Evaluation of carbon dioxide angiography in lower limb angioplasties of peripheral arterial disease patients with borderline chronic kidney disease compared to the standard contrast agent

Introduction: Assessment of carbon dioxide (CO2) angiography for its efficacy and limitations in lower limb angioplasties for chronic limb-threatening limb ischemia needs to be evaluated in detail, as the use of CO2 as a contrast agent has a distinct advantage over conventional iodinated contrast medium (ICM) in patients with borderline chronic kidney disease (CKD), with respect to nephrotoxicity caused by the later. Aims and Objectives: To study the quality of angiography images obtained with CO2 as a contrast agent and the efficacy of CO2 angiography in guiding lower limb angioplasties for critical limb ischemia. Design: This was a prospective, observational, comparative, cohort study. Study Period: September 2017–December 2018. Materials and Methods: Patients of critical limb ischemia with raised serum creatinine level (>1.49 mg/dL) who were not on the dialysis and undergoing endovascular revascularization were enrolled in the study. Hand injections were made using CO2 Angioset. Intraoperative evaluation of image quality obtained using CO2 was done by two vascular surgeons and compared with conventional contrast medium. Necessary therapeutic intervention was performed using CO2 angiography image if reliable image was acquired using the same. Results: A total of 100 patients were evaluated consisting of 176 arterial segments, out of which 145 segments required use of ICM and 31 segments were intervened using CO2 only as a contrast agent (19 superficial femoral artery, 6 common iliac artery, 2 pop artery, 3 external iliac artery, and 1 anterior tibial artery). Assessment of scores given by the observer 1 and observer 2 was performed by their comparison for the statistical significance using McNemar–Bowker test and was found to be statistically significant with P = 0.02. Kendall's Tau b coefficient is 0.74 (significant) and Cohen's kappa is 0.63 (significant). Good-quality images were seen in above the knee (ATK) segment in 39.3% and moderate in 57.8%. However, below the knee (BTK) segments received poor image quality score in majority, i.e., 82.6%. There was significant reduction observed in the total volume of ICM. No major adverse reaction/complication encountered during the procedures was observed, except pain being the most common and distressing complication. Conclusions: CO2 angiography is a very useful tool in the armamentarium of vascular surgeon, especially while performing angioplasties for peripheral arterial disease in borderline CKD patients,