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.

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.

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 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.

Incus replacement malleostapedotomy in quiescent chronic otitis media with a mobile stapes footplate: an alternative to TORP in select cases.

OBJECTIVE: To review the results of malleostapedotomy for incus replacement in the setting of quiescent chronic otitis media and a mobile stapes footplate and to discuss the potential application for this technique in select cases. PATIENTS: Seven individuals having undergone malleostapedotomy in the setting of quiescent chronic otitis media and a mobile stapes footplate between 2004 and 2009. INTERVENTION: Review of surgical results and hearing outcomes as measured by preoperative and postoperative pure-tone audiometry. MAIN OUTCOME MEASURES: Closure of preoperative air-bone gap and change in preoperative versus postoperative pure-tone bone conduction thresholds. RESULTS: Improvement in air-bone gap was noted in 6 of 7 subjects with an average closure of 17 dB. In 5 of 7 subjects, the air-bone gap was closed to 20 dB or less, and in 3 of 7 subjects, the air-bone gap was closed to 10 dB or less. No significant changes in postoperative bone conduction pure-tone average thresholds were noted. No immediate or delayed complications were encountered over an average follow-up time of 23.6 months (range, 5-42 mo). CONCLUSION: Although the data are limited by the small sample size, malleostapedotomy seems to be a potentially safe and effective alternative to placement of a total ossicular replacement prosthesis in properly selected specialized instances of quiescent chronic otitis media. Further study is recommended to more definitively establish the safety and efficacy of this technique.

Clinical analysis of intratympanic tympanosclerosis: etiology, ossicular chain findings, and hearing results of surgery.

CONCLUSION: The success rate (57.5%) in this study is not high for surgical treatment of tympanosclerosis, and therefore lends further evidence that intratympanic tympanosclerosis has been considered intractable for reconstructive surgery. OBJECTIVE: To investigate the clinical findings and surgical results of intratympanic tympanosclerosis. METHODS: From January 1989 to December 2006, a total of 1523 tympanoplasties were performed. Of these, 84 tailored tympanomastoidectomies were performed for tympanosclerosis in 80 patients. RESULTS: The incidence of intratympanic tympanosclerosis with chronic ear disease was 5.5%. Chronic otitis media was the most common etiologic factor for the tympanosclerosis (79 ears, 94.1%). Tympanosclerosis in the middle ear cavity was most often found around the malleus handle (67 ears, 79.8%), and more than half of the cases of tympanosclerosis (43 ears, 51.2%) had multiple areas affected by the sclerotic tissue. Tympanosclerotic fixation of the stapes was found in 31 ears (36.9%), and an intact ossicular chain was seen in 57 ears (67.9%). There was a postoperative improvement in hearing in 42 ears (57.5%).

[Effects of different surgical techniques for otosclerosis].

OBJECTIVE: To compare the effectiveness of three surgical techniques for otosclerosis. METHOD: Retrospective analysis was made of patients with otosclerosis who had received surgical treatment during 1993-2005. There were totally 70 patients (76 ears) in which 30 patients (33 ears) underwent total stapedectomy with original stapes, 24 patients (27 ears) underwent small fenestra stapedotomy with Teflon piston artificial stapes and 16 patients (16 ears) underwent stapes mobilization or elevation. Both the hearing results including closure of postoperative air-bone gap and change of postoperative bone conduction threshold at different frequencies and percentages of postoperative vertigo control are compared statistically among three general groups and among two subgroups(stapes mobilization group with 5 cases/ 5 ears and stapes elevation group with 11 cases/ 11 ears). RESULT: There were no statistically significant differences in postoperative speech pure tone average threshold in closing air-bone gap among three groups. Compared with ears treated by otal stapedectomy with original stapes, ears treated by small fenestra stapedotomy and stapes mobilization or elevation, more decreased air-bone gap and lower rates of post-operative sensorineural hearing loss (SNHL) and dizziness at high frequencies were found. CONCLUSION: Although the acceptable effects were found in 3 groups, the better hearing threshold at high frequencies and lower incidence of complications can be obtained in patients with otosclerosis underwent small fenestra stapedotomy and stapes mobilization or elevation. It is suggested that small fenestra stapedotomy with Teflon piston artificial stapes is an ideal surgical treatment for otosclerosis.

Rosen mobilization of the stapes: does it have a place in modern otology?

We describe two patients with stapes fixation, in both of whom Rosen mobilization seemed to be the most prudent surgical choice. In both cases, a useful hearing gain was achieved initially. In the patient with otosclerosis, the conductive hearing loss recurred and a stapedectomy was subsequently carried out. In the patient with congenital stapes fixation, the hearing gain was maintained for two years eight months. We believe that this technique still has a place in stapes surgery in rare instances.

[Long term results stape surgery]. / Wyniki odlegle w otosklerozie.

For many years otosclerosis has been an interesting otologic problem in regard to pathological and clinical aspects. Many various conceptions of otosclerosis development which finally lead to the stapes immobility in the oval window were discussed. Resent genetic studies indicate that genetic factors as a cause of otosclerosis possibly in combination with other factors localize 3 genes responsible for otosclerosis to chromosom 15q25q-q26, 7q34-36, 6p21-22. The aim of the study was audiometric evaluation of 1380 patients out of 1716 stapes operations performed in years 1973-2004. Audiometric assessment for air and bone conduction was performed according to the European Academy of Otology and Neuro-Otology (EAO-NO) criteria. Postoperative air-bone gap 11-20 dB for speech frequencies (500, 1000, 2000, 4000 Hz) was obtained in 64.8% and in 28.9% was less than 10 dB. Postoperative air-bone gap (11-20 dB) recognized as a good result is determined by factors such as preoperative hearing loss, onset and duration of the disease, advanced and multiple otosclerotic foci, patient's age etc. Actually postoperative air-bone gap shows the improvement of air and bone thresholds obtained post stapedotomy versus preoperative air bone gap. In previous years an "over-closure" effect was taken into consideration. Hearing improvement post stapes surgery which included the "over closure" effect was obviously better. The authors indicate the necessity of standardization of audiometric results post ear surgery.