Evaluation of stapes mobilization in the 21st century for conductive hearing loss in the otosclerotic ear.

PURPOSE: Compare outcomes of stapes mobilization and stapedectomy performed by a single surgeon for the otosclerosis. MATERIALS AND METHODS: A retrospective chart review of adult patients who underwent stapes mobilization or stapedectomy for otosclerosis was performed. Operative notes reviewed; patients included if diagnosed with otosclerosis without another otologic disease that could contribute to their hearing loss and all required data were available. Pre-and post-operative audiograms at 1, 6, and 12-months were evaluated to compare the air-bone gaps between the mobilization and stapedectomy procedures. The rates of sensorineural hearing loss also were compared. Student t-tests and multiple regression models were used to ascertain the association between improvement in post-operative air-bone gaps, sensorineural hearing loss, and the procedure undertaken. RESULTS: Sixty-seven (n = 67) patients with 108 procedures were included for analysis. No substantial difference between the surgical subgroups was found when comparing stapes mobilization to stapedectomy, and there was no evidence to suggest that either surgical procedure was superior to the other based on the data obtained and analyzed. Improvements in air-bone gap averaged 15.79 dB for stapes mobilization and 19.23 dB for stapedectomy. The results of the study showed no evidence of post-operative sensorineural hearing loss or change in air-bone gaps when comparing virgin to "revision" stapedectomy largely in patients who had failed previous mobilization. CONCLUSION: Stapes mobilization provides a conservative approach to otosclerosis patients suffering from conductive hearing loss. Stapedectomy can be used to correct failed mobilization.

Imaging of otosclerosis. / Bildgebung der Otosklerose.

BACKGROUND: Otosclerosis is an important cause of hearing loss and a widespread pathology in ENT medicine. Although a high diagnostic value of CT with impact on therapy is emphasized in the literature, the disease is seldom seen in the radiological routine diagnostics due to ENT findings often being diagnostic. Radiologists detect it rather more often in cases of unclear hearing loss or cochlear implant candidates. The findings may be very subtle. They require a target search and an optimal imaging technique. METHODS: This review article is based on a selective search of the literature in PubMed without any time frame restrictions as well as on the long clinical experience of the authors. RESULTS: The paper focuses on imaging aspects of otosclerosis: current role, advice for imaging technique, characteristic imaging signs, radiological differential diagnoses and findings after stapedoplasty. Pathology, clinical signs and therapeutic options are summarized briefly. CONCLUSIONS: With an optimal technique and sufficient radiological experience otosclerosis can be correctly diagnosed by imaging in a high percentage of cases. Radiology plays the key role in the diagnosis of retrofenestral otosclerosis. It can provide valuable information for the management of complications after stapedotomy. KEY POINTS: · X-ray cross-sectional imaging continues to be the method of first choice in the radiological diagnostics of otosclerosis. · With an optimal imaging technique and sufficient experience otosclerosis can be radiologically detected. · In complications after stapedoplasty, causes can be identified supporting the indication for a reoperation. CITATION FORMAT: · Kösling K, Plontke SK, Bartel S. Imaging of otosclerosis. Fortschr Röntgenstr 2020; 192: 745 - 753.

Stapedotomy with incus vibroplasty - A novel surgical solution of advanced otosclerosis and its place among existing therapeutic modalities - Hungarian single institutional experiences.

OBJECTIVE: To delineate the advantages and steps of stapedotomy with incus vibroplasty, to assess the safety and efficacy of this method via the authors' experiences, and to overview the literature regarding other surgical options in advanced otosclerosis determining the place of stapedotomy with incus vibroplasty in the therapeutic range. METHODS: Four patients were enrolled in the study presenting severe mixed hearing loss of at least one side on pure tone audiometry. Based on complementary audiological examinations including stapedial reflex test and multifrequency tympanometry, all cases were suspected as advanced otosclerosis. Stapedotomy with incus vibroplasty - the combination of laser stapedotomy and simultaneous Vibrant Soundbridge implantation - was performed in each patient. Preoperative pure tone average, speech recognition thresholds and word recognition scores were compared to one-year postoperative free-field values with the implant switched on focusing on functional gain. RESULTS: Among 4 participants (3 females, 1 male) the mean age (SD) was 66 years (35). In three cases Nitinol, in one case NitiBond piston was inserted. One-year postoperative free-field functional gains were 30 dB, 34 dB, 42 dB and 51 dB, respectively. One-year postoperative free-field speech recognition thresholds were 45 dB, 45 dB, 49 dB and 50 dB, respectively, while word recognition scores were 70%, 70%, 70% and 75%, respectively. CONCLUSION: Postoperative results in our serie regarding pure tone average and word recognition score proved to be better than those found in the literature. Stapedotomy with incus vibroplasty - through sufficient air-bone gap closure and simultaneous sensorineural component management - seems to be a promising surgical solution in advanced otosclerosis, requiring further investigation.

