Round window application of an active middle ear implant (AMEI) system in congenital oval window atresia

Introduction: In patients with conductive and mixed hearing loss, implantable hearing devices such as active middle ear implants (AMEIs) and bone conduction implants (BCIs) are established alternatives when conventional hearing aids fail. Although bone conduction (BC) thresholds are routinely used as eligibility criteria, their role as frequency-specific predictors of postoperative functional outcomes remains poorly defined. This study aimed to evaluate the influence of preoperative BC thresholds across the audiometric spectrum on postoperative speech recognition outcomes after implantation with AMEIs and BCIs. Methods: A retrospective observational study was conducted at a tertiary referral center including patients implanted with BCIs or AMEIs. Pre- and postoperative audiological data were analyzed, including air and bone conduction thresholds, frequency-segmented BC measures (low, mid, and high frequencies), cochlear frequency gradient (ΔBC Slope), and speech recognition scores (SRSs) at 65 dB HL one year after implantation. Results: 102 patients were included (50 BCI, 52 AMEI). Both implant types achieved significant postoperative improvements in tonal thresholds and SRS compared with pre-implantation values (all p < 0.001). High-frequency BC thresholds (BC-High, 4–6 kHz) showed a significant inverse correlation with postoperative SRS in both BCI (r = −0.382, p = 0.001) and AMEI users (r = −0.398, p < 0.001), and emerged as the only independent predictor in multivariable models (BCI: β = −0.533, p = 0.022; AMEI: β = −0.491, p = 0.020). Low- and mid-frequency BC measures were not associated with postoperative speech outcomes (all p > 0.05). ROC analyses demonstrated excellent discriminative performance of BC-High for identifying suboptimal outcomes, with area under the curve values of 0.92 for BCI (p = 0.001) and 0.94 for AMEI (p = 0.002), and implant-specific cutoff values of >47 dB HL and >61 dB HL, respectively. Conclusions: High-frequency BC thresholds showed the strongest association with postoperative speech recognition after implantable hearing rehabilitation. BC-High could function as a prognostic marker of functional outcome rather than an eligibility criterion, providing clinically meaningful information to refine preoperative counseling and individualized decision-making within current indication frameworks.

Active middle ear implants, such as the Vibrant Soundbridge, are used as an important part in the rehabilitation of sensorineural, conductive hearing, or mixed hearing loss. The attachment of the Vibrant Soundbridge at the round window and the usage of the Vibroplasty couplers strongly expanded the application of the Vibrant Soundbridge.The Vibrant Soundbridge is developed for patients who have an intolerance to hearing aids and a moderate to profound sensorineural hearing loss. The VSB also provides an optimal solution for patients with failed middle ear reconstructions or patients with atresia. To capture the improvement with the VSB Implant with different hearing losses a literature analysis was conducted. The functional gain was analyzed for 107 patients with conductive hearing loss and for 214 patients with sensorineural hearing loss out of 14 studies.Patients with conductive and mixed hearing loss resulted in a functional gain from 30 to 58 dB with the VSB. Patients with a pure sensorineural hearing loss showed a functional gain of 23-30 dB. The VSB bone conduction threshold shift was analyzed for all studies conducted in the years between 2000 and 2009. In 11 of the 16 studies there was no significant (p=0.05) change found. In 5 studies, the pre- to post-surgical bone conduction threshold shift was less than 10 dB. None of these studies measured a threshold shift of more than 10 dB.The flexible attachment at either the long process of the incus with sensorineural hearing loss, with an conductive hearing loss at the round window or the use of Vibroplasty couplers at the oval window, head of the stapes or round window makes the VSB an extremely versatile instrument. If patients can't wear conventional hearing aids, had failed middle ear reconstructions or atresia the VSB presents, due to the significant hearing improvement in any type of hearing loss, an ideal solution.

