Computational Fluid Dynamics as an Engineering Tool for the Reconstruction of Endovascular Prosthesis Endoleaks

Background and objectives: Endovascular prosthesis placement is a predominant surgical procedure to reduce the risk of aneurysm rupture in abdominal aortic aneurysm patients. The formation of an endoleak is a major complication of stent-graft placement. Therefore, the aim of this study was to determine the influence of stent-graft's spatial configuration on the risk of leakage under realistic flow conditions. Materials and Methods: We analyzed data collected from 10 male patients 55 +/- 3 years old after CTA who had undergone endovascular treatment. Computational Fluid Dynamics technique was applied for the reconstruction of blood hemodynamic. Two cases of the stent-graft were analyzed each time, with and without the endoleak, reconstructed from one patient data with the endoleak. Endoleak-free geometries were prepared by virtual closure of the opening. Results: It was observed that high value of the blood velocity around the endoleak may provoke its slowly rupture, which may increase the blood flow to the aneurysm sack in the case of type II endoleaks. Moreover, the appearance of endoleak reduces the average blood velocity in the entire stent-graft which in some cases may contribute to blood coagulation. Furthermore, no clot can form at the site of the endoleak due to the high value of wall shear stress near of the endoleak which prevents thrombosis.