Mechanical characterization and modeling of mesh implants
Medical mesh implants are applied to support soft body tissues [Schumpelick V.et al., Chirurg, Vol. 70, 876-887, 1999]. Different types of meshes are available, characterized by the manufacturing technique, the pore size and the material [Klosterhalfen B. et al., Expert Review of Medical Devices, Vol. 2, No. 1, 103-117, 2005]. From the clinical point of view, it is desired to apply the optimal implant with respect to the patient-specific requirements. Therefore, it is essential to determine the mechanical behavior of both, the affected biological tissue and the available meshes for its repair. A preliminary study was carried out recently in our laboratory [7s].
This project aims at the application of mesh implants for prolapse repair. Therefore, the mechanical properties of the vaginal wall are examined. Furthermore, different configurations of the mesh implants, the dry mesh, the explanted mesh including ingrown body tissue and the in-vivo state are investigated.
The experimental methods include an optical measurement technique for local strain analysis in uniaxial and biaxial tension tests. For in-vivo measurements, an aspiration device, particularly adapted for the application on the vaginal wall is used. In addition, the biological tissues are analyzed histologically.
A numerical study of the mesh implants is performed at the meso-scale. The characteristic parameters of the different mesh configurations, leading to the specific mesh kinematics and the global mechanical response are evaluated and modeled.
Bringing together the experimental and the numerical investigations leads to an inverse problem. Its solution helps to find a correlation between the histological events and the mechanical characteristics of the mesh implants.
Group Prof. Jan Deprest, Centre for Surgical Technologies, KU-Leuven
Mahmood Jabareen, Technion Haifa, Israel
Scheiner, Bajka, Perucchini, USZ, Obstetrics and Gynecology, Zurich