Automated Carbon Dioxide Angiography in Comparison to Iodinated Contrast Medium Angiography During Fenestrated/Branched Endovascular Abdominal Aortic Aneurysm Repair (F/B-EVAR)

Carbon Dioxide (CO2)-based angiography is a digital subtraction angiography (DSA), where CO2 is used as an intra-arterial contrast agent. This practice started in 1970s and it is commonly used for patients who have an impaired renal function, allergy to iodinated contrast media (ICM) or that could have a contrast-induced nephropathy (CIN) risk.

Carbon dioxide is an effective and low-risk alternative to ICM, which is nowadays used in endovascular procedures, thanks to its unique properties, such as no risk for nephrotoxicity or allergic reaction. For many years, the two most important restrictions for this technique consisted of: 1) the absence of a delivery system that could minimize the risk of air contamination during the CO2 angiography and allow controlled injection (in terms of pressure and volume of injection) of the CO2 and 2) the absence of a customized imaging protocol for a better visualization of CO2 during DSA acquisition.

Now, with the availability of an automated CO2 injector system (Angiodroid Srl, Italy) and the improvement in image acquisition protocols, CO2 angiography is increasingly used for vascular imaging and endovascular procedures.

Fenestrated and branched endovascular aortic repair (F/B-EVAR) for thoracoabdominal aortic aneurysms (TAAAs) is nowadays considered the treatment of first choice, due to its reduced procedure-related morbidity and mortality, when compared to open repair.

A peculiarity of these procedures is the need of high volumes of contrast media, which are not needed in case of open repair. This increases the related risk of impaired kidney function at the short- and long-term.