5 Discussion
In our study the ADHEAR system was applied to an inhomogeneous group of patients with middle ear diseases of multiple etiologies suffering from a uni- or bilateral CHL or MHL. As a control group, the ADHEAR system was applied to healthy subjects with an artificial occluded outer ear canal. The patients and healthy subjects were aided with the ADHEAR system regardless of the indication criterion of the system.
In patients with a middle ear disease, 10 patients aided with a softband BAHA 5 Power system and the ADHEAR system led to a significant improvement of speech intelligibility in quiet and in noise, compared to the unaided situation. Similar results were found in a pilot study by Skarzynski et al.(17). Another study on 11 patients after middle ear surgery showed a significant improvement of speech intelligibility for monosyllables in quiet by 46% with the ADHEAR system compared to the unaided situation. The authors concluded that this adhesive BCHD may considerably improve treatment of patients with even short-term HL.
In patients with chronic inflammation of the outer ear canal and/or the middle ear, a conventional hearing aid is often refused by the doctor during conservative treatment. Even after middle ear surgery or surgery of the outer ear canal there is also a need for a temporary alternative for hearing improvement. In these cases, a softband BAHA system or an adhesive BCHD may be an alternative to improve hearing.
A softband BAHA system is sometimes refused by the patients due to social stigmatization and sweating, especially in summer. Therefore, we initialized the study starting in summer to prove whether the ADHEAR system is an alternative to a softband BAHA system or not.
According to the company information, the adhesive adapter is designed for single use and can remain on the skin for 3-7 days(9, 12, 15, 18). Considering the statements in the questionnaires, in four out of 33 participants of the study, the adhesive adapter detached more than 2 times per day due to sweating. The reported daily use and the comfort level was high, suggesting good patients’ acceptance. Additionally, no allergic reactions or other skin alteration were observed in all participants. However, for a few patients the adhesive solution is not satisfactory such that the softband BAHA remains an alternative. Patients with long-time experience for the ADHEAR and the softband BAHA system reported a higher wearing comfort and longer wearing time with the ADHEAR system than the softband BAHA system. Similar results were reported by Neumann et al.(16) and Dahm et al.(18). More data are needed to conclude that an adhesive solution is the preferred option.