The new Nucleus 5 model cochlear implant: a new surgical technique and early clinical results

The Nucleus 5 or CI500 series cochlear implants are the new generation of Nucleus(®) cochlear implants. The receiver-stimulator package has a low profile without a pedestal projecting from the medial surface. This study aimed to demonstrate that the new design can facilitate a minimally invasive surgical approach, without the need for tie-down sutures and without a seat drilled for the receiver-stimulator package.

The surgical technique involved placing the device directly on the surface of the bone in a secure sub-periosteal pocket with a channel drilled for the lead. A well or ramped seat was not drilled and tie-down sutures were not used. Measurements were taken from the transmitting coil to the tragus and the coil to the lobule immediately after implantation, and serially thereafter to document implant position.

To date, over 200 implants have been performed with the Nucleus 5 device. In all cases, healing was uneventful without major complications. Of 137 patients with at least 6-week follow-up data, 8% showed a measurement change of greater than 1 cm whereas only 4.4% demonstrated any clinically evident movement. None had any complications relating to migration and none required repositioning of the device.

The new design can safely be inserted without drilling a well for the receiver-stimulator package. Some early post-operative movement of the package was observed which caused no clinical impact. This modified surgical technique reduces the risk of intracranial complications and reduces operating time.