A computational fluid dynamics investigation of blood shear stress and shear-induced platelet activation in rotational atherectomy

Rotational atherectomy (RA) is widely used for lesion preparation in severely calcified coronary lesions; however, shear-induced platelet activation associated with high-speed rotating burr may contribute to complications such as slow-flow and no-reflow. Therefore, clarifying the distribution and mechanisms of high-shear regions in blood and identifying the dominant regions responsible for shear-induced platelet activation, are important for improving RA procedures. However, these issues have received limited attention in previous studies on RA. In this study, a three-dimensional computational fluid dynamics model with Lagrangian particle tracking was used to investigate high-shear regions and the regions dominantly contributing to shear-induced platelet activation during RA. The effects of rotational speed, lumen diameter, and burr diameter on shear stress and platelet activation potential were examined. The results show that high-shear regions mainly form at the radial jet originating near the burr equator, in the flow adjacent to the vessel wall after radial jet impinges on the wall, and in the narrow high-velocity regions near the rotating surfaces of shaft and burr.Platelet activation potential was dominated by the burr segment, mainly due to the high-shear region near the burr surface and, to a lesser extent, the high-shear region associated with the radial jet. Higher rotational speed, smaller lumen diameter, and larger burr diameter increased platelet activation potential by increasing shear stress and exposing more blood flow to high-shear regions. These findings provide mechanistic insights into high-shear regions and shear-induced platelet activation during RA and may help guide further procedural improvements to reduce periprocedural complications.