A simple DSA method to detect air contamination during CO2 venous studies.

Area of Science:

• Medical Imaging
• Interventional Radiology
• Vascular Imaging

Background:

• Carbon dioxide (CO2) is increasingly used as a contrast agent for visualizing central veins, inferior vena cava, and portal vein.
• Air contamination is a significant complication in CO2 venous studies, posing potential risks to patients.

Purpose of the Study:

• To evaluate a simple digital subtraction angiography (DSA) method for detecting air contamination during CO2 venous studies.
• To differentiate between CO2 and air based on their dissolution characteristics in the venous system.

Main Methods:

• In domestic swine, varying volumes of CO2 (5, 10, 20 cm3) and a fixed volume of air (5 cm3) were injected into the inferior vena cava.
• DSA was performed using a cross-table lateral projection to visualize gases trapped in the right atrium.
• The dissolution time of CO2 and air was recorded, and vital signs were monitored.

Main Results:

• DSA successfully visualized trapped gases in the right atrium for both CO2 and air.
• CO2 was rapidly absorbed, with 5 cm3 clearing in an average of 46 seconds, while air remained visible for over 5 minutes.
• Increased CO2 doses prolonged dissolution time, but it remained significantly shorter than air.
• Vital signs remained stable throughout the procedures.

Conclusions:

• DSA is an effective method for distinguishing CO2 from air contamination in venous studies due to the rapid absorption of CO2.
• Suspect air contamination if gas remains visible in the right atrium beyond 90 seconds post-injection.
• This technique enhances patient safety during CO2-enhanced venous imaging procedures.