Objective:To investigate the surgical effects of round window implantation of vibrant soundbridge(VSB)for patients with congenital oval window atresia.Method:Retrospectively analyze the clinical information of 9 cases of congenital oval window atresia as well as the pre-and post-operative hearing and speech results. Three of them had undergone or attempted the vestibulotomy but obtained poor results. All cases underwent round window implantation of VSB. Result:All patients obtained an improvement of 21-33 dBHL after implantation. In the speech recognition rate test, the average increase of disyllabic words was 62%, and 60% in the sentence test. During the follow-up of 51 months in average, 2 cases had a decline of auditory benefit and finally 1 case regained the improvement after reoperation. Conclusion:Round window implantation can get a fairly good result in congenital oval windows atresia cases.

We compared the audiologic benefits of active middle ear implants with those of passive middle ear implants with hearing aids in mixed hearing loss, and also compared the outcomes of stapes vibroplasty with those of round window vibroplasty. Retrospective chart review. Thirty-four patients with mixed hearing loss due to chronic otitis media were treated with a middle ear implant. Of these, 15 were treated with a passive middle ear implant (conventional ossiculoplasty with a partial ossicular replacement prosthesis), nine with an active middle ear implant coupling to the stapes, and 10 with an active middle ear implant coupling to the round window. Patients underwent pure-tone/free-field audiograms and speech discrimination tests before surgery and 6 months after surgery, and the results of these tests were compared. The active middle ear implant resulted in better outcomes than the passive middle ear implant with hearing aids at mid to high frequencies (P < .05). Patients who received either a stapes vibroplasty or a round window vibroplasty showed comparable hearing gain except at 8,000 Hz (48.9 dB vs. 31.0 dB, P < .05). Patients who received a stapes vibroplasty showed an improvement even in bone conduction at 1,000 Hz and 2,000 Hz (both P < .05). Active middle ear implantation could be a better option than treatment with passive middle ear implants with hearing aids for achieving rehabilitation in patients with mixed hearing loss. Vibroplasty via either oval window or round window stimulation shares similar good results. 4 Laryngoscope, 127:1435-1441, 2017.

Active middle ear implants (aMEI) are being increasingly used for hearing restoration in congenital aural atresia. The existing gradings used for CT findings do not meet the requirements for these implants. Some items are expendable, whereas other important imaging factors are missing. We aimed to create a new grading system that could describe the extent of the malformation and predict the viability and challenges of implanting an aMEI. One hundred three malformed ears were evaluated using HRCT of the temporal bone. The qualitative items middle ear and mastoid pneumatization, oval window, stapes, round window, tegmen mastoideum displacement and facial nerve displacement were included. An anterior- and posterior round window corridor, oval window and stapes corridor were quantified and novelly included. They describe the size of the surgical field and the sight towards the windows. The ears were graded on a 16-point scale (16-13 easy, 12-9 moderate, 8-5 difficult, 4-0 high risk). The strength of agreement between the calculated score and the performed implantations was good. The comparison of the new 16-point scale with the Jahrsdoerfer score showed that both were able to conclusively detect the high-risk group; however, the new 16-point scale was able to further determine which malformed ears were favorable for aMEI, which the Jahrsdoerfer score could not do. The Active Middle Ear Implant Score for aural atresia (aMEI score) allows more precise risk stratification and decision making regarding the implantation. The use of operative corridors seems to have significantly better prognostic accuracy than the Jahrsdoerfer score.

