Suprarenal fixation: effect on blood flow of an endoluminal stent wire across an arterial orifice.
OBJECTIVE
To investigate what effect, if any, the presence of a stent wire in front of a renal artery has on the volume flow rate of blood through the renal artery.


METHODS
Experimental, numerical, and analytical modeling methods were used to test 4 separate stent wire configurations: a stent wire across the center of an artery orifice, an off-center wire placed at one-quarter the arterial diameter, a V-shaped wire with its vertex at the center, and 2 stent wires at one-third-diameter spacing.


RESULTS
For all the configurations studied, the presence of stent wires has a minimal effect on the blood flow rate into an artery of >/=3-mm diameter, with most flow rates decreasing by around 1%. This is true provided that there is no buildup of material on the wire. When material buildup was "encouraged" to occur, then decreases in flow rate of up to 40% were observed. The numerical and analytical methods indicated that the flow rates would, in most cases, decrease by around 3% to 10%.


CONCLUSIONS
A bare stent wire in front of a >3-mm-diameter artery decreases the flow rate minimally, providing there is no material on the wire. Although the numerical and analytical methods indicated a greater effect on flow, the approximations required for these 2 methods to obtain meaningful solutions suggest that the experimental results are the most accurate. Nonetheless, the analytical equations provided a useful approximation for determining the effect on blood flow due to the presence of a stent wire.
Liffman
Kurt
K
Energy & Thermofluids Engineering, CSIRO/MIT, Highett, Victoria, Australia.
Lawrence-Brown
Michael M D
MM
Semmens
James B
JB
Sutalo
Ilija D
ID
Bui
Anh
A
White
Flyn
F
Hartley
David E
DE
D017130:Angioplasty; D017544:Aortic Aneurysm, Abdominal / Q000503:physiopathology* / Q000601:surgery; D001783:Blood Flow Velocity / Q000502:physiology*; D019917:Blood Vessel Prosthesis Implantation; D018056:Hemorheology; D006801:Humans; D008955:Models, Cardiovascular; D012077:Renal Artery / Q000503:physiopathology*; D012078:Renal Artery Obstruction / Q000503:physiopathology* / Q000601:surgery; D012079:Renal Circulation / Q000502:physiology*; D015607:Stents