Learning Objectives:
Introduction: The range of candidates for middle implants, either the Rion middle ear implant (Rion MEI) or the Vibrant Sound Bridge (VSB), has been restricted to patients with conductive or mixed hearing loss in Japan and most of the candidates had received previous middle ear surgeries without favorable functional results. Some of the patients have chronic middle ear pathologies which should be controlled before middle ear implantation.
Patients and methods: The Rion MEIs were implanted between 1994 and 2000 in 6 patients. Five of them had had radical mastoidectomy and one had previous canal-wall up surgery. Four patients with a dry mastoid cavity were implanted in one stage with closure of the external ear canal, whereas one patient having an infected mastoid cavity required a two-stage procedure for implantation. The round window vibroplasty technique was employed for VSB between 2012 and 2013 in 6 patients. Among six patients, two patients having a radical mastoidectomy cavity with a retroauricular opening, one patient with failed atresia surgery and one patient following canal wall up tympanoplasty needed preparatory operations before VSB implantation.
Results: All middle ear devices implanted in a two-stage procedure tolerated well in patients who had had severe middle ear diseases and/or eustachian tube dysfunction at the time of the preparatory operations.
Discussion: More than thirty years' experience with the Rion MEI in Japan had shown that postoperative retraction of the tympanic membrane occurred in a fairly high proportion of the patients with eustachian tube dysfunction, potentially causing mechanical interactions and/or protrusion of the vibrator. In order to avoid such uncomfortable situations, we prefer to prepare for a sufficient middle ear space before implantation with lateralization of the tympanic membrane or canal closure supplemented with a pedicled temporalis muscle flap or with a temporo-parietal fascia flap.
