Biomechanics of the Aortic Root and Ascending Aorta in Patients With Marfan Syndrome

This study investigated how Marfan syndrome (MFS), a connective tissue disorder associated with aortic dilation and dissection, alters the biomechanical properties of the aortic root and ascending aorta. Human surgical specimens were collected from patients with MFS, bicuspid-valve aneurysms (BAV), tricuspid-valve aneurysms, type A dissections, and normal donor aortas. Biaxial tensile testing and delamination peeling were used to evaluate low-strain modulus, energy loss, and interlamellar adhesion strength. In the aortic root, MFS tissue did not differ significantly from other groups, indicating preserved low-strain and interlamellar mechanical behavior. In contrast, ascending aortic tissue from MFS patients exhibited clear pathological deviations, including significantly reduced delamination strength, increased viscoelastic energy loss, and lower low-strain modulus compared to normal and BAV aneurysms. These results demonstrate that the ascending aorta in MFS undergoes distinct structural compromise, helping clarify mechanisms of dissection vulnerability and informing risk stratification and surgical timing in connective-tissue aortopathies.