Comparison of two different titanium couplers for an active middle ear implant

Round-Window Vibroplasty: Systematic Review and Meta-Analysis of Audiological Effectiveness With Different Round-Window Coupling Techniques

OBJECTIVE

Active middle ear implants can be directly coupled to the round-window (RW) membrane via RW Vibroplasty. The objectives of this systematic review were to summarize data on different RW coupling techniques and to investigate their effect on audiological and safety outcomes using meta-analyses.

DATABASES REVIEWED

PubMed (MEDLINE), Cochrane Library, and Embase (DIMDI).

METHODS

All publications reporting on audiological outcomes in human patients after RW Vibroplasty were included. Two independent reviewers carried out screening and data extraction. Meta-analyses and meta-regression were used to evaluate the potential effects of surgical and demographic parameters on primary audiological outcomes. Adverse events were extracted and tabulated for qualitative analysis.

RESULTS

Fourteen different combinations of surgical coupling parameters were identified in 61 included publications. Overall, data from 23 publications could be used for meta-analyses. Significantly better aided sound-field thresholds were reported for RW Vibroplasty performed without a dedicated coupler and using fascia as interponate, compared with RW Vibroplasty with an RW coupler or without an interponate. These effects were not found in other outcomes (i.e., functional gain, word recognition score). Reporting of adverse events was relatively heterogeneous, with 32 explicit mentions of revision surgery after the loss of coupling efficacy.

CONCLUSION

There are numerous publications investigating the effectiveness of coupling active middle ear implants to the RW membrane. However, studies are typically undersampled and of low evidence level. Using meta-analyses, weighted means, and qualitative analyses enabled a summary of the existing literature on audiological and safety outcomes after RW Vibroplasty. Individual selection of the most appropriate coupling modality with standardized intraoperative measurement and careful patient follow-up may be considered key factors for achieving effective RW coupling.

Audiological Results with the SAMBA Audio Processor in Comparison to the Amadé for the Vibrant Soundbridge

BACKGROUND

Since its introduction in 1996, the Vibrant Soundbridge (VSB) has been upgraded with several improved generations of processors. As all systems are compatible, implanted patients can benefit from new technologies by upgrading to the newest processor type available.

OBJECTIVES

The aim of this study was to compare the performance of the new (current) SAMBA processor with the previous Amadé processor.

METHODS

Twenty subjects monaurally implanted with a VSB and the Amadé processor tested the new SAMBA processor for a trial period of 4 weeks. We measured air conduction and bone conduction thresholds, unaided thresholds, and aided free field thresholds with both devices. Speech performance in quiet using the Freiburg monosyllabic test at 65 dB SPL (S0) was compared. The speech intelligibility in noise was determined using the Oldenburg sentence test measured in different listening conditions (S0NVSB/S0Ncontra) and microphone settings (omni/directional vs. adaptive directivity).

RESULTS

Word recognition scores in quiet with the SAMBA were still significantly lower than with the Amadé after the 4 weeks trial period but improved over the following year. Speech intelligibility with the SAMBA was significantly better than with the Amadé in omnidirectional mode and comparable with the Amadé in directional mode. Hence, the adaptive directionality provides an advantage in difficult hearing situations such as noisy environments. The subjective benefit was evaluated using the Abbreviated Profile of Hearing Aid Benefit and the Speech, Spatial and Qualities-C questionnaire. Results of the questionnaires demonstrate an overall higher level of satisfaction with the new SAMBA speech processor than with the older processor.

CONCLUSION

The SAMBA enables similar speech perception in quiet but more flexible adaptation in acoustically challenging environments compared to the previous Amadé processor.

Long-Term Outcomes of Vibroplasty Coupler Implantations to Treat Mixed/Conductive Hearing Loss