Evaluation of Functional Outcomes after Stapes Surgery in Patients with Clinical Otosclerosis in a Teaching Institution

Introduction Otosclerosis is a primary disease of the temporal bone that leads to stapes ankylosis. Hearing loss is the main symptom. Treatment includes surgery, medical treatment, and sound amplification therapy alone or in combination. Objective To evaluate the functional outcomes of patients with clinical diagnosis of otosclerosis undergoing primary stapes surgery in a teaching institution. Method Retrospective descriptive study. Results A total of 210 ears of 163 patients underwent stapes surgery. Of the 163 patients, 116 (71.2%) underwent unilateral surgery and 47 (28.8%) underwent bilateral surgery. Six of the 210 operated ears had obliterative otosclerosis. The average preoperative and postoperative air-bone gap was 32.06 and 4.39 dB, respectively. The mean preoperative and postoperative bone conduction threshold was 23.17 and 19.82 dB, respectively. A total of 184 (87.6%) ears had a residual air-bone gap <10 dB, and 196 (93.3%) had a residual air-bone gap ±15 dB. Two patients (0.95%) had severe sensorineural hearing loss. Conclusion Stapes surgery showed excellent functional hearing outcomes in this study. This surgerymay be performed in educational institutions with the supervision of experienced surgeons.

Lack of Evidence for Nonotosclerotic Stapes Fixation in Human Temporal Bone Histopathology.

HYPOTHESIS: Nonotosclerotic stapes fixation does not represent a significant cause of stapes ankylosis in patients undergoing stapedectomy; the vast majority have otosclerosis. BACKGROUND: Nonotosclerotic stapes fixation has been proposed as the diagnosis in 30 to 40% of patients undergoing stapedectomy (after excluding rare congenital, systemic, and syndromic causes of stapes fixation and tympanosclerosis). This finding was based on the histopathologic evaluation of total stapedectomy surgical specimens. Since these specimens do not include the surrounding otic capsule, the histopathologic evidence of otosclerosis may be missed. METHODS: Human temporal bone specimens from patients who underwent stapes mobilization, stapedotomy, or stapedectomy during life were evaluated for histologic evidence of otosclerosis. Patients with a history of temporal bone trauma, tympanosclerosis, and congenital, systemic, or syndromic causes of stapes fixation were excluded. Therefore, most temporal bone donors carried a clinical diagnosis of otosclerosis. RESULTS: Two hundred ten specimens from three temporal bone collections were independently evaluated. Otosclerosis was found on histology in 99% (207/210). Therefore, the incidence of nonotosclerotic stapes fixation was 1% (3/210). In two of the three patients who did not have otosclerosis, the contralateral temporal bone had otosclerosis on histopathologic evaluation. These patients may have had otosclerosis in the footplate only (which was removed at the time of surgery and not available for review). CONCLUSION: Nonotosclerotic stapes fixation is not likely a distinct pathologic classification from otosclerosis. Most patients diagnosed with nonotosclerotic stapes fixation likely have otosclerosis, but do not have otosclerotic foci in the stapes itself.

Objective Measurements of Ossicular Chain Mobility Using a Palpating Instrument Intraoperatively.

