Impact of elastin-collagen fiber connections on failure positions in aortic tissues: Experimental and simulation analysis

Abstract

Aortic aneurysms, characterized by local dilation of the aorta, often lead to catastrophic ruptures. Although aneurysm size is a well-established risk factor, smaller aneurysms can also rupture, indicating unclear rupture mechanisms. This study aims to elucidate the role of elastin-collagen fiber connections in failure positions within the aortic wall. Using porcine thoracic aorta samples, uniaxial tensile tests under a multiphoton microscope were conducted to capture images of elastin and collagen fibers. Potential connection points were identified by tracking fiber displacements. Simulation models—unconnected, connected, and partially connected fibers—were developed to analyze the impact of these connections on stress and failure positions. Results showed that up to 10% of crossing points were possibly connected; however, these connections had minimal effects on deformation, stress, and failure positions in collagen fibers, although they influenced stress in elastin fibers. This study confirms that elastin and collagen fiber connections do not significantly affect the initiation sites of aortic rupture. This work advances the understanding of aortic rupture mechanisms, highlighting the complexity of fiber interactions within the arterial wall.