Middle ear implant in conductive and mixed congenital hearing loss in children

Active middle ear implant can be used in children and adolescents with congenital hearing loss. The authors report their experience with the semi implantable Medel Vibrant Soundbridge(®) (VSB) in the audiologic rehabilitation of such patients.

In this retrospective study, audiological and surgical data of 10 children (10.5±4 years) implanted with 12 VSB in 2 tertiary cares ENT Departments were analysed.

Two children with bilateral external auditory canal (EAC) atresia and mixed hearing loss (mean air conduction (AC) thresholds=65dB HL) were bilaterally implanted. Eight children presented with microtia associated with EAC atresia bilaterally (n=3) and unilaterally (n=5). All of them had a conductive hearing loss in the implanted ear (mean (AC) thresholds were 58.75dB HL preoperatively). The Floating Mass Transducer was crimped on the long process of the incus (n=8) or on the suprastructure of the stapes (n=4). There were no intra- or postoperative surgical complications. All the children wore their implants after 5 weeks. Postoperative mean bone conduction (BC) thresholds were unchanged. The mean aided thresholds with VSB (four frequencies warble tones at 0.5, 1, 2 and 4 kHz) were 28dB HL (± 10). Word discrimination threshold in quiet conditions in free field with the VSB unilaterally activated was 50% at 38dB SPL (± 9).

The results indicate that satisfaction of the children and their parents is very encouraging but surgeons should be cautious with this new approach in relation to the pinna reconstruction and to possible risks to inner ear and facial nerve.