A comparison between standard and dedicated stents for coronary bifurcations: structural and fluid dynamic numerical simulations

Stenting implantation in coronary bifurcations remains a challenging area in interventional cardiology. Nowadays the concurrent use of two devices is limited and the culotte technique is a commonly applied procedure. A new dedicated device has been proposed on the market to overcome the main drawback of this procedure which is the wide overlap region in the main branch. The aim of this work is to investigate the culotte technique both from a structural and fluid dynamic point of view, comparing the behavior of the dedicated stent with a standard one. Structural simulations of the stenting procedure were carried out by means of a commercial finite element code. Then, obtained realistic final geometrical configurations were used as fluid domains to perform transient CFD analyses. The biomechanical influence of the two-stents culotte technique was investigated in terms of easiness of implantation, von Mises stresses in the device, velocity and wall shear stress (WSS) patterns. Results showed that the dedicated stent facilitates the access to the main branch in comparison with the standard stent (63.4% of area available for an optimal re-crossing against 10.9%) and reduces the metal-to-artery ratio and the deformation of stent struts. Moreover, the dedicated stent caused a smaller area (28.7% against 35.5%) with WSS lower than 0.1 Pa, values considered critical for the restenosis process. This work indicates that new dedicated approaches could contribute to improve the biomechanical influence of the current treatment for coronary bifurcations.