Hemodynamic Phenomena in Fusiform Aneurysms-II: Pulsatile Flow Conditions

Pressure and flow distributions are reported at different pulsatile flows for four latex fusiform aneurysm models. The accuracy of results by Pitot-static techniques is examined in terms of experimental evidence and theoretical considerations. Pressure distributions within the aneurysm are associated with the Reynolds number, the degree of wall divergence, and the degree of sac dilation, and these parameters are interactive. The Bernoulli principle was usually inapplicable, and higher peak pressures may be seen where measured velocities may lead one to predict lower pressures. The presence of such localized high pressures depends on whether disturbed flow occurs at that location. There may be little qualitative difference in the patterns of velocity and pressure within an aneurysm between pulsatile and steady flow conditions. However, with pulsatile flow, the presence of distributed flow may be more obvious and commence closer to the proximal end of the aneurysm.