Gas Separation Properties of the Dense Polymer-Zeolite Powder Composite Membranes

The natural balance in the Earth's atmosphere is significantly influenced by the human emission of the combustion products, mainly carbon dioxide. Therefore, strong efforts are directed in the direction of the reduction of that emission. The solution might be searched in the direction of the construction of the membrane that would be highly transparent to the carbon dioxide, but not transparent to the other gases commonly present in the waste gases (oxygen, nitrogen, hydrogen, methane). One of the feasible designs for this purpose is dense, non-porous membranes, with zeolite particles dispersed in the polymer matrix. Zeolite particles should increase the solubility of the carbon dioxide, and thus enhance its permeability. In this paper, the possibility of application of polyether-b-amide (with 60% of PEG) as a polymer matrix was tested. For the inorganic component, four different zeolite types with three different pore geometries were tested. The influence of the additive which was added in order to provide good contact between the highly polar and charged zeolite inorganic particle, and hydrophobic polymer chains was also tested

Medical, Technical and Audiological Outcomes of Hearing Rehabilitation with the Bonebridge Transcutaneous Bone-Conduction Implant: A Single-Center Experience

Bone-conduction implants are a standard therapeutic option for patients with conductive, unilateral, or mixed hearing loss who either do not tolerate conventional hearing aids or can benefit from surgery. The aim of this study was to evaluate long-term medical and technical outcomes, and audiological results with the Bonebridge transcutaneous bone-conduction implant. This retrospective study included all patients implanted with a bone-conduction hearing implant at a tertiary medical referral center between March 2012 and October 2018. Medical and technical outcomes included the mean length of implant usage, medical and technical complications (skin and wound infection, lack of benefit, technical failure), explantations and revisions, coupling approaches, implant failure rate, implant survival and the implant loss for added follow-up years. Auditory results were measured by functional hearing gain and the Freiburger monosyllabic test at 65 dB sound pressure level. Sixty-four patients were included in the study; five of these were implanted bilaterally (69 devices). Five unilaterally implanted patients were lost to follow-up. The mean follow-up was 27.1 months (range: 0.2 months–6.3 years). The mean implant usage was 25.9 months (range: 0.2 months–6.3 years). Fifty-seven implants (89.1%) were in use at the end of the follow-up period. Complications occurred in six ears (9.4%). Five implants (7.8%) were explanted without reimplantation. Device failure occurred in one implant (1.6%), which was possibly caused by recurrent head trauma. The rate of implant loss due to technical device failure (damage to device) was 1 per 72 follow-up years. The mean improvement on the Freiburger monosyllabic test (52.1%, p = 0.0001), and in functional hearing gain across frequencies (26.5 dB, p = 0.0001) was significant. This single-center follow-up reveals the medical and technical reliability of a transcutaneous bone-conduction implant for hearing rehabilitation because complication and revision rates were low. The majority of patients still used the device at the end of the observation period. Implantation resulted in favorable hearing outcomes in comparison to that of unaided conditions. Cautious patient selection mainly regarding co-morbidities, the history of chronic otologic diseases and proper surgical technique seems to be crucial in reducing complications

Progressive Sensorineural Hearing Loss in Vibrant Soundbridge Users Requiring Cochlear Implantation

Less than 20% of patients with sensorineural hearing loss (HL) provided with the Vibrant Soundbridge (VSB) experience a progressive HL and warrant cochlear implantation (CI). The aim of this study was to identify possible predictors of progressive HL prior to VSB implantation. This retrospective study included all consecutive ears with sensorineural HL provided with the VSB between 1998 and 2016. The patient cohort was divided in a study group comprising patients who underwent CI (CI group) after years of VSB usage and those who did not require VSB replacement during the observational time (control group). Pre- and postoperative pure-tone audiometry thresholds were compared among the two groups. Fifteen out of 81 VSB devices (18.5%) required a CI. The CI group had higher preoperative air-conduction (AC) thresholds than the control group (64.3 ± 8.9 dB vs. 56.3 ± 12.9 dB; p = 0.007) at the time of the VSB implantation. On average, the CI group was significantly younger (39.1 ± 12.3 years vs. 52.6 ± 16.2 years; p = 0.003). In conclusion, VSB users with higher preoperative AC thresholds and younger age at the time of VSB implantation might be at risk for progressive HL within the upcoming eight years and need a further CI surgery. Preoperative counseling is particularly advisable in this patient group

The Laryngoscope / Long-term outcome of hearing rehabilitation with an active middle ear implant

Objective To assess the audiological and longterm medical and technical followup outcomes of an active middle ear implant. Methods This was a retrospective medical chart analysis of all patients provided with an active middle ear implant in a tertiary academic medical referral center between September 1, 1998, and July 31, 2015. Main outcome measures were medical and technical complications, revisions, reimplantations, explantations, coupling approaches, mean time of use, pre and postoperative hearing thresholds, functional hearing gain across frequencies (2504,000 Hz), and Freiburg monosyllablic word test at 65 dB. Results One hundred and three patients were identified. Fifteen were implanted bilaterally (n = 118 Vibrant Soundbridge devices [MEDEL, Innsbruck, Austria]). Seventyseven devices were implanted for sensorineural and 41 for mixed and conductive hearing loss. Patients used the implant for 6.7 years (range 0.7 months17.9 years) on average. Ninetyone patients (77.12%) were using the device at the end of the observation period. An overall complication rate of 16.1% was observed. The revision and explantation rates were higher for devices implanted between 2004 and 2006. The device failure rate was 3.4%. Audiological evaluation showed significant hearing gains for both hearing loss patient groups. Conclusion This longterm followup reveals the reliability of the active middle ear implant in a single center. Overall complication rate and device failure rate are acceptable. The complication rate was higher during implementation of alternative coupling approaches. The audiological benefit was satisfactory in patients with all hearing loss types. The majority of implanted patients used the implant at the end of the observation period.(VLID)341189

Impact of surgeons' experience and the single-shot perioperative antibiotic prophylaxis on outcome in stapedotomy.

BackgroundThe aim of this study was to evaluate whether surgeons´ experience and perioperative single-shot antibiotic prophylaxis affect outcome of patients undergoing stapes surgery.Patients and methodsWe retrospectively evaluated audiological outcomes and postoperative complications of 538 consecutive patients who underwent stapes surgery at a single tertiary referral center between 1990 and 2017. Effects of different clinical variables, including single-shot antibiotic prophylaxis and surgeons' experience on outcome were assessed.Results538 patients underwent 667 stapedotomies and postoperative complication rate was 7.5% (n = 50). Air conduction and air-bone gap closure improved significantly after surgery (14.2 ± 14.8 dB, p = 0.001; 14.5 ± 12.8 dB, p = 0.001). Multivariate analysis revealed that 6 years or less of surgical experience was independently associated with a higher incidence of persisting or recurrent conductive hearing loss (p = 0.033, OR 5.13) but perioperative application of antibiotics had no significant effect on outcome.ConclusionFirst, clinical outcome regarding persisting or recurrent conductive hearing loss caused by incus necrosis and prosthesis luxation is linked to surgical performance. This underlines the need for a meticulous training and supervision of less experienced surgeons performing stapes surgery. Second, our results do not support the need for perioperative antibiotic prophylaxis in stapes surgery. Potential standard limitations of retrospective cohort studies (selection bias, confusion bias etc.) could play a role in interpreting our results. However, the probability for these limitations is minimized due to the large patient sample