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

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

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

Conditions
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Thoracoabdominal Aortic Aneurysm

Intervention / Treatment
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* Diagnostic Test: CO2 angiography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with indication for treatment of complex TAAA according to accepted international guidelines Provided informed consent Exclusion Criteria: Severe COPD (Chronic Obstructive Pulmonary Disease), GOLD Stage 3 and 4 Known atrium- or ventricular septal defect with right-left-shunt Current participation in other interventional studies

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 95 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Diagnostic Test: CO2 angiography|A supplemental CO2 angiography will be performed before and after the stent graft placement.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Technical success | Technical success in terms of detecting the ostium of the visceral vessels as well as of the hypogastric arteries (defined as 100% accuracy when compared to the iodinated contrast agent angiography) | at the time the intervention | 
| CO2 sensitivity and specificity compared to iodinated contrast agent angiography | CO2 sensitivity and specificity compared to iodinated contrast agent angiography in detecting dissections, stenosis, occlusions or bleeding of the target vessel. The comparison will be blinded and retrospective. | at the time the intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Image quality | Image quality with regard to the CO2 angiography defined as poor, moderate and good. The analysis of the images will be retrospective. | at the time the intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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FEVAR, BEVAR, CO2, complex aortic aneurysm