Objective: To evaluate the long-term safety and performance of four different vibroplasty couplers (round window, oval window, CliP and Bell coupler) in combination with an active middle ear implant. Methods: This was a multicentre, prospective, long-term study including 5 German hospitals. Thirty adult subjects suffering from conductive or mixed hearing loss were initially enrolled for the study, 24 of these were included in the final analysis with up to 36 months of postsurgical follow-up data. Bone conduction and air conduction were measured pre- and postoperatively to evalu ate safety. Postoperative aided sound field thresholds and Freiburger monosyllable word recognition scores were compared to unaided pre-implantation results to confirm performance. Additional speech tests compared postoperative unaided with aided results. To determine patient satisfaction, an established quality-of-life questionnaire developed for conventional hearing aid usage was administered to all subjects. Results: Mean postoperative bone conduction thresholds remained stable throughout the whole study period. Mean functional gain for all couplers investigated was 38.5 ± 11.4 dB HL (12 months) and 38.8 ± 12.5 dB HL (36 months). Mean word recognition scores at 65 dB SPL increased from 2.9% in the unaided by 64.2% to 67.1% in the aided situation. The mean postoperative speech reception in quiet (or 50% understanding of words in sentences) shows a speech intelligibility improvement at 36 months of 17.8 ± 12.4 dB SPL over the unaided condition. The signal-to-noise ratio (SNR) improved by 5.9 ± 7.2 dB SNR over the unaided condition. High subjective device satisfaction was reflected by the International Inventory for Hearing Aids scored very positively. Conclusion: A significant improvement was seen with all couplers, and audiological performance did not significantly differ between 12 and 36 months after surgery.

Comparison of Alternative Coupling Methods of the Vibrant Soundbridge Floating Mass Transducer

The active middle ear implant Vibrant Soundbridge© provides a variety of coupling modalities of the floating mass transducer (FMT) to various structures of the ossicular chain and the round window. A retrospective analysis was performed on 125 subjects (n = 137 ears) (1) to compare the efficacy of the different FMT coupling modalities with increasing degree of hearing loss, (2) to compare the performance in speech outcome and the effective gain between the coupling types, and (3) to evaluate the risk of additional hearing loss of each coupling procedure. The patients were grouped according to their type of FMT coupling into incus vibroplasty (incus group, n = 59), round window vibroplasty with coupler (RWC group, n = 23), round window vibroplasty without coupler (RW group, n = 22), and oval window vibroplasty with coupler (OWC group, n = 33). For each coupling group, pre- and postoperative thresholds, the results of the Freiburg monosyllable test at 65 dB SPL, and the effective gain across frequencies (0.5-6 kHz) were evaluated. A logistic regression function was used to describe the relationship between word recognition scores (WRS, in % correct) and the mean bone conduction (BC) hearing loss. The surgical procedure had no clinically relevant effect on BC thresholds of patients in each coupling group. The BC pure tone average (PTA4) for 50% WRS predicted by the model function was similar for the incus (48.2 dB nHL), RW (47.8 dB nHL), and OWC (49.0 dB nHL) groups, but higher for the RWC group (67.9 dB nHL). However, the median WRS was 80% or better with no significant differences in speech perception between coupling types (Kruskal-Wallis test, p = 0.229). The effective gain shows an advantage for the incus coupling between 0.5 and 2 kHz over the other coupling types. The performance of the FMT coupling modalities is equally good for patients with a mild-to-moderate hearing loss, but the efficacy of coupling types differs for patients with greater hearing loss (>48 dB BC HL).

Subtotal petrosectomy and Codacs™: new possibilities in ears with chronic infection

Subtotal petrosectomy combined with obliteration of the tympanomastoid is a standard procedure to treat temporal bones in patients with radical cavity and chronic infections. Currently, patients with profound-to-severe sensorineural hearing loss are often fitted with cochlear implants. In the case of profound mixed hearing loss, active middle ear implants have been used successfully. The new Codacs™ system provides an effective treatment for patients with severe-to-profound mixed hearing loss; however, only aerated middle ears have been treated with this device. The question arises whether the Codacs™ can be implanted in patients with radical cavity or ears with chronic otorrhea. Of the 41 patients who were implanted with the Codacs™ at the department, 4 received the device after subtotal petrosectomy and obliteration with abdominal fat. Clinical and audiological results were assessed. The device was implanted without any complications in the obliterated subtotal petrosectomy. The preliminary results of the first two patients showed stable bone conduction thresholds and indicated improved speech intelligibility in quiet and noise. Implanting the Codacs™ device after subtotal petrosectomy and obliteration with abdominal fat has been proven to be a feasible and suitable procedure for patients with radical cavity or chronic otorrhea. The speech intelligibility outcome directly after activation was comparable to patients with aerated middle ears.