Biomechanical Modeling of Intrasac Pressure Changes and Vascular Remodeling After Endovascular Repair of Abdominal Aortic Aneurysms

Endovascular repair (EVAR) is a minimally invasive method of repairing an abdominal aortic aneurysm (AAA) that is associated with shorter hospital stay, lower mortality, and other advantages compared with open surgery. During this operation, a stent graft is introduced through a femoral artery and is deployed with the proximal portion below the renal arteries. After EVAR, the aneurysm sac should ideally be excluded from aortic blood flow resulting in a much lower intrasac pressure than the systemic pressure. In reality, the intrasac pressure varies from case to case. For a successful EVAR, intrasac pressure gradually decreases to around 20–40 mmHg over time, while in many patients intrasac pressure remains relatively high or even close to the systemic pressure for some cases. Our literature study [1] indicates that intrasac pressure has a significant impact on post EVAR AAA size changes. Additionally, post-EVAR remodeling depends not only of the values of the intrasac pressure but also on how the pressure has changed over a period of time.