The Specimen Preparation Laboratory is equivalent to a standard temporal bone laboratory with an attached histology unit. Its premises are equipped for surgical training and performing preliminary test procedures on prepared specimens. This enables services covering the entire field of ear, nose and throat surgery to be provided. The main focus is on the cochlear implant and the middle-ear implant.
As the demands made on cochlear implants are constantly changing, the manufacturers modify electrode design to meet new requirements. The focus here is on optimizing signal transmission, preservation of residual hearing, and avoiding damage to the inner ear.
The prototypes are implanted in the cochlea by means of a simulated operation. Here, surgeons are trained in necessary adjustments to operative techniques and electrode behaviour assessed. With the subsequent histological treatment of the prepared specimens, use of the hard-ground technique enables the position of the electrodes and possible damage profiles to be shown clearly – with additional usage of radiological imaging methods (DVT, µ-CT) – and evaluated. The findings are incorporated directly into the optimization of the prototypes.
Left: Mid-modiolar section of a human cochlea (30x magnification) with implanted electrode (and without damage profile)
Middle: Detail view of the left image (100x magnification)
Right: Corrosion model of a human inner ear with vestibular organ
This work is carried out in close cooperation with work groups from the Department of Otolaryngology at Hannover Medical School (MHH), VIANNA and the cochlear implant manufacturers.
Precisely the same can be done with middle-ear implants, bone-anchored auditory systems, brain implants and middle-ear prostheses.
The Specimen Preparation Laboratory provides an opportunity for visiting scientists and physicians (from Russia, Kazakhstan, Poland, Israel and other countries) to familiarize themselves with, and gain training in, the new implantation techniques and types of implant.
Prof. Prof. h.c. Dr. med. T. Lenarz: Lenarz.Thomas@mh-hannover.de
P. Erfurt: Erfurt.Peter@mh-hannover.de