A computational investigation of the geometric factors affecting the severity of renal arterial stenoses

An arterial stenosis, or a constriction of an artery, can lead to higher pressure losses than those seen in a healthy artery which, in turn, can disrupt normal functioning of the body. Depending on the type, size, and location of a stenosis, the decision to intervene might be made. Because many arterial stenoses can be characterized by improved medical imaging, insights into the effects of stenosis geometry on pressure loss could provide important information for medical decision making. Computational fluid dynamics (CFD) provides a means of relatively quick investigation of various stenotic artery geometries. In this work, CFD simulations varying axial location of a stenosis, stenosis eccentricity, stenosis percent occlusion, and shape were performed. The simulated arteries were models of pathologic human renal arteries. The results indicate that pressure loss across a stenosis has no dependence on stenosis eccentricity. Pressure loss was shown not to be affected significantly by the axial location of the stenosis, but it was affected strongly by the stenosis structure. The most significant dependence was on percent stenosis; simulations indicated a critical percent stenosis of approximately 75–80%, above which pressure loss increases drastically. The critical percent stenosis identified here is consistent with guidelines used by physicians.