BACKGROUND: The judgment of a normal or impaired mobility of middle ear ossicles is based on palpation and depends highly on the surgeon's subjective experience. The aim of this study was to develop and test a palpating instrument recording force and vector and allowing to support the surgeon's subjective impression with objective measurement results. STUDY DESIGN: Prospective recordings at surgery. SETTING: Tertiary referral center. PATIENTS AND METHODS: A fiberoptic force-sensing element allowing force measures in three orthogonal directions was integrated into a handheld 45 degree hook and tested in temporal bones. Clinical data series from patients with a functionally normal chain (e.g., cochlear implants (CI)) and impaired ossicles (otosclerosis) were collected. The ossicles were palpated until their first movements out of the resting stage were visualized, the applied force, and vector were recorded by an independent observer. RESULTS: Four CI and 19 otosclerosis patients were further evaluated. The minimum detectable force change of the sensor was 0.2 gF (2 mN). In the otosclerosis patients the average force applied to move the malleus was 9.5 gF, on the incus 8.7 gF. These values were slightly lower after separation of the incudostapedial joint, reaching 8.5 gF and 6.9 gF, respectively. The fixed stapes showed a rigidity of 14.7 gF or higher. The values were lower in the CI group measuring 4.4 gF, 4.1 gF, and 3.3 gF on the three ossicles, respectively. CONCLUSIONS: We were able to produce a disposable, easy-to-handle palpating probe that enables the otologist to record continuously tip contact forces in three dimensions during his standard palpation of each ossicle. Normative values were reproduced for each ossicle, as well as increased rates for stapes fixation in otosclerosis.

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

OBJECTIVE: Factors affecting postoperative hearing results of patients with otosclerosis were analyzed. METHODS: Included were 191 patients with otosclerosis in whom 234 primary stapes surgeries were performed from August 1991 to December 2011 by one surgeon in three tertiary hospitals. Evaluation of factors affecting postoperative hearing thresholds at individual frequencies were performed by logistic regression analysis. RESULTS: Closure of the air-bone gap (ABG) after surgery was good at 2kHz, but poor at 4kHz and frequencies under 1kHz. In addition, improvement at 8kHz was worse than that at any other frequency. Multivariate logistic regression analysis by the stepwise method showed that under the mean preoperative ABG (odds ratio [OR]=2.42), unilaterality (OR=2.53) and male sex (OR=2.65) were significantly better prognostic factors at 250Hz. At 500Hz, under mean preoperative ABG (OR=2.56) was the significantly better factor. No significant factors were found at 1kHz. Cochlear otosclerosis (OR=3.57) was a significantly worse prognostic factor at 2kHz. Under mean preoperative ABG (OR=2.82) and younger age (OR=1.03) were significantly better prognostic factors at 4kHz. At 8kHz, worse preoperative air conduction threshold (OR=1.96) was a significantly better prognostic factor. CONCLUSION: Preoperative ABG, preoperative air conduction threshold, cochlear otosclerosis, male sex, laterality and age were significant prognostic factors for postoperative hearing outcome in otosclerosis patients. Especially, preoperative ABG was a significant prognostic factor at multiple frequencies. We suppose that patients with larger preoperative ABG have some other otosclerotic lesions outside the oval window niche.

Numerical study of Hough technique in surgery of otosclerosis, using the finite element method.

PURPOSE: Otosclerosis is a metabolic bone disease of the otic capsule that can cause the stapes fixation, resulting in conductive hearing loss or, in a profound sensorineural deafness threshold. Surgery is one of the possible treatments for the otosclerosis. To repair small focus of otosclerosis in the anterior crus of the stapes, in 1960, Hough suggested the implementation of a technique in which part of the anterior crus is fractured and the stapes turned. As a result, the posterior crus of the stapes is the only connection with the inner ear. In this work, the outcome of Hough's surgical technique was simulated. METHODS: Based on computerized images, a finite element model of middle ear ossicles and tympanic membrane was created, as well as a model where the stapes has changed. The discretization of the tridimensional solid model was made using the ABAQUS software. The mechanical properties used were taken from the literature and adequate boundary conditions were applied. RESULTS: The results obtained with the Hough technique simulation were compared with a representative model of the normal ear, taking into account the displacements obtained on the central part of the stapes footplate and the maximum principal stress in the stapes crus. CONCLUSIONS: The results obtained are closer to the normal ear model, therefore Hough technique stands out as a good option to correct small focus of otosclerosis.

The effect of stapes fixation on hearing results in tympanosclerosis treated by mobilization.

