Carbon Dioxide Guided Endovascular Aortic Aneurysm Repair in Impaired Renal Function: Propensity Score Matched Study

Carbon dioxide (CO₂) is the preferred contrast agent in patients with impaired renal function and or contrast allergy and, particularly, in patients who require large volumes of contrast for complex endovascular procedures. In this study, the aim was to clarify the possible protective effects of CO₂ guided endovascular aneurysm repair (EVAR) for patients with impaired renal function by propensity score matching.

A retrospective analysis of the database was performed for 324 patients having EVAR between January 2019 and January 2022. A total of 34 patients treated with CO₂ guided EVAR were evaluated. This cohort was matched for age, sex, pre-operative serum creatinine levels and glomerular filtration rate (GFR) levels and specific comorbidities to obtain homogeneous groups that included only patients with impaired renal function (eGFR < 60 mL/min/1.73m²). The primary endpoint was to compare the decrease in eGFR from baseline and development of contrast induced nephropathy (CIN) using propensity score matching. Secondary endpoints were the need for renal replacement therapy, other peri-procedural morbidity and mortality.

Thirty-one patients (9.6%) of the total population developed CIN. There was no difference in the rate of CIN development between the standard EVAR group and the CO₂ guided EVAR group in the unmatched population (10% vs. 3%, p = .15). After matching, the decrease in eGFR values after the procedure was more pronounced for the standard EVAR group (from 44 to 40 mL/min/1.73m², interaction p = .034). Meanwhile, CIN development was more frequent for the standard EVAR group (24% vs. 3%, p = .027). In matched patients, early death did not differ between the groups (5.9% vs. 0, p = .15) CONCLUSION: Patients with impaired renal function are at higher risk of CIN after an endovascular procedure. CO₂ guided EVAR is a safe, effective, and feasible treatment option, especially for patients with impaired renal function. CO₂ guided EVAR may be a protective measure for contrast induced nephropathy.