Learning Objectives: To give some hint of the principles that should drive for an appropriate selection of the correct auditory implantable device in case of chronic middle ear disease.
Background: Bone Conductive Implants (BCI) are widely used since several decades for the auditory rehabilitation of conductive and mixed hearing loss as well as for Single-sided Deafness (SSD). In mixed hearing loss, the role of Active Middle Ear Implants (AMEI) has recently been emphasised, with application and direct driving of the remnants of the ossicular chain or on the round window membrane. The present study aims to identify the best candidature on the ground of pre-operative personalised headband test.
Material and Methods: At the Implanting Center of Rome La Sapienza, Sant'Andrea Hospital, a consecutive series of subjects were evaluated for an auditory rehabilitation involving the use of electronic, surgically-implanted devices. A thorough audiometric evaluation was performed under the unaided condition and when wearing a simulation device, such as with the headband, personalised according to the individual subject's performances. The clinical conditions related to the ear pathology or to an eventual surgical sequel were also taken into account.
Results: A BCI was indicated in all cases with conductive hearing loss and in the mixed cases when the BC threshold was not measured beyond 40 dB at all the tested frequencies. When the BC threshold was beyond this threshold limit but not beyond 65 dB especially at the high frequencies, an AMEI was advised. Considering that these advanced mixed cases were often present as a sequel of open tympanoplasty for cholesteatoma, a round window coupling of the AMEI was advised.
Discussion: A thorough, individualised pre-operative test represents the best approach for the choice of the rehabilitative device, especially in absence of precise guidelines. From our experience, a round window application could always be indicated in stable, open tympanoplasty sequel and a concomitant advanced form of mixed hearing loss.
