AORTA RENAL OSTIUM

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Related to our work on drug-eluting stents, we are considering the flow in the aorta renal ostium. The hemodynamics in this region has a significant effect on the efficacy of the DES, as we have shown both computationally and experimentally. Our current work continues with an analysis of 3D pulsatile flow.

Hemodynamic features such as flow separation and recirculating flows play important role in the development and progressions of atherosclerosis (build up of fats, cholesterol and other substances in the arterial wall). For instance, the spiral flow is an observed flow rotation in the cross-section of arteries that usually stems from the curved and tapered geometry of the blood vessel. This flow feature has been shown to reduce the size of recirculation zones and contribute to the improved renal perfusion. The understanding of such flow features provide a means to better understand the initiation and the progression of atherosclerosis and assist with the prevention and intervention plan.  Experimentally, flow visualization is possible by using tracer particles and laser illumination to produce velocity field (Particle Image Velocimetry). The following figures show the experimental set up as well as post-processed flow visualization image. Fulker et al. (2017) "Flow visualisation study of spiral flow in the aorta-renal bifurcation"

Flow visualisation study of spiral flow
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Flow visualisation study of spiral flow

Further, computational simulations were conducted to investigate the combinative effects of flow spirality, renal-to-aorta flow ratio as well as the exercise conditions. The study showed that the renal arterial stenosis (narrowing of blood vessels) are more likely to develop when longer recirculation zone is present. This happens when the flow entering the renal artery is small. Spiral flow was found to reduce the length of the recirculation zone, especially in resting condition and low renal-toaorta flow ratios. Javadzadegan et al. (2017) "Recirculation zone length in renal artery is affected by flow spirality and renal-toaorta flow ratio"

Recirculation zone length in renal arter