Dysfunction screening in experimental arteriovenous grafts for hemodialysis using inflow and outflow hemodynamic game analysis

Hemodialysis access stenosis leading to dysfunction occurs at the venous anastomsis site or the outflow vein. Information from the inflow stenosis, such as blood pressure, flow velocity, and flow resistance increases, allows dysfunction screening from early clots and thrombosis to the progress of outflow stenosis. To prevent access complications, such as inflow / outflow stenosis and steal syndrome, this study proposes the dysfunction screening in experimental arteriovenous grafts (AVGs) for hemodialysis using inflow and outflow hemodynamic game analysis. In physical examinations, a stenosis limits flow volume, and then the pressure at a stenotic locus rapidly falls between inflow and outflow. Therefore, pressure drop and flow resistance can be estimated based on variations in flow volume. The quantitative differences can be applied to evaluate the risk of access dysfunction, in terms of the degree of stenosis (DOS). With the differential pressure sensors, the measured pressure drop, AP, is used to estimate the injection velocity, Vinj, and resistance (Res) index through an experimental AVG. A cooperative game (CG) based decision-making model is then utilized to evaluate the risk of an AVG dysfunction. The proposed model is implemented with the LabVIEW graphical programming. For an equivalent human circulation system, a total of 72 measurements were made at each inflow and outflow site, at locations ± lDa, l = 5,10,17 and Da = 0.635cm. At least 6 measurements were made at each location under various DOS with varying 50% to 95%. The findings indicate that the proposed measurement method and decision-making model can be carried out in practical examinations during hemodialysis.