We aimed to investigate the effect of stapes fixation on hearing results in patients who underwent mobilization surgery due to tympanosclerosis (TS). Seventy-nine patients were retrospectively analyzed and divided into two groups. Forty-four (55.7%) patients with mobile stapes were classified as group 1, and 35 (44.3%) patients with fixed stapes were classified as group 2. Improvement of the air-bone gap (ABG) to become less than 20 dB and the pure-tone average (PTA) by at least 10 dB postoperatively were accepted as success criteria. The PTA and ABG levels were significantly improved in both groups. The pre- and post-operative PTAs were 46.57 ± 15.55 and 25.84 ± 15.47 dB, respectively, in group 1 (p = 0.001). The pre- and post-operative PTAs were 55.64 ± 12.69 and 36.20 ± 14.47 dB, respectively, in group 2 (p = 0.001). The pre- and post-operative ABG levels were 35.36 ± 10.53 and 16.91 ± 8.54 dB, respectively, in group 1 (p = 0.001). The pre- and post-operative ABG levels were 41.68 ± 8.78 and 22.20 ± 10.03 dB, respectively, in group 2 (p = 0.001). A gain ≥10-dB in the PTA in groups 1 and 2 was found in 34 (77.2 %) and 23 (65.7%) patients, respectively, and the difference between the groups was not significant (p = 0.684). The post-operative AGB in groups 1 and 2 was less than 20 dB in 32 (72.7%) and 21 (60%) patients, respectively, and the difference between the groups was not significant (p = 0.733). No significant negative effect of stapes fixation on post-operative hearing results in TS was detected. Successful results can be obtained with a mobilization procedure, even if the stapes is fixed.

Anomalous facial nerve in congenital stapes fixation.

OBJECTIVE: The aim of this article was to assess the prevalence and influence of anomalous facial nerves in patients undergoing surgery for congenital stapes anomalies. PATIENTS: The medical records of all patients who underwent surgery for congenital stapes fixation between January 1999 and December 2012 were retrospectively reviewed. An abnormal facial nerve was found in 7 ears in 5 patients (from a total of 62 ears). MAIN OUTCOME MEASURES: The patients' temporal bone computed tomography results, operation records, video clips, and preoperative and postoperative hearing tests were reviewed. RESULTS: Oval window atresia was found in all 7 ears, and the facial nerves in all 7 ears ran inferior medially over the atretic oval window niche. The atretic plate was fenestrated into the vestibule in the superior margin of the facial nerve. A piston wire was anchored to the long process of the incus in 3 ears, to the handle of the malleus in 3 ears, and attached to the tympanic membrane in 1 ear. The postoperative ABG at long-term follow-up was 13.1 dB (SD, 4.6 dB; range, 8.8-18.3 dB). No patient had postoperative facial weakness. CONCLUSION: An anomalous facial nerve was found in 11.2% of ears in patients undergoing surgery for congenital stapes fixation. Despite the anomalous course of facial nerves in these patients, vestibular fenestration was successful without facial nerve damage. The audiometric outcome at long-term follow-up was serviceable hearing for all cases.

Sound localization performance improves after canaloplasty in unilateral congenital aural atresia patients.

OBJECTIVE: To investigate the changes in sound localization ability in the horizontal plane after canaloplasty in unilateral congenital aural atresia (CAA) patients. STUDY DESIGN: Prospective interventional study. SETTING: Tertiary referral center. PATIENTS: Twenty-eight patients with unilateral CAA were enrolled. All patients had unilateral conductive hearing loss. INTERVENTIONS: Canaloplasty. MAIN OUTCOME MEASURES: Pure tone audiometry, sound localization test, and the Speech, Spatial, and Quality questionnaire (SSQ) were administered preoperatively, 6 and 12 months postoperatively. For the sound localization test, 8 loudspeakers were positioned in a circle at 45-degree intervals, and patients were instructed to identify the speaker from which sound was coming. Mean correct response rate and mean error degree were calculated for each patient. The correct lateralization rate to the ipsilesional/contralesional stimuli was also calculated. RESULTS: Mean hearing threshold decreased from preoperatively 63.8 to 39.4 dB 12 months after canaloplasty. Mean correct response rate and error degree at preoperative evaluation were 26.0% and 60.7 degrees, respectively, and these were respectively improved to 58.5% and 27.8 degrees postoperatively. Respective mean correct lateralization rate to ipsilesional stimuli after canaloplasty improved from 20.6% to 84.0%, and that to contralesional stimuli slightly improved from 93.8% to 98.8%. Patients with good postoperative hearing (<40 dBHL) showed better sound localization results. In addition, self-assessment scores of spatial domain in the SSQ questionnaire were significantly improved after the operation. CONCLUSION: Sound localization performance improved significantly after canaloplasty. Canaloplasty could provide better localization benefit and subjective improvement in spatial sensation to unilateral CAA patients.

