The Hemodynamic Influence due to the Inclusion of the Full Aorta on a Patient Specific Stent Graft (SG) Device

Abdominal Aortic Aneurysms (AAA) is one of the major cardiovascular diseases that can lead to death if left untreated. An AAA is defined as a permanent and irreversible localised dilation of the infrarenal aorta. Aneurysms can result from accidents, arteriosclerosis, and high blood pressure or as a congenital disease. There are currently two surgical treatments for acute AAA, open surgery or minimally invasive repair (also known as the endovascular repair procedure). The objective of both methods is to isolate the aneurysm sac from the systemic blood pressure and flow to minimise the risk of arterial wall rupture [1]. Preliminary results for endovascular procedures have been promising with short-term results comparable with conventional surgical repair. This is especially the case for patients with small and medium sized AAAs. Long-term results are not so encouraging with stent graft migration, endoleaks, material failure and aneurysm rupture all being reported [2]. A well known complication with this endovascular procedure is the late migration of the graft in which most of the migrations are diagnosed after the first 12 months after the procedure. Multi-factors, including iliac bifurcation angle, stent graft size, blood pressure, stent graft wall compliance, iliac branch curvature, and neck length have been reported to influence device migration. The drag force acting on the bifurcated stent grafts (SG) is one of the main reasons for stent graft migration [3].