ABSTRACT

Background: Renal artery stenosis (RAS) is the most common cause of secondary hypertension. Significant stenosis causes poor control of hypertension, worsening of renal function, left ventricle hypertrophy and heart failure. The goal of renal artery revascularization is to preserve renal function, improve the blood pressure (BP) control and prevent cardiovascular complications. Renal artery (RA) stenting proved to be a safe minimally invasive treatment, which may improve BP control and preserve renal function. Contrast-induced nephropathy (CIN) is one of the most serious complications caused by iodinated contrast angiography. Because the feasibility and safety of CO2 angiography-guided renal artery stenting have been reported, CO2 angiography is expected to reduce CIN. The aim of this study was to evaluate the safety of CO2 as contrast agents during angiography in the diagnosis and percutaneous treatment of RAS in patients with chronic renal insufficiency.

Materials and Methods: Patients who underwent renal artery stenting using CO2 angiography with chronic renal insufficiency (serum creatinine level > 1.5 mg/dL) in a single center were retrospectively reviewed. Patients were referred for angiography and potential percutaneous revascularization on the basis of the clinical history, physical and radiologic examination. The diagnostic CO2 angiography was performed as previously described. Arterial access was obtained via the common femoral artery. The collection syringe volume was typically set at 20 ml for flush aortograms (to deliver 60 ml of CO2) with a two-way stopcock. Angioplasty procedures using balloon-expandable stents were performed according to standard interventional techniques. Baseline and follow-up clinical data including patient demographics, comorbidities, laboratory tests, number and types of anti-hypertensive medications, indications for the procedure and complications were collected from the medical notes and hospital information system.

Results: A total of 35 patients (26 males and 9 females; mean age 71.97 ± 7.42) were incorporated into the study. Diabetes mellitus was present in 31.5% of patients. Creatinine level and mean eGFR at baseline were 1.8 and 37.7 mL/min/1.73m2 respectively. The procedural and angiographic

success rate was 100%. There were no severe complications. One puncture site complication (hematoma) occurred. One patient developed chest pain but recovered uneventfully. After the procedure, eGFR increased to 42.30 ml/ min/1.73m2 and serum creatinine level decreased to 1.66.

Discussion and Conclusion: The use of CO2 as an angiographic contrast agent in pa- patients with suspected renal artery stenosis and ischemic nephropathy is a safe alternative to the use of iodinated contrast material. CO2 does not result in an increase in the incidence of complications compared with iodinated contrast material.