Comparison of stapedotomy minus prosthesis, circumferential stapes mobilization, and small fenestra stapedotomy for stapes fixation.

OBJECTIVE: To compare the outcomes of 3 surgical techniques for primary stapes fixation: stapedotomy minus prosthesis (STAMP), circumferential stapes mobilization (CSM), and small fenestra stapedotomy (SFS). STUDY DESIGN: Retrospective review of 277 primary cases operated for stapes fixation from 1997 to 2007. SETTING: Tertiary academic center. PATIENTS: Consecutive adult and pediatric cases operated for conductive hearing loss because of stapes fixation. INTERVENTIONS: STAMP was performed for otosclerosis limited to the anterior footplate, CSM was conducted for congenital stapes fixation, SFS was performed for more extensive otosclerosis or anatomic contraindications to STAMP/CSM. MAIN OUTCOME MEASURES: Pure-tone audiometry was performed preoperatively and postoperatively (3-6 wk) and the most recent long-term results (≥ 12 mo). RESULTS: Ninety-nine ears in 90 patients had audiologic follow-up data over 12 months. Sixty-seven ears (68%) underwent SFS, 16 (16%) STAMP, and 16 (16%) CSM. There was significant improvement in average air conduction (AC) thresholds and air-bone gap (ABG) for all techniques. Mean ABG for SFS closed from 29 to 7.1 dB (SD, 6.0), for STAMP from 29 to 3.8 dB (SD, 5.8 dB), and for CSM from 34 to 20 dB (SD, 8.2 dB). AC results were better in the STAMP than in the SFS group, especially in high frequencies. Bone conduction improvements were seen in all groups, highest in STAMP (4.3 dB) and CSM (3.8 dB) groups, but the differences between groups were not statistically significant. CONCLUSION: Satisfactory hearing results were achieved with all the techniques, and STAMP showed better hearing outcomes, especially in high frequencies. CSM is a good option for children and patients in whom it is desirable to avoid a footplate fenestration or prosthesis. CSM and STAMP had significantly higher rates of revision for refixation than SFS.

Comparison of KTP, Thulium, and CO2 laser in stapedotomy using specialized visualization techniques: thermal effects.

High-speed thermal imaging enables visualization of heating of the vestibule during laser-assisted stapedotomy, comparing KTP, CO2, and Thulium laser light. Perforation of the stapes footplate with laser bears the risk of heating of the inner ear fluids. The amount of heating depends on absorption of the laser light and subsequent tissue ablation. The ablation of the footplate is driven by strong water absorption for the CO2 and Thulium laser. For the KTP laser wavelength, ablation is driven by carbonization of the footplate and it might penetrate deep into the inner ear without absorption in water. The thermal effects were visualized in an inner ear model, using two new techniques: (1) high-speed Schlieren imaging shows relative dynamic changes of temperatures up to 2 ms resolution in the perilymph. (2) Thermo imaging provides absolute temperature measurements around the footplate up to 40 ms resolution. The high-speed Schlieren imaging showed minimal heating using the KTP laser. Both CO2 and Thulium laser showed heating below the footplate. Thulium laser wavelength generated heating up to 0.6 mm depth. This was confirmed with thermal imaging, showing a rise of temperature of 4.7 (±3.5) °C for KTP and 9.4 (±6.9) for Thulium in the area of 2 mm below the footplate. For stapedotomy, the Thulium and CO2 laser show more extended thermal effects compared to KTP. High-speed Schlieren imaging and thermal imaging are complimentary techniques to study lasers thermal effects in tissue.

Effect of cochlear window fixation on air- and bone-conduction thresholds.

