Vestibular Organ and Cochlear Implantation–A Synchrotron and Micro-CT Study

Background: Reports vary on the incidence of vestibular dysfunction and dizziness in patients following cochlear implantation (CI). Disequilibrium may be caused by surgery at base, leading to functional disturbances receptors endolymphatic duct system (EDS) which are located nearby. Here, we analyzed three-dimensional (3D) anatomy this region, aiming optimize surgical approaches limit damage organ. Material Methods: A total 22 fresh-frozen human temporal bones underwent synchrotron radiation phase-contrast imaging (SR-PCI). One bone micro-computed tomography (micro-CT) after fixation staining with Lugol's iodine solution (I 2 KI) increase tissue contrast. We used volume-rendering software create 3D reconstructions segmentation that allowed precise assessment anatomical relationships topography. Macerated ears belonging Uppsala collection were also used. Drilling insertion CI electrodes was performed metric analyses different trajectories. Results Conclusions: SR-PCI micro-CT demonstrated complex basal region cochlea, apparatus, EDS. a cochleostomy disturb organ function injuring space disrupting fluid barriers. The saccule is particular risk due its proximity area explain immediate long-term post-operative vertigo. Round window less traumatic inner ear, however it affect receptors.