Optimized design of a non-isopeak-ring endovascular stent graft for thoracic aortic aneurysm

To optimize the design of the stent graft (SG) with a non-isopeak-ring, this study investigates the radial support and bending flexibility properties of SGs with different spacing, number of peaks, and peak heights. Numerical simulation and physical experiments were used to compare the mechanical properties of isopeak-ring SGs and non-isopeak-ring SGs. Greater spacing of stent rings can provide greater bending flexibility; fewer peaks in the stent ring result in more radial support and less spring-back force. The SG design featuring a gradient of five wave peaks and a minimum stent ring spacing of 5 mm has the best flexibility. The relationship in terms of radial support force magnitude is as follows: isopeak-ring with heights of 13 mm > combination > gradient > isopeak-ring with heights of 16 mm. Additionally, the smaller the peak height, the greater its radial support. It is found that the gradient SG with five peaks not only provides sufficient radial support but also demonstrates superior flexibility compared to other types of SGs.