In vitro comparison of the leakage of carbon dioxide and iodine contrast medium in a bleeding model

Abstract Purpose This study aimed to evaluate the effect of carbon dioxide (CO₂) on the sensitivity of bleeding detection by comparing the hydrodynamics of CO₂ and iodine contrast medium using a bleeding model. Materials and methods We created a bleeding model with large and small wounds in simulated blood vessels. A syringe was connected to the bleeding model and a blood pressure transducer, and the circuit was filled with CO₂ and iodine contrast medium. The piston of the syringe was pressed, and then the flow rate and intravascular pressure of the CO₂ and iodine contrast medium leaking from the bleeding model were measured. The volume, sphere-equivalent diameter, and sphere-equivalent area of the leaked contrast medium were compared. Results At a constant flow rate, the intravascular pressure required for the model to leak was lower for the CO₂ than for the iodine contrast medium, and it was also lower for larger wounds. The CO₂ contrast medium leakage volume, equivalent circle diameter, and equivalent circle area were greater than those of the iodine contrast medium, and they were also greater for larger wounds. Conclusions In the bleeding model, the CO₂ contrast medium may be more prone to leakage than the iodine contrast medium in large and small wounds. In terms of visibility, the CO₂ contrast medium may be more likely to detect leakages than the iodine contrast medium.