Steady and pulsatile flow fields in an end-to-side arterial anastomosis model.
We investigated the flow field within a rigid-walled in vitro model of an end-to-side 45 degree anastomosis in an attempt to identify possible hemodynamic factors that may contribute to the pathogenesis of distal anastomotic intimal hyperplasia. A high-resolution photochromic tracer technique was used to visualize the flow in orthogonal planes and to determine the axial wall shear stress profiles for both steady and pulsatile flows over a range of physiologically relevant conditions. The flow field showed qualitative similarities to those seen in curved vessel: rapidly moving fluid from the graft section affects the bed of the host vessel, that is, the wall opposite the anastomosis, eventually advancing down the host vessel in a spiraling motion. A small mobile separation zone was noted at the toe of the anastomosis. Comparison of wall shear stress profiles with previously reported preferential sites for the development of intimal hyperplasia supported a low wall shear stress and/or flow separation pathogenesis hypothesis. One notable exception was the bed of the host artery that appeared to be subjected to a complex hemodynamic environment.
Ojha
M
M
Institute of Biomedical Engineering, University of Toronto, Ontario, Canada.
Ethier
C R
CR
Johnston
K W
KW
Cobbold
R S
RS
D001166:Arteriovenous Shunt, Surgical / Q000379:methods*; D001783:Blood Flow Velocity; D006801:Humans; D066298:In Vitro Techniques; D020366:Methylmethacrylate; D008768:Methylmethacrylates; D008955:Models, Cardiovascular; D008961:Models, Structural; D011673:Pulsatile Flow; D013314:Stress, Mechanical
D008768:Methylmethacrylates; D020366:Methylmethacrylate