Suprameatal approach for cochlear implantation in 45 Chinese children

Abstract

To investigate the feasibility of applying the suprameatal approach (SMA) for cochlear implantation in Chinese children with profound sensory hearing loss, and to demonstrate a technical modification incorporated in the procedure due to an observed racial difference. Retrospective study. University hospital. Forty-five Chinese children (total 47 ears) with profound sensory hearing loss were surgically treated from May 2005 to May 2006. The patients were followed anywhere from 1 month to 20 months post-surgery, with 30 patients being followed for more than 6 months. All patients received cochlear implantation through the suprameatal approach. In this procedure, the cochleostomy was performed in one stage after the suprameatal tunnel was finished, rather than the two-stage approach described by Kronenberg (who firstly introduced the suprameatal approach). Three patients with low-lying dura (which is considered to be the contraindication for cochlear implantation with SMA) were treated with a further modified surgical approach. Among the 47 ears, full electrode pairs were completely inserted in 45 ears without surgical difficulties, but 1 ear was only fitted with 9 pairs of electrodes because of an ossified cochlea, and another with just 8 pairs of electrodes due to serious cochlear dysplasia. An intraoperative "gusher" occurred in the dysplasia case, and a small piece of temporalis muscle was used, along with biology glue, to seal the cochleostomy and prevent further leakage. In 1 case, the electrode was inserted into the cochlea through the tunnel lateral to the chorda tympani because adhesion had occurred between the incus and chorda tympani. There were no postoperative complications in any case. Thirty cases exhibited better hearing or speech development from cochlear implantation after more than 6 months of follow-up. The SMA was found to be a simple and safe technique for cochlear implantation in Chinese children. It enables wide exposure of the middle ear, and is especially suitable for cases with a narrow facial recess, an anteriorly located facial nerve, or an ossified cochlea. It is almost impossible to injure the facial nerve or the chorda tympani nerve. The cochleostomy can be performed in one stage in those patients with a normal cochlea. With some modifications, a low-lying dura will not be the absolute contraindication of SMA.