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

We aimed to compare the hydrodynamic values of carbon dioxide (CO₂) and iodine contrast media for bleeding detection using an in vitro model.

We created a bleeding model with large and small wounds in simulated blood vessels. We connected a syringe to the bleeding model and the blood pressure transducer, filling the circuit with CO₂ and iodine contrast media. The syringe’s piston was pressed, and the flow rate and intravascular pressure of the CO₂ and iodine contrast media leaking from the bleeding model were measured. We compared each leaked contrast medium’s volume, sphere-equivalent diameter, and sphere-equivalent area. These values were analyzed to compare the visibility of the leakage objectively.

At a constant flow rate, the intravascular pressure required for the model to leak was lower for the CO₂ than that for the iodine contrast medium. The CO₂ contrast medium leakage volume, equivalent circle diameter, and equivalent circle area were greater than those of the iodine one. These values indicate higher CO₂ visibility during fluoroscopy.

In the bleeding model, a CO₂ contrast medium may be more prone to leakage than the iodine one in large and small wounds. Regarding visibility, a CO₂ contrast medium may be more likely to detect leakage than an iodine one.