Simple and Effective Techniques to Minimise Contrast Dosage During Infrarenal Endovascular Aneurysm Repair

Endovascular aortic repair (EVAR) is the standard of care for abdominal aortic aneurysms owing to its minimally invasive nature and favourable peri-operative outcomes. However, reliance on iodinated contrast media (ICM), including unnecessarily high volumes, raises concerns regarding contrast induced nephropathy, particularly in patients with pre-existing renal impairment. This study describes simple, pragmatic, and cost effective strategies to minimise ICM use during EVAR and presents an institutional experience.

Three contrast injection strategies were applied, designated the wet protocol (ICM only), mixed protocol (ICM + carbon dioxide [CO₂]), and dry protocol (CO₂ only). Key strategies included meticulous pre-operative planning using C-arm optimisation and bony landmarks, automated contrast injector systems for controlled (specifically 'low volume, high rate') ICM delivery, and selective adoption of CO₂ angiography using the CO₂mmander II System (AngioAdvancements, Fort Myers, FL, USA).

An exemplar analysis was undertaken of 150 patients (98 men and 52 women, mean age 76 ± 7 years) who underwent infrarenal EVAR between March 2017 and June 2025 by author A.C., applying these contrast protocols. These were used accordingly: wet protocol (n = 120), mixed protocol (n = 26), and dry protocol (n = 4). The median ICM volume used in the wet protocol was 36 mL (interquartile range 18 mL), and 16 mL (interquartile range 18.5 mL) in the mixed protocol. A significant improvement in post-EVAR estimated glomerular filtration rate was noted for the wet protocol (p < 0.001, paired t test), whereas for the mixed protocol, the improvement was marginal (p = 0.053, paired t test). Such approaches reduce contrast dose overall and are particularly valuable for patients at risk of contrast induced nephropathy, supporting safer and more individualised EVAR practice. This experience demonstrates that these pragmatic techniques significantly reduce ICM use without compromising technical success or safety. Application of CO₂ angiography is dependent on access to appropriate injection systems. Such considerations can be applied to the operative workflow at the time of multidisciplinary peri-operative discussion.