases by 15.7 dB on average. Based on pure-tone average (0.5, 1.0, 2.0, 4.0 kHz), 40.6% of all cases showed an ABG ≤10 dB. 44.9% of all cases did no longer need a HA after stapes surgery. A power HA would fulfill both audiological criteria at all 4 frequencies in 81.6% of cases that needed a HA postoperatively. However, 18.4% would not be sufficiently treatable at 1 or more frequencies (15.0% in G1, 3.4% in G2).

CONCLUSIONS

The present study identified a subset of patients with mixed hearing loss after stapes surgery that cannot be treated sufficiently with available power HAs. As the residual ABG is an important reason for this lack of treatment success, the advancement of alternative hearing devices that circumvent the middle ear, such as powerful active middle ear implants, is indicated.

Predictors of hearing outcomes after stapes surgery in otosclerosis

Background: The current surgical treatment of otosclerosis is stapes surgery; however, few studies have reported the predictors of surgical outcomes.Aim/objective: This study aimed to investigate the prognostic predictors for postoperative hearing outcomes.Materials and methods: A total of 181 ears in 152 patients undergoing stapes surgery at a tertiary referral centre in Taiwan from 1996 to 2016 were retrospectively enrolled and preoperative and intraoperative parameters were obtained. Univariate and multivariate analyses were used to determine independent predictors of postoperative hearing outcomes. A regression model was also established. Hearing success was defined as a postoperative air-bone gap (ABG) ≤10 dB.Results: In univariate analysis, the absence of floating footplate during surgery (p = .003) and small preoperative ABG (p = .014) were associated with successful hearing outcomes. Multivariate logistic regression analysis further revealed the absence of floating footplate during surgery (p = .010) and small preoperative ABG (p = .015) remained independent predictors of postoperative hearing success.Conclusions and significance: Preoperative audiometric data and intraoperative finding may provide surgeons and patients with a better insight into surgical outcomes.

The clinical characteristics of otosclerosis and benefit from stapedotomy: our experience of 48 patients (58 ears)

Background: Stapedotomy has been proved to be one of the most efficient procedure to treat otosclerosis, various factors contribute to the diversity of the outcomes and controversial results exist from previous studies. Objectives: We evaluated clinical characteristics and outcomes of stapedotomy, as well as possible predictive factors of a successful outcome. Materials and methods: This retrospective study evaluated 58 ears from 48 patients with demographic data, plus short-term follow-up of hearing outcomes of 28 ears, and evaluated variables using univariate general linear regression analyses. Results: The average operation age was 41.54 years. A total of 87.5% (42/48) patients presented with bilateral otosclerosis. 39.66% (23/58) ears had CT finding before the surgery. Patients with persistent tinnitus accounted for 53.45% (31/58) and the average preoperative ABG of the 58 ears was 32.22 dB. We achieved good postoperative air-bone gaps (ABGs) overall but poor ABG closure at 4 kHz. No predictive factors were identified in the 28 ears that were followed up. Conclusions and significance: Delayed surgery may be attributable to insufficient recognition of otosclerosis. The fenestration size could be the reason for poor ABG closure at high frequency. However, more cases and longer follow-ups are required to confirm our findings.

Analysis of factors affecting postoperative functional outcome in patients with otosclerosis

OBJECTIVE

This study aimed to analyze the factors affecting postoperative hearing results of patients with otosclerosis.

METHODS

Medical records of 245 patients with clinical otosclerosis who underwent stapes surgery at our center from January 2009 to December 2018 were reviewed. The retrospectively collected data included patients' demographics, clinical characteristics, pre- and postoperative audiometric data, size of preoperative air-bone gap (ABG) (small/large). The patients were categorized into two groups according to the postoperative functional outcome: Group 1 consisted of patients with a postoperative ABG of ≤10dB and Group 2 comprised those with a postoperative ABG of >10dB. Evaluation of factors affecting functional outcome were performed by logistic regression analysis. Receiver operating characteristics (ROC) curve was generated to obtain the cut-off points for preoperative ABG.

RESULTS

There were no statistically significant differences between the two groups in terms of age group (p=0.393), gender (p=0.670), operated side (p=0.370), and laterality of disease (p=0.607). There were 42 patients (31.6%) with a small ABG and 91 patients (68.4%) with a large ABG in group 1, and six (13.6%) and 38 patients (86.4%), respectively in group 2. There was a statistical significant difference between the groups in terms of the size of preoperative ABG (p=0.020). In group 1, the mean preoperative air conduction (AC) threshold and preoperative ABG were significantly lower than in group 2 (p<0.001 and p<0.001, respectively). There was no statistically significant difference between the groups in terms of the preoperative bone conduction (BC) threshold (p=0.406). Preoperatively, the AC threshold and large ABG were found to be significantly poorer prognostic factors (p<0.001; 95%CI: 1.031-1.210 and p=0.037; 95%CI: 1.063-7.023, respectively). Preoperative ABG cut-off threshold for functional success was found to be 34.5dB. The functional success rate was significantly higher in patients with a preoperative ABG of <34.5 than in patients with a preoperative ABG of ≥34.5dB (p<0.001).

CONCLUSION

The preoperative AC threshold and large ABG were poor prognostic factors for postoperative hearing outcome in patients with otosclerosis. The functional outcomes were similar in patients with a preoperative small ABG and those with a preoperative ABG of <34.5dB. A preoperative ABG cut-off value of <34.5dB should be possibly considered as a parameter for predicting surgical success in otosclerosis and seems to be useful in clinical practice.

"Third Window" and "Single Window" Effects Impede Surgical Success: Analysis of Retrofenestral Otosclerosis Involving the Internal Auditory Canal or Round Window

Background and Objectives: We aimed to identify prognostic computed tomography (CT) findings in retrofenestral otosclerosis, with particular attention paid to the role of otosclerotic lesion area in predicting post-stapedotomy outcome. Materials and Methods: We included 17 subjects (23 ears) with retrofenestral otosclerosis who underwent stapedotomy. On preoperative CT, the presence of cavitating lesion and involvement of various subsites (cochlea, round window [RW], vestibule, and semicircular canal) were assessed. Pre- and post-stapedotomy audiometric results were compared according to the CT findings. The surgical outcomes were analyzed using logistic regression with Firth correction. Results: Cavitating lesions were present in 15 of 23 ears (65.2%). Involvement of the RW was the strongest predictor of unsuccessful surgical outcome, followed by involvement of the internal auditory canal (IAC) and the cochlea. Conclusions: RW and IAC involvement in retrofenestral otosclerosis were shown to predict unsuccessful outcomes. While a “third window” effect caused by extension of a cavitating lesion into the IAC may dissipate sound energy and thus serve as a barrier to desirable postoperative audiological outcome, a “single window” effect due to an extension of retrofenestral otosclerosis into the RW may preclude a good surgical outcome, even after successful stapedotomy, due to less compressible cochlear fluid and thus decreased linear movement of the piston.