OBJECTIVE: The aim of this study is to obtain an alternative angiographic diagnostic method which can be used in patients at a high risk for the use of iodine contrast medium. MATERIALS AND METHODS: Twenty-six patients with chronic renal failure whose fistulas were assessed by digital angiography were first evaluated using iodine contrast medium. Subsequently, carbon dioxide was used as contrast medium, and the images were printed in angiographic film. The angiographic studies were evaluated for opacification, radiological diagnosis and vessel diameter by two independent vascular surgeons; the author performed a comparative analysis of the measurement of the artery and the vein, and respiratory frequency before and after contrast injection. RESULTS: The results obtained with the statistical analysis using kappa coefficient showed agreement between the two doctors and were 0.3217 for opacification, 0.5583 for radiological diagnosis and of 0.4298 for the analysis of vessel diameter. For the carbon dioxide technique, no significant difference was seen in the comparative analysis of the measures of the artery (p = 0.3657) and vein (p = 0.2041), in the position measurements and dispersion; the analysis of the position measurements and dispersion for respiratory frequency showed no significant difference. CONCLUSION: We concluded that this method can be used as an alternative for angiographic study in patients with history of allergy or risk of nephrotoxicity.

Keywords: Angiography using carbon dioxide, Renal failure, Arteriovenous fistula

OBJECTIVE: To compare duplex ultrasound and computed tomography (CT) angiography in terms of their performance in detecting endoleaks, as well as in determining the diameter of the aneurysm sac, in the postoperative follow-up of endovascular abdominal aortic aneurysm repair. MATERIALS AND METHODS: This was a prospective study involving 30 patients who had undergone endovascular repair of infrarenal aortoiliac aneurysms. Duplex ultrasound and CT angiography were performed simultaneously by independent radiologists. Measurements of the aneurysm sac diameter were assessed, and the presence or absence of endoleaks was determined. RESULTS: The average diameter of the aneurysm sac, as determined by duplex ultrasound and CT angiography was 6.09 ± 1.95 and 6.27 ± 2.16 cm, respectively. Pearson's correlation coefficient showing a statistically significant correlation (R = 0.88; p < 0.01). Comparing the duplex ultrasound and CT angiography results regarding the detection of endoleaks, we found that the former had a negative predictive value of 92.59% and a specificity of 96.15%. CONCLUSION: Our results show that there is little variation between the two methods evaluated, and that the choice between the two would have no significant effect on clinical management. Duplex ultrasound could replace CT angiography in the postoperative follow-up of endovascular aneurysm repair of the infrarenal aorta, because it is a low-cost procedure without the potential clinical complications related to the use of iodinated contrast and exposure to radiation.

Keywords: Aneurysm; Aorta, abdominal; Endovascular procedures; Ultrasonography; Angiography/methods.