Vascular mechanics of the coronary artery

This paper describes our research into the vascular mechanics of the corona ry artery and plaque. The three sections describe the determination of arte rial mechanical properties using intravascular ultrasound (IVUS), a constit utive relation for the arterial wall, and finite element method (FEM) model s of the arterial wall and atheroma, Methods: Inflation testing of porcine left anterior descending coronary art el ies was conducted, The changes in the vessel geometry were monitored usi ng IVUS, and intracoronary pressure was recorded using a pressure transduce r. The creep and quasistatic stress/strain responses were determined, A Standard Linear Solid (SLS) was modified to reproduce the non-linear elas tic behavior of the arterial wall. This Standard Non-linear Solid (SNS) was implemented into an axisymetric thick-walled cylinder numerical model, Fin ite element analysis models were created for five age groups and four level s of stenosis using the Pathobiological Determinants of Atherosclerosis You th (PDAY) database, Results: The artel ies exhibited nonlinear elastic behavior The total tissu e creep strain was epsilon(creep) = 0.082 +/- 0.018 mm/mm. The numerical mo del could reproduce both the non-linearity of the porcine data and time dep endent behavior of the arterial wall found in the literature with a correla tion coefficient of 0.985. Increasing age had a strong positive correlation with the shoulder stress l evel, (r = 0.95), The 30 % stenosis had the highest shoulder stress due to the combination of a fully formed lipid pool and a thin cap, Conclusions: Studying the solid mechanics of the arterial wall and the athe roma provide important insights into the mechanisms involved in plaque rupt ure.