Professor Christian Gasser

KTH Royal Institute of Technology, Stockholm

Christian Gasser is Professor of Biomechanics at KTH Royal Institute of Technology, Stockholm. He holds a Master of Mechanical Engineering (1997) and a PhD in Civil Engineering (2001), both from Graz University of Technology, Austria. The development and application of advanced numerical techniques to solve realistic (bio)engineering and clinical problems, is Gasser’s main research objective. Constitutive models for anisotropic finite strain materials have been implemented in all major Finite Element simulation packages, such as ANSYS, ABAQUS, COMSOL, etc, and Gasser’s translational biomechanics research led to A4clinicsRE, commercial biomechanical-based simulation software for clinical decision making. In 2022 he has been listed as KTH’s most influential researcher in Biomedical Engineering, and his work led so far to more than 16k Google Scholar citations. He received a Humboldt Research Award from Germany, and Gasser is designated 2024 Odqvist lecturer, a distinction awarded by the Swedish national mechanics committee. He is Associate Editor of Int. J. for Num. Meth. in Biomed. Engrg, in the editorial board of Mechanics of Soft Materials and a EMMCC member, principal founder of ARTEC Diagnosis AB and VASCOPS GmbH, and serves a legal expert for skiing accident reconstruction at Oberlandesgericht, Graz, Austria.

Abstract:
The biomechanics-based rupture risk assessment. Patient selection through FEM-based postprocessing of medical images

An Abdominal Aortic Aneurysm (AAA), the balloon-like expansion of the aorta, is a common disease in the elderly. If the risk of aortic rupture exceeds the interventional risks, elective clinical treatment (AAA repair) is indicated and generally performed when the largest transverse aortic diameter exceeds 5.5cm in males or 5.2cm in females [1]. However, such a diameter-based risk assessment has a very poor specificity and many AAAs that would not rupture during lifetime, are currently repaired, while at the same time aortas keep rupturing below said thresholds. In contrast, the biomechanics-based rupture risk assessment (BRRA) assumes the aorta to rupture as soon as the aortic wall stress exceeds wall strength. It is a generic concept and allows the integration of multiple risk factors, thereby providing a more individualized AAA risk assessment [2]. From a patient treatment perspective, the BRRA may be seen as (Finite Element Method-based) postprocessing of Computed Tomography-Angiography (CT-A) images that have been acquired by routinely clinical examinations. The present talk reviews the state-of-the-art of the BRRA, where key elements are illustrated by following the workflow of commercial software (A4clinicsRE, Vascops GmbH, Austria). The validity of the underlying model assumptions is scrutinized and the value of clinical validation studies discussed. As supported by a significant body of clinical and bioengineering research, the BRRA is now on the verge of being integrated within the clinical decision-making process.

[1] Wanhainen et al. Eur J Vasc Endovasc Surg 57, 2019
[2] Gasser et al. Int J Num Meth Biomed Engrg 28, 2022