Data from pre- and post-implant CT angiographic images of two sample patients that underwent endovascular repair of AAA with the Cook Zenith^® stent-graft were collected and used to generate eight juxtarenal models featuring four configurations of suprarenal fixation stent wires crossing the renal artery ostia. The four wire crossing configurations can be seen in Figure 1.

Using a two-way fluid structure interaction analysis, the blood flow pattern, flow velocity, wall pressure, and wall shear stress at the renal arteries pre- and post-implant were analyzed and compared. The stent wire thickness was modeled with a diameter of 0.4, 1.0, and 2.0 mm. The 0.4 mm diameter is comparable with the suprarenal struts of the Cook ZENITH^® and Medtronic TALENT stent-graft. The results of this study indicate that flow velocity to the renal artery was mainly affected by the thickness of stent wires and the configuration of stent wires crossing the renal ostium. According to the authors, "The flow velocity was reduced by 20 - 30% in most of the situations when the stent wire thickness increased to 1.0 and 2.0 mm. Of the four types of configuration, the single wire crossing centrally resulted in the highest reduction of flow velocity, ranging from 21% to 28.9% among three different wire thicknesses." Additionally, the pre-stent-grafting laminar flow to the renal arteries was observed to be turbulent after wires were placed across the renal ostia.