Conclusion: Active middle ear implant (AMEI) implantation in children and adolescents is safe and provides improved hearing results. No statistical difference in hearing outcomes was shown in the group of patients affected by chronic middle ear diseases versus aural atresia. Also, the transducer location (round window versus oval window placement) did not lead to different outcomes in hearing abilities. Objectives: (1) To assess the hearing outcomes with the active implant Vibrant Soundbridge (VSB) in children and adolescents. (2) To evaluate whether functional results of the subjects in the study could depend on the hearing loss etiology (chronic middle ear diseases versus aural atresia) or on transducer location (round window versus oval window placement). Methods: The study was carried out with a retrospective, single-subject, repeated measures design, and included 22 children and adolescents with conductive or mixed hearing loss due to aural atresia or chronic middle ear diseases. Preoperative and postoperative pure tone air conduction (AC) and bone conduction (BC) thresholds were measured to demonstrate implantation safety. Free-field warble tone and speech audiometry were performed to assess postoperative hearing abilities with and without the VSB. Results: No significant changes in mean BC or AC thresholds between preoperative and postoperative conditions were seen in the 22 patients. Mean PTA4 functional gain was 30.7 dB. Averaged over all 22 patients, word recognition at 65 dB SPL changed from an average of 19% in the unaided postoperative condition to 97% in the VSB-aided condition. Functional results were independent of hearing loss etiology and transducer location.

Comparison of auditory responses determined by acoustic stimulation and by mechanical round window stimulation at equivalent stapes velocities

Active middle ear implants (AMEI) amplify mechanical vibrations in the middle ear and transmit them to the cochlea. The AMEI includes a floating mass transducer (FMT) that can be placed using two different surgical approaches: "oval window (OW) vibroplasty" and "round window (RW) vibroplasty." The OW and RW are windows located on the cochlea. Normally, sound stimulus is transmitted from the middle ear to cochlea via the OW. RW vibroplasty has been suggested as an alternative method due to the difficulty of applying OW vibroplasty in patients with ossicle dysfunction. Several reports compare the advantages of each approach through pre and postoperative hearing tests. However, quantitatively assessing the treatment effect is challenging due to individual differences in pathologies. This study investigates the vibration transmission efficiency of each surgical approach using a finite-element model of the human cochlea. Vibration of the basilar membrane (BM) of the cochlea is simulated by applying the stimulus through the OW or RW. Pathological conditions, such as impaired stapes mobility, are simulated by increasing the stiffness of the stapedial annular ligament. RW closure due to chronic middle ear diseases is a common clinical occurrence and is simulated by increasing the stiffness of the RW membrane in the model. The results show that the vibration amplitude of the BM is larger when the stimulus is applied to the RW compared to the OW, except for cases of RW membrane ossification. The difference in these amplitudes is particularly significant when stapedial mobility is limited. These results suggest that RW vibroplasty would be advantageous, especially in cases of accompanying stapedial mobility impairment. Additionally, it is suggested that transitioning to OW vibroplasty could still ensure a sufficient level of vibratory transmission efficiency when placing the FMT on the RW membrane is difficult due to anatomical problems in the tympanic cavity or confirmed severe pathological conditions around the RW.

Mechanical stimulation through a cochlear third window into the scala tympani in a chinchilla model with normal and fixed stapes can generate cochlear responses equivalent to acoustic stimuli. Cochlear stimulation via the round window (RW) using active middle ear implants (AMEIs) can produce physiologic responses similar to acoustic stimulation including in a model of stapes fixation. However, pathologic conditions, such as advanced otosclerosis, can preclude delivery of sound energy to the cochlea through the oval window and/or the RW. Cochlear microphonic (CM) and laser Doppler vibrometer measurements of stapes and RW velocities were performed in 6 ears of 4 chinchillas. Baseline measurements to acoustic sinusoidal stimuli (0.25-8 kHz) were made. Measurements were repeated with an AMEI driving the RW or a third window to the scala tympani before and after stapes fixation. AMEI stimulation of the third window produced CM waveforms with morphologies similar to acoustic stimuli. CM thresholds with RW and third-window stimulation were frequency dependent but ranged from 0.25 to 10 and 0.5 to 40 mV, respectively. Stapes fixation, confirmed by laser Doppler vibrometer measurements, resulted in a significant frequency dependent impairment in CM thresholds up to 13 dB (at <3 kHz) for RW stimulation and a nonsignificant frequency-dependent improvement of up to 10 dB (at >3 kHz) via third-window stimulation. AMEI mechanical stimulation through a third window into the scala tympani produces physiologic responses nearly identical to acoustic stimulation including in a model of stapes fixation with decreased efficiency.

