ISBN 978-3-8439-2688-1

978-3-8439-2688-1, Reihe Mathematik

Simon Zimny
Hemodynamic Flow Simulation in Patient Specific Cerebral Aneurysms

211 Seiten, Dissertation Rheinisch-Westfälische Technische Hochschule Aachen (2015), Softcover, A5

Zusammenfassung / Abstract

In recent years, the hemodynamics in cerebral aneurysms has been studied at length and methods of treatment have improved significantly. Besides the well known surgical clipping and endovascular coiling technique, the use of flow diverter stents is becoming more and more popular. The main idea of this non-invasive treatment technique is to change the hemodynamics in the aneurysm cavity, such that blood clotting is triggered. Due to the thrombus formation the aneurysm dome is occluded and prevented from rupturing.

One of the key quantities leading to the coagulation of blood, is the wall shear stress (WSS). On the one hand, high WSS triggers the activation of platelets, the endothelium to release collagen XII or, in case of very high WSS, damages erythrocytes such that hemoglobin is released. On the other hand, proinflammatory genes favoring blood coagulation are upregulated in areas of low WSS. The activated platelets, as well as the production of fibrin strands lead to the thrombus formation in areas of low WSS.

This thesis deals with the numerical simulation of hemodynamics in patient specific aneurysm geometries. A particular focus is on the resulting WSS pattern in the aneurysm geometries investigated. In order to compare the influence of flow diverters on the hemodynamics in the aneurysm cavity, simulations without stent, as well as stents of different porosity are carried out. In addition, the influence of a prescribed sinusoidal motion of the aneurysm wall on the WSS is investigated in detail.