gms | German Medical Science

The use of new, high-quality imaging techniques e.g. Rotational Tomography (RT) opens new possibilities for immediate quality control in middle ear surgery. This is an essential task in order to evaluate precisely post-operative circumstances like e.g. coupling of inserted middle ear prostheses. RT allows depiction of anatomical structures offering comparable quality like Computed Tomography (CT). In contrast RT includes a comparingly lower radiation exposure and almost artefact-free visualization of metallic middle ear implants.

We performed experimental investigations in 15 temporal bone specimen. All specimen underwent simulated middle ear surgery including titanium prosthesis insertion (TORP, PORP). Laser-Doppler-Vibrometry (LDV) was used in all specimen pre- and post-operatively in order to define the transfer function after the reconstructive procedure. We furthermore evaluated specific coupling angles of the inserted implants either towards the tympanic membrane (TM) or the malleus handle (MH) by using 3-D post-processing of RT-data.

Excellent visualization was achieved in all specimen. RT allowed precise localization of inserted implants in the reconstructed middle ear. Furthermore coupling- and inclination angles of middle ear prostheses towards TM or MH were determined. Investigations using LDV enabled correlation between postoperative functional outcome and coupling angles.

Due to our experimental results RT seems to be a valuable and promising tool for estimation of postoperative functional results. This imaging technique opens new possibilities for immediate postoperative quality control.