Flow patterns through side holes of venous cannula in mock circulation loop

Cannulae with multi-staged side holes (SHs) for venous drainage are widely used for performing extracorporeal circulation. Various types of catheters are used worldwide; however, data on the flow performance of each catheter are lacking or inaccurate. Clinical applications are often intuitive. In this study, we aimed to develop a mock circulation loop for cannula performance evaluation. We found no differences in the rate of change in the flow rate through each SH as the pump flow increased when the pump flow rate was 250 to 750 mL/min. When the pump flow rate was ≥ 750 mL/min, there was an increase in the rate of change in the flow rate through each side hole toward the proximal side hole and the percentage inflow of the proximal side hole and decrease in percentage inflow toward the distal side hole, as the pump flow increased. Thus, we believe that the desired venous drainage can be applied to patients, and the fluid dynamical structures of catheters in the human body can be estimated according to the type of catheter or its location in the human body. The findings of this study will aid in designing new catheters.