The effect of celiac and renal artery outflows on near-wall velocities in the porcine iliac arteries

The effects of the outflow of aortic blood through the celiac and renal art eries on the flow field in the external iliac arteries were studied under s teady and physiologically realistic pulsatile flow conditions. Laser Dopple r velocimetry (LDV) measurements were made close to the medial, lateral, ve ntral, and dorsal walls of the external iliac branches of a clear, flow-thr ough replica of a porcine aorta and its daughter vessels. The outflow from each branch of the replica was controlled so that the infrarenal aortic flo w rate and the flow partition at the aortic trifurcation were the same for all experiments. LDV measurements were made with how exiting through both t he renal and celiac artery ostia, only the celiac ostium, and neither ostiu m. The steady flow results indicate that while the outflow through the rena l arteries did not have a significant effect on near wall shear rate in the external iliac arteries, the flow through the celiac artery did. However, in pulsatile flow, three indices of near wall velocity in the iliac arterie s were unaffected by celiac artery outflow, while a fourth showed a small e ffect that can be attributed to differences in minimum velocity. These resu lts indicate that reliable simulations of blood flow in the external iliac arteries can be carried out without including the renal and celiac vessels, provided that the correct infrarenal flow wave is used. They also demonstr ate that the flow field downstream of a region, such as a branch, that stro ngly alters the flow, can be nearly independent of the velocity field enter ing the region. (C) 2000 Biomedical Engineering Society. [S0090-6961(00)005 03-8].