Automated Carbon Dioxide Angiography in Fenestrated/Branched Endovascular Abdominal Aortic Aneurysm Repair

Overview

Carbon Dioxide (CO2)-based angiography is a digital subtraction angiography (DSA), where CO2 is used as an intra-arterial contrast agent. 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. The present study will specifically examine the safety of the use of CO2 as intra-arterial contrast agent using the Angiodroid automated CO2-injection system during F/B-EVAR procedures. Furthermore, the current study will focus on image quality during the different steps of the procedure with the aim of standardize injection parameters (volume and pressure) for the detection of the ostium of the visceral vessels as well as of the iliac arteries, all defined as target vessels.

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. The literature on CO2 angiography still lacks on studies regarding the systematic use of the technique in F/B-EVAR procedures. The present study will specifically examine the safety of the use of CO2 as intra-arterial contrast agent using the Angiodroid automated CO2-injection system during F/B-EVAR procedures. Furthermore, the current study will focus on image quality during the different steps of the procedure with the aim of standardize injection parameters (volume and pressure) for the detection of the ostium of the visceral vessels as well as of the iliac arteries, all defined as target vessels. The main study hypothesis is that the automated standardized injection of CO2 could provide the same angiographic information and image quality as ICM, which is nowadays used as standard contrast agent in endovascular procedures.