Zero-Contrast EVAR Can Be Reached Using Automated Carbon Dioxide Digital Angiography, Endoaortic Balloon Occlusion, and IVUS

Objective: To introduce a new method to enhance the visualization of renal arteries and the accuracy of graft deployment during CO 2 -assisted endovascular (EV) aneurysm repair (EVAR). Methods: A retrospective observational study of consecutive EVAR cases assisted with CO 2 angiography (CO 2 Angio) was conducted. This nonrandomized design reflects real-life progressive attempts to enhance the reliability of CO 2 and intravascular ultrasound (IVUS), minimizing the use of iodinated contrast (IC) and radiation, respectively. Cases were divided into 3 groups according to consecutive periods: CO 2 Angio ( n = 7), CO 2 Angio and balloon occlusion of the infrarenal aorta (CO 2 Angio + EVclamp, n = 11), and CO 2 Angio + EVclamp + IVUS ( n = 18). IC was permitted in case of insufficient visualization with CO 2 Angio during any phase of the procedure. Demographic, clinical, and procedure variables (volume of IC and CO 2 , radiation, fluoroscopy time, leaks) were collected from electronic clinic histories and statistically analyzed. Results: A significant decrease was found in the third group, after introducing both techniques, for total radiation (air kerma; 3,039 ± 2,792.3 vs 3,434.7 ± 1,289.2 vs 2,284.6 ± 841.5 mGy, P = 0.041), radiation per area, dose area product (47 ± 34.7 vs 54.5 ± 15.3 vs 41.3 ± 12.8 mGy×m 2 , P = 0.03), and IC volume (104.3 ± 102.4 vs 89.2 ± 53.9 vs 15.4 ± 27.4 mL, P < 0.001), arriving at the goal of “zero contrast” in the last 12 patients. No significant differences were detected in fluoroscopy time, total operative time, total CO 2 volume, or change in renal function. Conclusions: The introduction of endoluminal occlusion with a balloon and the use of IVUS in CO 2 -assisted EVAR enabled us to achieve the objective of zero contrast and a progressive decrease in radiation dose.