HYPOTHESIS: In the absence of patent cochlear windows, cochlear fluid inertia depends on the presence of a "third window" as a major component of the bone-conduction response. BACKGROUND: Studies have shown conflicting results regarding changes in air and bone conduction whenever, the round window, oval window, or both windows were occluded. METHOD: The study was performed in a tertiary university-affiliated medical center. Auditory brain responses to clicks and 1-kHz tone bursts delivered by air and bone conduction were tested in 5 adult-size fat sand rats. The round window membrane (total, 7 ears) was sealed with Super Glue, and auditory brain response testing was repeated. Thereafter, the stapes footplate was firmly fixated, and auditory brain responses were recorded for a third time. RESULTS: Round-window fixation induced a significant increase in air-conduction thresholds to clicks from 36.4 ± 0.9 to 69.3 ± 4.1 dB SPL, with no significant change in bone-conduction thresholds. When the stapes footplate was immobilized as well, air conduction increased by another 20 dB, on average, with no change in bone conduction. A similar deterioration was seen in response to 1 kHz stimulus. CONCLUSION: These findings support and complement earlier studies in the same animal model, suggesting that when the pressure outlet through the cochlear windows are abolished, still bone conduction displaces the cochlear partition probably because of a functioning "third window."

[A new method for the fixation of sound-conducting elements of the middle ear during ossiculoplasty].

The objective of the present work was to estimate the possibilities of the application of platelet-enriched plasma as a filtering material for ossiculoplasty. The results of surgical interventions on 120 patients presenting with chronic suppurative otitis media are reported. All the patients underwent closed-type sanation surgery (differential atticoanthrotomy) including either complete or partial restoration of the sound conduction mechanism in the middle ear. Platelet-enriched plasma was applied into the tympanic cavity of 55 patients as a fixing material for the reconstruction of the chain of the auditory ossicles. Ossiculoplasty without additional fixation was performed in 65 patients comprising the control group. The results of the study indicate that a clot of platelet-enriched plasma may be a good fixing material for the reconstruction of the entire chain of auditory ossicles and can be used for all types of ossiculopasty.

Congenital ossicular chain anomalies associated with a mobile stapes footplate: surgical results for 23 ears.

OBJECTIVES: We describe the audiometric results following surgery in a consecutive series of patients with a congenital ossicular middle ear disorder that was associated with a mobile stapes footplate. METHODS: We performed a retrospective analysis of patient charts from a tertiary referral center. A total of 23 patients (23 ears) underwent exploratory tympanotomy and ossicular reconstruction between 1986 and 2001. The main outcome measure was the audiometric results. RESULTS: Overall, we observed a mean gain in air conduction pure tone average of 17 dB (from 47 dB to 30 dB), a sensorineural deterioration of 3 dB, and a mean postoperative air-bone gap of 19 dB (mean preoperative air-bone gap of 38 dB). The air-bone gap closure was 20 dB or less in 15 of the 23 cases (65%), in agreement with the few results reported in the literature. Moreover, the audiometric results remained stable. In the syndromic group, the mean gain in air conduction was only 13 dB, which was worse than that observed for the nonsyndromic ears. CONCLUSIONS: Surgery for congenital ossicular chain anomalies with a concomitant mobile stapes footplate provides positive audiometric outcomes. Most ears had some sensorineural impairment (10 to 20 dB), which influenced the final hearing level attained after surgery. Preoperative assessment is mandatory to search for syndromal diagnoses, which might be important for patient counseling and prognosis.

Comparison of ear-canal reflectance and umbo velocity in patients with conductive hearing loss: a preliminary study.

OBJECTIVE: The goal of the present study was to investigate the clinical utility of measurements of ear-canal reflectance (ECR) in a population of patients with conductive hearing loss in the presence of an intact, healthy tympanic membrane and an aerated middle ear. We also sought to compare the diagnostic accuracy of umbo velocity (VU) measurements and measurements of ECR in the same group of patients. DESIGN: This prospective study comprised 31 adult patients with conductive hearing loss, of which 14 had surgically confirmed stapes fixation due to otosclerosis, 6 had surgically confirmed ossicular discontinuity, and 11 had computed tomography and vestibular evoked myogenic potential confirmed superior semicircular canal dehiscence (SCD). Measurements on all 31 ears included pure-tone audiometry for 0.25 to 8 kHz, ECR for 0.2 to 6 kHz using the Mimosa Acoustics HearID system, and VU for 0.3 to 6 kHz using the HLV-1000 laser Doppler vibrometer (Polytec Inc, Waldbronn, Germany). We analyzed power reflectance |ECR| as well as the absorbance level = 10 × log10(1 - |ECR|). All measurements were made before any surgical intervention. The VU and ECR data were plotted against normative data obtained in a companion study of 58 strictly defined normal ears (). RESULTS: Small increases in |ECR| at low-to-mid frequencies (400-1000 Hz) were observed in cases with stapes fixation, while narrowband decreases were seen for both SCD and ossicular discontinuity. The SCD and ossicular discontinuity differed in that the SCD had smaller decreases at mid-frequency (∼1000 Hz), whereas ossicular discontinuity had larger decreases at lower frequencies (500-800 Hz). SCD tended to have less air-bone gap at high frequencies (1-4 kHz) compared with stapes fixation and ossicular discontinuity. The |ECR| measurements, in conjunction with audiometry, could successfully separate 28 of the 31 cases into the three pathologies. By comparison, VU measurements, in conjunction with audiometry, could successfully separate various pathologies in 29 of 31 cases. CONCLUSIONS: The combination of |ECR| with audiometry showed clinical utility in the differential diagnosis of conductive hearing loss in the presence of an intact tympanic membrane and an aerated middle ear and seems to be of similar sensitivity and specificity to measurements of VU plus audiometry. Additional research is needed to expand upon these promising preliminary results.

