In previous published research, the deployment of flow-diversion increases the intra-aneurysmal pressure by 20 mmHg in the case with a pre-aneurysm stenosis. The purpose of this study is to learn the influence to the aneurysm when a pre-aneurysm stenosis exists which may threaten people's health even more severely. In the present research, idealized models of straight and curved blood vessels with both aneurysm and pre-aneurysm stenosis were established, with altering the degree of stenosis, the distance between stenosis and aneurysm and the curvature of parent artery. As the degree of stenosis increases, the reattachment length increases in straight vessels. Different positions of reattachment points to aneurysm neck affect the flow pattern inside the aneurysm. In the model with higher degree of stenosis and smaller distance between stenosis and aneurysm, the flow pattern and the direction of vortexes inside the aneurysm are affected by the recirculation after stenosis. Driven by inertial force, reattachment length decreases as the curvature of the parent artery increases, and stream inside the aneurysm is affected only when the distance between stenosis and aneurysm is short enough. In all models, the pressure drop inside the aneurysm increases as the degree of stenosis increases, creating a lower pressure environment in the aneurysm.
- numerical simulation