Automated Carbon Dioxide Angiography for the Evaluation and Endovascular Treatment of Diabetic Patients With Critical Limb Ischemia

Abstract

Purpose: To test the safety, efficacy, and diagnostic accuracy of automated carbon dioxide (CO₂) angiography (ACDA) for the evaluation of diabetic patients with critical limb ischemia (CLI) and baseline renal insufficiency and compare ACDA with iodinated contrast medium (ICM) during endovascular treatment. Methods: From November 2014 to January 2015, 36 consecutive diabetic patients (mean age 74.8±5.8 years; 27 men) with stage ≥3 chronic kidney disease (CKD ≥3) and CLI underwent lower limb angiography with both CO₂ and ICM followed by balloon angioplasty in a prospective single-center study. The primary outcome measure was the safety and efficacy of ACDA as the exclusive agent to guide angioplasty in this cohort. The secondary outcomes were the safety and diagnostic accuracy of ACDA injection as compared with ICM digital subtraction angiography (DSA) for invasive evaluation of these patients. Results: ACDA safely and effectively guided angioplasty in all patients without complications. Transcutaneous oxygen pressure improved from 11.8±6.3 to 58.4±7.6 mm Hg (p<0.001). There were no complications related to ACDA during diagnostic imaging and no significant changes in the estimated glomerular filtration rate from baseline to 24 hours (44.7±13.3 vs 47.0±0.8 mL/min/1.73 m²; nonsignificant). The diagnostic accuracy of CO₂ was 89.8% (sensitivity 92.3%; specificity 75%; positive predictive value 95.5%; negative predictive value 63.1%). There was no statistically significant difference in the qualitative diagnostic accuracy between the media (p=0.197). Conclusion: ACDA is an accurate, safe, and effective technique that can be utilized to guide endovascular interventions in diabetics with CLI and baseline CKD ≥3. Larger multicenter randomized studies are needed to validate these results.