To evaluate hearing outcomes and postoperative complications among patients with middle and external ear malformations undergoing active middle ear implantation with Vibrant Soundbridge® (VSB). Review of the literature. Studies published in English, Portuguese, or Spanish at the following databases: PubMed, MEDLINE, Scopus, Web of Science, EMBASE, and Cochrane Library were searched. The search strategy yielded a total of 141 potentially relevant studies. Of these, ten were included in this analysis. The mean preoperative air conduction threshold was 66.7 ± 6.2 dB. The mean air-bone gap was 46 ± 7.7 dB. VSB implantation resulted in mean hearing gain of 40.5 ± 7.1 dB in the air-conduction thresholds among the evaluated frequencies. The speech recognition index if the Floating Mass Transducer (FMT) was placed in the short process was 86.0% ± 9.6%, with significant difference when compared to long process coupling (p = 0.035) and the round window coupling (p = 0.048). Bone conduction thresholds did not worsen in any of the studies included in the present review. VSB implantation resulted in a mean hearing gain of 40 dB at air conduction thresholds.

Background: Simple or non-syndromic types of oval window (OW) or round window (RW) atresia are relatively rare in clinical. Few studies have assessed bone conduction (BC) hearing in OW or RW atresia patients, with some reporting that BC hearing lies within the normal range, whereas others observing impaired BC hearing.Aims/Objectives: This study explored the effect of blocking the OW and RW during BC in cat models.Material and Methods: Twenty-four cats were randomly divided into three immobilization groups (OW blockage, RW blockage, and OW + RW blockage) and control group. Each immobilization group also had the initial control state before blockage. Medical adhesive and ear mould glue were used to immobilise the stapes footplate and RW, respectively. Comparisons were made of the auditory brainstem response (ABR) thresholds before and after immobilization for the three immobilization groups during three different stimuli [air conduction (AC) click, BC click, and BC pure tones].Results: The AC click thresholds increased after immobilisation in three experimental groups compared to the control group (p < .05). The AC click thresholds increased compared to their initial control state after all three immobilization groups (p < .05). With an increase in frequency from 2 to 8 kHz, there was a general decrease in the difference between pre- and post-immobilization BC hearing thresholds in all three immobilization groups. The BC click threshold and BC tone thresholds at 2–4 kHz in both OW blockage and OW + RW blockage groups exceeded those in RW blockage group (p < .05).Conclusions and Significance: The use of medical adhesive and ear mould glue for the blockages of OW and RW, respectively in cats was feasible. The effect of blocking the OW and RW in BC hearing was larger at low frequencies than high frequencies between 2 and 8 kHz. OW blockage had a greater effect than RW blockage on BC hearing at 2–4 kHz range.

Active middle ear implants such as the vibrant sound bridge (VSB) have been placed on the round window (RW) in patients with conductive or mixed hearing loss, with satisfactory hearing results. Several observations show that the mechanism of RW stimulation is not completely understood. The purpose of the present study was to compare different coupling procedures between the transducer and the RW in order to contribute to an understanding of the mechanism of RW stimulation. Five fat sand rats underwent ablation of the left ear and opening of the right bulla, followed by baseline measurements of thresholds of auditory nerve brainstem evoked responses (ABR) to air and bone conduction click stimuli. Subsequently the malleus and incus were removed from the right middle ear, modeling a conductive hearing loss in which the VSB on the RW is indicated. In the next stage of the experiment, a rod attached to the bone vibrator was placed gently on the RW membrane and then on saline fluid applied to the RW niche. ABR thresholds were recorded following both placements. Mean baseline ABR threshold in response to air conduction stimuli was 48 ± 4 dB; mean ABR threshold when the rod was placed on the dry RW membrane was 99 ± 12 dB; mean ABR threshold when the rod was in the saline on RW niche was 79 ± 7 dB. ABR thresholds were better (lower) with stimulation of fluid on the RW membrane compared to direct stimulation of the RW, providing further evidence of a direct fluid pathway.

