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 CO2-assisted endovascular (EV) aneurysm repair (EVAR). METHODS: A retrospective observational study of consecutive EVAR cases assisted with CO2 angiography (CO2Angio) was conducted. This nonrandomized design reflects real-life progressive attempts to enhance the reliability of CO2 and intravascular ultrasound (IVUS), minimizing the use of iodinated contrast (IC) and radiation, respectively. Cases were divided into 3 groups according to consecutive periods: CO2Angio (n = 7), CO2Angio and balloon occlusion of the infrarenal aorta (CO2Angio + EVclamp, n = 11), and CO2Angio + EVclamp + IVUS (n = 18). IC was permitted in case of insufficient visualization with CO2Angio during any phase of the procedure. Demographic, clinical, and procedure variables (volume of IC and CO2, 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×m2, 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 CO2 volume, or change in renal function. CONCLUSIONS: The introduction of endoluminal occlusion with a balloon and the use of IVUS in CO2-assisted EVAR enabled us to achieve the objective of zero contrast and a progressive decrease in radiation dose.