Congenital stapes ankylosis associated with another ossicular chain anomaly: surgical results in 30 ears.

OBJECTIVE: To describe the audiometric results after stapes surgery in a consecutive series of patients with stapes footplate ankylosis combined with another ossicular middle ear anomaly. STUDY DESIGN: A retrospective analysis of charts collected between 1986 and 2001. SETTING: A tertiary referral center. PATIENTS: A total of 25 patients (30 ears) underwent exploratory tympanotomies and ossicular reconstruction. MAIN OUTCOME MEASURE: Audiometric results. RESULTS: Overall, a mean gain in air conduction of 18 dB (from 49 dB to 31 dB) and a mean postoperative air-bone gap (ABG) of 20 dB (mean preoperative ABG, 40 dB) were observed. The ABG closure was 20 dB or less in 70% of cases, which is in agreement with the few results reported in the literature. Moreover, the audiometric results remained stable. In the group of ears with a syndrome, the mean gain of air conduction was only 19 dB, which was comparable to that observed among nonsyndromic ears. CONCLUSIONS: Surgery for congenital stapes footplate ankylosis with a concomitant ossicular chain anomaly can provide worthwhile hearing improvement. The ABG closure was 20 dB or less in 21 of 30 ears (70%). Most ears had some sensorineural impairment (10-20 dB), which influenced the final hearing level after surgery. Over recent decades, the technique of the malleostapedotomy procedure has been improved. Preoperative assessment is mandatory for syndromal diagnoses, which might be important for patient counseling and prognosis.

Carhart notch 2-kHz bone conduction threshold dip: a nondefinitive predictor of stapes fixation in conductive hearing loss with normal tympanic membrane.

OBJECTIVE: To evaluate the significance of the Carhart notch (a 2-kHz bone conduction threshold dip [2KBD]) in the diagnosis of stapes fixation by comparing its incidence among ears with various ossicular chain abnormalities. DESIGN: Retrospective study. SETTING: University hospital. PATIENTS: A total of 153 ears among 127 consecutive patients with a congenital ossicular anomaly or otosclerosis. MAIN OUTCOME MEASURES: The 2KBD depth was defined as the threshold at 2 kHz minus the mean of thresholds at 1 and 4 kHz. The presence of 2KBD (depth, ≥10 dB), 2KBD depth, relationship between 2KBD depth and air-bone gap, and 2-kHz bone conduction recovery after operation were evaluated in a stapes fixation group (which included cases of otosclerosis and congenital stapes fixation), an incudostapedial joint detachment group, and a malleus or incus fixation group. RESULTS: A 2KBD was present in 32 of 102 stapes fixation ears (31.4%), 5 of 19 incudostapedial joint detachment ears (26.3%), and 6 of 20 malleus or incus fixation ears (30.0%) (12 ears had other diagnoses). The mean (SD) 2KBD depths were 17.3 (5.2) dB in the stapes fixation group, 18.5 (2.2) dB in the incudostapedial joint detachment group, and 16.3 (2.1) dB in the malleus or incus fixation group. No statistically significant differences were noted among these 3 groups. No correlation was noted between 2KBD depth and air-bone gap extent. Recovery of 2-kHz bone conduction threshold in the stapes fixation group was less than that in the other 2 groups. CONCLUSION: Incidence of 2KBD was similar among the stapes fixation, incudostapedial joint detachment, and malleus or incus fixation groups, implying that 2KBD is not a useful predictor of stapes fixation.