"Assessing the employment of Carbon Dioxide Angiography in Endovascular Aneurysm Repair: A Systematic Review and Meta-Analysis"

Abstract

BACKGROUND Endovascular aortic aneurysm repair (EVAR) traditionally relies on iodinated contrast media (ICM), which can be problematic in patients with renal insufficiency or iodine allergy. Carbon dioxide (CO2) has emerged as a valuable alternative to mitigate these risks. Although CO2 angiography has been performed in various vascular procedures for years, further investigation is required to thoroughly assess its benefits, limitations, and potential for general application on EVAR procedures. This systematic review with meta-analysis aims to evaluate the safety and efficacy of CO2 angiography in EVAR, focusing on its impact on renal function, procedural success, complication rates and adverse events. MATERIALS AND METHODS A comprehensive literature search was conducted using PubMed, Cochrane Library, Scopus and ISI databases to identify studies published up to January 2025 that assessed CO2 angiography use in EVAR. The primary endpoint of safety was acute kidney injury (AKI) occurrence, represented by deviation in serum creatinine levels, estimated glomerular filtration rate, chronic kidney disease (CKD) stage, RIFLE criteria or ARISe classification. Efficacy was evaluated based on technical success rates and adverse events. The incidence of acute kidney injury was pooled by random-effects meta-analysis, with sources of heterogeneity being explored by meta-regression. Assessment of studies' quality was performed using National Heart, Lung, and Blood Institute (NHLBI) Study Quality Assessment Tool for observational cohorts and cross-sectional studies, and Risk of Bias 2 tools. RESULTS Eight studies involving 1699 patients were included, with 581 undergoing EVAR with CO2 angiography and 1118 receiving ICM. All of them were observational studies, 3 of them being prospective and the remaining of retrospective nature. There was no statistical difference between the EVAR cohort assessed with CO2 angiography and the ICM angiography cohort, with an overall AKI risk ratio of 0.65 (95% CI: 0.27-1.56) (I2=0%). However, CO2 angiography is associated with longer procedural times and higher radiation exposure in some studies. The intraoperative endoleak detection rate was similar, or slightly higher, in the CO2 group. CO2-related adverse events reported, such as abdominal pain and nausea, were mostly mild and resolved spontaneously. No significant differences in mortality rates were observed between the groups. CONCLUSION CO2 angiography is effective in reducing postoperative renal function deterioration and shows comparable safety and efficacy to ICM in EVAR procedures. Nevertheless, further large-scale randomized trials are needed to validate these findings and are pivotal for optimizing CO2 angiography as a viable alternative to ICM in clinical practice.