Hemodynamic Effects of Endoleak Formation in Abdominal Aortic Aneurysm Patients with Stent-Graft Implants

Endoleaks may evolve and become severe post-surgical complications in patients with abdominal aortic aneurysms (AAAs). After endovascular aortic aneurysm repair (EVAR), endoleaks may induce EVAR failure. Therefore, the early detection and management of endoleak development could help reduce the need for reoperation. An endoleak is characterized by blood flow that leaks into the cavity between the stent-graft (SG) and aneurysm sac. Comprehensive hemodynamic analysis can identify the relationship of flow-induced wall stress and endoleak formation. Given this hypothesis, a numerical analysis of fluid-structure interaction was performed in this study. SG geometry and AAA flow dynamics were incorporated using the physiological conditions of three patient-specific models of AAA after EVAR. Endoleak locations were well matched to the local peak locations of von Mises stress in the aneurysm bulges of these patients. Further investigation on the associated blood flow structures could provide insights on the physical relationship between hemodynamic force and endoleak formation. The presented analytical procedure offers a reliable alternative for endoleak prediction and detection. This method may be used for post-EVAR patient care with sophisticated imaging techniques such as magnetic resonance, computed tomography, and digital subtraction angiography.