February 23, 2023

ORCHESTRAMUS: improving Ossicular-chain ReConstruction in Human Ear with Synchrotron-based Tomography, Rapid Analyses and MUlti-Scale approaches

7th Call, iPostdoc

Short Summary

Deterioration of hearing is a significant problem in all age categories worldwide: the WHO estimates that one in ten people will have disabling hearing loss by 2050. Ossicular abnormalities in the middle ear can lead to conductive hearing loss and a reconstructive surgery (ossiculoplasty) is often needed, while still plagued by a high failure rate. In this project, synchrotron radiation-based X-ray dynamic micro-tomography will enable the direct visualization of the tiny and fast movements of the three auditory ossicles in entire human middle ears under a wide range of acoustic stimulation frequencies and intensities, and the ossicular chain biomechanics will be quantitatively characterized by an automated high-throughput analysis pipeline. These dynamic analyses will be completed by the description of the nano-scale arrangement of the auditory ossicles with small-angle X-ray scattering tensor tomography. Conducted on healthy and then reconstructed human middle ears with numerous configurations and surgical techniques, this project will shed light on the optimal design and positioning of prostheses as well as the optimal sculpting procedure of autologous material, globally improving ossiculoplasty success rate.

Goals

This project aims to characterize the biomechanics of healthy and reconstructed human middle ears, by the direct visualization of the ossicular motions with synchrotron radiation-based X-ray dynamic micro-tomography, and by the description of the nano-scale arrangement of the auditory ossicles with small-angle X-ray scattering tensor tomography. Ultimately, the results will be made available to the otolaryngology community via a database and visualization capabilities as training tools to support personalized clinical practices.

Significance

The completion of this project will lead to an unprecedent state of knowledge about the human middle ear biomechanics, and will allow the collection of a vast amount of dynamic data on a significant number of middle ear configurations. The quantitative dynamic analysis of ossicular chains reconstructed with various surgical procedures will provide strong guidance on the optimal design and positioning of prostheses, and the sculpting procedure of autologous material in ossiculoplasty will be improved by a better understanding of the nano-scale organization of the auditory ossicles, leading to a higher long-term surgical success rate.

Background

Ossicular abnormalities in the middle ear can lead to conductive hearing loss and a reconstructive surgery (ossiculoplasty) is often needed, while still plagued by a high failure rate. Today, the resculpting of autologous ossicles is the main surgical technique, as the alternatively used titanium prosthesis may lead to foreign body reaction or inflammation. However, considerable heterogeneities regarding the design and positioning of the prostheses are reported in the literature, and the impact of the sculpting procedure on the mechanical properties of the ossicles and on the nano-organization of the collagen fibrils is completely lacking.