INTRODUCTION: This study examines the mechanical properties of thoracic aortic false aneurysms (TAFA) and how the use of vascular prostheses, native vessels, and anastomoses affects their development. This is done through tensile testing, simulating a Bentall procedure, which is the most common surgery leading to TAFA development. METHODS: We conducted uniaxial tensile tests on the native right and left coronary arteries from five cadaveric donors. They were anastomosed to two vascular prostheses in the longitudinal and circumferential directions to assess their mechanical responses under load. RESULTS AND DISCUSSION: All anastomosis specimens ruptured on the native vessel side, with no breaches occurring on the prosthesis side. The P2 prosthesis exhibited a mechanical response closer to that of the native vessel compared to the P1 prosthesis. There were no statistically significant differences in wall thickness or mechanical properties between the left and right coronary artery samples, leading to the merging of these groups. The strain of the anastomosis in the longitudinal direction was significantly higher than in the circumferential direction. In both directions, the strain at the onset of rupture was greater than that of the native vessel, with a particularly notable difference in the longitudinal direction. Although there was no significant difference in stress values between the longitudinal and circumferential directions, forces per suture were slightly higher in the circumferential direction. CONCLUSION: Using the "endo-button buttress technique" with a double-layer anastomosis can help distribute the load and reduce stress. An alternative option is to use a Carrel patch to reinforce the connection between the target site and the conduit. Additionally, autologous pericardium can be employed for reinforcement.

• Keywords
• Aortic pseudoaneurysm, Bentall procedure, Coronary arteries, Tensile testing, Thoracic aortic false aneurysm,
• MeSH
• Anastomosis, Surgical MeSH
• Aortic Aneurysm, Thoracic * surgery   physiopathology   MeSH
• Aorta, Thoracic * surgery   physiopathology   MeSH
• Blood Vessel Prosthesis * MeSH
• Coronary Vessels surgery   physiopathology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Stress, Mechanical MeSH
• Cadaver MeSH
• Aneurysm, False * surgery   physiopathology   MeSH
• Tensile Strength MeSH
• Aged MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

Aortic dissection is a life-threatening disease that consists in the development of a tear in the wall of the aorta. The initial tear propagates as a discontinuity leading to separation within the aortic wall, which can result in the creation of a so-called false lumen. A fatal threat occurs if the rupture extends through the whole thickness of the aortic wall, as blood may then leak. It is generally accepted that the dissection, which can sometime extend along the entire length of the aorta, propagates via a delamination mechanism. The aim of the present paper is to provide experimentally validated parameters of a mathematical model for the description of the wall's cohesion. A model of the peeling experiment was built in Abaqus. The delamination interface was described by a piecewise linear traction-separation law. The bulk behavior of the aorta was assumed to be nonlinearly elastic, anisotropic, and incompressible. Our simulations resulted in estimates of the material parameters for the traction-separation law of the human descending thoracic aorta, which were obtained by minimizing the differences between the FEM predictions and the delamination force given by the regression of the peeling experiments. The results show that the stress at damage initiation, Tc, should be understood as an age-dependent quantity, and under the assumptions of our model this dependence can be expressed by linear regression as Tc = - 13.03·10-4·Age + 0.2485 if the crack front advances in the axial direction, and Tc = - 7.58·10-4·Age + 0.1897 if the crack front advances in the direction of the aortic circumference (Tc [MPa], Age [years]). Other model parameters were the stiffness K and the separation at failure, δf-δc (K = 0.5 MPa/mm, δf-δc = 0.1 mm). The material parameters provided by our study can be used in numerical simulations of the biomechanics of dissection propagation through the aorta especially when age-associated phenomena are studied.

• Keywords
• Aging, Cohesive model, Crack, Damage, Finite elements method, Fracture,
• MeSH
• Finite Element Analysis MeSH
• Aorta, Thoracic * physiology   MeSH
• Biomechanical Phenomena MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Stress, Mechanical MeSH
• Models, Cardiovascular MeSH
• Computer Simulation MeSH
• Aged MeSH
• Aging physiology   MeSH
• Traction MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Aged MeSH
• Publication type
• Journal Article MeSH