Comparison of the mechanical properties of bypass grafts: Experimental assays

ObjectiveOne prevalent therapeutic strategy for addressing atherosclerosis is using an alternative blood supply route to the heart, referred to as bypass surgery. In these surgeries, the saphenous vein, radial artery, and internal mammary artery are commonly used to create this bypass route. Unfortunately, due to negligence regarding the compatibility of the graft with the host tissue, reoperation is often required after several years. One method that can aid in selecting a suitable vein for bypass is simulating the solid-fluid interaction, and performing such simulations requires knowledge of the mechanical properties of bypass grafts. Therefore, extracting the mechanical properties of bypass grafts is essential.MethodsIn this study, human bypass grafts were subjected to uniaxial tensile testing, and their elastic modulus was extracted and compared. Additionally, the hyperelastic properties of these grafts were extracted using the Mooney-Rivlin model for use in numerical software.ResultsThe average elastic modulus in the circumferential direction for radial artery, mammary artery, and saphenous vein samples were determined to be 1.384 ± 0.268 MPa, 3.108 ± 1.652 MPa, and 7.912 ± 2.509 MPa, respectively. Based on the results of uniaxial tests, the saphenous vein exhibited the highest stiffness among the three vascular tissues.ConclusionThe mechanical characterization results of the bypass vessels can be applied to the clinical studies of heart diseases. They may help develop an appropriate treatment approach.