Implanting active middle ear implants (AMEI) at the round window has become a standard procedure to restore hearing for patients with moderate inner ear or mixed hearing loss. The round window (RW)-Coupler was developed as an alternative coupling aid to fit smaller RW diameters and require less drilling in the RW niche. The question arises whether using the RW-Coupler is useful and a safe procedure compared with the nonuse of the RW-Coupler Forty-nine German-speaking patients were implanted with either a RW-Coupler attached to an AMEI floating mass transducer (FMT) or without coupler. They were evaluated preoperatively and postoperatively for bone and air conduction thresholds with and without the implant, as well as speech perception tests. Bone conduction thresholds remained stable preoperatively and postoperatively. The patient's functional gain was slightly better with the RW-Coupler. Focusing on the average speech perception performances, both groups presented an improvement of speech perception above 80% at 65 dB HL. RW-Coupler-Vibroplasty was found to be a safe procedure, which produced good results in this group of patients with mixed hearing loss.

The coupling efficiency of a semi-implantable active middle ear implant with an electromagnetically driven floating mass transducer coupled to a middle ear ossicle or the round window can only be quantified postoperatively in cooperative patients by measuring behavioral vibroplasty in situ thresholds in comparison with bone conduction thresholds. The objective of the study was to develop a method to objectively determine the vibroplasty in situ thresholds by determining calibration factors from the relation between the objective and behavioral vibroplasty in situ thresholds. Prospective experimental study. Fifteen patients, implanted with an active middle ear implant for at least 6 months. Diagnostic. Vibroplasty in situ thresholds measured objectively by auditory steady state responses (floating mass transducer [FMT]ASSR). Subjective vibroplasty in situ thresholds were measured in this experimental ASSR set-up (FMTsubj.) and behaviorally by pure-tone audiometry (vibrogram). All thresholds were obtained at 500, 1000, 2000, and 4000 Hz. Thresholds could be objectively measured by ASSR in all patients. Differences between the FMTASSR and FMTsubj. were statistically significant but small. A significant correlation was found between the FMTASSR and the vibrogram thresholds at 4000 Hz but not for the other test frequencies. The method is feasible to measure objective vibroplasty in situ thresholds in active middle ear implant users. Since calibration factors could not be determined for all frequencies, the method is only applicable to comparatively determine the coupling efficiency of the floating mass transducer.

To evaluate the long-term medical and technical results, implant survival, and complications of the semi-implantable vibrant soundbridge (VSB), otologics middle ear transducer (MET), and the otologics fully implantable ossicular stimulator (FIMOS). Retrospective cohort study. Patients with chronic external otitis and either moderate to severe sensorineural or conductive/mixed hearing loss. Tertiary referral center. Implantation with the VSB, MET, or FIMOS. Medical complications, number of reimplantations, and explantations. Ninety-four patients were implanted, 12 patients with a round window or stapes application. 28 patients were lost to follow-up. The average follow-up duration was 4.4 years (range, 1 month-15 years). 128 devices were evaluated: (92 VSB, 32 MET, 4 FIMOS). 36 devices (28%) have been explanted or replaced (18 VSB, 14 MET, 4 FIMOS). Device failure was 7% for VSB, 28% for MET, and 100% for FIMOS. In 16 patients (17%) revision surgery (n = 20) was performed. Twenty patients (21%) suffered any medical complication. Medical and technical complications and device failures have mostly occurred in the initial period of active middle ear implants (AMEI) implementation and during clinical trials or experimental procedures. All four FIMOS had technical difficulties. An important decrease in the occurrence of both medical and technical complications was observed. Application in more recent years did not show any complications and the recent device failure rates are acceptable. Magnetic resonance imaging (MRI) incompatibility should be taken into account when indicating AMEI.