Safety and Feasibility of Carbon Dioxide Angiography for Stenting of Atherosclerotic Renal Artery Stenosis: A Retrospective Comparative Study

Objective: To evaluate the technical feasibility and procedural safety of carbon dioxide (CO2) angiography during renal artery stenting compared with iodinated contrast angiography, and to identify baseline factors associated with postprocedural improvement in renal function. Materials and Methods: This single-center, retrospective study involved 99 patients who underwent renal artery stenting, with 37 in the CO2 angiography group and 62 in the iodinated contrast medium control group. Kidney disease progression was described as a decline in the estimated glomerular filtration rate (eGFR) of ≥20% and/or evolution to end-stage disease. Improvement in function was stated as a ≥25% increment in eGFR within one month after the procedure. Demographic, periprocedural, and postprocedural variables were compared between the two groups (CO2 versus control group). Receiver operating characteristic curve analyses were done to specify cut-off values for renal function improvement in the CO2 group. Results: There were no significant differences in procedure time, complication rates, and technical challenges between the two groups. Improvement in kidney function after stenting was experienced more frequently in the CO2 group. Exploratory ROC (Receiever operating characteristic) analyses identified baseline serum creatinine and eGFR cut-off values of <1.9 mg/dL and >35 mL/min/1.73 m2, respectively, for discriminating patients with renal function improvement. Conclusions: CO2 can be safely and effectively used as an alternative contrast agent during renal artery stenting in patients with CKD (chronic kidney disease).