Safety of carboxy-angiography in patients with critical lower limb ischemia

Background: Critical lower limb ischemia (CLI) represents the most severe form of peripheral arterial disease, associated with high rates of morbidity, limb loss, and cardiovascular mortality. Timely and accurate vascular imaging is essential for diagnosis, treatment planning, and procedural guidance in patients undergoing endovascular or surgical revascularization. Conventional contrast angiography, while widely utilized, poses substantial risks in patients with chronic kidney disease (CKD), which is frequently present in the CLI population. Introduction: Carboxyangiography, or carbon dioxide (CO₂)-based angiography, has emerged as a promising alternative imaging modality that avoids the nephrotoxicity and allergic risks associated with iodinated contrast agents. Owing to its low viscosity and high solubility, CO₂ offers distinct hemodynamic and imaging advantages, particularly in infringingly interventions. Purpose: This review aims to evaluate the current evidence on the safety of carboxyangiography in patients with CLI, with a focus on procedure-related complications, hemodynamic effects, renal outcomes, and its clinical applicability across varying risk profiles. The review also addresses technical considerations and limitations associated with CO₂ angiography. Findings: Current literature suggests that carboxyangiography is generally safe when used in appropriately selected patients, especially for infringingly arterial imaging. The risk of adverse events such as vapor lock, transient hypotension, and neurovascular complications appears low when proper technique and precautions are employed. Importantly, carboxyangiography demonstrates a favorable renal safety profile, making it an attractive alternative in patients with moderate to severe CKD. However, limitations in image quality, operator experience, and contraindications in thoracic or cerebral vascular imaging remain challenges. Conclusion: Carboxyangiography represents a viable and safer alternative to iodinated contrast angiography in CLI patients, particularly those at high risk for contrast-induced nephropathy. Continued refinement of techniques and further prospective data are needed to fully establish its role in routine vascular practice.