Particle image velocimetry study of aorta-renal bifurcation.

Background: Haemodynamic parameters such as separated flow regions play a key role in the progression and development of atherosclerotic lesions in renal arteries, which typically originate at the renal ostium.

Objective: The aim of this study was to analyse the flow dynamics in a two-dimensional model of aorta-renal bifurcation, with a particular focus on the effect of aorta-to-renal flow ratio on flow separation regions.

Method: A particle image velocimetry (PIV) experiment was conducted in an acrylic model of the aorta-renal ostium and the relationship between renal-to-aorta flow ratio and separated flow region was investigated.

Results: For high flow ratios, a stagnation region was observed near the cranial side of the aorta. With a decrease in the flow ratio, however, this stagnation region disappeared. Furthermore, our results showed that an increase in the renal flow rate was associated with an increase in the length of the separated flow region, but a decrease in the width of the separation regions.

Conclusions: As the renal-to-aorta flow ratio increased a longer separation region was observed on the cranial side of the renal channel.